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Thread subject: Non Aggression.
Name Date Message
Marie 06/01/05 05:11 pm Is it my belief since the nestlings have shrunk to the number two that we do not see much if any aggression at this point. I read everyones postings since the death of # 4 and there seems to be a lack of obs re. aggression between these remaining chicks. This is an interesting phenomena if indeed the whomping has stopped. What are your opinions on this subject and am I just missing this kind of behaviour when I check in......
Tiger 06/01/05 05:23 pm No the aggression seems to have stopped.

Actually I have just been watching Bill Oddie talking about owls which have a rather similar hatching pattern to ospreys.

Russian dolls got mentioned so you can imagine for yourself what he was talking about.
Anne 06/01/05 05:27 pm Marie, I have been watching on and off for 3 days now and I have seen no aggression whatsoever. There is so much food coming in that sometimes they dont bother to get up and beg for some. And when the parents do feed them, they make sure that both chicks get their share. Whether the chicks develop sibling rivalry when they are older remains to be seen.
Marie 06/01/05 05:30 pm Good, that is very interesting that we are seeing a decrease in that kind of behaviour between these two chicks. Let's hope Mom and Dad stuff them with plenty of fish... ;-))
Tiger 06/01/05 05:51 pm If you remember Cz (Chick #1 from last year) was only aggressive when her food was threatened.

This year # 1 was aggressive without any reason.

Shall we call it Atilla?

Celeste 06/01/05 08:40 pm I do like that name!.......I haven't watched the cam all day, but this morning the "glares" that chick 1 was giving to chick 2 were really "threatening", but Chick 2 did glare back! It was really interesting and charming to watch these two chicks who were alone in the nest, peering over the edge and discovering their new world. It would make a great clip!
Tim P 06/01/05 10:14 pm This may be the calm before the storm.

Marie 06/01/05 11:48 pm Having spent a couple of hours with my biology friend and ''picked his brains'' I can now suggest that as long as the two chicks are much the same size in the nest and there isn't a major disparity in weight and build then it is less likely there will be any aggression. This of course can change if food supply diminishes. It is when there is more than two chicks in the nest and major differences in age and size that there is likely to be a lot of aggression. Parent birds react and respond to the loudest calls and the biggest GAPE( mouth)( they stuff it quickly to keep it quiet so it naturally gets most of the food. ALSO if the first chick to hatch is a female (in an eagles nest) there is less likely to be siblicide( chick killing by a sibling). If a male chick /eaglet is first hatched then it is likely that there will be siblicide. Over time, it has been suggested that in the realm of eagles the first egg laid is predominately a female egg these days. Haven't got data for Ospreys.
Anne 06/02/05 06:20 am Thats really interesting Marie.However, having read Celeste's posts from last night about some fighting, I think I may have spoken too soon.
karen 06/02/05 07:51 am Based on the Obs this Am I see the era of peace is over!
Marie 06/02/05 09:21 am Yes I see I spoke too soon................apparently siblicide is most often seen during the first two to three weeks...............ospreys are different to eagles obviously.

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Tom Throwe
Last modified: Sat Feb 18, 2006