Hi Geoff,
Re Q1. That is hard to know without doing experiments on captive birds,
where you could control these things. I wonder though if it has been
done and why someone would bother. There is another component to the
question and that is what is the time delay from copulation to
fertilisation? My guess is that in birds it is short. But not in all
animals. In many insects this may be months or maybe years, where the
female mates only once and then goes on breeding for the rest of her
life. In some bats I believe it is months, when the mating occurs months
before the ovulation and the sperm is stored waiting for the ovulation.
But I am not aware of any birds doing that.
In birds it may well vary between species but my guess is 2 or 3 days.
I'm sure there would be books with info about this but I don't have time
right now. Info may be most likely available for chickens and a few
other domestic species.
Re Q2. Again hard to know but most likely in practice yes. During the
time when the eggs are being formed most birds copulate frequently. So
unless you have found a non randy bird, there is likely to be several
copulations during the period of possible fertilisation and egg laying.
So I strongly suspect it is more likely than not that the copulations
leading to the fertilisations leading to the egg laying on different
days were different copulations.
This is not a comment on White-bellied Sea-Eagle as distinct from any
other bird.
Philip
-----Original Message-----
From:
On Behalf Of Geoff
Hutchinson
Sent: Thursday, 30 June 2011 12:24 PM
To:
Subject: Egg Laying In Raptors
I know there are a lot of knowledgeable people that read these emails.
The question is:
From the time of fertilisation how may days is it till the egg is laid?
If another egg is laid a few days later is it fertilised on another
occasion?
The question is about the White-bellied Sea-Eagle but I am sure there is
no
specific info on them but any info on birds of the same size would be of
interest.
Thanks
Geoff Hutchinson
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