Its still hot out here in the valley, but I am looking forward to the autumn, and the arrival of our backyard companions for the winter - especially the White-Crowned Sparrows pictured above. Do you have a bird feeder in your yard or are thinking of setting one up? Do you worry about the merits of doing so? What's a bird feeder's carbon footprint, for example, if you just buy commercially grown and sold seed from the grocery store? Or are you willing to go the extra mile to actually create a wildlife-friendly habitat (perhaps even a certified one)? If you answer yes to any/all of the above, check out the recent Ask Umbra column over at Grist for a good discussion and advice to get you started. Apart from this column itself, and its prequel, there is a lot of useful information in the comments threads.
Of course, my own research on urban birds suggests that our provisioning of bird-feeders (and abundant food waste) creates a radically different (and much more predictable) food supply regime in cities, resulting in fatter birds and larger populations (of many but not all species) in the short term, and potential weakening of selection pressures in the long-term leaving them more vulnerable to other changes in habitat.
To take just one example: is simply providing seeds (even if you use a mix of seeds) enough? Seeds are great for adult birds of many species, but most species still need insects to feed their young, and if we are not careful, we may be creating an attractive sink habitat where all the adult birds want to hang out for the easy food, but there isn't enough for them to actually raise babies! An ecological trap, in other words.
Could the recent decline of House Sparrows throughout the old world (their original home, yes!) and in parts of the new, for example, be because they've become too dependent on our largesse (and our food harvesting and wasting habits), and become stuck in our ecological traps like fast-food junkies? I suspect so. One comprehensive study in the UK found that lack of insects to feed the young was a key driver of population declines. Surely what we are doing to their food resources is more more important than the alternative hypothesis popular in some quarters that cellphone towers are causing these mysterious declines? Or does the electromagnetic radiation from these towers really work in even more mysterious ways?
So where do I stand on the issue? I don't think we need to stop feeding birds - after all we started the problem by paving / building over their natural habitats, so it is only fair that we compensate them somehow. But we need to do more than simply buying those bags of seeds from the grocery store and putting them our in nice little (or big) feeders in our yards. We need to think more broadly about the ecology of these birds we attract to our yards, and try to provide them with whole habitats rather than just fast food. And Umbra Fisk and her readers offer a number of good suggestions on getting that ball rolling in your yard.
Happy backyard birding this winter then!