Canary mysteriously died?

Question

My aunt had 4 canaries. All around a couple months old. She was given them by a friend who had them in pretty poor condition. One of the 4 was very aggressive towards the others so she gave that one back. Then she had 3 canaries left (all in the same cage).

One of the canaries, the male, suddenly started sleeping at the bottom of the cage acting very lethargic for a few days. Then is died.

She didn't use any chemicals or harmful things around the birds. What could have caused a young canary to just die?

Answer 1

If he was kept in very poor conditions prior to your aunt getting him, he was most likely sick before he ever arrived in her home.  He may have had a respiratory illness that eventually took it's toll.  If the "friend" kept the cages filthy or in an area that was not well-ventilated, the illness could've set in easily and it would've taken some time for the bird to succumb to the illness and die.  I'm sorry your aunt lost her pet. Not that it helps her with her loss, but it sounds like it's not her fault at all.

**ADD**

Another thing to consider:  Were the other three, including the one given back, females?  Was the one who died the only male?  If the one she gave back was a female, it's possible it was mated to the male who died.  If that was the case, the male could've died "from a broken heart."  It happens sometimes with mated birds.  If their mate dies or is taken away, the survivor sort of just wastes away themselves until they die.