Decomposing an elevational gradient in predation by insectivorous birds
Abstract Insectivorous birds have ecologically important effects on prey abundance, behavior, and evolution, and through top‐down control, birds indirectly reduce herbivory and promote plant growth. While several studies sought to characterize biogeographic patterns in top‐down control by birds, var...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2024-02-01
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| Series: | Ecosphere |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/ecs2.4790 |
| _version_ | 1797254123576360960 |
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| author | Lydia S. Dean Carla Vázquez‐González Sierra Hellwitz Luis Abdala‐Roberts Kailen A. Mooney |
| author_facet | Lydia S. Dean Carla Vázquez‐González Sierra Hellwitz Luis Abdala‐Roberts Kailen A. Mooney |
| author_sort | Lydia S. Dean |
| collection | DOAJ |
| description | Abstract Insectivorous birds have ecologically important effects on prey abundance, behavior, and evolution, and through top‐down control, birds indirectly reduce herbivory and promote plant growth. While several studies sought to characterize biogeographic patterns in top‐down control by birds, variation in bird predation along elevational gradients is not well characterized in terms of both its commonness and the mechanisms underlying such variation. Here, we characterized variation in bird predation along a 700‐m montane elevation gradient using artificial clay caterpillars, assessing the roles of variation in aridity, other elevational effects not associated with aridity (e.g., most notably growing season length), and bird abundance and diversity. Multivariate models revealed increasing attack rates with aridity (when controlling for the effects of elevation) and elevation (when controlling for aridity). Because aridity declines with elevation, elevational patterns were not detectable in a univariate analysis. Bird abundance (but not diversity) decreased with elevation (but not aridity) and did not provide an explanation for our results, suggesting that the underlying mechanisms were behaviorally based. We speculate that the declining abundance of insect prey with elevation and aridity leads to increased bird foraging efforts and thus the likelihood of attacking clay caterpillars. If widespread, these dynamics have important consequences for both the interpretation of predation bioassays generally and our understanding of the multivariate drivers of variation in top‐down control by predators and predation risks experienced by prey. |
| first_indexed | 2024-03-07T19:46:38Z |
| format | Article |
| id | doaj.art-a5e8d62a39f1484e87c663246f98cae1 |
| institution | Directory Open Access Journal |
| issn | 2150-8925 |
| language | English |
| last_indexed | 2024-04-24T21:44:57Z |
| publishDate | 2024-02-01 |
| publisher | Wiley |
| record_format | Article |
| series | Ecosphere |
| spelling | doaj.art-a5e8d62a39f1484e87c663246f98cae12024-03-21T02:06:54ZengWileyEcosphere2150-89252024-02-01152n/an/a10.1002/ecs2.4790Decomposing an elevational gradient in predation by insectivorous birdsLydia S. Dean0Carla Vázquez‐González1Sierra Hellwitz2Luis Abdala‐Roberts3Kailen A. Mooney4Department of Ecology and Evolutionary Biology University of California‐Irvine Irvine California USADepartment of Ecology and Evolutionary Biology University of California‐Irvine Irvine California USADepartment of Ecology and Evolutionary Biology University of California‐Irvine Irvine California USADepartamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias Universidad Autónoma de Yucatán Mérida MexicoDepartment of Ecology and Evolutionary Biology University of California‐Irvine Irvine California USAAbstract Insectivorous birds have ecologically important effects on prey abundance, behavior, and evolution, and through top‐down control, birds indirectly reduce herbivory and promote plant growth. While several studies sought to characterize biogeographic patterns in top‐down control by birds, variation in bird predation along elevational gradients is not well characterized in terms of both its commonness and the mechanisms underlying such variation. Here, we characterized variation in bird predation along a 700‐m montane elevation gradient using artificial clay caterpillars, assessing the roles of variation in aridity, other elevational effects not associated with aridity (e.g., most notably growing season length), and bird abundance and diversity. Multivariate models revealed increasing attack rates with aridity (when controlling for the effects of elevation) and elevation (when controlling for aridity). Because aridity declines with elevation, elevational patterns were not detectable in a univariate analysis. Bird abundance (but not diversity) decreased with elevation (but not aridity) and did not provide an explanation for our results, suggesting that the underlying mechanisms were behaviorally based. We speculate that the declining abundance of insect prey with elevation and aridity leads to increased bird foraging efforts and thus the likelihood of attacking clay caterpillars. If widespread, these dynamics have important consequences for both the interpretation of predation bioassays generally and our understanding of the multivariate drivers of variation in top‐down control by predators and predation risks experienced by prey.https://doi.org/10.1002/ecs2.4790biotic interactionsbird predationclimate gradientsnatural enemiesPopulus tremuloidespredator–prey interactions |
| spellingShingle | Lydia S. Dean Carla Vázquez‐González Sierra Hellwitz Luis Abdala‐Roberts Kailen A. Mooney Decomposing an elevational gradient in predation by insectivorous birds Ecosphere biotic interactions bird predation climate gradients natural enemies Populus tremuloides predator–prey interactions |
| title | Decomposing an elevational gradient in predation by insectivorous birds |
| title_full | Decomposing an elevational gradient in predation by insectivorous birds |
| title_fullStr | Decomposing an elevational gradient in predation by insectivorous birds |
| title_full_unstemmed | Decomposing an elevational gradient in predation by insectivorous birds |
| title_short | Decomposing an elevational gradient in predation by insectivorous birds |
| title_sort | decomposing an elevational gradient in predation by insectivorous birds |
| topic | biotic interactions bird predation climate gradients natural enemies Populus tremuloides predator–prey interactions |
| url | https://doi.org/10.1002/ecs2.4790 |
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