Review
Hygric Niches for Tropical Endotherms

https://doi.org/10.1016/j.tree.2020.06.011Get rights and content
Under a Creative Commons license
open access

Highlights

  • Precipitation regimes define patterns of tropical biogeography and seasonality, and are a strong selective force on tropical taxa.

  • The mechanistic links between anomalies in rainfall and endotherm responses are poorly known, in contrast to an extensive literature on thermal physiology.

  • Mounting evidence documents both positive and negative behavioral, physiological, and demographic responses to temporal variation in precipitation in birds and mammals.

  • Anthropogenic changes in precipitation are spatially heterogeneous, involving increases or decreases in total rainfall combined with shifts in the timing and magnitude of rainfall events with unknown consequences for the majority of affected taxa.

  • We fill a conceptual gap to expand the dimensionality of climatic niches required to interpret and predict precipitation responses based on organismal processes and thermal niche theory.

Biotic selective pressures dominate explanations for the evolutionary ecology of tropical endotherms. Yet, abiotic factors, principally precipitation regimes, shape biogeographical and phenological patterns in tropical regions. Despite its importance, we lack a framework for understanding when, why, and how rain affects endotherms. Here, we review how tropical birds and mammals respond to rain at individual, population, and community levels, and propose a conceptual framework to interpret divergent responses. Diverse direct and indirect mechanisms underlie responses to rainfall, including physiological, top-down, and food-related drivers. Our framework constitutes a roadmap for the empirical studies required to understand the consequences of rainfall variability. Identifying the patterns and mechanisms underpinning responses to temporal variation in precipitation is crucial to anticipate consequences of anthropogenic climate change.

Keywords

abiotic selection
climate change
elevational gradients
precipitation
thermal physiology

Cited by (0)

3

www.aliceboyle.net

@

Twitter: @birdfiddler (W.A. Boyle); @e_shogren (E.H. Shogren).