Posted by ravens at October 28th, 2009

It does appear to be true that ravens neither live nor forage in the vicinity of Monterey. And there seems to be no obvious reason, at least to this amateur naturalist, for this odd range limit. C. brachyrhynchos loves it here, as do two species of jays. Can’t imagine there is a predator here that does not exist elsewhere in the state, and there is an overpopulation of C. corax everywhere else. I cannot think of any other factors that would affect ravens but not crows. This leaves me with only one rather weak hypothesis. This is one of the first places that humans with guns settled in California. They may have brought with them rural beliefs about predation of ravens on newborn livestock, or may have been shooting at ravens for other reasons. And then a cultural taboo on the area has been passed on by the birds ever since. This seems to have happened in the eastern US as well, so maybe it is not totally far-fetched.

As with crows and the Santa Monica mountains, there is some kind of zone in the normal range of the species that is simply passed over. Maybe I should go back to investigating the no-crow zone at home. It might be too simple to put it down to absence of lawns and other anthropogenic factors. As for Monterey and crows, there are plenty, probably too many, but I have not had time to see what they are really living on. Some are clearly local pairs, comfortable in their neighborhood trees, but down by the shore and downtown, there are lots of juvenile gangs having all sorts of fun in the strong winds and competing with all the other urban birds – which here includes Euphagus cyanocephalus, or Brewer’s blackbird. Over in Carmel, the latter seems to fill the niche usually occupied by sparrows in the most built-up areas, but that’s only a passing observation.