Modelling the nesting habitat requirements of the Wedge-tailed Eagle Aquila audax in the Australian Capital Territory using nest site characteristics
| Posted: |
08/12/2014 |
| Author(s): |
|
Nest site characteristics of the Wedge-tailed Eagle Aquila audax were investigated during the 2011 breeding season within the Australian Capital Territory (ACT). Our objectives were to determine the nesting habitat requirements of this species in the ACT by surveying nest sites and identifying differences between habitat characteristics of nest trees and reference trees and active and inactive nest sites. A landscape model was created using maximum entropy distribution modelling (MaxEnt), predicting suitable nesting habitat for Wedge-tailed Eagles by extrapolating fi eld measurements. This study found that during the 2011 breeding season Wedge-tailed Eagles in the ACT showed a preference for northeast facing aspects (P <0.01). Nests were located midslope, at elevations between 457 and 777 metres on slopes less than 30 degrees. Nests averaged 13 ± 3 metres above the ground (range 5–19 m, n = 34), in trees averaging 18 ± 3 metres tall (rang e 11–26 m, n = 34). Our results agree with previous research on Wedge-tailed Eagles in that the species chooses the largest trees available by height (P <0.0001) and girth (P <0.0001). Distance to urban areas from nests was measured using GIS spatial analysis, and revealed active nests to be on average 2850 metres (± 1.70 m) (range 350–7100 m) from built-up areas. The mapping and modelling applications used in this study identifi ed the Molonglo and Murrumbidgee River corridors as essential breeding and foraging habitat for the Wedge-tailed Eagle. These applications can be used to aid management for the conservation of the Wedge-tailed Eagle, and species of concern such as the Little Eagle Hieraaetus morphnoides by identifying potential areas of nesting habitat and assessing the risks of future urban development.
>> Download Complete PDF | File Size: 2.18mb
