Saturday, November 21, 2009

Horny Great Horned Owls


It's that time of year again!

Friday morning at 3:00 a.m.. and this morning at 4:30 a.m. I was serenaded awake (jolted awake?) by a pair of Great Horned Owls duet calling to each other just outside my lanai. I was sleeping on the floor of my living room directly in front of the lanai when they started calling to each other. I walked out onto the lanai and found them perched in a large pine tree not 100 feet from the edge of my home. Pretty cool!

If you go to this link you can hear an excellent example of a pair of a duetting pair of Great Horned Owls. The site seems to be a bit anthropomorphic and the announcer a tad too dramatic but the voices of the duetting birds are exactly as I heard them this morning.

The Florida Breeding Bird Atlas states that Great Horned Owls begin laying eggs as early as December so the birds outside my window are right on schedule for their courtship singing. I just wish they would do it a tad earlier in the evening, like at sunset, when I'm not trying to sleep.

The fact that Great Horned Owls are singing this early is a result of geography. In Kansas they are known to start nesting as early as January. In a book on the Breeding Birds of the Platte River Valley that Gary Lingle and I wrote long ago, we reported that the earliest date for active Great Horned Owls at the latitude of central Nebraska was February 21. And in my natal Wisconsin Great Horned Owls usually weren't actively sitting on eggs in a nest until the first week of March.

I would imagine that the resident Great Horned Owls here are nesting now so they can take advantage of the colder winter weather. With an incubation period of 28 days and an additional 35 days in the nest until the young fledge, eggs laid in mid-December would hatch in mid-January and the young would be out of the nest by late February. This would provide a nice buffer of about two months before the temperatures get hotter. Try to imagine a female Great Horned Owl sitting on eggs in a nest at the top of a tree in late April during the blazing south Florida sun, and you get an idea of why they nest when its cool outside.

I remember well in 1975 climbing to a Great Horned Owl nest in a forest in Pierce County Wisconsin not far from where I went to college. A fellow student had found the nest with two chicks in it and I wanted to band them. The nest was about 70 feet up in a sturdy white pine tree. The day before my attempt to band these young birds, Dave Evans who has been banding hawks and owls at Hawk Ridge in Duluth Minnesota since the late 1960s warned me to make certain I was wearing a football helmet when I climbed to the nest. I asked him why and Dave said "Just wear the damned thing."

The next day I climbed 70 feet up in this 100 foot tall white pine tree. When I first put my climbing spikes in the bark of the lower part of the tree I saw the female flush from the nest and then sit on a branch not far away. As I climbed higher in the tree I could hear the young start to get vocal and the adult was calling to them. Just as I poked my head up over the side of the nest and was eye level with the young, my then-wife Ruth yelled from below "Watch out!" It was then that I felt a tremendous collision of something on the back of my head. Ruth told me later that she watched the adult owl as it flew from its perch, clenched its talons together, and then hit me on the back of the head with both feet curled up like fists. I immediately understood why Dave Evans said to wear the football helmet, and I never climbed to a another Great Horned Owl nest after that night.

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