Mr. Alice:

In the past, you’ve talked about how the big black birds we see in San Diego are ravens, not crows. Well, lately, I’ve had lots of big, noisy black birds in the trees around my house. My friend swears they’re crows, not ravens. Who do I believe? And, whatever they are, how can I get rid of them?

— Mena G., North Park

Okay. I give. In the past year; even Matthew Alice has noticed growing populations of crows cawing and flapping their way west. Time was when most San Diego crows stuck to their territories in the mountains, while the ravens had things under control on the western slopes. ‘But it’s the same old immigrant story. Population pressures, food supplies, jobs...things start getting hot in one place, and the hardy species will strike out for the frontiers, So no longer can it be said that the big black birds along the coast are more likely to be ravens; now they’re equally likely — maybe more likely, in some places — to be crows.

The two are pretty easy to tell apart. Crows are smaller, scrappier, and more active, with higher-pitched voices, and more likely to be in small flocks rather than in pairs or solo, as ravens are. More reliably, wait until you see them flying, then look at their back ends. If the trail’s edge of the tail is a straight line. it’s a crow. If it sticks out in a peak in the middle, it’s a raven. (Perched, however, they look pretty much alike.) They’re both scavengers and can live sumptuously on our discards. As for getting rid of crows, all I can do is quote a local farmer, “Ha-ha-hahahahaha!”