Urban Naturalist: Special sparrows

story by bernard brown | photo by christian hunoldEveryone knows what a sparrow is, right? Those ubiquitous little birds that compete with the pigeons for crumbs in front of park benches across Philadelphia? Well, they are and they aren’t. Most of them, Eurasian house sparrows, don’t belong here. They’re completely different birds in a completely different family than our native sparrows, except that they look almost the same.

They’re all Little Brown Birds (LBBs). That’s birder lingo for, you guessed it, all the little brown birds that look the same. For a long time I’ve known native sparrows were out there, but I figured they were way out there, in the forests and meadows, not in the urban jungles in which I live and work. But then I sawLBBs (presumptive house sparrows) in the garden that looked a little off: crisp stripes on the heads where I expected patches, sharper beaks, longer tails. I had a hard time getting a good look, though. They seemed to materialize out of dead leaves and twigs, and then zip back into the bushes before my brain could work through the search patterns.

I treasure the moment when the background monotony resolves into beautiful diversity. My “sparrows” category was starting to crack. Soon it shattered into multiple fascinating species of birds, each with its own natural history. This is one of the highlights of learning about the natural world, though in this case it took a morbid walk in Center City for the vision to come fully into focus. Keith Russell, outreach coordinator for Audubon in Philadelphia, let me tag along one October as he collected dead migratory birds for building-collision research. Several were white-throated sparrows (from upstate Pennsylvania into Canada), and it was easier to get a good look at them dead (however depressing). At the end of the shift, Russell paused at a pocket park next to a skyscraper and cocked his head with a grin. Little “chip” sounds around us meant we were in the presence of white-throated sparrows, live ones.

It turns out that a lot of the migrating white-throated sparrows, presumably ones that figure out how to avoid windows, spend the winter in Philadelphia. “They’re everywhere,” Tony Croasdale, a naturalist and environmental educator, told me. “Cobbs Creek, Temple’s campus, Center City.”

There is a downside to wintering in Center City. “They do make up a large proportion of the window strikes,” Russell noted when we spoke recently. “This is partly because they’re so common, but they like the habitat around Center City. They might see buildings as acceptable habitat.”

So, what is that LBB you’re looking at on your way to work this fall? It’s probably a house sparrow, but take a closer look. Aside from the white throat and the different shape, white-throated sparrows have dark stripes running back from the tops of their heads. Russell pointed out that the white-throats move differently than our house sparrows. “House sparrows hop on the ground. [White-throated sparrows] jump forward and scoot back, scratching at the leaves to see what’s underneath.”

Croasdale noted that the song sparrow, another native, lives in overgrown Philadelphia fields (meaning vacant lots) year round, and that we have several other sparrow species in our parks.

The next time you’re walking just about anywhere in Philadelphia, take a closer look at the LBBs. They just might be something special.

Bernard Brown is an amateur field herper, part-time bureaucrat and director of the PB&J Campaign (pbjcampaign.org), a movement focused on the benefits of eating lower on the food chain. Read about his forays into the natural world at phillyherping.blogspot.com.