Bob,
This is an old technique. Way back in the 1970’s when my late boss Wayne Braithwaite and I were working on ducks in the swamps of western NSW, we used a similar device to test the incubation stage of eggs we found in the nests of several species. It didn’t seem to have any adverse effect on the hatching rate but then again duck eggs are reasonably big. I don’t think it would be advisable to use it on small passerine eggs.
Cheers,
Mark
From: Bob Rusk [
Sent: Tuesday, 30 April 2013 7:46 PM
To: COG
Subject: [canberrabirds] eggs
Seemingly in the field she used a small clear plastic beaker filled with water in which she popped the eggs in, recorded the flotation position and replaced the eggs within seconds of them being tested.
PS- IT SHOULD BE NOTED THAT NO HARMFUL CHEMICALS WERE USED OR THAT ANY BIRD WAS HARMED DURING THESE EXPERIMENTS .
