Since today started out sunny and the prediction was for snow, I played hooky. I skipped my indoor Tai Chi class in favor of outdoor nature photography.
The thought of seeing bald eagles at Boulder Reservoir again pulled me out of my warm apartment. But when I got there just after 8, I was surprised and disappointed to see the gate closed (checking the city’s website later taught me that they don’t open the gate until 9). I could have hiked in from the gate. But when I used my binoculars to scan the trees by the Res, I didn’t see them.
Instead, I went on to Boulder County’s Twin Lakes Open Space hoping for better luck there. At Twin Lakes I hunted for a Great Horned Owl that I’d seen there. This time I was lucky.
Looking carefully in the cottonwoods, I spotted one near where I had seen them before, but much higher. As I set up my tripod the owl paid me no mind as it tried to sleep. But I think a crow was watching me watch the owl. Then, when the crow saw the owl, it called. Great Horned Owls hunt at night and sleep during the day, but crows sleep at night and hunt during the day. Soon more than a dozen crows were squawking and flying all around the owl. I had heard about mobbing, before but this was the first time I had seen it.
“Crows especially hate Great Horned Owls, their main predator, and take particular delight in harassing these hapless raptors as they nap during the day, often calling in friends to participate in the chase,” says the BirdHobbyist website. A study in Texas by Frederick Gehlbach, who observed 134 mobbing, concluded that, “Mobbing evolved principally to warn young birds and mates that a known dangerous predator was in their midst,” according to Dr. Wayne Lynch’s beautiful and definitive Owls of the United States and Canada.
The crows woke up the Great Horned Owl. During the mobbing, the owl looked all around and at one point looked straight at me.
Click on the picture above to enlarge
After the crows departed but before I left, the owl decided that flying a few feet to another cottonwood might be a better place to get some sleep. But before that, the owl had to get one more sleepy look at that tall stranger in its midst.