At the end of last week, we finally received the results of the blood tests that would inform us of the sex of the chicks!
On arrival, the chicks were all weighed and measured and their sex was estimated from these measurements. The females having all round larger dimensions than the males, being heavier and the larger of the two sexes as is the case with all birds of prey. In adult white-tailed eagles, females weigh an average of 6-7kg and males 4.5-5.5kg
On June 22nd, it was assumed that we had an even sex ratio in the 2012 cohort-3 females and 3 males, and we put a male and a female in each aviary….HOWEVER, our estimations proved to be wrong! It turns out that we actually have 4 females and 2 males!! The bird thought to be a male was actually a small and very light female!
As the birds have grown over the past few weeks, Heather and I had suspected that the birds in aviary 2 were of the same sex as there was no significant difference in their size like there is in the other aviaries. The interaction between them is also different to that between the other pairs.
Since the project started in2007, we have ended up with more males than females surviving, so we are pleased with what these results have shown. We have a bit more of a balance now!!
A male and female chick in the aviaries...can you guess which is which?