Disentangling controls on animal abundance: Prey availability, thermal habitat, and microhabitat structure

Abstract The question of what controls animal abundance has always been fundamental to ecology, but given rapid environmental change, understanding the drivers and mechanisms governing abundance is more important than ever. Here, we determine how multidimensional environments and niches interact to...

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Main Authors: Emma A. Higgins, Doreen S. Boyd, Tom W. Brown, Sarah C. Owen, Adam C. Algar
Format: Article
Language:English
Published: Wiley 2021-08-01
Series:Ecology and Evolution
Subjects:
Online Access:https://doi.org/10.1002/ece3.7930
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author Emma A. Higgins
Doreen S. Boyd
Tom W. Brown
Sarah C. Owen
Adam C. Algar
author_facet Emma A. Higgins
Doreen S. Boyd
Tom W. Brown
Sarah C. Owen
Adam C. Algar
author_sort Emma A. Higgins
collection DOAJ
description Abstract The question of what controls animal abundance has always been fundamental to ecology, but given rapid environmental change, understanding the drivers and mechanisms governing abundance is more important than ever. Here, we determine how multidimensional environments and niches interact to determine population abundance along a tropical habitat gradient. Focusing on the endemic lizard Anolis bicaorum on the island of Utila (Honduras), we evaluate direct and indirect effects of three interacting niche axes on abundance: thermal habitat quality, structural habitat quality, and prey availability. We measured A. bicaorum abundance across a series of thirteen plots and used N‐mixture models and path analysis to disentangle direct and indirect effects of these factors. Results showed that thermal habitat quality and prey biomass both had positive direct effects on anole abundance. However, thermal habitat quality also influenced prey biomass, leading to a strong indirect effect on abundance. Thermal habitat quality was primarily a function of canopy density, measured as leaf area index (LAI). Despite having little direct effect on abundance, LAI had a strong overall effect mediated by thermal quality and prey biomass. Our results demonstrate the role of multidimensional environments and niche interactions in determining animal abundance and highlight the need to consider interactions between thermal niches and trophic interactions to understand variation in abundance, rather than focusing solely on changes in the physical environment.
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spelling doaj.art-871a33061e2c468b90d9a8332bb630502022-12-21T22:40:54ZengWileyEcology and Evolution2045-77582021-08-011116114141142410.1002/ece3.7930Disentangling controls on animal abundance: Prey availability, thermal habitat, and microhabitat structureEmma A. Higgins0Doreen S. Boyd1Tom W. Brown2Sarah C. Owen3Adam C. Algar4School of Geography University of Nottingham Nottingham UKSchool of Geography University of Nottingham Nottingham UKSchool of Geography University of Nottingham Nottingham UKSchool of Geography University of Nottingham Nottingham UKDepartment of Biology Lakehead University Thunder Bay ON CanadaAbstract The question of what controls animal abundance has always been fundamental to ecology, but given rapid environmental change, understanding the drivers and mechanisms governing abundance is more important than ever. Here, we determine how multidimensional environments and niches interact to determine population abundance along a tropical habitat gradient. Focusing on the endemic lizard Anolis bicaorum on the island of Utila (Honduras), we evaluate direct and indirect effects of three interacting niche axes on abundance: thermal habitat quality, structural habitat quality, and prey availability. We measured A. bicaorum abundance across a series of thirteen plots and used N‐mixture models and path analysis to disentangle direct and indirect effects of these factors. Results showed that thermal habitat quality and prey biomass both had positive direct effects on anole abundance. However, thermal habitat quality also influenced prey biomass, leading to a strong indirect effect on abundance. Thermal habitat quality was primarily a function of canopy density, measured as leaf area index (LAI). Despite having little direct effect on abundance, LAI had a strong overall effect mediated by thermal quality and prey biomass. Our results demonstrate the role of multidimensional environments and niche interactions in determining animal abundance and highlight the need to consider interactions between thermal niches and trophic interactions to understand variation in abundance, rather than focusing solely on changes in the physical environment.https://doi.org/10.1002/ece3.7930abundanceAnolishabitat structuremicrohabitatpopulation sizeprey availability
spellingShingle Emma A. Higgins
Doreen S. Boyd
Tom W. Brown
Sarah C. Owen
Adam C. Algar
Disentangling controls on animal abundance: Prey availability, thermal habitat, and microhabitat structure
Ecology and Evolution
abundance
Anolis
habitat structure
microhabitat
population size
prey availability
title Disentangling controls on animal abundance: Prey availability, thermal habitat, and microhabitat structure
title_full Disentangling controls on animal abundance: Prey availability, thermal habitat, and microhabitat structure
title_fullStr Disentangling controls on animal abundance: Prey availability, thermal habitat, and microhabitat structure
title_full_unstemmed Disentangling controls on animal abundance: Prey availability, thermal habitat, and microhabitat structure
title_short Disentangling controls on animal abundance: Prey availability, thermal habitat, and microhabitat structure
title_sort disentangling controls on animal abundance prey availability thermal habitat and microhabitat structure
topic abundance
Anolis
habitat structure
microhabitat
population size
prey availability
url https://doi.org/10.1002/ece3.7930
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AT sarahcowen disentanglingcontrolsonanimalabundancepreyavailabilitythermalhabitatandmicrohabitatstructure
AT adamcalgar disentanglingcontrolsonanimalabundancepreyavailabilitythermalhabitatandmicrohabitatstructure