Habitat loss, fragmentation, and degradation are the leading causes of faunal population declines. Substantial effort has been invested in identifying how these landscape changes are related to population parameters. However, to effectively mitigate declines, we must understand the underlying mechanisms impacted by landscape change. Woodland-dependent avian insectivores seem particularly vulnerable, and decline at rates disproportionately greater than other foraging guilds. This pattern suggests that reduced food availability in less-wooded landscapes may be a contributing factor. However, the evidence supporting this hypothesis is sparse.
 
I adopted a multidisciplinary approach to investigate the mechanisms driving population changes of an avian insectivore in highly-modified landscapes by integrating physiological indices with measures of prey availability and landscape structure. Using the eastern yellow robin in the Brigalow Belt South bioregion as a case study species, I addressed five key research questions:
 
  1. How do movement restrictions in fragmented landscapes negatively impact faunal populations, and are there biases in research effort allocated to each of the key mechanisms?
  2. How does the association between site occupancy and landscape structure change over time, and how effective are individual condition measures at signalling future changes to population dynamics?
  3. How is prey density related to woodland extent and how does this differ when nutritional value is taken into consideration?
  4. How well do measures of prey density explain the variation in the physiological condition of robins, and how have patterns of condition changed over time?
  5. How does experimentally increasing food availability for an avian insectivore impact individual condition in landscapes with varying degrees of woodland cover?

Funding: 

  • APA Scholarship
  • Research grant, Birds Queensland
  • Student research grant, Australasian Society for the Study of Animal Behaviour
  • Stuart Leslie Bird Research Award, BirdLife Australia
  • Student research grant, Wildlife Preservation Society of Queensland

Advisors: Assoc Prof Martine MaronDr Todd McWhorter

 

Project members

Anita Cosgrove

Anita Cosgrove

PhD candidate