Home & Garden Columns

Wild Neighbors: Birds in Berkeley: Doves, Hawks, Crows and the Long View

By Joe Eaton
Tuesday October 02, 2007

A few weeks back I got a nice e-mail message from Fran Haselsteiner (and belated thanks to you), which read in part:  

“What I would like to know is: What happened to all the mourning doves? When I moved to Berkeley in the mid-’80s, they were everywhere. Now they seem to have been replaced by crows, which weren’t here in large numbers then. What gives?” 

Good question, or set of questions. I have to admit that I hadn’t been paying close attention to the mourning doves. We used to have them in the yard, and they nested, or attempted to nest, on the block; they weren’t very good at construction or maintenance. But lately? And how long has it been since the last sighting? 

The decline of the doves, if there is a decline, has been a lot more subtle than the rise of the crows. I have a 1971 checklist showing the American crow as an occasional visitor to the Berkeley Hills, defined so as to include the UC campus. Now they’re ubiquitous, hanging out in raucous flocks, gathering silently on wires like a road-show company of The Birds, playing crowball at the new Derby Street athletic field. (Crowball is a leisurely sport that involves a lot of standing around in the grass.) West Nile was supposed to have thinned their ranks, but it doesn’t look like that’s happened.  

The crows inspire a fair amount of alarm in some people, at the least a concern that they’re raiding the nests of other, more desirable species. And they may be for all I know. I don’t know if anyone has been studying them. There might be a causal relationship between crow abundance and dove scarcity. But you have to be careful about such assumptions; multiple variables may be in play.  

Consider the hawks, for example. This town is a more hospitable place for hawks than you might think, at least for Cooper’s hawks. Ralph Pericoli, who helps run the Cooper’s Hawk Intensive Nesting Survey for the Golden Gate Raptor Observatory, says 13 pairs of these mid-sized hawks nested or attempted to nest in Berkeley this year; the average is 11. That’s one of the highest densities recorded in any urban area. 

The hawks seem to have adapted behaviorally to the city setting. “They were once considered a secretive species of the deep forest,” says Pericoli. You couldn’t get anywhere near their wildland nests without setting off the parent hawks. But in Berkeley, they’re unfazed by pedestrians, barking dogs, or traffic noises. 

Pericoli speculates that the Cooper’s hawk density may be related to the life cycle of street trees; enough trees have become mature enough to look like good nest sites. Then, too, people aren’t shooting at them. Our urban chicken farmers are less prone than their rural counterparts to blast any passing hawk out of the sky. 

There’s also abundant hawk chow here. Although Coops, especially young ones, may take rodents (two juveniles that died this summer were found to have lethal doses of brodifacoum, a potent rat poison, in their livers), they’re primarily bird-eaters. A hunting hawk’s beat will include all the local birdfeeders.  

And their favorite prey? According to a 2003 survey of the contents of coughed-up pellets, that would be a near tie between the mourning dove (24.4 percent of 455 prey remains) and the American robin (23.4 per cent.) Rock pigeons, western scrub-jays, and house sparrows accounted for most of the rest of the prey samples. 

So are the hawks responsible for the decline of the doves? Again, I don’t know if there’s any data. So many other things can affect bird populations: changes in habitat (less open space for foraging?), changes in climate, diseases. And sometimes we just don’t have a clue.  

This is a roundabout way of admitting that I have no answers for Fran Haselsteiner. But her letter has gotten me ruminating about changes in Berkeley’s bird fauna over time, and reviewing some old references. And it looks like this may turn into a string of columns. 

Next time out: whatever happened to the yellow warblers? 

If anyone knows of a local nest, or singing males that appeared to be on territory, or any sightings outside the spring and fall migration periods, I’d like to hear about it.  



Photograph by Ron Sullivan. 

A pair of mourning doves: declining in Berkeley? 


Joe Eaton’s “Wild Neighbors” column appears every other Tuesday in the Berkeley Daily Planet, alternating with Ron Sullivan’s “Green Neighbors” column on East Bay trees.