- ‘Habitat’ refers to both known habitat for the species (i.e. in or near habitat where the species has been recorded) and potential habitat (i.e. areas of habitat with appropriate characteristics for the species and within the species' potential range which have not yet been surveyed).
- If in doubt about whether a site represents potential habitat for this species, contact the Threatened Species Section for further advice.
- The known range of Tasmania's Wedge-tailed Eagle includes the whole of mainland Tasmania from the coast to the Central Highlands, and many of the larger offshore islands.
- Nesting habitat includes the following elements: patches of mature (including old-growth) forest, or forest with mature/old-growth elements, normally greater than 10 ha in area; nest trees usually tall (25-75 m), large and robust mature eucalypts, generally taller than the canopy; nests are often constructed in the tallest and largest tree at a site, and usually located within the canopy even when the nest tree is taller; nests typically occur on the lee (sheltered) aspect of the site (or where hills shelter an otherwise exposed site), with the nest situated below the ridge level for protection from prevailing winds. Less typical habitat may sometimes be used (e.g. where the habitat has been much modified) where food is readily available.
What to avoid
- Disturbance (visible, or extreme audible) to a nesting eagle - this can result in the death of eggs or chicks, through exposure to cold, heat or predation while adults are absent - including:
- people or loud machinery too near the nest during the breeding season
('too near' can be many hundreds of metres if in direct line of sight of the nest);
- residential development near nesting habitat; and
- investigating nests during the breeding season.
- Removal of nest trees or surrounding vegetation (the same nest may be used intermittently over decades)
- Risks of collisions with tall structures where the structure is difficult for an eagle to perceive in flight (e.g. power lines, horizontal axis wind turbines, guy wires).
Breeding season and levels of disturbance
- The Wedge-tailed Eagle breeding season is July to January inclusive, noting that in some years this may be extended into February due to the birds breeding for a longer period. The breeding season includes the highly sensitive courting period, when birds are at or near the nest assessing levels of disturbance and nest suitability just prior to laying; this courting period most often occurs in July, but may begin with nest lining in June. The majority of Wedge-tailed Eagle breeding activity typically occurs between August and January, but this varies between eagle pairs and from year to year. In some years chicks will not fledge until as late as March, with disturbance prior to this event potentially causing young birds to attempt to fly before they are fully fledged.
- The Threatened Species Section may be able to advise on the timing of the current season.
- If a nesting eagle perceives a disturbance as a threat, even from hundreds of metres away, it may leave its eggs or chicks at risk of cold, heat and predation. It may desert its nest site for years and long after the disturbance has ceased.
- A disturbance is more likely to disrupt breeding if: visible; louder; more intense; closer (either vertically or horizontally); over a longer period; more frequent; across a larger area; earlier in the breeding season; above the nest; people are visible; people are looking towards the nest; during the day; helicopters are involved; during extreme weather.
- Wedge-tailed eagles vary in their tolerance levels, and some may eventually nest in areas near certain levels of regular disturbance after some months or years spent assessing an area. However, a small additional disturbance may then be 'the straw that breaks the camel's back', i.e. enough to disrupt breeding, sometimes for years.
- Eagles are more tolerant of ongoing disturbance that began in an area before they started nesting, than they are of disturbance that is introduced once they are nesting.