PARENT SESSION
Oral Session #24: Conservation and Biodiversity: Birds and arthropods.
Presiding: C. Bock
Monday, August 5. 1:00 PM to 3:45 PM. Mesquite Room, Radisson.
Traits of birds predict their responses to increasing pastoralism: a 25-year, continent-scale study.
DAVIES, KENDI*,1, MELBOURNE, BRETT1, CUNNINGHAM, ROSS2, JAMES, CRAIG3, GRIFFIN, GRAHAM3, 1 University of California, Davis, CA2 Australian National University, Australia3 CSIRO Sustainable Ecosystems, Australia
ABSTRACT- Life history traits can act as surrogates for extinction risk when we lack data about population dynamics. We looked at how 118 arid-zone species responded to the density of artificial watering points in the Australian arid zone, and how these responses related to traits of species. The number of watering points in this landscape reflects the intensity of pastoralism. Bird data were from two atlases collected by volunteers between 1977-1981 and 1996-2001. Bird species responded to both the increase in availability of water in the landscape and degradation caused by grazing. This meant that responses were detected at multiple spatial scales: species either declined, increased or did not change in abundance at the landscape scale, while locally either declining, increasing or not responding to density of watering points. The relationships between the responses of species and their traits were complex. Small, ground-nesting birds were more likely to have declined near watering points than large birds with other nesting habits. Trophic group, feeding habitat and clutch size were also related to the responses of species but in complex ways that were difficult to generalize.
KEY WORDS: Arid-zone, Grazing, Birds, Traits