Slate's Green Lantern column tackles the question of what makes a bird eco-friendly. The discussion is pretty involved, and includes questions of local vs. organic. Here's an excerpt:
Organic turkeys, which haven't been given antibiotics, are a popular choice among green-minded consumers such as yourself (though apparently more due to the potential health implications than anything else). There is certainly a growing body of evidence that organic farming techniques may increase agricultural yields over the long haul, by maintaining soil and water quality. However, these findings apply primarily to crops, rather than animals. And you'll have to pay a significant premium to go organic: When shopping for his bird this past weekend, the Lantern was disappointed to find organic turkeys going for at least a dollar more per pound than their Grade A counterparts. (Slate's own Sara Dickerman discovered a few years back that the extra cost doesn't necessarily translate into a tastier turkey.)
If cash-flow problems put organic turkeys just outside your reach this November, you can still green your festivities by breaking slightly with tradition: Instead of serving turkey, serve a couple of nice chickens. According to a landmark Cornell University study from 10 years ago, it take 13 units of fossil fuel to produce a single unit of turkey protein; for broiler chickens, on the other hand, the ratio is a mere 4:1.Whatever you end up eating, have a great holiday!