Study Information about Sydney Olympic Park

White-bellied Sea-Eagles - 2018

-----------------------------------------------------------------------------------------------

Click on a Graphic to see a larger view

-----------------------------------------------------------------------------------------------

Judy Harrington, Geoff Hutchinson, Jon Irvine, BirdLife Southern NSW.

Delayed incubation 2018:
On June 11 at 5:33pm the first egg was laid (SE21). During that first night, a cold June night, the egg was uncovered for around 7.5 hours, with the female standing on the nest or a branch nearby. The female incubated for a total of only 3 hours and 15 minutes. On the following day the egg was uncovered for just over 3.5 hours. The pair shared incubation duty, the male for 5 hours and the female 2 hours. On the second night, the egg was uncovered even longer for 8.5 hours. By Day 2, incubation time increased and the egg was uncovered for 1 hour total.
This increased incubation on Day 2 indicated that full incubation of the first egg was delayed by some 36 hours from lay, with the egg uncovered for nearly 20 hours total. That night the egg was only uncovered for 1.5 hours, with incubation as usual by the female. On Day 3 the egg was only uncovered for 48 minutes with the pair sharing incubation again.

Graph Night-time incubation      Graph Night-time incubation
Graph 1: Night-time incubation between first and second egg laid

Graph Night-time incubation      Graph Night-time incubation
Graph 2: Day-time incubation between first and second egg laid

On the 4th night, June 14, the second egg was laid at 6:15pm (SE22) 73 hours after the first egg. Full incubation continued with the female on the nest all night. The eggs were uncovered only 1.5 hours total, with the female up and down briefly, rolling the eggs and stretching The following day with 2 eggs in the nest both parents incubated almost equally. The eggs were only uncovered for 30 minutes total. That night the female was on nest all night and the eggs uncovered only 20 minutes. However their usual behaviour was altered as the male incubated for 1 hour after disturbance on the nest tree. Daytime and night time full incubation then continued until hatch, with the eggs only briefly uncovered and both sharing incubation.

SE-22 Measurements
SE-22 Measurements

___________________________________________________________________________________