Or bird cozies:
A good yarn: Knitters make sweaters for penguins after oil spill - TODAY.com
I'm 26, and a "young" 26. I could be married with a house and kids, but I'm not quite there yet.
I think you're right about an interest in science and nature bringing people towards both hobbies. I had noticed that both FirstRays and Repotme sell bird feeders. I think that part of my interest in both is that I'm feeling intellectually bored now that I'm not in school, and I need something to study.
If you have a smartphone, you should check out the free app "Google Sky Map." Once you calibrate it, you can point your phone in any direction and it will tell you which stars you're looking at. It's fun to use in bed at night, because it sort of gives you a window up through the ceiling, and you can know which constellations are overhead.
Another good app is iBird Pro, which has a database of bird calls, with a selection of different sounds for each bird.