When we did our (exhaustive) photographic survey of birds during May this year, we usually encountered a subset of what we began to call “everyday birds” — that is, the birds you can count on seeing every day. When you step outside your front (or back) door you likely encounter some of these “everyday birds”: Crows, Robins, Blue Jays, Cardinals, Chickadees, House Finches, Goldfinches, and if you live in very urban areas, the ever-present House Sparrows and Starlings.
Some of the everyday birds: American Crow, Blue Jay, House Sparrow, Chickadee, Goldfinch, Robin, House Finch, Cardinal
Why are these birds so common, or so commonly seen in our residential communities?
Actually, there’s a simple answer: we have made our front yards and backyards into buffet tables for birds, with fruits, seeds, feeders, nest boxes, and lots of vegetation for growing insects; we have planted trees and shrubs for birds to hide, nest, mate, and feed in, and provided them with water structures to bathe in; the grass is short so reptilian and mammalian predators like snakes and foxes that love eggs and chicks can’t hide there; and the vegetation is diverse and structurally complex so that many bird species can coexist there.
My backyard garden, surrounded by big trees, has something for all the little critters that inhabit it.
Goldfinches, one of the many “everyday birds” love to pick apart the flowers of the Cup Plant in late summer, and before then, they dine on a variety of seeds in several types of sunflowers and coneflowers in the backyard garden. In this garden there are seeds for them to consume, plant material for nests, feeders for the scarce food times, and vegetative cover to protect them.
This urban or rural/farm landscape transformed by humans is an open and easily exploited niche. However, birds must adapt to the presence of the humans there, and some do this much more easily and successfully than others.
House Sparrows, for example, are now so dependent on living in densely populated areas of humans (and their bird feeders and hedges) or around farmers’ barns that they are found only there. This species that originated in the Middle East became intimately linked to human agriculture and has spread over the globe by following humans everywhere they live.
The story of how House Sparrows became “the most common bird in the world” is a good read in Smithsonian magazine.
Quite by accident, Tree Swallows have become increasingly common in the past couple of decades as the Bluebird Recovery project introduced hundreds (if not thousands) of nest boxes into U.S. parks to help “save” the Bluebirds from being extirpated by hole-nesting Starlings and House Sparrows. So, now we put up two nest boxes instead of just one for the Bluebird, and the two species can coexist in the same territory. Neither species is deterred by humans walking by the nest or that come to peer into or open the boxes, although Tree Swallows will definitely dive-bomb you when you get to close to the nest.
Male Tree Swallow entering its nest box at a nearby park.
Our backyards are havens for not just birds, but tree frogs, toads, house mice, woodland mice, chipmunks and squirrels, prey for other, bigger birds to feast on. The other day I saw a FB video of a Great Blue Heron that walked from a pond near someone’s backyard right into the garden area and captured a chipmunk that boldly sat by a bird feeder chomping on seed! Great Horned Owls and Barred Owls, as well, have become more common in urban areas because of this buffet of tasty prey available, courtesy of human gardening habits.
Great Blue Herons don’t just occupy every pond and and lakeside in urban landscapes, but as good opportunistic hunters, they sometimes invade the backyard as well.
Bird feeders attract lots of birds, and those of us who love to feed birds make sure they put a variety of seed out to increase the bird diversity in their backyards. However, Cooper’s Hawks have recently discovered this urban mecca of bird diversity as well, and now they are becoming one of the most common urban raptors.
This juvenile Cooper’s Hawk landed on the bird bath in the backyard, looked around at the birds scuttling for cover and made a grab at one, landing on the grass — without its prey.
This is just the tip of the iceberg in the discussion of “why are some birds so common?”, and I’ll try to address other reasons for avian success in another set of posts. So, stay tuned.