1
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Martin BE, Mrnak JT. Stable isotopes reveal trophic ontogeny in Cisco (Coregonus artedi). JOURNAL OF FISH BIOLOGY 2024. [PMID: 38992895 DOI: 10.1111/jfb.15874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 05/13/2024] [Accepted: 06/29/2024] [Indexed: 07/13/2024]
Abstract
Cisco (Coregonus artedi) are a widespread, cold-water zooplanktivore native to North America. Although Cisco are generally referred to as an "obligate zooplanktivore," there is some evidence that the species exhibits considerable variability in trophic niche. Here, we assessed how Cisco body size relates to trophic position, that is, trophic ontogeny. We analysed 13C and 15N isotopes from Cisco ranging from 127 to 271 mm in body length (n = 66) from Trout Lake, Vilas County, Wisconsin, USA. 15N isotopes showed smaller Cisco had a trophic position of ~3, which steadily increased to ~3.5 for larger Cisco. Further, 13C isotope signatures showed Cisco transitioned to be more pelagically reliant (lower 13C signatures). Using gillnet catch data, we found that larger Cisco were using deeper habitats than smaller Cisco. Our results support that Cisco have significant variability in trophic niche even though they are traditionally thought of as an obligate planktivore. Overall, we emphasize that researchers should be cautious when generalizing Cisco trophic function, particularly when considering the broader food web.
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Affiliation(s)
- Benjamin E Martin
- Environmental Change Initiative, University of Notre Dame, Notre Dame, Indiana, USA
| | - Joseph T Mrnak
- Center for Limnology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Wisconsin Department of Natural Resources, Office of Applied Science, Escanaba Lake Research Station, Boulder Junction, Wisconsin, USA
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2
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Wong MKL, Didham RK. Global meta-analysis reveals overall higher nocturnal than diurnal activity in insect communities. Nat Commun 2024; 15:3236. [PMID: 38622174 PMCID: PMC11018786 DOI: 10.1038/s41467-024-47645-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 04/09/2024] [Indexed: 04/17/2024] Open
Abstract
Insects sustain key ecosystem functions, but how their activity varies across the day-night cycle and the underlying drivers are poorly understood. Although entomologists generally expect that more insects are active at night, this notion has not been tested with empirical data at the global scale. Here, we assemble 331 quantitative comparisons of the abundances of insects between day and night periods from 78 studies worldwide and use multi-level meta-analytical models to show that insect activity is on average 31.4% (CI: -6.3%-84.3%) higher at night than in the day. We reveal diel preferences of major insect taxa, and observe higher nocturnal activity in aquatic taxa than in terrestrial ones, as well as in warmer environments. In a separate analysis of the small subset of studies quantifying diel patterns in taxonomic richness (31 comparisons from 13 studies), we detect preliminary evidence of higher nocturnal richness in tropical than temperate communities. The higher overall (but variable) nocturnal activity in insect communities underscores the need to address threats such as light pollution and climate warming that may disproportionately impact nocturnal insects.
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Affiliation(s)
- Mark K L Wong
- School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia.
- CSIRO Health & Biosecurity, Centre for Environment and Life Sciences, Floreat, WA, 6014, Australia.
| | - Raphael K Didham
- School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
- CSIRO Health & Biosecurity, Centre for Environment and Life Sciences, Floreat, WA, 6014, Australia
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3
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Yang X, Deng Y, Qin J, Luo K, Kang B, He X, Yan Y. Dietary Shifts in the Adaptation to Changing Marine Resources: Insights from a Decadal Study on Greater Lizardfish ( Saurida tumbil) in the Beibu Gulf, South China Sea. Animals (Basel) 2024; 14:798. [PMID: 38473183 DOI: 10.3390/ani14050798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/24/2024] [Accepted: 02/29/2024] [Indexed: 03/14/2024] Open
Abstract
Understanding dietary behavior during the individual development of marine predators and its temporal variations elucidates how species adapt to changes in marine resources. This is crucial for predicting marine predators' habitat selection and the natural population's responses to environmental changes. The authors conducted a comparative analysis of dietary shift strategies and trophic level variations in Greater lizardfish (Saurida tumbil) in the Beibu Gulf during two distinct periods (2010 and 2020) using stomach content and stable isotope analysis methods. Possible driving factors for these changes were also explored. Changes in the fishery community structure and the decline in the abundance of primary prey resources have led the S. tumbil population to diversify their prey species, utilize alternative resources, and expand their foraging space. However, the species' foraging strategy, characterized by chasing and preying on schooling and pelagic prey, promoted stability in their feeding behavior across spatial and temporal scales. The main prey items remained demersal and pelagic fish species, followed by cephalopods and crustaceans. Similar to other generalist fish species, ontogenetic dietary shifts (ODSs) indicated a partial transition towards larger prey items. However, the timing and magnitude of the ODSs varied between the two periods, reflecting life-history variations and adaptive adjustments to environmental changes. In comparison to 2010, the population's mean body length (BL) increased in 2020, and the proportion of the population feeding on pelagic-neritic prey significantly increased. However, the δ15N values were lower, indicating that the shift in the ecological niche of preferred prey from demersal to pelagic-neritic was the primary cause of the decrease in trophic levels. In the future, we will conduct further quantitative research integrating the spatiotemporal data of both predators and prey to clarify the relationships between marine predators' feeding behavior, trophic levels, and changes in prey community structure.
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Affiliation(s)
- Xiaodong Yang
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
| | - Yujian Deng
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
| | - Jiao Qin
- Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang 524000, China
| | - Konglan Luo
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
| | - Bin Kang
- Fisheries College, Ocean University of China, Qingdao 266003, China
| | - Xiongbo He
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
- Guangdong Provincial Engineering and Technology Research Center of Far Sea Fisheries Management and Fishing of South China Sea, Guangdong Ocean University, Zhanjiang 524088, China
| | - Yunrong Yan
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China
- Guangdong Provincial Engineering and Technology Research Center of Far Sea Fisheries Management and Fishing of South China Sea, Guangdong Ocean University, Zhanjiang 524088, China
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4
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Sun K, Ray S, Gupta N, Aldworth Z, Stopfer M. Olfactory system structure and function in newly hatched and adult locusts. Sci Rep 2024; 14:2608. [PMID: 38297144 PMCID: PMC10830560 DOI: 10.1038/s41598-024-52879-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/24/2024] [Indexed: 02/02/2024] Open
Abstract
An important question in neuroscience is how sensory systems change as animals grow and interact with the environment. Exploring sensory systems in animals as they develop can reveal how networks of neurons process information as the neurons themselves grow and the needs of the animal change. Here we compared the structure and function of peripheral parts of the olfactory pathway in newly hatched and adult locusts. We found that populations of olfactory sensory neurons (OSNs) in hatchlings and adults responded with similar tunings to a panel of odors. The morphologies of local neurons (LNs) and projection neurons (PNs) in the antennal lobes (ALs) were very similar in both age groups, though they were smaller in hatchlings, they were proportional to overall brain size. The odor evoked responses of LNs and PNs were also very similar in both age groups, characterized by complex patterns of activity including oscillatory synchronization. Notably, in hatchlings, spontaneous and odor-evoked firing rates of PNs were lower, and LFP oscillations were lower in frequency, than in the adult. Hatchlings have smaller antennae with fewer OSNs; removing antennal segments from adults also reduced LFP oscillation frequency. Thus, consistent with earlier computational models, the developmental increase in frequency is due to increasing intensity of input to the oscillation circuitry. Overall, our results show that locusts hatch with a fully formed olfactory system that structurally and functionally matches that of the adult, despite its small size and lack of prior experience with olfactory stimuli.
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Affiliation(s)
- Kui Sun
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Subhasis Ray
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
- Plaksha University, Sahibzada Ajit Singh Nagar, Punjab, India
| | - Nitin Gupta
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
- Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Zane Aldworth
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Mark Stopfer
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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5
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Cantwell-Jones A, Tylianakis JM, Larson K, Gill RJ. Using individual-based trait frequency distributions to forecast plant-pollinator network responses to environmental change. Ecol Lett 2024; 27:e14368. [PMID: 38247047 DOI: 10.1111/ele.14368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 01/02/2024] [Accepted: 01/04/2024] [Indexed: 01/23/2024]
Abstract
Determining how and why organisms interact is fundamental to understanding ecosystem responses to future environmental change. To assess the impact on plant-pollinator interactions, recent studies have examined how the effects of environmental change on individual interactions accumulate to generate species-level responses. Here, we review recent developments in using plant-pollinator networks of interacting individuals along with their functional traits, where individuals are nested within species nodes. We highlight how these individual-level, trait-based networks connect intraspecific trait variation (as frequency distributions of multiple traits) with dynamic responses within plant-pollinator communities. This approach can better explain interaction plasticity, and changes to interaction probabilities and network structure over spatiotemporal or other environmental gradients. We argue that only through appreciating such trait-based interaction plasticity can we accurately forecast the potential vulnerability of interactions to future environmental change. We follow this with general guidance on how future studies can collect and analyse high-resolution interaction and trait data, with the hope of improving predictions of future plant-pollinator network responses for targeted and effective conservation.
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Affiliation(s)
- Aoife Cantwell-Jones
- Georgina Mace Centre for The Living Planet, Department of Life Sciences, Silwood Park, Imperial College London, Ascot, UK
| | - Jason M Tylianakis
- Georgina Mace Centre for The Living Planet, Department of Life Sciences, Silwood Park, Imperial College London, Ascot, UK
- Bioprotection Aotearoa, School of Biological Sciences, Private Bag 4800, University of Canterbury, Christchurch, New Zealand
| | - Keith Larson
- Climate Impacts Research Centre, Department of Ecology and Environmental Sciences, Umeå University, Umeå, Sweden
| | - Richard J Gill
- Georgina Mace Centre for The Living Planet, Department of Life Sciences, Silwood Park, Imperial College London, Ascot, UK
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6
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Zou HX, Schreiber SJ, Rudolf VHW. Stage-mediated priority effects and season lengths shape long-term competition dynamics. Proc Biol Sci 2023; 290:20231217. [PMID: 37752843 PMCID: PMC10523084 DOI: 10.1098/rspb.2023.1217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/29/2023] [Indexed: 09/28/2023] Open
Abstract
The relative arrival time of species can affect their interactions and thus determine which species persist in a community. Although this phenomenon, called priority effect, is widespread in natural communities, it is unclear how it depends on the length of growing season. Using a seasonal stage-structured model, we show that differences in stages of interacting species could generate priority effects by altering the strength of stabilizing and equalizing coexistence mechanisms, changing outcomes between exclusion, coexistence and positive frequency dependence. However, these priority effects are strongest in systems with just one or a few generations per season and diminish in systems where many overlapping generations per season dilute the importance of stage-specific interactions. Our model reveals a novel link between the number of generations in a season and the consequences of priority effects, suggesting that consequences of phenological shifts driven by climate change should depend on specific life histories of organisms.
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Affiliation(s)
- Heng-Xing Zou
- Program in Ecology and Evolutionary Biology, Department of BioSciences, Rice University, Houston, TX 77005, USA
| | | | - Volker H. W. Rudolf
- Program in Ecology and Evolutionary Biology, Department of BioSciences, Rice University, Houston, TX 77005, USA
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7
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Gayford JH, Godfrey H, Whitehead DA. Ontogenetic morphometry of the brown smoothhound shark Mustelus henlei with implications for ecology and evolution. J Morphol 2023; 284:e21608. [PMID: 37458085 DOI: 10.1002/jmor.21608] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/17/2023] [Accepted: 05/29/2023] [Indexed: 07/18/2023]
Abstract
The central tenet of ecomorphology links ecological and morphological variation through the process of selection. Traditionally used to rationalise morphological differences between taxa, an ecomorphological approach is increasingly being utilised to study morphological differences expressed through ontogeny. Elasmobranchii (sharks, rays and skates) is one clade in which such ontogenetic shifts in body form have been reported. Such studies are limited to a relatively small proportion of total elasmobranch ecological and morphological diversity, and questions remain regarding the extent to which ecological selection are driving observed morphometric trends. In this study, we report ontogenetic growth trajectories obtained via traditional linear morphometrics from a large data set of the brown smoothhound shark (Mustelus henlei). We consider various morphological structures including the caudal, dorsal and pectoral fins, as well as several girth measurements. We use an ecomorphological approach to infer the broad ecological characteristics of this population and refine understanding of the selective forces underlying the evolution of specific morphological structures. We suggest that observed scaling trends in M. henlei are inconsistent with migratory behaviour, but do not contradict a putative trophic niche shift. We also highlight the role of predation pressure and sex-based ecological differences in driving observed trends in morphometry, a factor which has previously been neglected when considering the evolution of body form in sharks.
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Affiliation(s)
- Joel H Gayford
- Department of Life Sciences, Imperial College London, Ascot, UK
- Marine Research and Conservation Department, Investigación Tiburones México A.C, La Paz, Mexico
- Shark Measurements, London, UK
| | - Hana Godfrey
- Marine Research and Conservation Department, Investigación Tiburones México A.C, La Paz, Mexico
| | - Darren A Whitehead
- Marine Research and Conservation Department, Investigación Tiburones México A.C, La Paz, Mexico
- Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, La Paz, México
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8
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Gill BA, Wittemyer G, Cerling TE, Musili PM, Kartzinel TR. Foraging history of individual elephants using DNA metabarcoding. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230337. [PMID: 37416829 PMCID: PMC10320352 DOI: 10.1098/rsos.230337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 06/07/2023] [Indexed: 07/08/2023]
Abstract
Individual animals should adjust diets according to food availability. We used DNA metabarcoding to construct individual-level dietary timeseries for elephants from two family groups in Kenya varying in habitat use, social position and reproductive status. We detected at least 367 dietary plant taxa, with up to 137 unique plant sequences in one fecal sample. Results matched well-established trends: elephants tended to eat more grass when it rained and other plants when dry. Nested within these switches from 'grazing' to 'browsing' strategies, dietary DNA revealed seasonal shifts in food richness, composition and overlap between individuals. Elephants of both families converged on relatively cohesive diets in dry seasons but varied in their maintenance of cohesion during wet seasons. Dietary cohesion throughout the timeseries of the subdominant 'Artists' family was stronger and more consistently positive compared to the dominant 'Royals' family. The greater degree of individuality within the dominant family's timeseries could reflect more divergent nutritional requirements associated with calf dependency and/or priority access to preferred habitats. Whereas theory predicts that individuals should specialize on different foods under resource scarcity, our data suggest family bonds may promote cohesion and foster the emergence of diverse feeding cultures reflecting links between social behaviour and nutrition.
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Affiliation(s)
- Brian A. Gill
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, RI 02912, USA
- Institute at Brown for Environment and Society, Brown University, Providence, RI 02912, USA
| | - George Wittemyer
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523, USA
- Save the Elephants, Nairobi, Kenya
| | - Thure E. Cerling
- Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112, USA
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA
| | - Paul M. Musili
- Botany Department, East African Herbarium, National Museums of Kenya, Nairobi, Kenya
| | - Tyler R. Kartzinel
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, RI 02912, USA
- Institute at Brown for Environment and Society, Brown University, Providence, RI 02912, USA
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9
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Saltini M, Vasconcelos P, Rueffler C. Complex life cycles drive community assembly through immigration and adaptive diversification. Ecol Lett 2023. [PMID: 37125448 DOI: 10.1111/ele.14216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 03/13/2023] [Accepted: 03/20/2023] [Indexed: 05/02/2023]
Abstract
Most animals undergo ontogenetic niche shifts during their life. Yet, standard ecological theory builds on models that ignore this complexity. Here, we study how complex life cycles, where juvenile and adult individuals each feed on different sets of resources, affect community richness. Two different modes of community assembly are considered: gradual adaptive evolution and immigration of new species with randomly selected phenotypes. We find that under gradual evolution complex life cycles can lead to both higher and lower species richness when compared to a model of species with simple life cycles that lack an ontogenetic niche shift. Thus, complex life cycles do not per se increase the scope for gradual adaptive diversification. However, complex life cycles can lead to significantly higher species richness when communities are assembled trough immigration, as immigrants can occupy isolated peaks of the dynamic fitness landscape that are not accessible via gradual evolution.
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Affiliation(s)
- Marco Saltini
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
- Swedish Collegium for Advanced Study (SCAS), Uppsala, Sweden
| | - Paula Vasconcelos
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
| | - Claus Rueffler
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
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10
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Stallings CD, Nelson JA, Peebles EB, Ellis G, Goddard EA, Jue NK, Mickle A, Tzadik OE, Koenig CC. Trophic ontogeny of a generalist predator is conserved across space. Oecologia 2023; 201:721-732. [PMID: 36843229 DOI: 10.1007/s00442-023-05337-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 02/12/2023] [Indexed: 02/28/2023]
Abstract
Consumers can influence ecological patterns and processes through their trophic roles and contributions to the flow of energy through ecosystems. However, the diet and associated trophic roles of consumers commonly change during ontogeny. Despite the prevalence of ontogenetic variation in trophic roles of most animals, we lack an understanding of whether they change consistently across local populations and broad geographic gradients. We examined how the diet and trophic position of a generalist marine predator varied with ontogeny across seven broadly separated locations (~ 750 km). We observed a high degree of heterogeneity in prey consumed without evidence of spatial structuring in this variability. However, compound-specific isotope analysis of amino acids revealed remarkably consistent patterns of increasing trophic position through ontogeny across local populations, suggesting that the roles of this generalist predator scaled with its body size across space. Given the high degree of diet heterogeneity we observed, this finding suggests that even though the dietary patterns differed, the underlying food web architecture transcended variation in prey species across locations for this generalist consumer. Our research addresses a gap in empirical field work regarding the interplay between stage-structured populations and food webs, and suggests ontogenetic changes in trophic position can be consistent in generalist consumers.
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Affiliation(s)
| | - James A Nelson
- Department of Biology, University of Louisiana Lafayette, Lafayette, LA, USA
| | - Ernst B Peebles
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | - Gregory Ellis
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
- Johns Hopkins All Children's Hospital, St Petersburg, FL, USA
| | - Ethan A Goddard
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | - Nathaniel K Jue
- Department of Biology and Chemistry, California State University, Monterey Bay, Seaside, CA, USA
| | - Alejandra Mickle
- Department of Biology, Florida State University, Tallahassee, FL, USA
- Office of Habitat Conservation-Restoration Center, NOAA Fisheries, Silver Spring, MD, USA
| | - Orian E Tzadik
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
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11
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Catella SA, Abbott KC. Effects of abiotic heterogeneity on species densities and interaction strengths lead to different spatial biodiversity patterns. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1071375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
During community assembly, abiotic factors can influence species at multiple stages during their life history, for example by affecting early settlement or establishment probabilities and thus initial densities (route 1: abiotic effects on density), or later by affecting the strength of biotic interactions during subsequent life stages (route 2: abiotic effects on interaction strengths). Since real abiotic landscapes are multivariate and complex, how these two distinct routes of abiotic influence affect community patterns has not been quantified. Using an individual-based spatially explicit simulation model, we compared scenarios where abiotic conditions shaped initial densities, interaction strengths, or both, of plant species with unique abiotic niches. We then partitioned the effect of the abiotic landscape on community patterns into components arising from variable density, variable interaction strengths, and their interaction. Even when plants responded to identical landscapes, variable density and variable interaction strengths led to different community patterns, and their combined effects were non-additive. Variable density promoted more spatial structure, while variable interaction strengths promoted higher local species richness. We highlight important implications these findings have in applied plant community ecology.
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12
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Skinner C, Pei YD, Morimoto N, Miyajima T, Wyatt ASJ. Stable isotopes elucidate body-size and seasonal fluctuations in the feeding strategies of planktivorous fishes across a semi-enclosed tropical embayment. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.942968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Reef fish may switch feeding strategies due to fluctuations in resource availability or through ontogeny. A number of studies have explored these trophodynamics using carbon (δ13C) and nitrogen (δ15N) stable isotopes, but additional tracers such as sulfur isotopes (δ34S) show strong potential in systems, where δ13C and δ15N results are ambiguous. We tested the utility of adding δ34S to conventional δ13C and δ15N analysis to detect seasonal and body size changes in resource use of two planktivorous damselfish, Dascyllus reticulatus and Dascyllus trimaculatus across the Puerto Galera embayment in the Philippines. We analyzed stable isotope ratios (δ13C, δ15N, and δ34S) in multiple fish tissues (liver, eye, and muscle) to represent different dietary time frames. We then compared fish tissue isotopes against particulate organic matter (POM) (δ13C and δ15N) and POM suspension feeder (the tunicate Polycarpa aurata: δ13C, δ15N, and δ34S) across the same sites. There were size-based and seasonal differences in damselfish resource use, the latter of which was most pronounced in the fast-turnover liver. Small fish (<70 mm) demonstrated significant seasonality, appearing to switch their resource use between the rainy season and the dry season, while there was no seasonal variation in larger fish (>70 mm). This suggests that smaller fish across the embayment employ an opportunistic feeding strategy to take advantage of fluctuating resource availability, while larger fish exhibits more consistent resource use. Isotope ratios of tunicates and POM further confirmed strong seasonality in this system and a lack of a spatial isotopic gradient. δ15N did not seem to contribute to consumer resource use patterns, while by contrast, δ34S fluctuated significantly between sampling periods and was crucial for demonstrating seasonality in resource use. We recommend including δ34S when attempting to disentangle seasonal differences in resource use in aquatic food webs using stable isotopes.
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13
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Takashina N. Linking multi-level population dynamics: state, role, and population. PeerJ 2022; 10:e13315. [PMID: 35582614 PMCID: PMC9107789 DOI: 10.7717/peerj.13315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 03/31/2022] [Indexed: 01/13/2023] Open
Abstract
The dynamics of an ecological community can be described at different focal scales of the species, such as individual states or the population level. More detailed descriptions of ecological dynamics offer more information, but produce more complex models that are difficult to analyze. Adequately controlling the model complexity and the availability of multiple descriptions of the concerned dynamics maximizes our understanding of ecological dynamics. One of the central goals of ecological studies is to develop links between multiple descriptions of an ecological community. In this article, starting from a nonlinear state-level description of an ecological community (generalized McKendrick-von Foerster model), role-level and population-level descriptions (Lotka-Volterra model) are derived in a consistent manner. The role-level description covers a wider range of situations than the population-level description. However, using the established connections, it is demonstrated that the population-level description can be used to predict the equilibrium status of the role-level description. This approach connects state-, role-, and population-level dynamics consistently, and offers a justification for the multiple choices of model description.
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14
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Geissinger EA, Beal BF, Ambrose WG. Stable isotopes reveal minimal spatial and temporal variation in diet of the wrymouth (
Cryptacanthodes maculatus
). Ecosphere 2022. [DOI: 10.1002/ecs2.3954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
| | - Brian F. Beal
- Division of Environmental and Biological Sciences University of Maine, Machias Machias Maine USA
| | - William G. Ambrose
- School of the Coastal Environment Coastal Carolina University Conway South Carolina USA
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15
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Halstead BJ, Rose JP, Clark D, Kleeman PM, Fisher RN. Multi‐scale patterns in the occurrence of an ephemeral pool‐breeding amphibian. Ecosphere 2022. [DOI: 10.1002/ecs2.3960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Brian J. Halstead
- U.S. Geological Survey Western Ecological Research Center, Dixon Field Station Dixon California USA
| | - Jonathan P. Rose
- U.S. Geological Survey Western Ecological Research Center, Santa Cruz Field Station Santa Cruz California USA
| | - Denise Clark
- U.S. Geological Survey Western Ecological Research Center, San Diego Field Station San Diego California USA
| | - Patrick M. Kleeman
- U.S. Geological Survey Western Ecological Research Center, Point Reyes Field Station Point Reyes Station California USA
| | - Robert N. Fisher
- U.S. Geological Survey Western Ecological Research Center, San Diego Field Station San Diego California USA
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16
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Pohl S, Bungum HZ, Lee KEM, Sani MAB, Poh YH, Wahab RBHA, Norma-Rashid Y, Tan EJ. Age and Appearance Shape Behavioral Responses of Phasmids in a Dynamic Environment. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.767940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Although morphological adaptations leading to crypsis or mimicry have been studied extensively, their interaction with particular behaviors to avoid detection or recognition is understudied. Yet animal behaviors interact with morphology to reduce detection risk, and the level of protection conferred likely changes according to the surrounding environment. Apart from providing a locational cue for predators, prey motion can also serve as concealing behavior in a dynamic environment to prevent detection by potential predators or prey. Phasmids are conventionally known to rely on their adaptive resemblance to plant parts for protection, and this resemblance may vary across life stages and species. However, little is known about how their behaviors interact with their appearance and their environment. We investigated two species of phasmids with varying morphology and color patterns at different ontogenetic stages and examined their behavioral responses to a wind stimulus as a proxy for a dynamic environment. While adult behaviors were mostly species-specific, behavioral responses of nymphs varied with appearance and environmental condition. Display of different behaviors classified as revealing was positively correlated, while the display of concealing behaviors, except for swaying, was mostly negatively correlated with other behaviors. Exhibition of specific behaviors varied with appearance and environmental condition, suggesting that these behavioral responses could help reduce detection or recognition cues. We discuss the differences in behavioral responses in the context of how the behaviors could reveal or conceal the phasmids from potential predators. Our results provide a novel investigation into adaptive resemblance strategies of phasmids through the interaction of behavior and morphology, and highlight the importance of considering the effects of dynamic environments on sending and receiving cues.
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Bodner K, Brimacombe C, Fortin M, Molnár PK. Why body size matters: how larger fish ontogeny shapes ecological network topology. OIKOS 2021. [DOI: 10.1111/oik.08569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Korryn Bodner
- Dept of Biological Sciences, Univ. of Toronto Scarborough ON Canada
- Dept of Ecology and Evolutionary Biology, Univ. of Toronto ON Canada
| | - Chris Brimacombe
- Dept of Ecology and Evolutionary Biology, Univ. of Toronto ON Canada
| | | | - Péter K. Molnár
- Dept of Biological Sciences, Univ. of Toronto Scarborough ON Canada
- Dept of Ecology and Evolutionary Biology, Univ. of Toronto ON Canada
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Thunell V, Lindmark M, Huss M, Gårdmark A. Effects of Warming on Intraguild Predator Communities with Ontogenetic Diet Shifts. Am Nat 2021; 198:706-718. [PMID: 34762572 DOI: 10.1086/716927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractSpecies interactions mediate how warming affects community composition via individual growth and population size structure. While predictions on how warming affects composition of size- or stage-structured communities have so far focused on linear (food chain) communities, mixed competition-predation interactions, such as intraguild predation, are common. Intraguild predation often results from changes in diet over ontogeny ("ontogenetic diet shifts") and strongly affects community composition and dynamics. Here, we study how warming affects a community of intraguild predators with ontogenetic diet shifts, consumers, and shared prey by analyzing a stage-structured bioenergetics multispecies model with temperature- and body size-dependent individual-level rates. We find that warming can strengthen competition and decrease predation, leading to a loss of a cultivation mechanism (the feedback between predation on and competition with consumers exerted by predators) and ultimately predator collapse. Furthermore, we show that the effect of warming on community composition depends on the extent of the ontogenetic diet shift and that warming can cause a sequence of community reconfigurations in species with partial diet shifts. Our findings contrast previous predictions concerning individual growth of predators and the mechanisms behind predator loss in warmer environments and highlight how feedbacks between temperature and intraspecific size structure are important for understanding such effects on community composition.
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Nakangu NF, Masese FO, Barasa JE, Matolla GK, Riziki JW, Mbalassa M. Influence of the changing environment on food composition and condition factor in Labeo victorianus (Boulenger, 1901) in rivers of Lake Victoria Basin, Kenya. AQUACULTURE AND FISHERIES 2021. [DOI: 10.1016/j.aaf.2021.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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20
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Postema EG. The effectiveness of eyespots and masquerade in protecting artificial prey across ontogenetic and seasonal shifts. Curr Zool 2021; 68:451-458. [PMID: 36090146 PMCID: PMC9450170 DOI: 10.1093/cz/zoab082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 09/28/2021] [Indexed: 12/25/2022] Open
Abstract
When constraints on antipredator coloration shift over the course of development, it can be advantageous for animals to adopt different color strategies for each life stage. Many caterpillars in the genus Papilio exhibit unique ontogenetic color sequences: for example, early instars that masquerade as bird feces, with later instars possessing eyespots. I hypothesize that larvae abandon feces masquerade in favor of eyespots due to ontogenetic changes in signaler size. This ontogenetic pattern also occurs within broader seasonal shifts in background color and predator activity. I conducted predation experiments with artificial prey to determine how potential signaling constraints (specifically size and season) shape predation risk, and consequently the expression of ontogenetic color change in Papilio larvae. Seasonally, both predation and background greenness declined significantly from July to September, though there was little evidence that these patterns impacted the effectiveness of either color strategy. Caterpillar size and color strongly affected the attack rate of avian predators: attacks increased with prey size regardless of color, and eyespotted prey were attacked more than masquerading prey overall. These results may reflect a key size-mediated tradeoff between conspicuousness and intimidation in eyespotted prey, and raise questions about how interwoven aspects of behavior and signal environment might maintain the prevalence of large, eyespotted larvae in nature.
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Affiliation(s)
- Elizabeth G Postema
- Department of Entomology and Nematology, University of California, Davis, CA 95616, USA
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21
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McDevitt-Galles T, Carpenter SA, Koprivnikar J, Johnson PTJ. How predator and parasite size interact to determine consumption of infectious stages. Oecologia 2021; 197:551-564. [PMID: 34405300 DOI: 10.1007/s00442-021-05010-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 08/02/2021] [Indexed: 01/02/2023]
Abstract
Parasites are important players in ecological communities that can shape community structure and influence ecosystem energy flow. Yet beyond their effects on hosts, parasites can also function as an important prey resource for predators. Predators that consume infectious stages in the environment can benefit from a nutrient-rich prey item while concurrently reducing transmission to downstream hosts, highlighting the broad importance of this interaction. Less clear, however, are the specific characteristics of parasites and predators that increase the likelihood of consumption. Here, we determine what combination(s) of predator and parasite morphological traits lead to high parasite consumption. We exposed the infectious stages (cercariae) of five trematode (fluke) taxa to aquatic insect predators with varying foraging strategies and morphologies. Across the 19 predator-parasite combinations tested, damselfly predators in the family Coenagrionidae were, on average, the most effective predators of cercariae, consuming between 13 and 55% of administered cercariae. Large-bodied cercariae of Ribeiroia ondatrae had the highest average vulnerability to predation, with 37-48% of cercariae consumed. The interaction between predator head width and cercariae tail size strongly influenced the probability of consumption: small-bodied predators were the most effective consumers, particularly for larger tailed parasites. Thus, the likelihood of parasite consumption depended strongly on the relative size between predator and parasite. Our study helps establish that predation on free-living parasites largely follows a broader predator-prey framework. This will help to identify which predator and parasite combinations will likely have high consumptive interactions, potentially reducing parasite transmission in natural populations.
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Affiliation(s)
| | - Sara A Carpenter
- Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
| | - Janet Koprivnikar
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Pieter T J Johnson
- Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
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Anaya-Rojas JM, Bassar RD, Potter T, Blanchette A, Callahan S, Framstead N, Reznick D, Travis J. The evolution of size-dependent competitive interactions promotes species coexistence. J Anim Ecol 2021; 90:2704-2717. [PMID: 34389988 DOI: 10.1111/1365-2656.13577] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 08/04/2021] [Indexed: 12/01/2022]
Abstract
Theory indicates that competing species coexist in a community when intraspecific competition is stronger than interspecific competition. When body size determines the outcome of competitive interactions between individuals, coexistence depends also on how resource use and the ability to compete for these resources change with body size. Testing coexistence theory in size-structured communities, therefore, requires disentangling the effects of size-dependent competitive abilities and niche shifts. Here, we tested the hypothesis that the evolution of species- and size-dependent competitive asymmetries increased the likelihood of coexistence between interacting species. We experimentally estimated the effects of size-dependent competitive interactions on somatic growth rates of two interacting fish species, Trinidadian guppies Poecilia reticulata and killifish Rivulus hartii. We controlled for the effects of size-dependent changes in the niche at two competitive settings representing the early (allopatric) and late (sympatric) evolutionary stages of a killifish-guppy community. We fitted the growth data to a model that incorporates species- and size-dependent competitive asymmetries to test whether changes in the competitive interactions across sizes increased the likelihood of species coexistence from allopatry to sympatry. We found that guppies are competitively superior to killifish but were less so in sympatric populations. The decrease in the effects of interspecific competition on the fitness of killifish and increase in the interspecific effect on guppies' fitness increased the likelihood that sympatric guppies and killifish will coexist. However, while the competitive asymmetries between the species changed consistently between allopatry and sympatry between drainages, the magnitude of the size-dependent competitive asymmetries varied between drainages. These results demonstrate the importance of integrating evolution and trait-based interactions into the research on how species coexist.
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Affiliation(s)
- Jaime M Anaya-Rojas
- Department of Biological Science, Florida State University, Tallahassee, FL, USA.,Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Ronald D Bassar
- Department of Biology, Williams College, Williamstown, MA, USA
| | - Tomos Potter
- Department of Zoology, University of Oxford, Oxford, UK
| | - Allison Blanchette
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Shay Callahan
- University of Illinois at Urbana-Champaign, Urbana-Champaign, IL, USA
| | - Nick Framstead
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - David Reznick
- Department of Evolution, Ecology and Organismal Biology, University of California, Riverside, CA, USA
| | - Joseph Travis
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
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23
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Borza P. Intraspecific variability in the filter mesh size of suspension feeding organisms: the case of invasive Ponto-Caspian corophiids (Crustacea: Amphipoda). PeerJ 2021; 9:e11245. [PMID: 33976975 PMCID: PMC8061577 DOI: 10.7717/peerj.11245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 03/18/2021] [Indexed: 11/20/2022] Open
Abstract
Suspension feeders play pivotal roles in the nutrient cycling of almost all aquatic ecosystems. Since sufficiently large differences in the filter mesh size (FMS) can lead to different food web positions, the inter- and intraspecific variability of this trait might be of community-level importance. The aim of this study was to quantify the range of FMS variation within the three invasive Ponto-Caspian Chelicorophium species based on a large material representing various conditions (1,224 specimens from 40 samples across Central Europe), characterize the components of variation within populations, identify the main factors determining intraspecific differences, and reveal how intraspecific variation affects the FMS overlaps among species. The FMS of the most widespread invader, C. curvispinum, varied within the broadest range (between 2.34–8.28 μm, compared to 2.51–5.97 μm in C. robustum and 1.08–3.23 μm in C. sowinskyi); nevertheless, the contribution of intraspecific plasticity to the invasion success of the species is not evident based on the present study. The within-individual variability of FMS increased with the individual mean of the trait and decreased with body size; however, it showed little differences among samples. The among-individual variation within samples could be partitioned into components related to body size (ontogenetic niche shift/differences among cohorts) and sex (ecological sexual dimorphism) as well as a seemingly random component (individual specialization), varying widely in extent and relative contributions. The FMS of C. curvispinum was significantly larger in the presence of C. sowinskyi than in allopatry, likely reflecting character displacement; however, it did not show further increase when C. robustum was also present. Similar differences could not be observed in C. sowinskyi. The FMS ranges of C. curvispinum and C. robustum never overlapped with that of C. sowinskyi in co-occurrence despite the considerable intraspecific differences among sites, suggesting that their interaction can be seen as a clear case of niche differentiation by food particle size. On the contrary, the strong overlaps observed between C. curvispinum and C. robustum indicate that other factors might play the primary role in their coexistence. The studied species appear to be suitable model organisms for identifying the drivers and mechanisms of FMS variability.
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Affiliation(s)
- Péter Borza
- Danube Research Institute, Centre for Ecological Research, Budapest, Hungary
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24
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Rudolf VHW, Eveland L. Ontogenetic diversity buffers communities against consequences of species loss. J Anim Ecol 2021; 90:1492-1504. [PMID: 33694228 DOI: 10.1111/1365-2656.13470] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 03/01/2021] [Indexed: 01/26/2023]
Abstract
Biodiversity can be measured at multiple organizational scales. While traditional studies have focused at taxonomic diversity, recent studies have emphasized the ecological importance of diversity within populations. However, it is unclear how these different scales of diversity interact to determine the consequence of species loss. Here we asked how predator diversity and presence of ontogenetic diversity within predator populations influences community structure. Ontogenetic diversity arises from shifts in the traits and ecology of individuals during ontogeny and it is one of the biggest sources of intraspecific diversity. However, whether it dampens or strengthens the negative consequences of with species loss is poorly understood. To study the interaction of species diversity and ontogenetic diversity, we experimentally manipulated predator species diversity and diversity of developmental stages within focal predator species and analysed their joint effect on predator and prey survival, biomass and prey community structure in experimental pond systems. While individual effects of ontogenetic diversity were often species specific, losing predator species from the community often had a much smaller or no effect on prey survival, biomass or community structure when all predator populations had high ontogenetic diversity. Thus, ontogenetic diversity within populations buffered against some of the consequences of biodiversity loss at higher organizational levels. Because the experiment controlled mean per capita size and biomass across structured versus unstructured populations, this pattern was not driven by differences in biomass of predators. Instead, results suggest that effects were driven by changes in the functional roles and indirect interactions across and within species. This indicates that even if all environmental conditions are similar, differences in the intrinsic structure of populations can modify the consequences of biodiversity loss. Together, these results revealed the importance of ontogenetic diversity within species for strengthening the resilience of natural communities to consequences of biodiversity loss and emphasize the need to integrate biodiversity patterns across organizational scales.
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25
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Dumouchel L, Bobe R, Wynn JG, Barr WA. The environments of Australopithecus anamensis at Allia Bay, Kenya: A multiproxy analysis of early Pliocene Bovidae. J Hum Evol 2021; 151:102928. [PMID: 33453510 DOI: 10.1016/j.jhevol.2020.102928] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 12/01/2020] [Accepted: 12/01/2020] [Indexed: 11/18/2022]
Abstract
Australopithecus anamensis, among the earliest fully bipedal hominin species, lived in eastern Africa around 4 Ma. Much of what is currently known about the paleoecology of A. anamensis comes from the type locality, Kanapoi, Kenya. Here, we extend knowledge of the range of environments occupied by A. anamensis by presenting the first multiproxy paleoecological analysis focusing on Bovidae excavated from another important locality where A. anamensis was recovered, locality 261-1 (ca. 3.97 Ma) at Allia Bay, East Turkana, Kenya. Paleoenvironments are reconstructed using astragalar ecomorphology, mesowear, hypsodonty index, and oxygen and carbon isotopes from dental enamel. We compare our results to those obtained from Kanapoi. Our results show that the bovid community composition is similar between the two fossil assemblages. Allia Bay and Kanapoi bovid astragalar ecomorphology spans the spectrum of modern morphologies indicative of grassland, woodland, and even forest-adapted forms. Dietary reconstructions based on stable isotopes, mesowear, and hypsodonty reveal that these bovids' diet encompassed the full C3 to C4 dietary spectrum and overlap in the two data sets. Our results allow us to confidently extend our reconstructions of the paleoenvironments of A. anamensis at Kanapoi to Allia Bay, where this pivotal hominin species is associated with heterogeneous settings including habitats with varying degrees of tree cover, including grasslands, bushlands, and woodlands.
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Affiliation(s)
- Laurence Dumouchel
- Department of Anthropology, Wichita State University, 1845 Fairmount Street, Wichita, KS 67260, USA.
| | - René Bobe
- Primate Models for Behavioural Evolution Lab, Institute of Cognitive & Evolutionary Anthropology, School of Anthropology, University of Oxford, 64 Banbury Rd, Park Town, Oxford, OX2 6PN, UK; Paleo-Primate Project Gorongosa, Gorongosa National Park, Sofala, Mozambique; Interdisciplinary Center for Archaeology and Evolution of Human Behaviour (ICArEHB), Universidade Do Algarve, Campus de Penha, Faro, 8005-139, Portugal
| | - Jonathan G Wynn
- Division of Earth Sciences, National Science Foundation, 2415 Eisenhower Avenue, Alexandria, VA 22314, USA
| | - W Andrew Barr
- Center for the Advanced Study of Human Paleobiology, The George Washington University, 800 22(nd)Street Northwest, Suite 6000, Washington, DC 20052, USA
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Faria L, Pie M, Salles F, Soares E. The Haeckelian shortfall or the tale of the missing semaphoronts. J ZOOL SYST EVOL RES 2020. [DOI: 10.1111/jzs.12435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Luiz Faria
- Instituto Latino‐Americano de Ciências da Vida e da NaturezaUniversidade Federal da Integração Latino‐Americana Foz do Iguaçu Brazil
| | - Marcio Pie
- Departamento de Zoologia Universidade Federal do Paraná Curitiba Brazil
| | - Frederico Salles
- Departamento de Entomologia Universidade Federal de Viçosa Viçosa Brazil
| | - Elaine Soares
- Instituto Latino‐Americano de Ciências da Vida e da NaturezaUniversidade Federal da Integração Latino‐Americana Foz do Iguaçu Brazil
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Nakazawa T, Katayama N. Stage-Specific Parasitism by a Mutualistic Partner Can Increase the Host Abundance. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.602675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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de Roos AM. Effects of life history and individual development on community dynamics: A review of counterintuitive consequences. Ecol Res 2020; 35:930-946. [PMID: 33380774 PMCID: PMC7756606 DOI: 10.1111/1440-1703.12174] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 05/30/2020] [Accepted: 08/07/2020] [Indexed: 11/27/2022]
Abstract
Even though individual life history is the focus of much ecological research, its importance for the dynamics and structure of ecological communities is unclear, or is it a topic of much ongoing research. In this paper I highlight the key life history traits that may lead to effects of life history or ontogeny on ecological communities. I show that asymmetries in the extent of food limitation between individuals in different life stage can give rise to an increase in efficiency with which resources are used for population growth when conditions change. This change in efficiency may result in a positive relationship between stage-specific density and mortality. The positive relationship between density and mortality in turn leads to predictions about community structure that are not only diametrically opposite to the expectations based on theory that ignores population structure but are also intuitively hard to accept. I provide a few examples that illustrate how taking into account intraspecific differences due to ontogeny radically changes the theoretical expectations regarding the possible outcomes of community dynamics. As the most compelling example I show how a so-called double-handicapped looser, that is, a consumer species that is both competitively inferior in the absence of predators and experiences higher mortality when predators are present, can nonetheless oust its opponent that it competes with for the same resource and is exposed to the same predator.
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Affiliation(s)
- André M. de Roos
- Institute for Biodiversity and Ecosystem DynamicsUniversity of AmsterdamAmsterdamNetherlands
- The Santa Fe InstituteSanta FeNew MexicoUSA
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29
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Wright SJ, Heurich M, Buchmann CM, Böcker R, Schurr FM. The importance of individual movement and feeding behaviour for long-distance seed dispersal by red deer: a data-driven model. MOVEMENT ECOLOGY 2020; 8:44. [PMID: 33133610 PMCID: PMC7594291 DOI: 10.1186/s40462-020-00227-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 10/09/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Long-distance seed dispersal (LDD) has strong impacts on the spatiotemporal dynamics of plants. Large animals are important LDD vectors because they regularly transport seeds of many plant species over long distances. While there is now ample evidence that behaviour varies considerably between individual animals, it is not clear to what extent inter-individual variation in behaviour alters seed dispersal by animals. METHODS We study how inter-individual variation in the movement and feeding behaviour of one of Europe's largest herbivores (the red deer, Cervus elaphus) affects internal seed dispersal (endozoochory) of multiple plant species. We combine movement data of 21 individual deer with measurements of seed loads in the dung of the same individuals and with data on gut passage time. These data serve to parameterize a model of passive dispersal that predicts LDD in three orientations (horizontal as well as upward and downward in elevation).With this model we investigate to what extent per-seed probabilities of LDD and seed load vary between individuals and throughout the vegetation period (May-December). Subsequently, we test whether per-seed LDD probability and seed load are positively (or negatively) correlated so that more mobile animals disperse more (or less) seeds. Finally, we examine whether non-random associations between per-seed LDD probability and seed load affect the LDD of individual plant species. RESULTS The studied deer dispersed viable seeds of at least 62 plant species. Deer individuals varied significantly in per-seed LDD probability and seed loads. However, more mobile animals did not disperse more or less seeds than less mobile ones. Plant species also did not differ significantly in the relationship between per-seed LDD probability and seed load. Yet plant species differed in how their seed load was distributed across deer individuals and in time, and this caused their LDD potential to differ more than twofold. For several plant species, we detected non-random associations between per-seed LDD probability and seed load that generally increased LDD potential. CONCLUSIONS Inter-individual variation in movement and feeding behaviour means that certain deer are substantially more effective LDD vectors than others. This inter-individual variation reduces the reliability of LDD and increases the sensitivity of LDD to the decline of deer populations. Variation in the dispersal services of individual animals should thus be taken into account in models in order to improve LDD projections.
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Affiliation(s)
- Stephen J. Wright
- Institute of Landscape and Plant Ecology, University of Hohenheim, 70599 Stuttgart, Germany
- Frankfurt Zoological Society, Bernhard-Grzimek-Allee 1, 60316 Frankfurt, Germany
| | - Marco Heurich
- Bavarian Forest National Park, 94481 Grafenau, Germany
- Chair of Wildlife Ecology and Management, Albert-Ludwigs-University of Freiburg, Freiburg im Breisgau, Germany
| | - Carsten M. Buchmann
- Institute of Landscape and Plant Ecology, University of Hohenheim, 70599 Stuttgart, Germany
| | - Reinhard Böcker
- Institute of Landscape and Plant Ecology, University of Hohenheim, 70599 Stuttgart, Germany
| | - Frank M. Schurr
- Institute of Landscape and Plant Ecology, University of Hohenheim, 70599 Stuttgart, Germany
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30
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Simulating the relative effects of movement and sociality on the distribution of animal-transported subsidies. THEOR ECOL-NETH 2020. [DOI: 10.1007/s12080-020-00480-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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31
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Seasonal and ontogenetic variation of whiting diet in the Eastern English Channel and the Southern North Sea. PLoS One 2020; 15:e0239436. [PMID: 32966332 PMCID: PMC7511009 DOI: 10.1371/journal.pone.0239436] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 09/05/2020] [Indexed: 11/19/2022] Open
Abstract
An accurate description of trophic interactions is crucial to understand ecosystem functioning and sustainably manage marine ecosystems exploitation. Carbon and nitrogen stable isotopes were coupled with stomach content analyses to investigate whiting (Merlangius merlangus, Linnaeus, 1758) feeding behavior in the Eastern English Channel and Southern North Sea. Whiting juveniles and adults were sampled in autumn and winter to investigate both ontogenetic and seasonal changes. In addition, queen scallops (Aequipecten opercularis) samples were collected along with fish to be used as isotopic benthic baseline. Results indicated an ontogenetic diet change from crustaceans to fish and cephalopods. In autumn, δ15N values generally increased with fish size while in winter, a decrease of δ15N values with fish size was observed, as a potential result of spatial variation in baseline δ15N values. In winter, a nutrient-poor period, an increase in feeding intensity was observed, especially on the copepod Temora longicornis. This study provides further insights into whiting trophic ecology in relation to ontogenetic and seasonal variations, and it confirms the importance of combining several trophic analysis methods to understand ecosystem functioning.
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32
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Intraspecific dietary variation in niche partitioning within a community of ecologically similar snakes. Evol Ecol 2020. [DOI: 10.1007/s10682-020-10078-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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33
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Székely D, Cogălniceanu D, Székely P, Denoël M. Adult-Juvenile interactions and temporal niche partitioning between life-stages in a tropical amphibian. PLoS One 2020; 15:e0238949. [PMID: 32925925 PMCID: PMC7489520 DOI: 10.1371/journal.pone.0238949] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/26/2020] [Indexed: 01/07/2023] Open
Abstract
Divergence in ecological niche offers organisms the opportunity of exploiting different food and habitat resources, scaling down competition and predation both among species, and within different age or size-classes of the same species. In harsh environments, where abiotic factors determine a clustering of resources during short timespans, competition and predation between organisms is likely to be enhanced. This is the case in tropical dry forests, where amphibians have limited opportunities to feed, their activity being restricted to the short rainy season. One way to maximize resource exploitation while avoiding predation risk is by adopting different diel activity patterns. We tested this hypothesis by comparing activity patterns in adults and recently metamorphosed juveniles of Pacific horned frogs (Ceratophrys stolzmanni) during field surveys and in an experimental study. Field surveys showed that the adults are strictly nocturnal, whereas freshly metamorphosed juveniles can be found active above ground at all hours, with a peak activity during daytime. The average body condition index of juveniles found active during the night was higher than that of juveniles found active during the day, suggesting that the weaker individuals may be constrained to being active during the day. On the other hand, in a laboratory experiment, juveniles that were visually exposed to adults moved less than those in the absence of adults. Both field and experimental observations indicate a temporal niche divergence between life stages. The results of the experiment offer support to the hypothesis that the juveniles in this species display an inverse activity pattern compared to adults, which can reduce competitive interactions and predation pressure from the larger conspecifics.
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Affiliation(s)
- Diana Székely
- Laboratorio de Ecología Tropical y Servicios Ecosistémicos - EcoSs Lab, Departamento de Ciencias Biológicas, Universidad Técnica Particular de Loja, Loja, Ecuador
- Faculty of Natural and Agricultural Sciences, Ovidius University Constanța, Constanța, Romania
- Laboratory of Ecology and Conservation of Amphibians (LECA), Freshwater and OCeanic science Unit of reSearch (FOCUS), University of Liège, Liège, Belgium
| | - Dan Cogălniceanu
- Faculty of Natural and Agricultural Sciences, Ovidius University Constanța, Constanța, Romania
- Asociation Chelonia, București, Romania
| | - Paul Székely
- Laboratorio de Ecología Tropical y Servicios Ecosistémicos - EcoSs Lab, Departamento de Ciencias Biológicas, Universidad Técnica Particular de Loja, Loja, Ecuador
- Asociation Chelonia, București, Romania
- * E-mail:
| | - Mathieu Denoël
- Laboratory of Ecology and Conservation of Amphibians (LECA), Freshwater and OCeanic science Unit of reSearch (FOCUS), University of Liège, Liège, Belgium
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Affiliation(s)
- Takefumi Nakazawa
- Department of Life Sciences National Cheng Kung University Tainan City Taiwan
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Mezőfi L, Markó G, Nagy C, Korányi D, Markó V. Beyond polyphagy and opportunism: natural prey of hunting spiders in the canopy of apple trees. PeerJ 2020; 8:e9334. [PMID: 32596048 PMCID: PMC7307562 DOI: 10.7717/peerj.9334] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 05/19/2020] [Indexed: 11/24/2022] Open
Abstract
Spiders (Araneae) form abundant and diverse assemblages in agroecosystems such as fruit orchards, and thus might have an important role as natural enemies of orchard pests. Although spiders are polyphagous and opportunistic predators in general, limited information exists on their natural prey at both species and community levels. Thus, the aim of this study was to assess the natural prey (realized trophic niche) of arboreal hunting spiders, their role in trophic webs and their biological control potential with direct observation of predation events in apple orchards. Hunting spiders with prey in their chelicerae were collected in the canopy of apple trees in organic apple orchards in Hungary during the growing seasons between 2013 and 2019 and both spiders and their prey were identified and measured. Among others, the composition of the actual (captured by spiders) and the potential (available in the canopy) prey was compared, trophic niche and food web metrics were calculated, and some morphological, dimensional data of the spider-prey pairs were analyzed. Species-specific differences in prey composition or pest control ability were also discussed. By analyzing a total of 878 prey items captured by spiders, we concluded that arboreal hunting spiders forage selectively and consume a large number of apple pests; however, spiders’ beneficial effects are greatly reduced by their high levels of intraguild predation and by a propensity to switch from pests to alternative prey. In this study, arboreal hunting spiders showed negative selectivity for pests, no selectivity for natural enemies and positive selectivity for neutral species. In the trophic web, the dominant hunting spider taxa/groups (Carrhotus xanthogramma, Philodromus cespitum, Clubiona spp., Ebrechtella tricuspidata, Xysticus spp. and ‘Other salticids’) exhibit different levels of predation on different prey groups and the trophic web’s structure changes depending on the time of year. Hunting spiders show a high functional redundancy in their predation, but contrary to their polyphagous nature, the examined spider taxa showed differences in their natural diet, exhibited a certain degree of prey specialization and selected prey by size and taxonomic identity. Guilds (such as stalkers, ambushers and foliage runners) did not consistently predict either prey composition or predation selectivity of arboreal hunting spider species. From the economic standpoint, Ph. cespitum and Clubiona spp. were found to be the most effective natural enemies of apple pests, especially of aphids. Finally, the trophic niche width of C. xanthogramma and Ph. cespitum increased during ontogeny, resulting in a shift in their predation. These results demonstrate how specific generalist predators can differ from each other in aspects of their predation ecology even within a relatively narrow taxonomic group.
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Affiliation(s)
- László Mezőfi
- Department of Entomology, Szent István University, Budapest, Hungary
| | - Gábor Markó
- Department of Plant Pathology, Szent István University, Budapest, Hungary.,Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University, Budapest, Hungary
| | - Csaba Nagy
- Research Institute for Fruitgrowing and Ornamentals, National Agricultural Research and Innovation Centre, Újfehértó, Hungary
| | - Dávid Korányi
- Institute of Ecology and Botany, "Lendület" Landscape and Conservation Ecology, Centre for Ecological Research, Vácrátót, Hungary.,GINOP Sustainable Ecosystems Group, Centre for Ecological Research, Tihany, Hungary
| | - Viktor Markó
- Department of Entomology, Szent István University, Budapest, Hungary
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Haas SM, Lortie CJ. A systematic review of the direct and indirect effects of herbivory on plant reproduction mediated by pollination. PeerJ 2020; 8:e9049. [PMID: 32551190 PMCID: PMC7289145 DOI: 10.7717/peerj.9049] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 04/02/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Plant reproduction is influenced by the net outcome of plant-herbivore and plant-pollinator interactions. While both herbivore impacts and pollinator impacts on plant reproduction have been widely studied, few studies examine them in concert. METHODOLOGY Here, we review the contemporary literature that examines the net outcomes of herbivory and pollination on plant reproduction and the impacts of herbivores on pollination through damage to shared host plants using systematic review tools. The direct or indirect effects of herbivores on floral tissue and reported mechanisms were compiled including the taxonomic breadth of herbivores, plants and pollinators. RESULTS A total of 4,304 studies were examined producing 59 relevant studies for synthesis that reported both pollinator and herbivore measures. A total of 49% of studies examined the impact of direct damage to floral tissue through partial florivory while 36% of studies also examined the impact of vegetative damage on pollination through folivory, root herbivory, and stem damage. Only three studies examined the effects of both direct and indirect damage to pollination outcomes within the same study. CONCLUSIONS It is not unreasonable to assume that plants often sustain simultaneous forms of damage to different tissues and that the net effects can be assessed through differences in reproductive output. Further research that controls for other relative drivers of reproductive output but examines more than one pathway of damage simultaneously will inform our understanding of the mechanistic relevance of herbivore impacts on pollination and also highlight interactions between herbivores and pollinators through plants. It is clear that herbivory can impact plant fitness through pollination; however, the relative importance of direct and indirect damage to floral tissue on plant reproduction is still largely unknown.
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Affiliation(s)
| | - Christopher J. Lortie
- Department of Biology, York University, Toronto, ON, Canada
- The National Center for Ecological Analysis and Synthesis, University of California, Santa Barbara, Santa Barbara, CA, USA
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Keppeler FW, Montaña CG, Winemiller KO. The relationship between trophic level and body size in fishes depends on functional traits. ECOL MONOGR 2020. [DOI: 10.1002/ecm.1415] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Friedrich W. Keppeler
- Department of Ecology and Conservation Biology Texas A&M University College Station Texas USA
| | - Carmen G. Montaña
- Department of Biology Stephen F. Austin State University Nacogdoches Texas USA
| | - Kirk O. Winemiller
- Department of Ecology and Conservation Biology Texas A&M University College Station Texas USA
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Studying animal niches using bulk stable isotope ratios: an updated synthesis. Oecologia 2020; 193:27-51. [DOI: 10.1007/s00442-020-04654-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 04/11/2020] [Indexed: 10/24/2022]
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Rusman Q, Lucas‐Barbosa D, Hassan K, Poelman EH. Plant ontogeny determines strength and associated plant fitness consequences of plant-mediated interactions between herbivores and flower visitors. THE JOURNAL OF ECOLOGY 2020; 108:1046-1060. [PMID: 32421019 PMCID: PMC7217261 DOI: 10.1111/1365-2745.13370] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/22/2020] [Indexed: 05/30/2023]
Abstract
Plants show ontogenetic variation in growth-defence strategies to maximize reproductive output within a community context. Most work on plant ontogenetic variation in growth-defence trade-offs has focussed on interactions with antagonistic insect herbivores. Plants respond to herbivore attack with phenotypic changes. Despite the knowledge that plant responses to herbivory affect plant mutualistic interactions with pollinators required for reproduction, indirect interactions between herbivores and pollinators have not been included in the evaluation of how ontogenetic growth-defence trajectories affect plant fitness.In a common garden experiment with the annual Brassica nigra, we investigated whether exposure to various herbivore species on different plant ontogenetic stages (vegetative, bud or flowering stage) affects plant flowering traits, interactions with flower visitors and results in fitness consequences for the plant.Effects of herbivory on flowering plant traits and interactions with flower visitors depended on plant ontogeny. Plant exposure in the vegetative stage to the caterpillar Pieris brassicae and aphid Brevicoryne brassicae led to reduced flowering time and flower production, and resulted in reduced pollinator attraction, pollen beetle colonization, total seed production and seed weight. When plants had buds, infestation by most herbivore species tested reduced flower production and pollen beetle colonization. Pollinator attraction was either increased or reduced. Plants infested in the flowering stage with P. brassicae or Lipaphis erysimi flowered longer, while infestation by any of the herbivore species tested increased the number of flower visits by pollinators.Our results show that the outcome of herbivore-flower visitor interactions in B. nigra is specific for the combination of herbivore species and plant ontogenetic stage. Consequences of herbivory for flowering traits and reproductive output were strongest when plants were attacked early in life. Such differences in selection pressures imposed by herbivores to specific plant ontogenetic stages may drive the evolution of distinct ontogenetic trajectories in growth-defence-reproduction strategies and include indirect interactions between herbivores and flower visitors. Synthesis. Plant ontogeny can define the direct and indirect consequences of herbivory. Our study shows that the ontogenetic stage of plant individuals determined the effects of herbivory on plant flowering traits, interactions with flower visitors and plant fitness.
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Affiliation(s)
- Quint Rusman
- Laboratory of EntomologyWageningen UniversityWageningenThe Netherlands
| | - Dani Lucas‐Barbosa
- Laboratory of EntomologyWageningen UniversityWageningenThe Netherlands
- Present address:
Bio‐communication & EcologyETH ZürichSchmelzbergstrasse 98092ZürichSwitzerland
| | - Kamrul Hassan
- Laboratory of EntomologyWageningen UniversityWageningenThe Netherlands
- Present address:
Hawkesbury Institute for the EnvironmentWestern Sydney UniversityLocked Bag 1797PenrithNSW2751Australia
| | - Erik H. Poelman
- Laboratory of EntomologyWageningen UniversityWageningenThe Netherlands
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Axelrod CJ, Laberge F, Robinson BW. Isolating the effects of ontogenetic niche shift on brain size development using pumpkinseed sunfish ecotypes. Evol Dev 2020; 22:312-322. [DOI: 10.1111/ede.12333] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Caleb J. Axelrod
- Department of Integrative BiologyUniversity of Guelph Guelph Ontario Canada
| | - Frédéric Laberge
- Department of Integrative BiologyUniversity of Guelph Guelph Ontario Canada
| | - Beren W. Robinson
- Department of Integrative BiologyUniversity of Guelph Guelph Ontario Canada
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Affiliation(s)
- Takefumi Nakazawa
- Dept of Life Sciences, National Cheng Kung Univ. No.1, University Road Tainan City 701 Taiwan
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Finch J, Walck JL, Hidayati SN, Kramer AT, Lason V, Havens K. Germination niche breadth varies inconsistently among three Asclepias congeners along a latitudinal gradient. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:425-438. [PMID: 29779252 DOI: 10.1111/plb.12843] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 05/14/2018] [Indexed: 06/08/2023]
Abstract
Species responses to climate change will be primarily driven by their environmental tolerance range, or niche breadth, with the expectation that broad niches will increase resilience. Niche breadth is expected to be larger in more heterogeneous environments and moderated by life history. Niche breadth also varies across life stages. Therefore, the life stage with the narrowest niche may serve as the best predictor of climatic vulnerability. To investigate the relationship between niche breadth, climate and life stage we identify germination niche breadth for dormant and non-dormant seeds in multiple populations of three milkweed (Asclepias) species. Complementary trials evaluated germination under conditions simulating historic and predicted future climate by varying cold-moist stratification temperature, length and incubation temperature. Germination niche breadth was derived from germination evenness across treatments (Levins Bn ), with stratified seeds considered less dormant than non-stratified seeds. Germination response varies significantly among species, populations and treatments. Cold-moist stratification ≥4 weeks (1-3 °C) followed by incubation at 25/15 °C+ achieves peak germination for most populations. Germination niche breadth significantly expands following stratification and interacts significantly with latitude of origin. Interestingly, two species display a positive relationship between niche breadth and latitude, while the third presents a concave quadratic relationship. Germination niche breadth significantly varies by species, latitude and population, suggesting an interaction between source climate, life history and site-specific factors. Results contribute to our understanding of inter- and intraspecific variation in germination, underscore the role of dormancy in germination niche breadth, and have implications for prioritising and conserving species under climate change.
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Affiliation(s)
- J Finch
- Program in Plant Biology and Conservation, Northwestern University, Evanston, IL, USA
- Deparment of Plant Science and Conservation, Chicago Botanic Garden, Glencoe, IL, USA
| | - J L Walck
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, USA
| | - S N Hidayati
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, USA
| | - A T Kramer
- Deparment of Plant Science and Conservation, Chicago Botanic Garden, Glencoe, IL, USA
| | - V Lason
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
| | - K Havens
- Deparment of Plant Science and Conservation, Chicago Botanic Garden, Glencoe, IL, USA
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Spatial and ontogenetic variation in isotopic niche among recovering fish communities revealed by Bayesian modeling. PLoS One 2019; 14:e0215747. [PMID: 30998793 PMCID: PMC6472828 DOI: 10.1371/journal.pone.0215747] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 04/08/2019] [Indexed: 11/19/2022] Open
Abstract
Exploitation and changing ocean conditions have resulted in altered species interactions and varied population dynamics within marine fish communities off northeast Newfoundland and southern Labrador, Canada. To understand contemporary species interactions, we quantified the isotopic niches, niche overlap, and ontogenetic niche change among seven dominant fish species using stable isotope analyses. Analyses used fishes from three regions differing in fish and prey diversities. Differences in fish and diet composition diversity among regions were found using Simpson’s inverse diversity index. The regions of lowest diversities had higher instances of niche overlap and higher percentage of niche overlap area. The region of highest diversity had the widest spread of niches with greater distances from the community centroid. Ontogenetic shifts were observed such that larger individuals shifted towards the community centroid with the exception of Atlantic cod. Atlantic cod in particular was found to consistently be the top predator of the analyzed species. Our results reveal: (a) overlap in isotopic niches and spread within niche space was correlated with fish and diet diversity; (b) ontogenetic shifts are important when considering a species’ niche and quantifying spatial variation in community niche profiles.
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Dance MA, Rooker JR. Cross-shelf habitat shifts by red snapper (Lutjanus campechanus) in the Gulf of Mexico. PLoS One 2019; 14:e0213506. [PMID: 30870449 PMCID: PMC6417787 DOI: 10.1371/journal.pone.0213506] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 02/22/2019] [Indexed: 11/19/2022] Open
Abstract
Habitat shifts that occur during the life cycles of marine fishes influence population connectivity and structure. A generalized additive modeling approach was used to characterize relationships between environmental variables and the relative abundance of red snapper Lutjanus campechanus over unconsolidated substrate on the continental shelf (<150 m) of the U.S. Gulf of Mexico (GoM) at three different life stages: juvenile (age-0, <125 mm FL), sub-adult (age-1-2, 125-300 mm FL), and adult (age-2+, >300 mm FL). Fisheries independent data (2008-2014) were used to develop separate models for both the eastern and western GoM, and final models were used to predict the relative availability of suitable habitat for each life stage across the two regions. Predictor variables included in final models varied by age class and region, with depth, dissolved oxygen, longitude, and distance to artificial structure common to most models. Depth was among the most influential variables in all models, and preferred depth increased with increasing size/age. Regional differences in fish-habitat relationships were also observed, as relative abundance of larger red snapper over unconsolidated substrates was more closely linked to artificial structure in the eastern GoM. The location of predicted high quality habitat for juvenile red snapper was greatest on the inner Texas shelf and a smaller area east of the Mississippi River Delta, suggesting these two areas may represent important nursery grounds for the respective regions. Clear ontogenetic shifts in the spatial distribution of predicted high quality habitat were evident in both the eastern (expansion from west to east with age) and western (shift from inshore to offshore) GoM. Given the unique population dynamics between the eastern and western GoM, improving our understanding of spatial and temporal variability in habitat quality may be important to maintaining connectivity between juvenile and adult habitats, and may enhance recovery and management of red snapper stocks in the GoM.
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Affiliation(s)
- Michael A. Dance
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America
| | - Jay R. Rooker
- Department of Marine Biology, Texas A&M University (Galveston Campus), Galveston, Texas, United States of America
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, Texas, United States of America
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Reum JCP, Blanchard JL, Holsman KK, Aydin K, Punt AE. Species‐specific ontogenetic diet shifts attenuate trophic cascades and lengthen food chains in exploited ecosystems. OIKOS 2019. [DOI: 10.1111/oik.05630] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Jonathan C. P. Reum
- School of Aquatic and Fishery SciencesUniv. of Washington1122 NE Boat StSeattle WA 98102 USA
- Centre for Marine Socioecology, Univ. of Hobart TAS Australia
| | - Julia L. Blanchard
- Inst. for Marine and Antarctic StudiesUniv. of Tasmania Hobart TAS Australia
- Centre for Marine Socioecology, Univ. of Hobart TAS Australia
| | - Kirstin K. Holsman
- Alaska Fisheries Science CenterNational Marine Fisheries ServiceNOAA Seattle WA USA
| | - Kerim Aydin
- Alaska Fisheries Science CenterNational Marine Fisheries ServiceNOAA Seattle WA USA
| | - André E. Punt
- School of Aquatic and Fishery SciencesUniv. of Washington1122 NE Boat StSeattle WA 98102 USA
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Orłowski G, Karg J, Jerzak L, Bocheński M, Profus P, Książkiewicz-Parulska Z, Zub K, Ekner-Grzyb A, Czarnecka J. Linking land cover satellite data with dietary variation and reproductive output in an opportunistic forager: Arable land use can boost an ontogenetic trophic bottleneck in the White Stork Ciconia ciconia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 646:491-502. [PMID: 30056236 DOI: 10.1016/j.scitotenv.2018.07.297] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/19/2018] [Accepted: 07/20/2018] [Indexed: 06/08/2023]
Abstract
Determining how the progressive loss of resources due to agricultural intensification and habitat degradation affect individual fitness and population persistence is a matter of urgency. Here we explored three major questions in order to extend knowledge of the relationship between reproduction rate, diet and energy intake in White Storks Ciconia ciconia based both on our own analysis of pellets and landscape properties sampled in 52 nests in south-western Poland, and published literature data. (1) How many individual prey items are needed to meet the daily energy requirements of nestlings over the brood rearing period? (2) How do the dietary patterns vary under different habitat conditions and what is the spatial scale responsible for these relationships? (3) Is reproductive output related to variations in landscape traits, and is diet variability related to intraspecific competition resulting from colonial breeding? In our estimation, the energy requirements of nestlings during the brood rearing period showed that the most profitable invertebrate prey items were Orthoptera and earthworms. Owing to the nestlings' gape-size constraint (precluding consumption of vertebrate prey items of the size of Common Voles), these most likely comprise the staple diet enabling survival during the first 20 days of life. The total energy content across all the pellets was a simple function (a negative correlation) of %arable land within a distance of 5 km around the nests. White Storks from nests of high-productivity pairs (with 3-4 fledglings and less %arable around) consumed equal %biomasses of invertebrate and vertebrate prey, while invertebrates prevailed in the diet of the low-productivity pairs. Our results suggest that a two-level ontogenetic trophic bottleneck may explain the low productivity of White Stork pairs in simplified landscapes with predominant arable land use. As a result of this, parent birds are unable to satisfy the growing energy demands of nestlings (1) by gathering a sufficient volume of abundant small-sized prey (early nestlings) and (2) by delivering energetically more profitable vertebrate prey at the time of the diet switch.
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Affiliation(s)
- Grzegorz Orłowski
- Institute of Agricultural and Forest Environment, Polish Academy of Sciences, Bukowska 19, 60-809 Poznań, Poland.
| | - Jerzy Karg
- Department of Nature Conservation, Faculty of Biological Sciences, University of Zielona Góra, Prof. Z. Szafrana 1, 65-516 Zielona Góra, Poland
| | - Leszek Jerzak
- Department of Nature Conservation, Faculty of Biological Sciences, University of Zielona Góra, Prof. Z. Szafrana 1, 65-516 Zielona Góra, Poland
| | - Marcin Bocheński
- Department of Nature Conservation, Faculty of Biological Sciences, University of Zielona Góra, Prof. Z. Szafrana 1, 65-516 Zielona Góra, Poland
| | - Piotr Profus
- Institute of Nature Conservation, Polish Academy of Sciences, al. A. Mickiewicza 33, 31-120 Krakow, Poland
| | - Zofia Książkiewicz-Parulska
- Department of General Zoology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Karol Zub
- Mammal Research Institute, Polish Academy of Sciences, ul. Waszkiewicza 1c, 17-230 Bialowieża, Poland
| | - Anna Ekner-Grzyb
- Department of Behavioural Ecology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, 61-614 Poznań, Poland
| | - Joanna Czarnecka
- Ecology Department, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland
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Reum JCP, Holsman KK, Aydin KY, Blanchard JL, Jennings S. Energetically relevant predator-prey body mass ratios and their relationship with predator body size. Ecol Evol 2019; 9:201-211. [PMID: 30680107 PMCID: PMC6342185 DOI: 10.1002/ece3.4715] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 10/19/2018] [Accepted: 10/24/2018] [Indexed: 12/03/2022] Open
Abstract
Food web structure and dynamics depend on relationships between body sizes of predators and their prey. Species-based and community-wide estimates of preferred and realized predator-prey mass ratios (PPMR) are required inputs to size-based size spectrum models of marine communities, food webs, and ecosystems. Here, we clarify differences between PPMR definitions in different size spectrum models, in particular differences between PPMR measurements weighting prey abundance in individual predators by biomass (r bio) and numbers (r num). We argue that the former weighting generates PPMR as usually conceptualized in equilibrium (static) size spectrum models while the latter usually applies to dynamic models. We use diet information from 170,689 individuals of 34 species of fish in Alaskan marine ecosystems to calculate both PPMR metrics. Using hierarchical models, we examine how explained variance in these metrics changed with predator body size, predator taxonomic resolution, and spatial resolution. In the hierarchical analysis, variance in both metrics emerged primarily at the species level and substantially less variance was associated with other (higher) taxonomic levels or with spatial resolution. This suggests that changes in species composition are the main drivers of community-wide mean PPMR. At all levels of analysis, relationships between weighted mean r bio or weighted mean r num and predator mass tended to be dome-shaped. Weighted mean r num values, for species and community-wide, were approximately an order of magnitude higher than weighted mean r bio, reflecting the consistent numeric dominance of small prey in predator diets. As well as increasing understanding of the drivers of variation in PPMR and providing estimates of PPMR in the north Pacific Ocean, our results demonstrate that that r bio or r num, as well as their corresponding weighted means for any defined group of predators, are not directly substitutable. When developing equilibrium size-based models based on bulk energy flux or comparing PPMR estimates derived from the relationship between body mass and trophic level with those based on diet analysis, weighted mean r bio is a more appropriate measure of PPMR. When calibrating preference PPMR in dynamic size spectrum models then weighted mean r num will be a more appropriate measure of PPMR.
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Affiliation(s)
- Jonathan C. P. Reum
- School of Aquatic and Fishery SciencesUniversity of Washington SeattleSeattleWashington
| | - Kirstin K. Holsman
- Alaska Fisheries Science CenterNational Marine Fisheries Service, NOAASeattleWashington
| | - Kerim Y. Aydin
- Alaska Fisheries Science CenterNational Marine Fisheries Service, NOAASeattleWashington
| | - Julia L. Blanchard
- Institute for Marine and Antarctic Studies and Centre for Marine SocioecologyUniversity of TasmaniaHobartTasmaniaAustralia
| | - Simon Jennings
- International Council for the Exploration of the SeaKøbenhavn VDenmark
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Rincón-Díaz MP, Pittman SJ, Arismendi I, Heppell SS. Functional diversity metrics detect spatio-temporal changes in the fish communities of a Caribbean marine protected area. Ecosphere 2018. [DOI: 10.1002/ecs2.2433] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
| | - Simon J. Pittman
- Marine Spatial Ecology Division's Biogeography Branch; National Centers for Coastal Ocean Science; U.S. National Oceanic and Atmospheric Administration; 1305 East-West Highway Silver Spring Maryland 20910 USA
- Marine Institute; Plymouth University; Drake Circus Plymouth Devon PL4 8AA UK
| | - Ivan Arismendi
- Department of Fisheries and Wildlife; Oregon State University; 104 Nash Hall Corvallis Oregon 97331 USA
| | - Selina S. Heppell
- Department of Fisheries and Wildlife; Oregon State University; 104 Nash Hall Corvallis Oregon 97331 USA
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Costa-Pereira R, Araújo MS, Olivier RDS, Souza FL, Rudolf VHW. Prey Limitation Drives Variation in Allometric Scaling of Predator-Prey Interactions. Am Nat 2018; 192:E139-E149. [DOI: 10.1086/698726] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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