New subject: bald eagles and nesting chronology (long)

8 Mar 2021

Today (March 3) Lisa Eye reports an adult bald eagle is sitting on the nest on Lower
Church St., northeast of Port Williams.  I just drove by the Blomidon Inn, which is
adjacent to the eagle nest at the Anglican Church in Wolfville.  An adult male eagle was
perched at the Inn, and a cursory look at the nest showed nothing; but an eagle sitting
down in the cup would be difficult to see.  At this time of year adults are known to
â€œpseudo-incubateâ€ without any eggs under them.

This is an interesting time of year for the eagles.  Now the paired adults should be on
their territories, showing ownership of the area around the nest, adding sticks and
redecorating, cementing their pair-bonds in various ways, and indulging in courtship and
perhaps mating behaviours.

Iâ€™ve been messing around with approximating dates for egg-laying (up to 3 eggs, takes a
week), growth of eaglets to fledging (requires 12 weeks or 84 days, until early July or
end of June, etc. 

Back-dating from early July results in approximately March 10-15 for egg-laying and April
15-20 for hatching of eaglets, which then donâ€™t become visible in the nests until early
to mid-May.

These are just vague guesses from someone who spends a lot of time monitoring local nests
from his car in eastern Kingâ€™s County.

Now think about how tough these birds are, i.e., no matter what the weather, the female
gets to sit on the eggs for very long periods of the day and night, for 35+ days, and then
sit on and guard the growing youngsters for weeks.

Here are a few more stats on bald eagles, from my memory:

Both sexes show white heads and tails at maturity, which takes about five years, and
females are much larger than males after fledging, averaging about a kilogram or two
pounds different.  The size differences are very noticeable even when the immatures are
growing in the nest.  The large adult females make very good nest defenders, whereas the
smaller males are more versatile hunters.  It is the males that provide most of the food
for the female and eaglets until the latter are a couple of months old.

Bald eagles are quite long-lived, up to nearly 30 years in the wild, versus up to almost
50 years in captivity.  

The largest bald eagle we weighed and measured at Acadia University was about 12 kilograms
(I need to check this) and had 87 inches of wingspan (7 feet 3 inches).  

Cheers from Jim in Wolfville

Re: bald eagles and nesting chronology (long)