Even if you can't bring a live bird in you can bring in a chicken/chick toy or stuffed bird. This is done at 4-H competitions.
As for the how-to projects if you want poultry related here are some ideas:
How to brood chicks. Include a model brooder with feeder and drinker, light or hover, bedding, and so on.
How to bathe a bird. If you're showing birds you'll already know how to do that.
A model of a good chicken coop or tractor showing placements of roosts, nest boxes, feeders, drinkers, predator protection and so on with explanations of why each thing is situated the way it is.
Edited to add: The real key to this is to practice it enough at home that you sound natural and relaxed when you do it in front of class.
.....Alan.