Goshawk Nw Norfolk Survey

Goshawk fledged young / recently used nest

GOSHAWK FLEDGED YOUNG / RECENTLY USED NEST

Fledged young

During the post-fledging period, young are still dependent on food being provided by the adults for at least six weeks. Fledged young can be found within several hundred metres of the nest area and loud begging calls can be heard from a distance. More calling occurs early in the morning before the young have been fed, although other surveys have found a peak of vocal activity in the middle of the day. Fledged young seen between mid July and mid August indicate that the nest area is probably within a quarter of a mile.

First flights to adjacent trees usually take place 38 to 46 days after hatching and smaller males tend to fledge before females. The young remain within 300m of the nest for two to three weeks until 65 days old, when their main flight feathers are complete. They then begin making longer movements until dispersal occurs between 65 to 90 days after hatching, although they can usually be recorded after that up to 1000m from the nest. They then gradually disperse further afield.

Dispersal

Dispersal can occur between four to seven weeks post-fledging for males and five to eight weeks for females, and can be abrupt. Some juveniles disperse quickly, usually by early September and up to a fair distance, roaming nomadically through the winter, while others can remain in the home range, even returning to the nest area. Ringing recoveries have shown dispersal to be no more than 50km in the first year.

Indicators of a recently active nest

If moulted feathers only are found at a nest site, together with down from the female and the nest shows green vegetation, this may indicate failure, though eggs may have been laid and incubation started. If no droppings or kills are found in the vicinity, it would indicate that young did not fledge. If nestling down, droppings and pluckings of prey are present, it indicates a successful nest.

1. Well formed nest structure with a flat rather than round bowl shape. May be quite flattened and appear to be smaller than an occupied nest as the nestlings damage and occasionally destroy the entire structure prior to fledging. The nest surface sometimes becomes tilted to one side by fledging time, the nest cup being barely visible.

2. Remnant prey remains or feathers are indicators that the nest was used recently, as they tend to disappear over a relatively short period. Fresh feathers and / or prey remains indicate occupancy during the current year. As the young grow and get closer to fledging, the vicinity of the nest area can resemble a charnel house.

3. Females begin moulting while incubating, rapidly losing four to five innermost primaries. Male feathers are typically harder to find as they’re scattered over a larger area and they tend to moult later in the summer.

4. Females defecate away from the nest during incubation. Detectable amounts of droppings aren’t visible at the nest until the nestlings are usually ten days old, when they begin defecating over the nest rim.

References:

Brown, R., Ferguson, J., Lawrence, M., Lees, D. Tracks and signs of the birds of Britain and Europe. Helm second edition

Cieslak, M., Bolestaw, D. Feathers: identification for bird conservation. Natura Publishing

Etheridge, B. et al Raptors: a field guide to survey and monitoring, second edition

Department of Fish and Game 2008 Habitat Conservation Program