a day ago
Attack of the clever crows
Bruce M. Beehler is a naturalist and author, whose books include 'Birds of Maryland, Delaware, and the District of Columbia,' and, most recently, 'Flight of the Godwit.'
Few of us who were of moviegoing age in 1963 can forget Alfred Hitchcock's 'The Birds,' a horror thriller set in Bodega Bay, California, that pitted flocks of angry crows, seagulls and other avians against Tippi Hedren and a cast of undeserving human victims. Particularly gruesome was the demise by crow attack of the likable schoolteacher played by Suzanne Pleshette. Though its thesis was preposterous, the film has gained in popularity over the years — adding to the already uncertain reputation of crows.
In general, crows elicit mixed reviews. They are intelligent, clever and innovative birds. But they are also feisty, conniving and predatory — known to pluck songbird eggs (and nestlings) from nests while helpless parent birds stand by and watch. Crows also get their reputation from their curiosity and cunning, as well as their occasional interactions with humans.
A recent development in our area demonstrates just how remarkable these birds really are. I live in the little southwestern Bethesda neighborhood of Brookmont, which overlooks Lock 5 of the C&O Canal and the Potomac River above Little Falls. Brookmont does not usually produce a great deal of excitement on the birding front. But lately, we have been seeing extraordinary behavior among our local fish crows (the lesser-known of the two crow species inhabiting the D.C. region).
For the 30-plus years my wife and I have lived here, fish crows have maintained a low profile. That abruptly changed this past spring. We were surprised over several days to find small parties of crows boldly settling onto our back porch, perching here and there, and showing little fear. Our dog, Scout, noticed and disliked the crows' presence. When we opened the back door, she would launch out barking at these unwelcome visitors. We didn't know why the crows were on our porch, but we rightly assumed they were up to no good.
Our nearest neighbors mentioned that they, too, were being visited by these crows, which they said were coming to harvest the stuffing from porch pillows to use in their nests. The birds actively attacked the pillows, snipping open the seams to get to the innards. When I queried the neighborhood via our email discussion group, more than 20 people replied that they had witnessed this same remarkable phenomenon. One even sent me photographs of the crows in action.
The birds were no doubt collecting the pillow stuffing to use as a soft inner lining to their large stick nests, to cosset the eggs and nestlings. Traditionally, the fish crow's nest lining is provided by bark, moss, plant fibers, mammal hair or pine needles. Brookmont's porches, it seems, offered an abundance of outdoor cushions filled with an all-new, fluffy and readily available nesting material.
That I was able to document dozens of reports of pillow-stuffing harvest from this spring indicates two interesting developments. First, one of the neighborhood crows must have somehow discovered the utility of pillow stuffing and learned how to crack open a cushion. Second, this clever bird must have then educated other crows in the neighborhood about this potential nesting-material bonanza. The pillow attacks are typically carried out by groups of four or five birds. I'm guessing these groups include experienced individuals who know the drill, and followers wishing to learn from the experienced birds.
This is an example of cultural learning in the fish crow. Without speaking, one crow informs others about a novel discovery so that members of the neighborhood assemblage (some of whom are most likely close relatives) can benefit.
The most famous historical example of avian cultural learning involved chickadee relatives — blue tits and great tits — in 1920s England. The birds learned to remove the caps from glass milk bottles delivered to front-door stoops in the early morning and then sip the bottle's tasty and nutritious contents. Over the decades, birds that learned this clever trick spread the knowledge to more and more of their fellows throughout Britain. More remarkably, this knowledge was eventually spread across the English Channel to Western Europe, proving that birds are more than unthinking avian robots and can indeed learn from one another.
That this learning transmission can be rapid is demonstrated by the sudden spread of the fish crow pillow attacks across Brookmont. But there is more. Like the birds in 'The Birds,' which no longer feared the humans who had taken over their habitat, the small groups of fish crows visiting our porches are unusually bold, often standing their ground when homeowners approach. That's not the retiring fish crow we're used to!
The birds' behavior might actually be evolving. If it is, let's hope their newfound audacity stops at outdoor furniture and doesn't develop into more Hitchcockian aggression. After all, these days, given humans' seemingly ever-growing onslaught against nature, our wild birds might have a legitimate reason to push back.
