title: Mapping evaporative water loss in desert passerines reveals an expanding threat of lethal dehydration.
abstract: Extreme high environmental temperatures produce a variety of consequences for wildlife, including mass die-offs. Heat waves are increasing in frequency, intensity, and extent, and are projected to increase further under climate change. However, the spatial and temporal dynamics of die-off risk are poorly understood. Here, we examine the effects of heat waves on evaporative water loss (EWL) and survival in five desert passerine birds across the southwestern United States using a combination of physiological data, mechanistically informed models, and hourly geospatial temperature data. We ask how rates of EWL vary with temperature across species; how frequently, over what areas, and how rapidly lethal dehydration occurs; how EWL and die-off risk vary with body mass; and how die-off risk is affected by climate warming. We find that smaller-bodied passerines are subject to higher rates of mass-specific EWL than larger-bodied counterparts and thus encounter potentially lethal conditions much more frequently, over shorter daily intervals, and over larger geographic areas. Warming by 4 °C greatly expands the extent, frequency, and intensity of dehydration risk, and introduces new threats for larger passerine birds, particularly those with limited geographic ranges. Our models reveal that increasing air temperatures and heat wave occurrence will potentially have important impacts on the water balance, daily activity, and geographic distribution of arid-zone birds. Impacts may be exacerbated by chronic effects and interactions with other environmental changes. This work underscores the importance of acute risks of high temperatures, particularly for small-bodied species, and suggests conservation of thermal refugia and water sources.
authors.affiliation: Department of Geography, University of Nevada, Reno, NV 89557; talbright@unr.edu wolf@unm.edu.|Program in Ecology, Evolution, and Conservation Biology, University of Nevada, Reno, NV 89557.
authors.forename: Thomas P
authors.identifier: 0000-0001-5159-2112
authors.initials: TP
authors.lastname: Albright
authors.affiliation: Department of Geography, University of Nevada, Reno, NV 89557.|Beltsville Agricultural Research Center, US Department of Agriculture, Beltsville Agricultural Research Center-West, Beltsville, MD 20705.
authors.forename: Denis
authors.initials: D
authors.lastname: Mutiibwa
authors.affiliation: Department of Biology, University of Massachusetts, Amherst, MA 01003.|Biology Department, University of New Mexico, Albuquerque, NM 87131-0001.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Gerson
authors.affiliation: Biology Department, University of New Mexico, Albuquerque, NM 87131-0001.
authors.forename: Eric Krabbe
authors.initials: EK
authors.lastname: Smith
authors.affiliation: Biology Department, University of New Mexico, Albuquerque, NM 87131-0001.
authors.forename: William A
authors.initials: WA
authors.lastname: Talbot
authors.affiliation: Biology Department, University of New Mexico, Albuquerque, NM 87131-0001.
authors.forename: Jacqueline J
authors.initials: JJ
authors.lastname: O'Neill
authors.affiliation: DST-NRF Centre of Excellence at the Percy FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Hatfield 0028, South Africa.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: McKechnie
authors.affiliation: Biology Department, University of New Mexico, Albuquerque, NM 87131-0001; talbright@unr.edu wolf@unm.edu.
authors.forename: Blair O
authors.initials: BO
authors.lastname: Wolf
mesh_terms: D000818:Animals; D001481:Basal Metabolism / Q000502:physiology*; D049628:Body Size / Q000502:physiology*; D001831:Body Temperature; D001833:Body Temperature Regulation / Q000502:physiology*; D057231:Climate Change; D003681:Dehydration / Q000401:mortality / Q000503:physiopathology; D006358:Hot Temperature; D015233:Models, Statistical; D046109:Passeriformes / Q000033:anatomy & histology / Q000502:physiology*; D062211:Spatio-Temporal Analysis; D014481:United States; D014867:Water / Q000502:physiology
chemical_list: D014867:Water
keywords: avian ecology; climate change; heat waves; physiological ecology; water balance