by Carl Strang
Mayslake Forest Preserve’s great horned owls are not raising any young this year, as I mentioned recently. They still are around, however, despite that setback.
On Friday I observed something I never have experienced before (at least, I find nothing similar in my great horned owl dossier or my memory). In the middle of a warm day, the male began hooting (though males are smaller than females their voices are lower pitched, and they generally produce fewer syllables in a call). After he hooted a couple of times, the female joined in. They proceeded to duet continuously for more than 15 minutes.
They remained perched in their favorite roosting area throughout, and were only a few trees apart, so these weren’t contact calls, and the owls weren’t chasing away a territorial intruder. The only times I have heard such lengthy periods of display in this species have been at dusk and at night, typically beginning in November when the birds are re-establishing their territories.
I have only a wild guess, here, as to what was going on. Reproductive behavior is hormonally regulated, and those hormones do not switch on and off quickly. With the failure of their nest those owls still have elevated (though probably diminishing) reproductive hormone levels. Energy that would have been going into feeding and brooding nestlings has no release, and so this peculiar lengthy duet was a result. Were the owls feeling anything? While it is tempting to attribute emotions to such a display, we cannot know what the experience of a bird is like. I won’t go so far as to say the owls weren’t feeling anything (we also cannot say that birds don’t feel emotions similar to ours), but will leave such speculation to others.