SAN DIEGO — In the early 1980s, the common crow came as far south as Carlsbad and could be found in East County.
"They weren't in the metro area of San Diego or near the coast. Since then, they've completely filled in by the late 1990s," said Phillip Unit, the Curator of Birds and Mammals at the San Diego Natural History Museum.
Now, jump ahead to the San Diego Bird Atlas from 1997 to 2002.
In areas where the crow was before the surge, the population has also grown.
"What we would have in Oceanside or Escondido is at least 10 times of what it was in the 1970s," Unit said.
And in the metro area of San Diego, the crow population has gone from zero to thousands.
You can see them in the evening head to their roost.
"Crows are very social birds and roost in San Diego," Unit said.
Some of the largest roosts are at the Plaza Bonita shopping center, Mission Valley and the east end of Lake Hodges.
Why the big roost?
"There's safety in numbers, and they are exchanging information with each other, especially when they fly off in groups. They're probably learning where good places to forage may be," Unit said.
What brought the crows into the metro area has a lot to do with what we have done.
"The urban environment does offer a lot of opportunity with so many trees," Unit said.
There is the question crows have on songbirds.
"Well, yes crows do take songbirds, this is a huge, but there are other areas with this problem," he said.
Phillip says that the domestic cat population is also a major contributor to the decrease.
Crows vs. Ravens
Ravens are even more widespread in San Diego. They are larger in size and have some other differences: a wedged-shaped tail, shaggy neck feathers in the adults, a larger beak with nostril feathers and a different call.
"Crows caw, the raven has a much lower croak, quaak, quaak," Unit said.
Love them or not, crows and ravens are part of San Diego's amazingly diverse bird population: over 450 different species, which is one of the largest in North America.
And if paid attention to, these birds are quite interesting to watch.
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