Trying to figure out the sex of my canary chicks, I have exhausted all three ways to "guess" - by activity level, longer middle toe, and to tap on the nest and the boys will duck down while the girls sit up and stare. The nest tap results in all three birds laying down and staring. Nobody puts their tails up, but nobody sits up, however all three stare. Confusing. Maybe they're too old for this test. Maybe they aren't old enough. An inspection of their toe length makes me think they could be males, as the longer toe seems quite a bit longer tan the other two toes, much more like their father and very unlike the mother bird's feet.
Today I put the three chicks on a towel on the floor. I kept the caged parents nearby so they could keep an eye on their babies, however they are pretty relaxed about my intrusions. The other times I removed the babies, it was to clean out the nest or clean poo off the babies' feet or feathers and I kept them in my hand. Oh what fun the babies had today! It was the first time they've been out of the nest, feet on the floor, and had room to stretch and hop. The babies flapped their sprouting wings. They hopped around and all three seemed pretty active. Baby Chick #3, being three days younger than the other two, is clearly smaller and weaker with less plumage. He would hop and then rest. His level is equivalent to the other two when they were three days younger, so I am not worried about him. I put the chicks apart and they would go toward each other to hover together as if they were in the nest. The biggest/oldest chick is stealing the scene, hopping on a dollar and coins (for size reference) and then joining his brothers for a rest. You can hear the adult male chattering, babies peeping and finally, the mother bird with her louder peeps at the end of the video.