Warning:  Cutting any birds nails can cause great injury to the bird and even death in extreme circumstances.  Cutting nails should be done under the supervision of a vet or experience bird keeper.  I have been cutting my canaries nails since 1989 and had my fair share of close calls.  Cutting the blood vessel within the nail will cause the canary to bleed.  If you do cut the nail to the point that it bleeds you can use a styptic powder to stop the bleeding enought to consult your closest vet.

Long nails should be cut to make life easier for the birds.  Long nails can get caught between cage bars or toys and will get in the way of their every day life.

You can trim your canarys nails by using a simple nail clipper.  

In this video below I demonstrate how to cut a canaries nails.

My bird room is very well lit and I can see the blood vessels clearly.