Yesterday was day 22 for our violaceous euphonia (Euphonia violacea) nest. With a typical incubation of 12-14 days, these eggs were assumed infertile, but we let the female sit on them a bit longer so that she would gain some experience going through the incubation process. But, alas, after sitting in a tropical rainforest for three weeks, they can begin to go bad, so we pulled them yesterday.
Below is the euphonia pair drinking their morning nectar; the male is the yellow/purple one on the left and the female is in her fabulous camouflage green on the right.
They chose a precarious nesting site, in the root ball of an orchid about 5 feet above the Amazon fish tank. You can see the dark entry to the nest in the crotch of the tree branch, right behind the vine. Both the male and female build the nest, and they like sites where they can create a little dome around the nest.
Euphonia eggs are about 1 cm long and look like those little Easter egg chocolates. Mmmmm…chocolate. Clutch size is 3-5 eggs, laid on consecutive days.
So how do we determine the fertility of the eggs? We carefully hold a light source to the egg in a dark room, and then can see what’s going on inside. This egg is infertile as you can clearly see the yolk floating around with no veining or any chick development. You can even see the air pocket in the upper 1/4 of the egg. Thanks to Rachael for taking this amazing photo: