I always try to encourage people to keep chickens, so here comes my rant. XD Even with a small yard, you can usually keep at least a few of them. My wife and I keep a small flock in our relatively large back yard, and I couldn't be happier with them. Depending on the methods you use, they are next to no maintenance and they cost practically nothing to feed, given the amount of absolutely delicious,
truly free-range eggs you get. We get wayyyy more eggs than we can eat, so we give them away to our neighbors. Better neighbor relations is always a good thing, haha. But really, they are incredibly easy to care for, they're durable (mostly), and they pay for their own upkeep. That's not even to mention that they're quite the entertaining characters to watch.
Having your own flock of chickens is very eco-friendly and far more animal-friendly, but it's more than that; I see those as bonuses. In the society that we live in these days, the majority of us could use a lesson or two in how to care for ourselves and not rely on everyone around us to do the work for us and deliver our goods to the nearest grocery store. Keeping chickens is a very easy, very cheap way to learn some of those skills. And to take it a step further, chicken poo makes some of the best fertilizer on the planet - compost it and use it to fertilize your own vegetable garden. Can you imagine a vegetable omelet in the morning using only ingredients right out of your own back yard, laid and picked that morning? Most of us can't imagine it, but I bet most of us wish we could. Heck, you can even build your own coop and learn some basic carpentry skills, though I'd suggest having some of those skills before tackling a big build, lol.
Here is the coop I built for our flock, before some recent modifications. Totally redid the nesting area so they can't roost on the boxes and poo into the nests.
But anyway, both my wife and I are firm believers that no back yard should be without chickens. I know people even keep chickens in Alaska down to -30°, probably others do so in even colder climates. Like I said, they're durable birds. We adore our flock and look out for their health and well-being as best we can because, the way I see it, they're looking out for ours too. Eggs are quite the superfood after all!