1
|
Shochat E, Nilsson C, Lisovski S, Chernetsov N. Editorial: Optimal bird migration: Implications for navigation, physiology, and stopover ecology. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1029958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
2
|
Schekler I, Smolinsky JA, Troupin D, Buler JJ, Sapir N. Bird Migration at the Edge – Geographic and Anthropogenic Factors but Not Habitat Properties Drive Season-Specific Spatial Stopover Distributions Near Wide Ecological Barriers. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.822220] [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
Stopping-over is critical for migrating birds. Yet, our knowledge of bird stopover distributions and their mechanisms near wide ecological barriers is limited. Using low elevation scans of three weather radars covering 81,343 km2, we quantified large-scale bird departure patterns during spring and autumn (2014–2018) in between two major ecological barriers, the Sahara Desert and Mediterranean Sea. Boosted Regression Tree models revealed that bird distributions differed between the seasons, with higher densities in the desert and its edge, as well as inland from the sea, during spring and a predominantly coastal distribution in the autumn. Bird distributions were primarily associated with broad-scale geographic and anthropogenic factors rather than individual fine-scale habitat types. Notably, artificial light at night strongly correlated with high densities of migrants, especially in the autumn. Autumn migrants also selected sites located close to water sources. Our findings substantially advance the understanding of bird migration ecology near ecological barriers and facilitate informed conservation efforts in a highly populated region by identifying a few high-priority stopover areas of migrating birds.
Collapse
|
3
|
Cohen EB, Lafleur JM, Moore FR. Density Dependent Refueling of Migratory Songbirds During Stopover Within an Urbanizing Coastal Landscape. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.837790] [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
Refueling performance is the primary currency of a successful migration as birds must maintain energy stores to achieve an optimal travel schedule. Migrating birds can anticipate heightened energy demand, not to mention increased uncertainty that energy demands will be satisfied, especially within an urbanizing landscape following long-distance flights. We tested the expectation that refueling performance of songbirds is reduced as densities increase at stopover sites in an urbanizing coastline of the Gulf of Mexico. We measured the density of migrating birds, their refueling performance, and arthropod abundance in two large tracts of contiguous forest paired with two small isolated patches embedded within residential settings throughout spring migration over the course of 2 years. Refueling performance declined with increasing migrant densities, even though the overall daily densities of birds stopping in these landscapes were relatively low and arthropod densities were low throughout. Habitat patch size alone did not account for differences in refueling performance, but smaller habitat patches more often concentrated migrants in higher densities where they experienced reduced refueling performance. We found support for density-dependent refueling performance during spring migration through a region where overall passage and stopover densities are low; suggesting that larger contiguous forest tracks within urban landscapes provide higher quality habitat for refueling and that effect is likely even more pronounced in landscapes within higher density migratory corridors. The nutritional challenges encountered during migration influence the overall pace of migration and changes in access to food resources due to increasing urbanization may ultimately impact optimal travel schedules.
Collapse
|
4
|
Schmaljohann H, Eikenaar C, Sapir N. Understanding the ecological and evolutionary function of stopover in migrating birds. Biol Rev Camb Philos Soc 2022; 97:1231-1252. [PMID: 35137518 DOI: 10.1111/brv.12839] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 12/14/2022]
Abstract
Global movement patterns of migratory birds illustrate their fascinating physical and physiological abilities to cross continents and oceans. During their voyages, most birds land multiple times to make so-called 'stopovers'. Our current knowledge on the functions of stopover is mainly based on the proximate study of departure decisions. However, such studies are insufficient to gauge fully the ecological and evolutionary functions of stopover. If we study how a focal trait, e.g. changes in energy stores, affects the decision to depart from a stopover without considering the trait(s) that actually caused the bird to land, e.g. unfavourable environmental conditions for flight, we misinterpret the function of the stopover. It is thus important to realise and acknowledge that stopovers have many different functions, and that not every migrant has the same (set of) reasons to stop-over. Additionally, we may obtain contradictory results because the significance of different traits to a migrant is context dependent. For instance, late spring migrants may be more prone to risk-taking and depart from a stopover with lower energy stores than early spring migrants. Thus, we neglect that departure decisions are subject to selection to minimise immediate (mortality risk) and/or delayed (low future reproductive output) fitness costs. To alleviate these issues, we first define stopover as an interruption of migratory endurance flight to minimise immediate and/or delayed fitness costs. Second, we review all probable functions of stopover, which include accumulating energy, various forms of physiological recovery and avoiding adverse environmental conditions for flight, and list potential other functions that are less well studied, such as minimising predation, recovery from physical exhaustion and spatiotemporal adjustments to migration. Third, derived from these aspects, we argue for a paradigm shift in stopover ecology research. This includes focusing on why an individual interrupts its migratory flight, which is more likely to identify the individual-specific function(s) of the stopover correctly than departure-decision studies. Moreover, we highlight that the selective forces acting on stopover decisions are context dependent and are expected to differ between, e.g. K-/r-selected species, the sexes and migration strategies. For example, all else being equal, r-selected species (low survival rate, high reproductive rate) should have a stronger urge to continue the migratory endurance flight or resume migration from a stopover because the potential increase in immediate fitness costs suffered from a flight is offset by the expected higher reproductive success in the subsequent breeding season. Finally, we propose to focus less on proximate mechanisms controlling landing and departure decisions, and more on ultimate mechanisms to identify the selective forces shaping stopover decisions. Our ideas are not limited to birds but can be applied to any migratory species. Our revised definition of stopover and the proposed paradigm shift has the potential to stimulate a fruitful discussion towards a better evolutionary ecological understanding of the functions of stopover. Furthermore, identifying the functions of stopover will support targeted measures to conserve and restore the functionality of stopover sites threatened by anthropogenic environmental changes. This is especially important for long-distance migrants, which currently are in alarming decline.
Collapse
Affiliation(s)
- Heiko Schmaljohann
- Institute for Biology and Environmental Sciences (IBU), Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, Oldenburg, 26129, Germany.,Institute of Avian Research, An der Vogelwarte 21, Wilhelmshaven, 26386, Germany
| | - Cas Eikenaar
- Institute of Avian Research, An der Vogelwarte 21, Wilhelmshaven, 26386, Germany
| | - Nir Sapir
- Department of Evolutionary and Environmental Biology and the Institute of Evolution, University of Haifa, 199 Aba Khoushy Ave, Haifa, 3498838, Israel
| |
Collapse
|
5
|
Domer A, Vinepinsky E, Bouskila A, Shochat E, Ovadia O. Optimal stopover model: A state-dependent habitat selection model for staging passerines. J Anim Ecol 2021; 90:2793-2805. [PMID: 34455596 DOI: 10.1111/1365-2656.13581] [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: 12/29/2020] [Accepted: 08/03/2021] [Indexed: 11/29/2022]
Abstract
During their seasonal migration, birds stage in areas comprising stopover sites of varying quality. Given that migrating birds have a limited information about their environment, they may land at a low-quality stopover site in which their fuel deposition rate (FDR) is low. Birds landing at such sites should decide either to extend their stopover duration or to quickly depart in search for a better site. These decisions, however, strongly depend on their body condition upon landing. To understand the decision-making process of passerines within a stopover area, comprising stopover sites of varying quality, prior to the crossing of a large ecological barrier, we constructed a state-dependent habitat selection model. The model assumes that even if migrating birds have an expectation of encountered area quality, they cannot control for their initial landing site. Once landing, movement between low- and high-quality stopover sites will occur only if the body condition of these birds is high to the extent that they can entail the energetic cost of movement. Birds in the model aim to maximize their fuel load at the end of the stopover period, to suffice for successfully crossing a large ecological barrier. The model is based on empirical data on autumn migrating Blackcaps Sylvia atricapilla, collected at two important stopover sites in the Negev desert of Israel. Migrating passerines staging at these two sites differ in their FDR and body condition. The model shows that the optimal behaviour when arriving at a low-quality stopover site is to abandon it quickly. However, as lean individuals cannot entail the costs of searching for an alternative site, they have no other choice but to stay there even if their chances to successfully cross the Sahara Desert ahead are low. Our model can be applied to other ecological systems. Proper use of this model may allow good assessment of stopover site quality, as indicated by the bird's FDR, regardless of specific site characteristics. Hence, it can help applying targeted management decisions regarding the maintenance of stopover sites or establishment of new ones.
Collapse
Affiliation(s)
- Adi Domer
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ehud Vinepinsky
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Amos Bouskila
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.,Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
| | - Eyal Shochat
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.,Yerucham Center of Ornithology and Ecology, Yerucham, Israel
| | - Ofer Ovadia
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| |
Collapse
|
6
|
Vergara‐Tabares DL, Blendinger PG, Tello A, Peluc SI, Tecco PA. Fleshy‐fruited invasive shrubs indirectly increase native tree seed dispersal. OIKOS 2021. [DOI: 10.1111/oik.08311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- David L. Vergara‐Tabares
- Univ. Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales Córdoba Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Inst. de Diversidad y Ecología Animal (IDEA) Córdoba Argentina
| | - Pedro G. Blendinger
- Inst. de Ecología Regional, Univ. Nacional de Tucumán & CONICET Tucumán Argentina
- Facultad de Ciencias Naturales e Instituto Miguel Lillo, Univ. Nacional de Tucumán Tucumán Argentina
| | - Agustina Tello
- Univ. Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales Córdoba Argentina
| | - Susana I. Peluc
- Univ. Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales Córdoba Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Inst. de Diversidad y Ecología Animal (IDEA) Córdoba Argentina
| | - Paula A. Tecco
- Inst. Multidisciplinario de Biología Vegetal (CONICET‐Univ. Nacional de Córdoba) Córdoba Argentina
- Facultad de Ciencias Exactas Físicas y Naturales, Univ. Nacional de Córdoba Córdoba Argentina
| |
Collapse
|
7
|
Cheeseman AE, Cohen JB, Ryan SJ, Whipps CM. Is conservation based on best available science creating an ecological trap for an imperiled lagomorph? Ecol Evol 2021; 11:912-930. [PMID: 33520175 PMCID: PMC7820145 DOI: 10.1002/ece3.7104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 11/02/2020] [Accepted: 11/13/2020] [Indexed: 11/11/2022] Open
Abstract
Habitat quality regulates fitness and population density, making it a key driver of population size. Hence, increasing habitat quality is often a primary goal of species conservation. Yet, assessments of fitness and density are difficult and costly to obtain. Therefore, species conservation often uses "best available science," extending inferences across taxa, space, or time, and inferring habitat quality from studies of habitat selection. However, there are scenarios where habitat selection is not reflective of habitat quality, and this can lead to maladaptive management strategies. The New England cottontail (Sylvilagus transitionalis) is an imperiled shrubland obligate lagomorph whose successful recovery hinges on creation of suitable habitat. Recovery of this species is also negatively impacted by the non-native eastern cottontail (Sylvilagus floridanus), which can competitively exclude New England cottontails from preferred habitat. Herein, we evaluate habitat quality for adult and juvenile New England and eastern cottontails using survival and density as indicators. Our findings did not support selection following an ideal free distribution by New England cottontails. Instead, selected resources, which are a target of habitat management, were associated with low survival and density and pointed to a complex trade-off between density, survival, habitat, and the presence of eastern cottontails. Further, movement distance was inversely correlated with survival in both species, suggesting that habitat fragmentation limits the ability of cottontails to freely distribute based on habitat quality. While habitat did not directly regulate survival of juvenile cottontails, tick burden had a strong negative impact on juvenile cottontails in poor body condition. Given the complex interactions among New England cottontails, eastern cottontails, and habitat, directly assessing and accounting for factors that limit New England cottontail habitat quality in management plans is vital to their recovery. Our study demonstrates an example of management for possible ecological trap conditions via the application of incomplete knowledge.
Collapse
Affiliation(s)
- Amanda E. Cheeseman
- Department of Environmental and Forest BiologySUNY College of Environmental Science and ForestrySyracuseNYUSA
| | - Jonathan B. Cohen
- Department of Environmental and Forest BiologySUNY College of Environmental Science and ForestrySyracuseNYUSA
| | - Sadie J. Ryan
- Quantitative Disease Ecology and Conservation (QDEC) LabDepartment of GeographyUniversity of FloridaGainesvilleFLUSA
- Emerging Pathogens InstituteUniversity of FloridaGainesvilleFLUSA
- School of Life SciencesUniversity of KwaZulu‐NatalDurbanSouth Africa
| | - Christopher M. Whipps
- Department of Environmental and Forest BiologySUNY College of Environmental Science and ForestrySyracuseNYUSA
| |
Collapse
|
8
|
Avery JD, Keller GS. Spring Migration Patterns of Birds In Montane Habitats of the Southwestern United States. SOUTHWEST NAT 2018. [DOI: 10.1894/0038-4909-63.1.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Julian D. Avery
- Department of Biology, Station 33, Eastern New Mexico University, Portales, NM 88130
- Present address of JDA: Department of Ecosystem Science and Management, Penn State University, 412 Forest Resources Building, University Park, PA 16802
- Present address of GSK: Department of Biology, Gordon College, Wenham, MA 01984
| | - Gregory S. Keller
- Department of Biology, Station 33, Eastern New Mexico University, Portales, NM 88130
- Present address of JDA: Department of Ecosystem Science and Management, Penn State University, 412 Forest Resources Building, University Park, PA 16802
- Present address of GSK: Department of Biology, Gordon College, Wenham, MA 01984
| |
Collapse
|
9
|
Kwon E, Houghton LM, Settlage RE, Catlin DH, Karpanty SM, Fraser JD. Estimating transient populations of unmarked individuals at a migratory stopover site using generalized N‐mixture models. J Appl Ecol 2018. [DOI: 10.1111/1365-2664.13243] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Eunbi Kwon
- Department of Fish and Wildlife Conservation Virginia Tech Blacksburg Virginia
| | | | | | - Daniel H. Catlin
- Department of Fish and Wildlife Conservation Virginia Tech Blacksburg Virginia
| | - Sarah M. Karpanty
- Department of Fish and Wildlife Conservation Virginia Tech Blacksburg Virginia
| | - James D. Fraser
- Department of Fish and Wildlife Conservation Virginia Tech Blacksburg Virginia
| |
Collapse
|
10
|
Differential fitness in field and forest explains density-independent habitat selection by gartersnakes. Oecologia 2016; 181:841-51. [PMID: 27016079 DOI: 10.1007/s00442-016-3605-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 03/07/2016] [Indexed: 10/22/2022]
Abstract
The ideal free distribution concept predicts that organisms will distribute themselves between habitats in a density-dependent manner so that individuals, on average, achieve the same fitness in each habitat. In ectotherms, environmental temperature has a strong impact on fitness, but temperature is not depletable and thus not density dependent. Can density-dependent habitat selection occur in ectotherms when habitats differ in thermal quality? We used an observational study of habitat selection by small snakes in field and forest, followed by manipulative habitat selection and fitness experiments with common gartersnakes in enclosures in field and forest to test this hypothesis. Snakes were much more abundant in the field, the habitat with superior thermal quality, than in the forest. Gartersnakes in our controlled experiment only used the forest habitat when snake density was highest and when food was more abundant in the forest; habitat selection was largely density independent, although there was weak evidence of density dependence. No female gartersnake gave birth in the forest enclosures, whereas half of the females gave birth in the field enclosures. Growth rates of females were higher in field than in forest enclosures. Overall, our data indicate that temperature appears to be the most important factor driving the habitat selection of gartersnakes, likely because temperature was more limiting than food in our study system. Snakes, or at least temperate snakes, may naturally exist at population densities low enough that they do not exhibit density-dependent habitat selection.
Collapse
|
11
|
Blendinger PG, Jiménez J, Macchi L, Martín E, Sánchez MS, Ayup MM. Scale-Dependent Spatial Match between Fruits and Fruit-eating Birds during the Breeding Season in Yungas Andean Forests. Biotropica 2015. [DOI: 10.1111/btp.12247] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Pedro G. Blendinger
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Tucumán Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas; Crisóstomo Álvarez 722 4000 Tucumán Argentina
| | - Julieta Jiménez
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Tucumán Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas; Crisóstomo Álvarez 722 4000 Tucumán Argentina
| | - Leandro Macchi
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Tucumán Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas; Crisóstomo Álvarez 722 4000 Tucumán Argentina
| | - Eduardo Martín
- Fundación Miguel Lillo; Miguel Lillo 205 4000 Tucumán Argentina
| | - Mariano S. Sánchez
- Consejo Nacional de Investigaciones Científicas y Técnicas; Crisóstomo Álvarez 722 4000 Tucumán Argentina
- Facultad de Ciencias Naturales e Instituto Miguel Lillo; Universidad Nacional de Tucumán; Miguel Lillo 205 4000 Tucumán Argentina
| | - María Marta Ayup
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Tucumán Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas; Crisóstomo Álvarez 722 4000 Tucumán Argentina
| |
Collapse
|
12
|
Kellermann JL, van Riper C. Detecting mismatches of bird migration stopover and tree phenology in response to changing climate. Oecologia 2015; 178:1227-38. [PMID: 25822114 DOI: 10.1007/s00442-015-3293-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Accepted: 03/06/2015] [Indexed: 10/23/2022]
Abstract
Migratory birds exploit seasonal variation in resources across latitudes, timing migration to coincide with the phenology of food at stopover sites. Differential responses to climate in phenology across trophic levels can result in phenological mismatch; however, detecting mismatch is sensitive to methodology. We examined patterns of migrant abundance and tree flowering, phenological mismatch, and the influence of climate during spring migration from 2009 to 2011 across five habitat types of the Madrean Sky Islands in southeastern Arizona, USA. We used two metrics to assess phenological mismatch: synchrony and overlap. We also examined whether phenological overlap declined with increasing difference in mean event date of phenophases. Migrant abundance and tree flowering generally increased with minimum spring temperature but depended on annual climate by habitat interactions. Migrant abundance was lowest and flowering was highest under cold, snowy conditions in high elevation montane conifer habitat while bird abundance was greatest and flowering was lowest in low elevation riparian habitat under the driest conditions. Phenological synchrony and overlap were unique and complementary metrics and should both be used when assessing mismatch. Overlap declined due to asynchronous phenologies but also due to reduced migrant abundance or flowering when synchrony was actually maintained. Overlap declined with increasing difference in event date and this trend was strongest in riparian areas. Montane habitat specialists may be at greatest risk of mismatch while riparian habitat could provide refugia during dry years for phenotypically plastic species. Interannual climate patterns that we observed match climate change projections for the arid southwest, altering stopover habitat condition.
Collapse
Affiliation(s)
- Jherime L Kellermann
- School of Natural Resources and Environment, University of Arizona, Tucson, AZ, 85721, USA,
| | | |
Collapse
|
13
|
Chudzińska ME, van Beest FM, Madsen J, Nabe‐Nielsen J. Using habitat selection theories to predict the spatiotemporal distribution of migratory birds during stopover – a case study of pink‐footed geese
Anser brachyrhynchus. OIKOS 2015. [DOI: 10.1111/oik.01881] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Magda E. Chudzińska
- Dept of Bioscience Aarhus Univ. Frederiksborgvej 399 DK‐4000 Roskilde Denmark
| | - Floris M. van Beest
- Dept of Bioscience Aarhus Univ. Frederiksborgvej 399 DK‐4000 Roskilde Denmark
| | - Jesper Madsen
- Dept of Bioscience Aarhus Univ. Grenåvej 14 DK‐8410 Rønde Denmark
| | - Jacob Nabe‐Nielsen
- Dept of Bioscience Aarhus Univ. Frederiksborgvej 399 DK‐4000 Roskilde Denmark
| |
Collapse
|
14
|
|
15
|
Pe'er G, Saltz D, Münkemüller T, Matsinos YG, Thulke HH. Simple rules for complex landscapes: the case of hilltopping movements and topography. OIKOS 2013. [DOI: 10.1111/j.1600-0706.2013.00198.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
16
|
Knight TW, Morris DW, Haedrich RL. Inferring Competitive Behavior from Population Census and Habitat Data. Isr J Ecol Evol 2013. [DOI: 10.1560/ijee.54.3-4.345] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
17
|
Moorhead D, Herman J, Pisarczyk E. Simulation Studies of Ideal Free Distribution and Competition. Isr J Ecol Evol 2013. [DOI: 10.1560/ijee.54.3-4.329] [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]
|
18
|
|
19
|
Blendinger PG, Ruggera RA, Núñez Montellano MG, Macchi L, Zelaya PV, Álvarez ME, Martín E, Acosta OO, Sánchez R, Haedo J. Fine-tuning the fruit-tracking hypothesis: spatiotemporal links between fruit availability and fruit consumption by birds in Andean mountain forests. J Anim Ecol 2012; 81:1298-1310. [DOI: 10.1111/j.1365-2656.2012.02011.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 05/20/2012] [Indexed: 10/28/2022]
Affiliation(s)
- Pedro G. Blendinger
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Av. Rivadavia 1917, C1033AAJ, Buenos Aires, Argentina
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Yerba Buena Tucumán Argentina
| | - Román A. Ruggera
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Av. Rivadavia 1917, C1033AAJ, Buenos Aires, Argentina
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Yerba Buena Tucumán Argentina
| | - M. Gabriela Núñez Montellano
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Av. Rivadavia 1917, C1033AAJ, Buenos Aires, Argentina
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Yerba Buena Tucumán Argentina
| | - Leandro Macchi
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Av. Rivadavia 1917, C1033AAJ, Buenos Aires, Argentina
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Yerba Buena Tucumán Argentina
| | - Patricia V. Zelaya
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Av. Rivadavia 1917, C1033AAJ, Buenos Aires, Argentina
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Yerba Buena Tucumán Argentina
| | - M. Eva Álvarez
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Yerba Buena Tucumán Argentina
| | - Eduardo Martín
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Av. Rivadavia 1917, C1033AAJ, Buenos Aires, Argentina
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Yerba Buena Tucumán Argentina
| | - Oriana Osinaga Acosta
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Yerba Buena Tucumán Argentina
| | - Rocío Sánchez
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Av. Rivadavia 1917, C1033AAJ, Buenos Aires, Argentina
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Yerba Buena Tucumán Argentina
| | - Josefina Haedo
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Av. Rivadavia 1917, C1033AAJ, Buenos Aires, Argentina
- Instituto de Ecología Regional; Universidad Nacional de Tucumán; CC 34 4107 Yerba Buena Tucumán Argentina
| |
Collapse
|
20
|
|
21
|
Wojciechowski MS, Jefimow M, Pinshow B. Heterothermy, and the energetic consequences of huddling in small migrating passerine birds. Integr Comp Biol 2011; 51:409-18. [PMID: 21693540 DOI: 10.1093/icb/icr055] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The success of migration of small passerine birds depends largely on effective refueling at stopover sites. In our previous studies, we found that hypothermia facilitates accumulation of fuel at the beginning of a stopover. Later we found that blackcaps, Sylvia atricapilla, might further reduce their energy expenditure by huddling while at rest. Here, we report experimental results supporting our hypothesis that huddling is beneficial to small migrating passerines both from energetic and thermoregulatory points of view. To test this hypothesis we measured metabolic rates and body temperatures of seven blackcaps placed in respirometry chambers overnight, either solitarily or in groups of three or four at ambient temperatures of 5, 10, and 15°C. Concurring with our predictions, huddling blackcaps maintained higher body temperatures than did solitary birds, but had mass-specific metabolic rates lower by ∼30% than those of solitary individuals. Based on our previous studies, we estimated energy savings through huddling to be comparable to energy savings through hypothermia in solitary blackcaps and suggest that huddling may be an important way of saving energy for small passerine birds resting at migratory stopovers. At the same time it might offer the additional benefit of lower risk of predation. In this light, we predict that huddling occurs frequently in nature, leading to significant savings of energy, faster accumulation of fuel, presumably lower risk of becoming a prey, more successful migration, and eventually increased fitness.
Collapse
Affiliation(s)
- Michał S Wojciechowski
- Department of Animal Physiology, Institute of General and Molecular Biology, Nicolaus Copernicus University, ul. Gagarina 9, PL 87-100 Toruń, Poland.
| | | | | |
Collapse
|
22
|
Lerner A, Sapir N, Erlick C, Meltser N, Broza M, Shashar N. Habitat availability mediates chironomid density-dependent oviposition. Oecologia 2011; 165:905-14. [PMID: 21212984 DOI: 10.1007/s00442-010-1893-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Accepted: 12/16/2010] [Indexed: 11/28/2022]
Abstract
Knowledge of density-dependent processes and how they are mediated by environmental factors is critically important for understanding population and community ecology of insects, as well as for mitigating harmful insect-borne diseases. Here, we tested whether the oviposition of chironomids (Diptera: Chironomidae; non-biting midges), known to carry the Cholera pathogen Vibrio cholerae, is density dependent and if it is mediated by habitat availability. We used two multiple choice experiments in habitat-limited and habitat-unlimited environments and performed isodar analysis on counts of egg batches after controlling the polarization of light reflected from the habitats, which is known to affect their attractiveness to ovipositing chironomids. We found that, when habitats are limited, egg batch isodars indicate that chironomid selection is density dependent. Although a greater number of individuals selected to oviposit in highly polarized sites, oviposition was also common in sites with low polarization. When habitats are unlimited, chironomid selection is either weakly density dependent, or completely density independent. Chironomids oviposit to a very large extent in sites with high level of polarization, oviposit to a small extent in sites with medium level of polarization, and almost completely disregard unpolarized sites. We suggest that ovipositing females consider the availability of habitats in their surroundings when they choose an oviposition site. When high quality habitats are scarce, more females opt to breed in low quality sites. These findings may be used to limit the spread of Cholera by controlling the habitats available for chironomid oviposition.
Collapse
Affiliation(s)
- Amit Lerner
- Department of Atmospheric Sciences, The Hebrew University of Jerusalem, Edmond J Safra Campus Giv'at-Ram, 91904 Jerusalem, Israel
| | | | | | | | | | | |
Collapse
|
23
|
Miller E, Coll M. Spatial distribution and deviations from the IFD when animals forage over large resource patches. Behav Ecol 2010. [DOI: 10.1093/beheco/arq096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
24
|
Tolon V, Dray S, Loison A, Zeileis A, Fischer C, Baubet E. Responding to spatial and temporal variations in predation risk: space use of a game species in a changing landscape of fear. CAN J ZOOL 2009. [DOI: 10.1139/z09-101] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Predators generate a “landscape of fear” within which prey can minimize the risk of predation by selecting low-risk areas. Depending on the spatial structure of this “landscape”, i.e., whether it is coarse- or fine-grained, prey may respond to increased risk by shifting their home ranges or by fine-scale redistributions within these ranges, respectively. We studied how wild boar ( Sus scrofa L., 1758) responded to temporal changes in risk in hunted areas (risky habitat) surrounding a nature reserve (refuge habitat). Animals with home ranges “in contact” with the reserve during the low-risk season were the only ones to shift toward the refuge when the risk increased. These shifts occurred at two temporal scales in response to the increased risk during the daytime and during the hunting season. Whereas animals not influenced by the reserve found food and shelter in forest during the hunting season, shifts to the refuge area were detrimental to the rather scarce forest areas in the reserve. This confirms that spatiotemporal changes in risk are major drivers of animal distribution when predation strongly limits their fitness. Their response is, however, scale-dependent and reflects at the individual level the perceived structure of their “landscape of fear”.
Collapse
Affiliation(s)
- V. Tolon
- Laboratoire d’Ecologie Alpine, Centre National de la Recherche Scientifique – Unité Mixte de Recherche (CNRS–UMR) N° 5553, Université de Savoie, bâtiment Belledonne, F-73376 Le Bourget-du-Lac, France
- Université de Lyon, F-69000, Lyon, France; Université Lyon 1 and CNRS–UMR N° 5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622, Villeurbanne, France
- Department of Statistics and Mathematics, Wirtschaftsuniversität Wien, Augasse 2-6, A-1090 Wien, Austria
- Ecole d’Ingénieurs de Lullier, S-1254 Jussy, Switzerland
- Office National de la Chasse et de la Faune Sauvage, Centre National d’Etude et de Recherche Appliquée – Cervidés et Sanglier, F-55 000 Bar-le-Duc, France
| | - S. Dray
- Laboratoire d’Ecologie Alpine, Centre National de la Recherche Scientifique – Unité Mixte de Recherche (CNRS–UMR) N° 5553, Université de Savoie, bâtiment Belledonne, F-73376 Le Bourget-du-Lac, France
- Université de Lyon, F-69000, Lyon, France; Université Lyon 1 and CNRS–UMR N° 5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622, Villeurbanne, France
- Department of Statistics and Mathematics, Wirtschaftsuniversität Wien, Augasse 2-6, A-1090 Wien, Austria
- Ecole d’Ingénieurs de Lullier, S-1254 Jussy, Switzerland
- Office National de la Chasse et de la Faune Sauvage, Centre National d’Etude et de Recherche Appliquée – Cervidés et Sanglier, F-55 000 Bar-le-Duc, France
| | - A. Loison
- Laboratoire d’Ecologie Alpine, Centre National de la Recherche Scientifique – Unité Mixte de Recherche (CNRS–UMR) N° 5553, Université de Savoie, bâtiment Belledonne, F-73376 Le Bourget-du-Lac, France
- Université de Lyon, F-69000, Lyon, France; Université Lyon 1 and CNRS–UMR N° 5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622, Villeurbanne, France
- Department of Statistics and Mathematics, Wirtschaftsuniversität Wien, Augasse 2-6, A-1090 Wien, Austria
- Ecole d’Ingénieurs de Lullier, S-1254 Jussy, Switzerland
- Office National de la Chasse et de la Faune Sauvage, Centre National d’Etude et de Recherche Appliquée – Cervidés et Sanglier, F-55 000 Bar-le-Duc, France
| | - A. Zeileis
- Laboratoire d’Ecologie Alpine, Centre National de la Recherche Scientifique – Unité Mixte de Recherche (CNRS–UMR) N° 5553, Université de Savoie, bâtiment Belledonne, F-73376 Le Bourget-du-Lac, France
- Université de Lyon, F-69000, Lyon, France; Université Lyon 1 and CNRS–UMR N° 5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622, Villeurbanne, France
- Department of Statistics and Mathematics, Wirtschaftsuniversität Wien, Augasse 2-6, A-1090 Wien, Austria
- Ecole d’Ingénieurs de Lullier, S-1254 Jussy, Switzerland
- Office National de la Chasse et de la Faune Sauvage, Centre National d’Etude et de Recherche Appliquée – Cervidés et Sanglier, F-55 000 Bar-le-Duc, France
| | - C. Fischer
- Laboratoire d’Ecologie Alpine, Centre National de la Recherche Scientifique – Unité Mixte de Recherche (CNRS–UMR) N° 5553, Université de Savoie, bâtiment Belledonne, F-73376 Le Bourget-du-Lac, France
- Université de Lyon, F-69000, Lyon, France; Université Lyon 1 and CNRS–UMR N° 5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622, Villeurbanne, France
- Department of Statistics and Mathematics, Wirtschaftsuniversität Wien, Augasse 2-6, A-1090 Wien, Austria
- Ecole d’Ingénieurs de Lullier, S-1254 Jussy, Switzerland
- Office National de la Chasse et de la Faune Sauvage, Centre National d’Etude et de Recherche Appliquée – Cervidés et Sanglier, F-55 000 Bar-le-Duc, France
| | - E. Baubet
- Laboratoire d’Ecologie Alpine, Centre National de la Recherche Scientifique – Unité Mixte de Recherche (CNRS–UMR) N° 5553, Université de Savoie, bâtiment Belledonne, F-73376 Le Bourget-du-Lac, France
- Université de Lyon, F-69000, Lyon, France; Université Lyon 1 and CNRS–UMR N° 5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622, Villeurbanne, France
- Department of Statistics and Mathematics, Wirtschaftsuniversität Wien, Augasse 2-6, A-1090 Wien, Austria
- Ecole d’Ingénieurs de Lullier, S-1254 Jussy, Switzerland
- Office National de la Chasse et de la Faune Sauvage, Centre National d’Etude et de Recherche Appliquée – Cervidés et Sanglier, F-55 000 Bar-le-Duc, France
| |
Collapse
|
25
|
Mari L, Casagrandi R, Gatto M, Avgar T, Nathan R. Movement Strategies of Seed Predators as Determinants of Plant Recruitment Patterns. Am Nat 2008; 172:694-711. [DOI: 10.1086/591687] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
26
|
Contreras-Garduño J, Canales-Lazcano J, Jiménez-Cortés JG, Juárez-Valdez N, Lanz-Mendoza H, Córdoba-Aguilar A. Spatial and temporal population differences in male density and condition in the American rubyspot, Hetaerina americana (Insecta: Calopterygidae). Ecol Res 2008. [DOI: 10.1007/s11284-008-0476-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
27
|
Tsurim I, Sapir N, Belmaker J, Shanni I, Izhaki I, Wojciechowski MS, Karasov WH, Pinshow B. Drinking water boosts food intake rate, body mass increase and fat accumulation in migratory blackcaps (Sylvia atricapilla). Oecologia 2008; 156:21-30. [DOI: 10.1007/s00442-008-0970-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Accepted: 01/11/2008] [Indexed: 10/22/2022]
|
28
|
Rodewald AD, Shustack DP. CONSUMER RESOURCE MATCHING IN URBANIZING LANDSCAPES: ARE SYNANTHROPIC SPECIES OVER-MATCHING. Ecology 2008; 89:515-21. [DOI: 10.1890/07-0358.1] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
29
|
Schauber EM, Goodwin BJ, Jones CG, Ostfeld RS. Spatial selection and inheritance: applying evolutionary concepts to population dynamics in heterogeneous space. Ecology 2007; 88:1112-8. [PMID: 17536397 DOI: 10.1890/06-1578] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Organisms in highly suitable sites generally produce more offspring, and offspring can inherit this suitability by not dispersing far. This combination of spatial selection and spatial inheritance acts to bias the distribution of organisms toward suitable sites and thereby increase mean fitness (i.e., per capita population increase). Thus, population growth rates in heterogeneous space change over time by a process conceptually analogous to evolution by natural selection, opening avenues for theoretical cross-pollination between evolutionary biology and ecology. We operationally define spatial inheritance and spatial selective differential and then combine these two factors in a modification of the breeder's equation, derived from simple models of population growth in heterogeneous space. The modified breeder's equation yields a conservative criterion for persistence in hostile environments estimable from field measurements. We apply this framework for understanding gypsy moth population persistence amidst abundant predators and find that the predictions of the modified breeder's equation match initial changes in population growth rate in independent simulation output. The analogy between spatial dynamics and natural selection conceptually links ecology and evolution, provides a spatially implicit framework for modeling spatial population dynamics, and represents an important null model for studying habitat selection.
Collapse
Affiliation(s)
- Eric M Schauber
- Cooperative Wildlife Research Laboratory and Department of Zoology, Southern Illinois University, Carbondale, Illinois 62901, USA.
| | | | | | | |
Collapse
|
30
|
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]
|
31
|
Amano T, Ushiyama K, Moriguchi S, Fujita G, Higuchi H. DECISION-MAKING IN GROUP FORAGERS WITH INCOMPLETE INFORMATION: TEST OF INDIVIDUAL-BASED MODEL IN GEESE. ECOL MONOGR 2006. [DOI: 10.1890/0012-9615(2006)076[0601:digfwi]2.0.co;2] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
32
|
Nocera JJ, Forbes GJ, Giraldeau LA. Inadvertent social information in breeding site selection of natal dispersing birds. Proc Biol Sci 2006; 273:349-55. [PMID: 16543178 PMCID: PMC1560037 DOI: 10.1098/rspb.2005.3318] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Accepted: 08/31/2005] [Indexed: 11/12/2022] Open
Abstract
Several species use the number of young produced as public information (PI) to assess breeding site quality. PI is inaccessible for synchronously breeding birds because nests are empty by the time the young can collect this information. We investigate if location cues are the next best source of inadvertent social information (ISI) used by young prospectors during breeding site choice. We experimentally deployed ISI as decoys and song playbacks of breeding males in suitable and sub-optimal habitats during pre- and post-breeding periods, and monitored territory establishment during the subsequent breeding season for a social, bobolink (Dolichonyx oryzivorus), and a more solitary species, Nelson's sharp-tailed sparrow (Ammodramus nelsoni). The sparrows did not respond to treatments, but bobolinks responded strongly to post-breeding location cues, irrespective of habitat quality. The following year, 17/20 sub-optimal plots to which bobolink males were recruited were defended for at least two weeks, indicating that song heard the previous year could exert a "carry-over attraction" effect on conspecifics the following year. Sixteen recruited males were natal dispersers, as expected when animals have little opportunity to directly sample their natal habitat quality. We suggest that differences in breeding synchronicity may induce an equivalent clinal distribution of ISI use.
Collapse
Affiliation(s)
- Joseph J Nocera
- Department of Biology, University of New Brunswick, Bag Service #45111, Fredericton, NB E3B 6E1, Canada.
| | | | | |
Collapse
|
33
|
Shochat E, Patten MA, Morris DW, Reinking DL, Wolfe DH, Sherrod SK. Ecological traps in isodars: effects of tallgrass prairie management on bird nest success. OIKOS 2005. [DOI: 10.1111/j.0030-1299.2005.13907.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
34
|
Affiliation(s)
- Alexander M. Mills
- Department of Zoology, University of Toronto, 25 Harbord Street, Toronto, Ontario, M5S 3G5 Canada
| |
Collapse
|
35
|
W. Morris D, E. Diffendorfer J, Lundberg P. Dispersal among habitats varying in fitness: reciprocating migration through ideal habitat selection. OIKOS 2004. [DOI: 10.1111/j.0030-1299.2004.12894.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
36
|
Sapir N, Abramsky Z, Shochat E, Izhaki I. Scale-dependent habitat selection in migratory frugivorous passerines. Naturwissenschaften 2004; 91:544-7. [PMID: 15455207 DOI: 10.1007/s00114-004-0564-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2004] [Accepted: 08/11/2004] [Indexed: 11/26/2022]
Abstract
Frugivorous migrants may select fruit-rich habitats en route to attain high food rewards, yet their stopover behavior may also be shaped by other considerations, such as predation risk. During 1996-2001 we investigated autumn stopover habitat use of three Sylvia warblers (sylviids; S. hortensis, S. atricapilla and S. curruca) and three Turdidae chats (turdids; Cercotrichas galactotes, Oenanthe hispanica and Phoenicurus phoenicurus) in planted groves of the fruiting tree Pistacia atlantica in Lahav Forest, Israel, which is located at the edge of a desert. We used fecal analysis, a constant-effort trapping scheme and field observations to estimate the extent of frugivory, and bird habitat and microhabitat selection with regard to natural fruit and foliage densities. We also measured bird microhabitat selection in a set of fruit-manipulated trees. We trapped a total of 2,357 birds during the course of the study. Although sylviids exhibited higher frugivory level than turdids, both species groups exhibited a similar significantly positive correlation between bird and fruit densities at the habitat scale. However, at the microhabitat scale, sylviids selected densely foliated trees, whilst turdids were randomly distributed among trees. Our findings suggest that both species groups selected fruit-rich stopover habitats to take advantage of the high food availability before the demanding migration journey. No other mechanism except predation avoidance can explain the sylviids' microhabitat selection; the migrants used foliage cover to reduce bird detectability by raptors. We conclude that en route passerines may use staging habitats in a sophisticated manner, by adopting scale-related behavior with regard to the availability of food and refuge cover.
Collapse
Affiliation(s)
- Nir Sapir
- Department of Life-Sciences, Ben-Gurion University, PO Box 653, 84105, Be'er-Sheva, Israel.
| | | | | | | |
Collapse
|
37
|
Jensen WE, Cully JF. Density-dependent habitat selection by brown-headed cowbirds ( Molothrus ater) in tallgrass prairie. Oecologia 2004; 142:136-49. [PMID: 15375686 DOI: 10.1007/s00442-004-1709-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2003] [Accepted: 08/16/2004] [Indexed: 10/26/2022]
Abstract
Local distributions of avian brood parasites among their host habitats may depend upon conspecific parasite density. We used isodar analysis to test for density-dependent habitat selection in brown-headed cowbirds ( Molothrus ater) among tallgrass prairie adjacent to wooded edges, and prairie interior habitat (>100 m from wooded edges) with and without experimental perches. Eight study sites containing these three habitat treatments were established along a geographical gradient in cowbird abundance within the Flint Hills region of Eastern Kansas and Oklahoma, USA. The focal host species of our study, the dickcissel ( Spiza americana), is the most abundant and preferred cowbird host in the prairie of this region. Cowbird relative abundance and cowbird:host abundance ratios were used as estimates of female cowbird density, whereas cowbird egg density was measured as parasitism frequency (percent of dickcissel nests parasitized), and parasitism intensity (number of cowbird eggs per parasitized nest). Geographical variation in cowbird abundance was independent of host abundance. Within study sites, host abundance was highest in wooded edge plots, intermediate in the experimental perch plots, and lowest in prairie interior. Cowbirds exhibited a pattern of density-dependent selection of prairie edge versus experimental perch and interior habitats. On sites where measures of cowbird density were lowest, all cowbird density estimates (female cowbirds and their eggs) were highest near (< or =100 m) wooded edges, where host and perch availability are highest. However, as overall cowbird density increased geographically, these density estimates increased more rapidly in experimental perch plots and prairie interiors. Variation in cowbird abundance and cowbird:host ratios suggested density-dependent cowbird selection of experimental perch over prairie interior habitat, but parasitism levels on dickcissel nests were similar among these two habitats at all levels of local cowbird parasitism. The density-dependent pattern of cowbird distribution among prairie edge and interior suggested that density effects on perceived cowbird fitness are greatest at wooded edges. A positive relationship between daily nest mortality rates of parasitized nests during the nestling period with parasitism intensity levels per nest suggested a density-dependent effect on cowbird reproductive success. However, this relationship was similar among habitats, such that all habitats should have been perceived as being equally suitable to cowbirds at all densities. Other unmeasured effects on cowbird habitat suitability (e.g., reduced cowbird success in edge-dwelling host nests, cowbird despotism at edges) might have affected cowbird habitat selection. Managers attempting to minimize cowbird parasitism on sensitive cowbird hosts should consider that hosts in otherwise less-preferred cowbird habitats (e.g., habitat interiors) are at greater risk of being parasitized where cowbirds become particularly abundant.
Collapse
Affiliation(s)
- William E Jensen
- United States Geological Survey, Kansas Cooperative Fish and Wildlife Research Unit, Division of Biology, Kansas State University, 205 Leasure Hall, Manhattan, KS 66506, USA.
| | | |
Collapse
|
38
|
|