Bird News

Kevin Ryan of Bay Road is without doubt the best birder in Easton. He has traveled the world on birding vacations so when he gives you a hint of what is around town you pay attention. He suggested at the beginning of November that I should watch the goldfinches and house finches at my feeder for the appearance of Pine Siskins. This has proven to  be a little more tricky than I had hoped. Here is a Pine Siskin.

OK, except for the hard to see yellow stripe on the wing, this would be what birders call an LBJ-little brown job-a category that includes lots of sparrows and other birds. The good news is the only sparrows visiting my feeders right now are easily identifiable House Sparrows. Unfortunately from an ID perspective I also have House Finches. Here's a lady house finch.

I hate to say this to a lady, but the easiest way to distinguish the two birds is that the finch has a big schnozz. Also, the lady finch in comparison is a plus size averaging an inch bigger and almost a quarter of an ounce heavier (a big deal in the bird world), but relative size is hard to determine in the field unless the two birds are sitting next to each other. The Siskin has a more more V-shaped tail while the Finch has a squarer one, but I've been doing a lot of feeder watching looking for that skinny beak. There are an estimated 22 million Pine Siskins in Canada, the USA, and Mexico so my day is coming!

The beaks of these finches reminds me of my favorite nature book 1994's The Beak of the Finch by Jonathan Weiner which traces examples of evolution in action. The title comes from a multiple decade experiment on one of the smaller Galapagos Islands. The finches in the Galapagos were one of the key finds that led Darwin to his great theory. This particular island switches between desert and lush vegetation with the changes in El Niño. A couple of scientists have been capturing, measuring, and banding all the finches on the island for many, many years. As the vegetation changes with the climate birds with bigger or smaller beaks are favored. If the island ever became permanently dry or permanently wet one beak size would become extinct and a new species would have evolved. That's also the story of the finch and the siskin who came from the same family and share a common ancestor. Both birds can eat small seeds like nyger (we generally call it thistle seed), but the House Finch can also chow down on bigger seeds like sunflower that would give the Pine Siskin some trouble.

Once again I have a problem since the seed mix I use in my general feeder includes unshelled sunflower as well as the shelled variety. It's a basic principle of ecology that everyone would rather eat potato chips on the couch instead of driving to a restaurant to eat lettuce. In other words all animals try to achieve the highest food value they can with the least effort. This means most birds regardless of beaks will eventually figure out they can get more calories, more easily by eating big chunks of unshelled sunflower rather than tediously shelling tiny nyger seeds. Not all birds, I watched a traditionalist Goldfinch spend fifeteen minutes shelling nyger yesterday while his buddies ate the sunflower.

Well time for lunch. Tomorrow a more successful outcome from one of Mr. Ryan's tips. Do you know your nuthatches?