Breeding habitat, nest-site characteristics and productivity of the little eagle (Hieraaetus morphnoides) near Armidale, New South Wales

Abstract

We aimed to elucidate nesting requirements and nest success of the threatened little eagle (<i>Hieraaetus morphnoides</i>). Nest sites (<i>n</i> = 12 active and 2–5 recent historical nests) near Armidale, New South Wales, were measured in 2017 at three scales: the nest tree, the nest woodland (≤25 m from the nest tree), and (using GIS) the landscape scale (within 200-m and 2-km radii of the nest). The eagles typically nested ≥14 m above ground in the canopy of emergent (>20 m tall) living eucalypts in sheltered positions (midslope, with a north-easterly to southerly aspect), in woodland patches >5 ha (mean 76 ha), <200 m (mean 78 m) from the woodland edge, though ≥11 m (mean 190 m) from an agricultural edge, ≥38 m (mean 485 m) from the nearest rural dwelling, >1 km from suburbia, and farther from sealed roads (mean 832 m) than gravel roads (mean 490 m) than minor tracks (mean 291 m). Breeding productivity in 2017–18 (<i>n</i> = 15 and 18 territories, respectively) was 0.91 young fledged per attempt (clutch laid) and 0.67 young fledged per occupied territory per year. Nest sites were used annually for at least 3–7 years. Nest abandonments or site shifts were associated with human disturbance (e.g. clearing, earthmoving, subdivision and construction in or beside the nest patch), death of the nest tree or nest stand ('eucalypt dieback' or rural tree decline), pindone baiting for rabbits (<i>Oryctolagus cuniculus</i>), and displacement by wedge-tailed eagles (<i>Aquila audax</i>) and ravens (Corvus sp.). As most little eagle nests were located on private land, we recommend, <i>inter alia</i>, greater protection of breeding habitat, nest sites and foraging habitat, woodland regeneration (especially riparian), and a buffer around established nests of ≥1 km from major developments such as urbanisation.