1
|
Dorfman A, Subach A, Scharf I. Snakes on a slope: strong anti-gravitactic responses and differential habitat use in the Saharan horned viper ( Cerastes cerastes) in the Negev desert. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221652. [PMID: 36968240 PMCID: PMC10031405 DOI: 10.1098/rsos.221652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 03/06/2023] [Indexed: 06/18/2023]
Abstract
The way species use their habitat dictates their intra- and interspecific interactions. We studied the effects of the microhabitat type and slope on the movement behaviour of the Saharan horned viper (Cerastes cerastes) in its natural habitat. This viper occurs in sand dunes and moves mostly by sidewinding. Additionally, we studied the microhabitat preference of desert rodents-the vipers' main prey. We placed the vipers on different natural dune slopes and recorded their behaviour. We found a strong anti-gravitactic response: vipers moved more frequently towards the top of the dune than in any other direction, despite a decrease in stride length with increasing slope. The foraging-related behaviour of the vipers was concentrated in the dune semi-stable areas rather than its stable or shifting sand areas. We measured rodent activity by placing seed trays in the dune allowing the rodents to collect seeds. Rodent activity was the highest in the shifting sands, closely followed by the semi-stable microhabitat. These results suggest the vipers use the semi-stable microhabitat mainly for foraging and may use the shifting sand areas as commuting routes between such areas. This study may be of use for conservation efforts of psammophilic species in desert dunes.
Collapse
Affiliation(s)
- Arik Dorfman
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Aziz Subach
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Inon Scharf
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| |
Collapse
|
2
|
Smith BJ, MacNulty DR, Stahler DR, Smith DW, Avgar T. Density-dependent habitat selection alters drivers of population distribution in northern Yellowstone elk. Ecol Lett 2023; 26:245-256. [PMID: 36573288 PMCID: PMC10107875 DOI: 10.1111/ele.14155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 10/26/2022] [Accepted: 11/02/2022] [Indexed: 12/28/2022]
Abstract
Although it is well established that density dependence drives changes in organismal abundance over time, relatively little is known about how density dependence affects variation in abundance over space. We tested the hypothesis that spatial trade-offs between food and safety can change the drivers of population distribution, caused by opposing patterns of density-dependent habitat selection (DDHS) that are predicted by the multidimensional ideal free distribution. We addressed this using winter aerial survey data of northern Yellowstone elk (Cervus canadensis) spanning four decades. Supporting our hypothesis, we found positive DDHS for food (herbaceous biomass) and negative DDHS for safety (openness and roughness), such that the primary driver of habitat selection switched from food to safety as elk density decreased from 9.3 to 2.0 elk/km2 . Our results demonstrate how population density can drive landscape-level shifts in population distribution, confounding habitat selection inference and prediction and potentially affecting community-level interactions.
Collapse
Affiliation(s)
- Brian J Smith
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, Utah, USA
| | - Daniel R MacNulty
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, Utah, USA
| | - Daniel R Stahler
- Yellowstone Center for Resources, National Park Service, Yellowstone National Park, Wyoming, USA
| | - Douglas W Smith
- Yellowstone Center for Resources, National Park Service, Yellowstone National Park, Wyoming, USA
| | - Tal Avgar
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, Utah, USA.,Biodiversity Pathways Ltd., British Columbia, Canada
| |
Collapse
|
3
|
Subach A, Dorfman A, Avidov B, Domer A, Samocha Y, Scharf I. Foraging behaviour, habitat use and population size of the desert horned viper in the Negev desert. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220326. [PMID: 35774136 PMCID: PMC9240687 DOI: 10.1098/rsos.220326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/13/2022] [Indexed: 05/03/2023]
Abstract
The desert horned viper occurs in the dunes of the northwestern Negev desert, Israel. We report on a 2 year study on the viper's behaviour and ecology in its natural habitat. We examined whether the vipers moved faster in a vegetation-dense microhabitat versus an open dune area and detected much slower movement in the former. We nevertheless detected no preference of the vipers for any of the dune areas. We suggest that the vipers trade-off the ease of movement on open areas with prey, which is probably more available in areas with denser vegetation. The activity was higher early in the season and the vipers were mostly active right after sunset, with a second smaller activity peak at sunrise, perhaps searching for burrows to spend the day. Fitting this explanation, movement at the track's end was less directional than at its beginning. We found inter-sexual and between-year differences. For example, females were larger than males in the second year of the study but not in the first one and the population seemed to be smaller in the second year of the study than in its first year. The information we provide on this viper may assist its conservation, as sand dunes are threatened habitats in Israel.
Collapse
Affiliation(s)
- Aziz Subach
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Arik Dorfman
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Bar Avidov
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Adi Domer
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Yehonatan Samocha
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Inon Scharf
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
4
|
Keil P, Wiegand T, Tóth AB, McGlinn DJ, Chase JM. Measurement and analysis of interspecific spatial associations as a facet of biodiversity. ECOL MONOGR 2021. [DOI: 10.1002/ecm.1452] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Petr Keil
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Deutscher Platz 5e 04103 Leipzig Germany
- Institute of Computer Science Martin Luther University Halle‐Wittenberg 06120 Halle (Saale) Germany
- Faculty of Environmental Sciences Czech University of Life Sciences Prague Kamýcká 129 Praha – Suchdol165 00 Czech Republic
| | - Thorsten Wiegand
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Deutscher Platz 5e 04103 Leipzig Germany
- Department of Ecological Modelling Helmholtz Centre for Environmental Research ‐ UFZ 04318 Leipzig Germany
| | - Anikó B. Tóth
- Centre for Ecosystem Sciences School of Biological, Earth and Environmental Sciences University of New South Wales Sydney NSW 2052 Australia
| | - Daniel J. McGlinn
- Department of Biology College of Charleston Charleston South Carolina 29401 USA
| | - Jonathan M. Chase
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Deutscher Platz 5e 04103 Leipzig Germany
- Institute of Computer Science Martin Luther University Halle‐Wittenberg 06120 Halle (Saale) Germany
| |
Collapse
|
5
|
Matis PA, Donelson JM, Bush S, Fox RJ, Booth DJ. Temperature influences habitat preference of coral reef fishes: Will generalists become more specialised in a warming ocean? GLOBAL CHANGE BIOLOGY 2018; 24:3158-3169. [PMID: 29658157 DOI: 10.1111/gcb.14166] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 03/24/2018] [Indexed: 06/08/2023]
Abstract
Climate change is expected to pose a significant risk to species that exhibit strong behavioural preferences for specific habitat types, with generalist species assumed to be less vulnerable. In this study, we conducted habitat choice experiments to determine how water temperature influences habitat preference for three common species of coral reef damselfish (Pomacentridae) that differ in their levels of habitat specialisation. The lemon damselfish Pomacentrus moluccensis, a habitat specialist, consistently selected complex coral habitat across all temperature treatments (selected based on local average seasonal temperatures naturally experienced in situ: ambient winter 22°C; ambient summer 28°C; and elevated 31°C). Unexpectedly, the neon damselfish Pomacentrus coelestis and scissortail sergeant Abudefduf sexfasciatus, both of which have more generalist habitat associations, developed strong habitat preferences (for complex coral and boulder habitat, respectively) at the elevated temperature treatment (31°C) compared to no single preferred habitat at 22°C or 28°C. The observed shifts in habitat preference with temperature suggest that we may be currently underestimating the vulnerability of some habitat generalists to climate change and highlight that the ongoing loss of complex live coral through coral bleaching could further exacerbate resource overlap and species competition in ways not currently considered in climate change models.
Collapse
Affiliation(s)
- Paloma A Matis
- School of Life Sciences, University of Technology Sydney, Broadway, NSW, Australia
| | - Jennifer M Donelson
- School of Life Sciences, University of Technology Sydney, Broadway, NSW, Australia
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia
| | - Stephen Bush
- School of Mathematical and Physical Sciences, University of Technology Sydney, Broadway, NSW, Australia
| | - Rebecca J Fox
- School of Life Sciences, University of Technology Sydney, Broadway, NSW, Australia
| | - David J Booth
- School of Life Sciences, University of Technology Sydney, Broadway, NSW, Australia
| |
Collapse
|
6
|
Boratyński Z, Brito JC, Campos JC, Cunha JL, Granjon L, Mappes T, Ndiaye A, Rzebik-Kowalska B, Serén N. Repeated evolution of camouflage in speciose desert rodents. Sci Rep 2017; 7:3522. [PMID: 28615685 PMCID: PMC5471182 DOI: 10.1038/s41598-017-03444-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 05/05/2017] [Indexed: 11/09/2022] Open
Abstract
There are two main factors explaining variation among species and the evolution of characters along phylogeny: adaptive change, including phenotypic and genetic responses to selective pressures, and phylogenetic inertia, or the resemblance between species due to shared phylogenetic history. Phenotype-habitat colour match, a classic Darwinian example of the evolution of camouflage (crypsis), offers the opportunity to test the importance of historical versus ecological mechanisms in shaping phenotypes among phylogenetically closely related taxa. To assess it, we investigated fur (phenotypic data) and habitat (remote sensing data) colourations, along with phylogenetic information, in the species-rich Gerbillus genus. Overall, we found a strong phenotype-habitat match, once the phylogenetic signal is taken into account. We found that camouflage has been acquired and lost repeatedly in the course of the evolutionary history of Gerbillus. Our results suggest that fur colouration and its covariation with habitat is a relatively labile character in mammals, potentially responding quickly to selection. Relatively unconstrained and substantial genetic basis, as well as structural and functional independence from other fitness traits of mammalian colouration might be responsible for that observation.
Collapse
Affiliation(s)
- Zbyszek Boratyński
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, 4485-661, Portugal.
| | - José C Brito
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, 4485-661, Portugal.,Department of Biology, Faculty of Science, University of Porto, Rua Campo Alegre, 4169-007, Porto, Portugal
| | - João C Campos
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, 4485-661, Portugal.,Department of Biology, Faculty of Science, University of Porto, Rua Campo Alegre, 4169-007, Porto, Portugal
| | - José L Cunha
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, 4485-661, Portugal
| | - Laurent Granjon
- IRD, UMR CBGP, Campus International de Baillarguet, CS 30016, 34988, Montferrier-sur-Lez cedex, France
| | - Tapio Mappes
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, P.O. Box 35, 40014, Finland
| | - Arame Ndiaye
- Department of Animal Biology, Faculty of Sciences and Technologies, University Cheikh Anta Diop, BP 5005, Dakar, Senegal
| | - Barbara Rzebik-Kowalska
- Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Sławkowska 17, 31-016, Kraków, Poland
| | - Nina Serén
- CIBIO-InBIO Associate Laboratory, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, 4485-661, Portugal
| |
Collapse
|
7
|
Subach A. Training barn owls: a powerful tool in ecological experiments. Isr J Ecol Evol 2016. [DOI: 10.1080/15659801.2015.1123851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Predators affect prey directly by predation and indirectly by triggering behavioral responses that aim at reducing predation risk. In this paper, I present a method for training an avian predator which can allow separating between its direct and indirect effects on prey in various experimental setups. Barn owls are found to be a valuable tool for empirically testing different hypotheses related to predator-prey interactions, population dynamics, and inter-specific competition, all performed in the field using authentic rodent prey and their natural predators. Barn owls are raised and trained to participate in field experiments using classical conditioning, and are trained either to catch rodents or only to fly above a certain area without making any attempt to attack the prey, simulating solely predation risk. Body mass is a crucial factor in the training procedure, and I thus define five body mass ranges that characterize different behavioral stages in the training of owls. A logistic model is used to calculate and to predict changes in the body mass during the growth and training periods of owls. Finally, I discuss several possible implications of the usage of trained barn owls in empirical studies.
Collapse
Affiliation(s)
- Aziz Subach
- Department of Life Sciences, Ben-Gurion University of the Negev
- Department of Zoology, Tel Aviv University
| |
Collapse
|
8
|
Kotler BP, Brown JS, Bleicher SS, Embar K. Intercontinental-wide consequences of compromise-breaking adaptations: the case of desert rodents. Isr J Ecol Evol 2016. [DOI: 10.1080/15659801.2015.1125832] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Desert rodent assemblages from around the world provide convergent, but independent crucibles for testing theory and deducing general ecological principles. The heteromyid rodents of North America and the gerbils of the Middle East and their predators provide such an example. Both sets of rodents face predation from owls and vipers, but the North American species possess unique traits that may represent macroevolutionary breakthroughs: rattlesnakes have infra-red sensitive sensory pits, and heteromyids have cheek pouches. To test their significance, we brought together two gerbils (Middle East), two heteromyid rodents (a kangaroo rat and a pocket mouse; North America) in a common setting (a vivarium in the Negev Desert), and quantified the “opinions” of the rodents towards the North American sidewinder rattlesnake and the Middle Eastern Saharan horned viper and the foraging behavior of each in the face of these snake predators plus owl predators. Gerbils are fairly evenly matched in their anti-predator abilities, while the heteromyids differ widely, and these seem to match well with and may determine the types of mechanisms of species coexistence that operate in the communities of each continent. Evolutionary history, macroevolutionary traits, and risk management therefore combine to determine the characteristics of the organisms and the organization of their communities.
Collapse
Affiliation(s)
- Burt P. Kotler
- Mitrani Department of Desert Ecology, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev
| | - Joel S. Brown
- Department of Biological Sciences (M/C066), University of Illinois at Chicago
| | - Sonny S. Bleicher
- Mitrani Department of Desert Ecology, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev
- Department of Biological Sciences (M/C066), University of Illinois at Chicago
| | - Keren Embar
- Mitrani Department of Desert Ecology, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev
| |
Collapse
|
9
|
Coker DJ, Hoey AS, Wilson SK, Depczynski M, Graham NAJ, Hobbs JPA, Holmes TH, Pratchett MS. Habitat Selectivity and Reliance on Live Corals for Indo-Pacific Hawkfishes (Family: Cirrhitidae). PLoS One 2015; 10:e0138136. [PMID: 26529406 PMCID: PMC4631501 DOI: 10.1371/journal.pone.0138136] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 08/25/2015] [Indexed: 11/19/2022] Open
Abstract
Hawkfishes (family: Cirrhitidae) are small conspicuous reef predators that commonly perch on, or shelter within, the branches of coral colonies. This study examined habitat associations of hawkfishes, and explicitly tested whether hawkfishes associate with specific types of live coral. Live coral use and habitat selectivity of hawkfishes was explored at six locations from Chagos in the central Indian Ocean extending east to Fiji in the Pacific Ocean. A total of 529 hawkfishes from seven species were recorded across all locations with 63% of individuals observed perching on, or sheltering within, live coral colonies. Five species (all except Cirrhitus pinnulatus and Cirrhitichthys oxycephalus) associated with live coral habitats. Cirrhitichthys falco selected for species of Pocillopora while Paracirrhites arcatus and P. forsteri selected for both Pocillopora and Acropora, revealing that these habitats are used disproportionately more than expected based on the local cover of these coral genera. Habitat selection was consistent across geographic locations, and species of Pocillopora were the most frequently used and most consistently selected even though this coral genus never comprised more than 6% of the total coral cover at any of the locations. Across locations, Paracirrhites arcatus and P. forsteri were the most abundant species and variation in their abundance corresponded with local patterns of live coral cover and abundance of Pocilloporid corals, respectively. These findings demonstrate the link between small predatory fishes and live coral habitats adding to the growing body of literature highlighting that live corals (especially erect branching corals) are critically important for sustaining high abundance and diversity of fishes on coral reefs.
Collapse
Affiliation(s)
- Darren J. Coker
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Andrew S. Hoey
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia
| | - Shaun K. Wilson
- Oceans Institute, The University of Western Australia, Crawley, Australia
- Marine Science Program, Department of Parks and Wildlife, Perth, Australia
| | - Martial Depczynski
- Oceans Institute, The University of Western Australia, Crawley, Australia
- Australian Institute of Marine Science, Oceans Institute, The University of Western Australia, Crawley, Australia
| | - Nicholas A. J. Graham
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Jean-Paul A. Hobbs
- Department of Environment and Agriculture, Curtin University, Perth, Australia
| | - Thomas H. Holmes
- Oceans Institute, The University of Western Australia, Crawley, Australia
- Marine Science Program, Department of Parks and Wildlife, Perth, Australia
| | - Morgan S. Pratchett
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia
| |
Collapse
|
10
|
Berger-Tal O, Embar K, Kotler BP, Saltz D. Everybody loses: intraspecific competition induces tragedy of the commons in Allenby's gerbils. Ecology 2015; 96:54-61. [PMID: 26236890 DOI: 10.1890/14-0130.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Interference competition may lead to a tragedy of the commons in which individuals driven by self-interest reduce the fitness of the entire group. We investigated this hypothesis in Allenby's gerbils, Gerbillus andersoni allenbyi, by comparing foraging behaviors of single vs. pairs of gerbils. We recorded strong interference competition within the foraging pairs. Competition reduced the amount of time the gerbils spent foraging, as well as foraging efficiency since part of the foragers' attention was directed toward detecting competitors (apparent predation risk). Single gerbils harvested significantly more food than the combined efforts of two gerbils foraging together. Competition reduced the success of both individuals within a pair by more than 50%, making this a case of the tragedy of the commons where each individual's investment in competition reduces the success of all individuals within the group, including its own. Despite their great costs, competitive behaviors will be selected for as long as one individual achieves higher fitness than the other. In nature, interspecific interactions, such as predation risk, may act to reduce and regulate the deleterious effects of intraspecific competition.
Collapse
|
11
|
Abstract
Science is an organized enterprise of inquiry which tries to tie together multiple strands of evidence to craft coherent explanations for disparate patterns in the natural world. Philosophers call this enterprise “inference towards the best explanation”. Such inferences at times depend upon detailed quantitative models, but at times one can rely upon the confluence of multiple strands of qualitative evidence. Humans are having unquestionable influences upon many aspects of the earth system at present, on land, in freshwater systems, and indeed the ocean, including devastating impacts on biodiversity. There are many patterns in the world at present – shrinking glaciers, shifting seasonal patterns in species’ life histories, and altered spatial distributions – which point to the signal of climate change, independent of the details of quantitative climate models. Yet, there are many other factors at play, often confounding clear assessment of the specific role of climate change in observed changes in the world. A deeper synoptic understanding of the drivers and impacts of climate change would be incredibly valuable and is urgently needed, even if in the end (though this seems increasingly unlikely) anthropogenic drivers were not the main factor underlying observed climate change.
Collapse
|
12
|
Interactive effects of salinity and a predator on mosquito oviposition and larval performance. Oecologia 2014; 175:565-75. [DOI: 10.1007/s00442-014-2930-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 03/06/2014] [Indexed: 11/25/2022]
|
13
|
Foraging in space and time structure an African small mammal community. Oecologia 2014; 175:521-35. [DOI: 10.1007/s00442-014-2926-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Accepted: 03/05/2014] [Indexed: 11/27/2022]
|
14
|
McGuire LP, Boyle WA. Altitudinal migration in bats: evidence, patterns, and drivers. Biol Rev Camb Philos Soc 2013; 88:767-86. [DOI: 10.1111/brv.12024] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 01/23/2013] [Accepted: 01/25/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Liam P. McGuire
- Advanced Facility for Avian Research; Department of Biology; University of Western Ontario; 1151 Richmond Street North London Ontario N6A 5B7 Canada
| | - W. Alice Boyle
- Advanced Facility for Avian Research; Department of Biology; University of Western Ontario; 1151 Richmond Street North London Ontario N6A 5B7 Canada
| |
Collapse
|
15
|
Katz MW, Abramsky Z, Kotler BP, Rosenzweig ML, Alteshtein O, Vasserman G. Optimal Foraging of Little Egrets and Their Prey in a Foraging Game in a Patchy Environment. Am Nat 2013; 181:381-95. [DOI: 10.1086/669156] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
16
|
Stevens RD, Tello JS, Gavilanez MM. Stronger tests of mechanisms underlying geographic gradients of biodiversity: insights from the dimensionality of biodiversity. PLoS One 2013; 8:e56853. [PMID: 23451099 PMCID: PMC3581556 DOI: 10.1371/journal.pone.0056853] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 01/17/2013] [Indexed: 11/29/2022] Open
Abstract
Inference involving diversity gradients typically is gathered by mechanistic tests involving single dimensions of biodiversity such as species richness. Nonetheless, because traits such as geographic range size, trophic status or phenotypic characteristics are tied to a particular species, mechanistic effects driving broad diversity patterns should manifest across numerous dimensions of biodiversity. We develop an approach of stronger inference based on numerous dimensions of biodiversity and apply it to evaluate one such putative mechanism: the mid-domain effect (MDE). Species composition of 10,000-km(2) grid cells was determined by overlaying geographic range maps of 133 noctilionoid bat taxa. We determined empirical diversity gradients in the Neotropics by calculating species richness and three indices each of phylogenetic, functional and phenetic diversity for each grid cell. We also created 1,000 simulated gradients of each examined metric of biodiversity based on a MDE model to estimate patterns expected if species distributions were randomly placed within the Neotropics. For each simulation run, we regressed the observed gradient onto the MDE-expected gradient. If a MDE drives empirical gradients, then coefficients of determination from such an analysis should be high, the intercept no different from zero and the slope no different than unity. Species richness gradients predicted by the MDE fit empirical patterns. The MDE produced strong spatially structured gradients of taxonomic, phylogenetic, functional and phenetic diversity. Nonetheless, expected values generated from the MDE for most dimensions of biodiversity exhibited poor fit to most empirical patterns. The MDE cannot account for most empirical patterns of biodiversity. Fuller understanding of latitudinal gradients will come from simultaneous examination of relative effects of random, environmental and historical mechanisms to better understand distribution and abundance of the current biota.
Collapse
Affiliation(s)
- Richard D Stevens
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America.
| | | | | |
Collapse
|
17
|
Scharf I, Ovadia O, Foitzik S. The advantage of alternative tactics of prey and predators depends on the spatial pattern of prey and social interactions among predators. POPUL ECOL 2011. [DOI: 10.1007/s10144-011-0286-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
18
|
Raveh A, Kotler BP, Abramsky Z, Krasnov BR. Driven to distraction: detecting the hidden costs of flea parasitism through foraging behaviour in gerbils. Ecol Lett 2010; 14:47-51. [PMID: 21070560 DOI: 10.1111/j.1461-0248.2010.01549.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Gerbilline rodents such as Allenby's gerbils (Gerbillus andersoni allenbyi), when parasitized by fleas such as Synosternus cleopatrae pyramidis, devote long hours of grooming to remove the ectoparasites. Yet no detrimental energetic or immunological effects of the ectoparasites have been found in adult Allenby's gerbil. Why should gerbils go to such trouble? We tested for the various ways that fleas can negatively affect gerbils by manipulating flea infestation on gerbils and the presence of a fox. We demonstrate that gerbils responded to fleas by leaving resource patches at higher giving-up densities. Furthermore, they stayed in those resource patches less time and left them at higher quitting harvest rates so long as a fox was also present. When flea-ridden, gerbils also abandoned using vigilance to manage risk and relied mainly on time allocation. Thus, having fleas imposed a foraging cost similar in nature to that arising from the risk of predation from foxes and may be even larger in magnitude. More than that, the presence of fleas acted as a magnifier of foraging costs, especially those arising from the risk of predation. The fleas reduced the gerbils' foraging aptitude and altered how they went about managing risk of predation. We hypothesize that fleas reduce the attention that gerbils otherwise have for foraging and predator detection. We suggest that this is the major cost of ectoparasitism.
Collapse
Affiliation(s)
- Ashael Raveh
- Department of Life Sciences, Ben-Gurion University of the Negev, 84105 Beer-Sheva, Israel.
| | | | | | | |
Collapse
|
19
|
Abstract
A unified theory in science is a theory that shows a common underlying set of rules that regulate processes previously thought to be distinct. Unified theories have been important in physics including the unification of electricity and magnetism and the unification of the electromagnetic with the weak nuclear force. Surprisingly, ecology, specifically the subfields of biodiversity and macroecology, also possess not one but at least six unified theories. This is problematic as only one unified theory is desirable. Superficially, the six unified theories seem very different. However, I show that all six theories use the same three rules or assertions to describe a stochastic geometry of biodiversity. The three rules are: (1) intraspecifically individuals are clumped together; (2) interspecifically global or regional abundance varies according to a hollow curve distribution; and (3) interspecifically individuals are placed without regard to individuals of other species. These three rules appear sufficient to explain local species abundance distributions, species-area relationships, decay of similarity of distance and possibly other patterns of biodiversity. This provides a unification of the unified theories. I explore implications of this unified theory for future research.
Collapse
Affiliation(s)
- Brian J McGill
- School of Natural Resources, University of Arizona, Bioscience East Rm 325, 1311 E. 4th St., Tucson, AZ 85721, USA.
| |
Collapse
|
20
|
Hui C, McGeoch MA, Reyers B, le Roux PC, Greve M, Chown SL. Extrapolating population size from the occupancy-abundance relationship and the scaling pattern of occupancy. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2009; 19:2038-2048. [PMID: 20014577 DOI: 10.1890/08-2236.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The estimation of species abundances at regional scales requires a cost-efficient method that can be applied to existing broadscale data. We compared the performance of eight models for estimating species abundance and community structure from presence-absence maps of the southern African avifauna. Six models were based on the intraspecific occupancy-abundance relationship (OAR); the other two on the scaling pattern of species occupancy (SPO), which quantifies the decline in species range size when measured across progressively finer scales. The performance of these models was examined using five tests: the first three compared the predicted community structure against well-documented macroecological patterns; the final two compared published abundance estimates for rare species and the total regional abundance estimate against predicted abundances. Approximately two billion birds were estimated as occurring in South Africa, Lesotho, and Swaziland. SPO models outperformed the OAR models, due to OAR models assuming environmental homogeneity and yielding scale-dependent estimates. Therefore, OAR models should only be applied across small, homogenous areas. By contrast, SPO models are suitable for data at larger spatial scales because they are based on the scale dependence of species range size and incorporate environmental heterogeneity (assuming fractal habitat structure or performing a Bayesian estimate of occupancy). Therefore, SPO models are recommended for assemblage-scale regional abundance estimation based on spatially explicit presence-absence data.
Collapse
Affiliation(s)
- Cang Hui
- Centre for Invasion Biology, Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa.
| | | | | | | | | | | |
Collapse
|
21
|
Gotelli NJ, Anderson MJ, Arita HT, Chao A, Colwell RK, Connolly SR, Currie DJ, Dunn RR, Graves GR, Green JL, Grytnes JA, Jiang YH, Jetz W, Kathleen Lyons S, McCain CM, Magurran AE, Rahbek C, Rangel TFLVB, Soberón J, Webb CO, Willig MR. Patterns and causes of species richness: a general simulation model for macroecology. Ecol Lett 2009; 12:873-86. [PMID: 19702748 DOI: 10.1111/j.1461-0248.2009.01353.x] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nicholas J Gotelli
- Department of Biology, University of Vermont, Burlington, VT 05405, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Gregory SD, Macdonald DW. Prickly coexistence or blunt competition? Opuntia refugia in an invaded rodent community. Oecologia 2008; 159:225-36. [DOI: 10.1007/s00442-008-1196-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2008] [Accepted: 09/29/2008] [Indexed: 11/25/2022]
|
23
|
Krivan V, Sirot E. Habitat selection by two competing species in a two-habitat environment. Am Nat 2008; 160:214-34. [PMID: 18707488 DOI: 10.1086/341016] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
We present a theoretical study of habitat selection strategies for two species that compete in an environment consisting of two different habitats. Our fitness functions are derived from the Lotka-Volterra competition equations, and we assume that individuals settle in the habitat in which their fitness is maximized. We derive an ideal free distribution across the habitats for both species. Our model provides analytical and graphical descriptions of individual habitat selection behavior, isolegs (the boundary lines separating regions where qualitatively different habitat preferences are predicted), and spatial population distributions. Our analysis reveals complex isolegs, several novel patterns of habitat distribution, and even situations where spatial strategies, as well as the relative abundances of coexisting species, exhibit only local stability. Hence, distributions of competing species may be determined not solely by their respective densities but also by the order of colonization. This happens, however, only for extreme levels of interspecific competition. In the situation where one competitor species is dominant over the other, our model predicts isolegs that qualitatively agree with observed behavioral patterns. However, our model predicts a greater variety of possible situations than has been previously described. Finally, we analyze the influence of habitat selection behavior on species isoclines and verify that increasing interspecific competition leads to habitat segregation.
Collapse
Affiliation(s)
- Vlastimil Krivan
- Department of Theoretical Biology, Institute of Entomology, Academy of Sciences of the Czech Republic and Faculty of Biological Sciences, Branisovská 31, 370 05 Ceské Budejovice, Czech Republic
| | | |
Collapse
|
24
|
McGill BJ, Etienne RS, Gray JS, Alonso D, Anderson MJ, Benecha HK, Dornelas M, Enquist BJ, Green JL, He F, Hurlbert AH, Magurran AE, Marquet PA, Maurer BA, Ostling A, Soykan CU, Ugland KI, White EP. Species abundance distributions: moving beyond single prediction theories to integration within an ecological framework. Ecol Lett 2007; 10:995-1015. [PMID: 17845298 DOI: 10.1111/j.1461-0248.2007.01094.x] [Citation(s) in RCA: 589] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Species abundance distributions (SADs) follow one of ecology's oldest and most universal laws--every community shows a hollow curve or hyperbolic shape on a histogram with many rare species and just a few common species. Here, we review theoretical, empirical and statistical developments in the study of SADs. Several key points emerge. (i) Literally dozens of models have been proposed to explain the hollow curve. Unfortunately, very few models are ever rejected, primarily because few theories make any predictions beyond the hollow-curve SAD itself. (ii) Interesting work has been performed both empirically and theoretically, which goes beyond the hollow-curve prediction to provide a rich variety of information about how SADs behave. These include the study of SADs along environmental gradients and theories that integrate SADs with other biodiversity patterns. Central to this body of work is an effort to move beyond treating the SAD in isolation and to integrate the SAD into its ecological context to enable making many predictions. (iii) Moving forward will entail understanding how sampling and scale affect SADs and developing statistical tools for describing and comparing SADs. We are optimistic that SADs can provide significant insights into basic and applied ecological science.
Collapse
Affiliation(s)
- Brian J McGill
- Department of Biology, McGill University, 1205 Ave Dr Penfield, Montreal, QC H3A 1B1, Canada.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Tsurim I, Abramsky Z, Kotler BP. The Effect of Food and Shelter on Habitat Selection by Granivorous Birds Over-Wintering in Shrub Steppes of the Northern Negev, Israel. Isr J Ecol Evol 2007. [DOI: 10.1560/ijee_53_1_59] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
26
|
Lindberg WJ, Frazer TK, Portier KM, Vose F, Loftin J, Murie DJ, Mason DM, Nagy B, Hart MK. Density-dependent habitat selection and performance by a large mobile reef fish. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2006; 16:731-46. [PMID: 16711059 DOI: 10.1890/1051-0761(2006)016[0731:dhsapb]2.0.co;2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Many exploited reef fish are vulnerable to overfishing because they concentrate over hard-bottom patchy habitats. How mobile reef fish use patchy habitat, and the potential consequences on demographic parameters, must be known for spatially explicit population dynamics modeling, for discriminating essential fish habitat (EFH), and for effectively planning conservation measures (e.g., marine protected areas, stock enhancement, and artificial reefs). Gag, Mycteroperca microlepis, is an ecologically and economically important warm-temperate grouper in the southeastern United States, with behavioral and life history traits conducive to large-scale field experiments. The Suwannee Regional Reef System (SRRS) was built of standard habitat units (SHUs) in 1991-1993 to manipulate and control habitat patchiness and intrinsic habitat quality, and thereby test predictions from habitat selection theory. Colonization of the SRRS by gag over the first six years showed significant interactions of SHU size, spacing, and reef age; with trajectories modeled using a quadratic function for closely spaced SHUs (25 m) and a linear model for widely spaced SHUs (225 m), with larger SHUs (16 standardized cubes) accumulating significantly more gag faster than smaller 4-cube SHUs (mean = 72.5 gag/16-cube SHU at 225-m spacing by year 6, compared to 24.2 gag/4-cube SHU for same spacing and reef age). Residency times (mean = 9.8 mo), indicative of choice and measured by ultrasonic telemetry (1995-1998), showed significant interaction of SHU size and spacing consistent with colonization trajectories. Average relative weight (W(r)) and incremental growth were greater on smaller than larger SHUs (mean W(r) = 104.2 vs. 97.7; incremental growth differed by 15%), contrary to patterns of abundance and residency. Experimental manipulation of shelter on a subset of SRRS sites (2000-2001) confirmed our hypothesis that shelter limits local densities of gag, which, in turn, regulates their growth and condition. Density-dependent habitat selection for shelter and individual growth dynamics were therefore interdependent ecological processes that help to explain how patchy reef habitat sustains gag production. Moreover, gag selected shelter at the expense of maximizing their growth. Thus, mobile reef fishes could experience density-dependent effects on growth, survival, and/or reproduction (i.e., demographic parameters) despite reduced stock sizes as a consequence of fishing.
Collapse
Affiliation(s)
- William J Lindberg
- Department of Fisheries and Aquatic Sciences, University of Florida, 7922 NW 71st Street, Gainesville, Florida 32653, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Wasserberg G, P. Kotler B, Abramsky Z. The role of site, habitat, seasonality and competition in determining the nightly activity patterns of psammophilic gerbils in a centrifugally organized community. OIKOS 2006. [DOI: 10.1111/j.0030-1299.2006.14302.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
28
|
Pinter-Wollman N, Dayan T, Eilam D, Kronfeld-Schor N. CAN AGGRESSION BE THE FORCE DRIVING TEMPORAL SEPARATION BETWEEN COMPETING COMMON AND GOLDEN SPINY MICE? J Mammal 2006. [DOI: 10.1644/04-mamm-a-194r2.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
29
|
Hawlena H, Abramsky Z, Krasnov BR. Ectoparasites and age-dependent survival in a desert rodent. Oecologia 2006; 148:30-9. [PMID: 16425045 DOI: 10.1007/s00442-005-0345-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2005] [Accepted: 12/14/2005] [Indexed: 11/28/2022]
Abstract
Host age is one of the key factors in host-parasite relationships as it possibly affects infestation levels, parasite-induced mortality of a host, and parasite distribution among host individuals. We tested two alternative hypotheses about infestation pattern and survival under parasitism in relation to host age. The first hypothesis assumes that parasites are recruited faster than they die and, thus, suggests that adult hosts will show higher infestation levels than juveniles because the former have more time to accumulate parasites. The second hypothesis assumes that parasites die faster than they are recruited and, thus, suggests that adults will show lower infestation levels because of acquired immune response and/or the mortality of heavily infested juveniles and, thus, selection for less infested adults. As the negative effects of parasites on host are often intensity-dependent, we expected that the age-related differences in infestation may be translated to lower or higher survival under parasitism of adults, in the cases of the first and the second hypotheses, respectively. We manipulated ectoparasite numbers using insecticide and assessed the infestation pattern in adult and juvenile gerbils (Gerbillus andersoni) in the Negev Desert. We found only a partial support for age-dependent parasitism. No age-related differences in infestation and distribution among host individuals were found after adjusting the ectoparasite numbers to the host's surface area. However, age-related differences in survival under parasitism were revealed. The survival probability of parasitized juveniles decreased in about 48% compared to unparasitized hosts while the survival probability of adults was not affected by ectoparasites. Our results suggest that the effect of host age on host-parasite dynamics may not explicitly be determined by age-dependent differences in ectoparasite recruitment or mortality processes but may also be affected by other host-related and parasite-related traits.
Collapse
Affiliation(s)
- Hadas Hawlena
- Department of Life Sciences and Ramon Science Center, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84105, Beer-Sheva, Israel.
| | | | | |
Collapse
|
30
|
P. Kotler B, R. Dickman C, Wasserberg G, Ovadia O. The use of time and space by male and female gerbils exploiting a pulsed resource. OIKOS 2005. [DOI: 10.1111/j.0030-1299.2005.13692.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
31
|
ABRAMSKY Z, ROSENZWEIG ML, ELBAZ M, ZIV Y. Does interspecific competition from congeners cause the scarcity of Gerbillus henleyi in productive sandy desert habitats? J Anim Ecol 2005. [DOI: 10.1111/j.1365-2656.2005.00956.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
32
|
Shochat E, Lerman SB, Katti M, Lewis DB. Linking optimal foraging behavior to bird community structure in an urban-desert landscape: field experiments with artificial food patches. Am Nat 2004; 164:232-43. [PMID: 15278846 DOI: 10.1086/422222] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2003] [Accepted: 04/05/2004] [Indexed: 11/03/2022]
Abstract
Urban bird communities exhibit high population densities and low species diversity, yet mechanisms behind these patterns remain largely untested. We present results from experimental studies of behavioral mechanisms underlying these patterns and provide a test of foraging theory applied to urban bird communities. We measured foraging decisions at artificial food patches to assess how urban habitats differ from wildlands in predation risk, missed-opportunity cost, competition, and metabolic cost. By manipulating seed trays, we compared leftover seed (giving-up density) in urban and desert habitats in Arizona. Deserts exhibited higher predation risk than urban habitats. Only desert birds quit patches earlier when increasing the missed-opportunity cost. House finches and house sparrows coexist by trading off travel cost against foraging efficiency. In exclusion experiments, urban doves were more efficient foragers than passerines. Providing water decreased digestive costs only in the desert. At the population level, reduced predation and higher resource abundance drive the increased densities in cities. At the community level, the decline in diversity may involve exclusion of native species by highly efficient urban specialists. Competitive interactions play significant roles in structuring urban bird communities. Our results indicate the importance and potential of mechanistic approaches for future urban bird community studies.
Collapse
Affiliation(s)
- Eyal Shochat
- Center for Environmental Studies, Arizona State University, Tempe, Arizona 85287, USA.
| | | | | | | |
Collapse
|
33
|
Abramsky Z, Rosenzweig ML, Belmaker J, Bar A. The impact of long-term continuous risk of predation on two species of gerbils. CAN J ZOOL 2004. [DOI: 10.1139/z04-007] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Individuals of Gerbillus allenbyi Thomas, 1918 were subjected to artificial illumination in large field enclosures (2-ha sandy-substrate plots in the Negev Desert, Israel). The illumination was similar to that provided by a full moon and was used to mimic the elevated risk of avian predation that accompanies a full moon. We artificially illuminated the enclosures during all hours of darkness for 3 consecutive months. In some cases, we also added individuals of Gerbillus pyramidum Geoffroy, 1825 to provide a competitive challenge for the G. allenbyi. In the presence of the light source, individuals of G. allenbyi shifted their foraging activity to favor experimental areas of darkness. They also foraged less in the open and more beneath bushes. In the absence of the light source, G. allenbyi shifted its activity from the subplot with G. pyramidum to the subplot without the competitor. However, the competitive effect of the G. pyramidum disappeared in plots that were artificially illuminated. These results closely resemble those of earlier experiments during which we increased the apparent risk of predation in brief pulses lasting only 2 h/night.
Collapse
|
34
|
Kelt DA, Meserve PL, Karina Nabors L, Forister ML, Gutiérrez JR. FORAGING ECOLOGY OF SMALL MAMMALS IN SEMIARID CHILE: THE INTERPLAY OF BIOTIC AND ABIOTIC EFFECTS. Ecology 2004. [DOI: 10.1890/02-4065] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
35
|
Kronfeld-Schor N, Dayan T. Partitioning of Time as an Ecological Resource. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2003. [DOI: 10.1146/annurev.ecolsys.34.011802.132435] [Citation(s) in RCA: 556] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Tamar Dayan
- Department of Zoology, Tel Aviv University, Tel Aviv 69978, Israel;
| |
Collapse
|
36
|
|
37
|
Eccard JA, Ylönen H. Interspecific competition in small rodents: from populations to individuals. Evol Ecol 2003. [DOI: 10.1023/a:1027305410005] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
38
|
|
39
|
Bakker VJ, Hastings K. Den trees used by northern flying squirrels (Glaucomys sabrinus) in southeastern Alaska. CAN J ZOOL 2002. [DOI: 10.1139/z02-155] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Northern flying squirrel (Glaucomys sabrinus) dens are reportedly associated with features characteristic of older forests, and den availability is a potential limiting factor in younger forests. We assessed den sites used by northern flying squirrels in southeastern Alaska, where we expected den-site selection to differ from more southerly forests, owing to increased thermal stress but reduced predation and competition. We located 27 squirrels in 76 dens and compared den trees with 1875 matched random trees. Most dens ([Formula: see text]73%) were in cavities and 21% were at heights of [Formula: see text]3 m. This high rate of cavity use, including cavities low in the bole, likely reflects the importance of weatherproof dens in this cool wet region. Northern flying squirrels preferentially used trees with indicators of cavity presence, selecting for snags and for larger diameter trees with bole entries, conks, abundant mistletoe, and dead tops. Although cavity availability is probably not limiting populations in this region currently, cavity-supporting trees would be one of the last elements of old-growth forests to develop in intensively logged stands. Retention of small groups of large snags and live trees exhibiting evidence of disease or physical defects would ensure availability of denning structures after logging.
Collapse
|
40
|
Pusenius J, Schmidt KA. The effects of habitat manipulation on population distribution and foraging behavior in meadow voles. OIKOS 2002. [DOI: 10.1034/j.1600-0706.2002.980207.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
41
|
Skalski GT, Gilliam JF. Feeding under Predation Hazard: Testing Models of Adaptive Behavior with Stream Fish. Am Nat 2002; 160:158-72. [DOI: 10.1086/341012] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
42
|
Cramer MJ, Willig MR. HABITAT HETEROGENEITY, HABITAT ASSOCIATIONS, AND RODENT SPECIES DIVERSITY IN A SAND–SHINNERY-OAK LANDSCAPE. J Mammal 2002. [DOI: 10.1644/1545-1542(2002)083<0743:hhhaar>2.0.co;2] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
43
|
Guthrie CG, Moorhead DL. Density-dependent habitat selection: evaluating isoleg theory with a Lotka-Volterra model. OIKOS 2002. [DOI: 10.1034/j.1600-0706.2002.970204.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
44
|
|
45
|
|
46
|
|
47
|
|
48
|
|
49
|
C. Patrick D. Healthy wrinkles for population dynamics: unevenly spread resources can support more users. J Anim Ecol 2001. [DOI: 10.1111/j.1365-2656.2001.00474.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
50
|
C. Patrick D. Healthy wrinkles for population dynamics: unevenly spread resources can support more users. J Anim Ecol 2001. [DOI: 10.1046/j.1365-2656.2001.00474.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|