Monday, November 23, 2009

Do Great Horned Owls Really Eat Cats? (Yes but only small ones, so another reason to keep Kitty in the house beyond songbird munching.)

The Great Horned Owl, Bubo virginianus, currently of Central Park, having a last minute nap before fly-0ut.

The other day I wondered if this Great Horned Owl might have a connection with the Great Horns in The New York Botanical Garden. After looking into it I found out that Great Horned Owls don't migrate but rather tend to stay within their limited hunting range of choice year round. I'd just assumed previously that the Great Horned Owl visitors we get in Central Park from time to time were migrating but as they don't migrate (though they will move to the next area of adequate prey in times of a dearth, but that isn't considered true migration) these owls may well be from our area.

Late fall is the time of year when young GHOs leave their parents and strike out on their own so these young owls may be the ones that Central Park hosts.

This non-migratory adaptation is considered rather remarkable as it is so rare in birds occupying GHO habitat types.

Speaking of which, how does one tell the age of a Great Horned Owl. The question came up the other day while watching the owl. The answer- you can't. Once a GHO is wearing adult plumage there is no way to discern its age. Typically the females are larger. An adult GHO is anywhere from 18 to 25 inches. The females weighing in at 3 to 4 and a half pounds, with the males typically 2 to 3 and a half pounds.

I also discovered that 90% of young GHOs that are banded on the nest and then recovered later in life have been found to have moved less then 80 kms from their natal area. So it is possible that the Great Horned Owl currently in Central Park has some relationship to those in the NYBG.

Typical Great Horned Owl prey includes- rodents of various sizes, song birds, geese, adult turkeys, small cats (Kitty should stay in the house anyway.), skunks, beavers, porcupines, beavers, snakes, Grouse, muskrats, eels, squirrels, rabbits and variety of other things that they can manage to nail.

They don't always get off scott free from these encounters with prey but have been found killed or severely injured by porcupines, skunks, snakes and other intended meals.




Beyond the Garden said...

great photo of the owl. It is interesting that Great Horned Owls don't migrate.

Donegal Browne said...

Thanks. It is interesting about their lack of migration, isn't it? Who knew Great Horned Owls were such "homebodies"?