We may have a remaining few weeks of summer, but I know better than that. September hit and there’s a nip to the air, leaves are starting to fall, and the vast majority of birds have stopped singing. Territoriality is of moot importance for most birds when breeding isn’t a factor for concern but I see fall signaled best in the city by a rapid change in a specific birds’ behavior: crows.
Like all our breeding birds, crows breed at a specific time of year, and that time is past. However, unlike neotropical migrants and many other resident species, which make a rather quiet pass between breeding and non-breeding, crows make quite the splash. Once they’ve reared their young to the point of self-sufficiency (though they may stay with their parents and a larger family group for some time), most of our local crows no longer sleep in their breeding territories but repair to a local roost site at night.
You have almost certainly seen behavior associated with this phenolocial switch. On either end of your day, you may have noticed commuters in the air.
Strands of black winging across the sky; crows going to and from their roosts. Some people may feel a twinge of fear when they spy these masses, recalling Hitchcock’s “The Birds”, but never fear, crows are doing nothing more ominous than what most of us do daily, go to and from work. While a crow may maintain a specific area of the city year-round, it may only sleep there part of the year.
Why they do this is a good question, without an absolute answer. Communal roosts offer birds a number advantages: many eyes for predators, information sharing on good places to forage, and an opportunity for genetic mingling. Crows are highly intelligent and social animals, so getting together in large flocks makes a lot of sense. People enjoy gathering as well, and for similar reasons, so it’s not too far fetched crows would do the same.
Crows may seem noisy and troublesome in small numbers, but they are truly cacophonous in these large roosts. There are a number of sites in urban places nearby and people notice them because of the raucous vocalizations and behaviors of hundreds or thousands of birds. Crows are also particularly playful and vocal when returning to their roosts at dusk. I can’t tell you specifically where crows from Capitol Hill are headed each night, but Foster Island in the Arboretum is a well known roost site, along with the undeveloped slopes of Queen Anne. People being infinitely studious, it’s not surprising that there’s a site dedicated to local crow movements, which displays known and surmised roost sites along other information on a crowd-sourced map.
In Seattle, it can be generally assumed we have American crows. This species is slightly larger but almost identical, in all but call, to it’s cousin the Northwestern crow which is endemic to our costal region North into Alaska. As European Americans moved across the continent, creating more open land and urban spaces, American crows have generally followed. Here in Seattle, we might well have historically had exclusively Northwestern crows, who prefer the quintessential Pacific Northwest forest and shoreline over the homogenous urban scramble that it became. Birders frequently tussle over which species to check off when birding in our region because we are at the confluence of these two nearly identical species (which may well be the same species).
Regardless of species conundrums, we can enjoy watching roosting behavior as our neighborhood commuters take off for the night. Twisting and cawing through twilight skies, they make a pretty addition to a sometimes dreary end of day. Just like us, they go home, talk about their day with friends and neighbors, and tuck in for the night.
Previously in Pikes/Pines