Oral Presentation AFSS/NZFSS Joint Conference 2019

Vegetated microhabitats are critical for avian access to arid zone waterholes (#54)

Simon E Votto 1 2 , Christine Schlesinger 1 , Fiona Dyer 2 , Valerie Caron 3 , Jenny Davis 1
  1. College of Engineering, IT and Environment, Charles Darwin University, Casuarina, Northern Territory, Australia
  2. Faculty of Science and Technology, University of Canberra, Bruce, Australian Capital Territory, Australia
  3. Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation , Black Mountain, ACT, Australia

Long lasting waterholes provide resources and habitats that are essential for the persistence of many avian species in arid landscapes, especially in hot and dry periods when water demand is high. As air temperatures rise under climate change, pressure on waterhole access for smaller subordinate species is likely to increase as larger predatory birds begin to frequent waterholes more often to hunt. We investigated if vegetated microhabitats facilitate surface water access for terrestrial avian species during periods of high surface water demand when predation risk is high. Camera trap data were collected at six long lasting waterhole sites in West MacDonnell and Watarrka National Parks across three sampling seasons throughout 2018 and 2019. Recorded species were assigned to functional groups, including nectarivores, granivores, carnivores, omnivores and insectivores. Similarities between functional group daily trapping rates (DTRs) (collected by the cameras) and microhabitat variables (determined a priori) were analysed using non-metric multidimensional scaling (NMDS). Nectarivores, small omnivores and small granivores showed significant positive relationships with distance (decreasing) to nearest shrub and percent cover variables. Large granivores, large omnivores, carnivores and insectivores showed no significant relationships with habitat variables collected during the study. With the number of days exceeding 35°C likely to increase under predicted climate change scenarios it is probable that periods of high avian water demand and predation risk will increase in the future. Our results suggest waterholes surrounded by vegetative cover provide subordinate avian species with refuge from predators and increase opportunities to safely access the water during these times.

  1. Abdu, S., Lee, A. T. K., & Cunningham, S. J. (2018). The presence of artificial water points structures an arid-zone avian community over small spatial scales. Ostrich, 89(4), 339-346. doi:10.2989/00306525.2018.1509904
  2. Aumann, T. (2001). Habitat use, temporal activity patterns and foraging behaviour of raptors in the south-west of the Northern Territory, Australia. Wildlife Research, 28(4), 365-378.
  3. Cade, T. J. (1965). Relations between raptors and columbiform birds at a desert water hole. The Wilson Bulletin, 77(4), 340-345.
  4. Lee, A. T. K., Wright, D., & Barnard, P. (2017). Hot bird drinking patterns: drivers of water visitation in a fynbos bird community. African Journal of Ecology, 55(4), 541-553. doi:doi:10.1111/aje.12384
  5. McKechnie, A. E., Gerson, A. R., McWhorter, T. J., Smith, E. K., Talbot, W. A., & Wolf, B. O. (2017). Avian thermoregulation in the heat: evaporative cooling in five Australian passerines reveals within-order biogeographic variation in heat tolerance. The Journal of Experimental Biology, 220(13), 2436-2444. doi:10.1242/jeb.155507
  6. Smit, B., Woodborne, S., Wolf, B. O., & McKechnie, A. E. (2018). Differences in the use of surface water resources by desert birds are revealed using isotopic tracers. PeerJ Preprints, 6, e3167v3163. doi:10.7287/peerj.preprints.3167v3
  7. Zhou, L., Chen, H., & Dai, Y. (2015). Stronger warming amplification over drier ecoregions observed since 1979. Environmental Research Letters, 10(6), 064012. doi:10.1088/1748-9326/10/6/064012