Thermally-driven thresholds in terrestrial avifauna waterhole visitation indicate vulnerability to a warming climate. (October 2020)

• Record Type: Journal Article
• Authors: Votto, Simon E.; Dyer, Fiona J.; Caron, Valerie; Davis, Jenny A.
• Is Part Of: Journal of arid environments. Volume 181(2020)
• Publication Date: 2020-10
• Subjects: Avian functional groups -- Arid zone -- Groundwater-dominated waterholes -- Thermal thresholds -- Climatic warming; Arid regions ecology -- Periodicals; Arid regions -- Periodicals; Écologie des régions arides -- Périodiques; Régions arides -- Périodiques; 577.54
• DOI: 10.1016/j.jaridenv.2020.104217
• Languages: English
• ISSNs: 0140-1963

Abstract

Abstract: Warming global climates represent major threats to avian populations, particularly those reliant on surface water within arid biomes. We investigated terrestrial avian use of groundwater-dominated arid zone waterholes in central Australia to identify species vulnerable to climate change. Camera traps set in Watarrka National Park recorded avian species over 14 months at three waterholes during 2014 and 2015. Recorded species were assigned to functional groups, which included nectarivores, granivores, carnivores and omnivores. Generalised Additive Mixed Models (GAMMs) were used to model daily trapping rates (DTRs) for each functional group at waterholes in relation to daily maximum temperature and days since last rainfall. Granivores exhibited high DTRs across the entire daily maximum temperature range (15 °C–43 °C). Increasing threshold responses beyond specific daily maximum temperatures were exhibited by nectarivores (35 °C), carnivores (30 °C) and omnivores (30 °C). The DTRs for all functional groups increased with days since last rainfall. These data indicate species within all functional groups are vulnerable to a warming climate, even those that are considered to be surface water independent, as increasing waterhole visitations in torrid conditions reduces foraging time and could lead to reduced fitness in particular individuals. Graphical abstract: Image 1 Highlights: Thirty five bird species were recorded at arid zone waterholes in central Australia. Nectarivore, carnivore and omnivore waterhole use intensified with temperature. Waterhole visitations from granivores were high across the entire temperature range. All functional groups increased waterhole visitation in increasingly dry conditions.