I like birdwatching! It can be a very fun recreational activity or citizen science.
My boss loves it too. I don't know much about it, although I do enjoy seeing unusual birds from time to time. 
I like it because you don't necessarily need anything special to birdwatch, unless you would like to buy binoculars or a telescope. But they aren't necessary!
Do you use bird feeders or anything else to attract them? I know some people like to attract hummingbirds to their gardens. 
I do! I have a very nice birdfeeder in my yard that my grandfather built. It attracts all kinds of different birds!
We have one that the squirrels keep getting into!
Yep, squirrels will get into the bird food, I guess they enjoy the same things! I enjoy the auditory aspects of birds, their singing etc