Do birds remove from the nest eggs that aren’t going to hatch?

I ask because the Great Horned Owls that have nested in the woods in back of our house these last eight winters have a failed nesting this year. We observed them mating (in fact, I filmed them once in late January), but the activity around their nesting site all but halted by mid-February. Then, on March 6th, I found a Great Horned Owl egg about a hundred feet from their nest. When I opened the egg, I found a blob filling half the cavity. It wasn’t developed: no discernible appendages or features.
I think I’ve read that birds remove eggs that aren’t viable, but I searched the internet and couldn’t find confirmation of that. If you can confirm my suspicion, I’d love to hear from you. The mystery of that egg sitting a hundred feet from the Sycamore is nagging me.


For an hour or more, I wondered about my sanity. I went to the woods yesterday afternoon to film the Great Horned Owls. I saw the male (he hooted, so that I knew it was him) and saw him fly further into the woods. A minute later I saw another owl fly in that direction, and soon afterwards I heard him screech as he did the day I filmed him copulating with her. So I trained the camera on the Sycamore where they nest hoping to catch some film of her returning–in case they do have eggs in there that she’s incubating. Then … WHAT? I saw movement in the hole. I was so excited: it’s a baby, I thought! But no. I caught a glimpse of it. That was no baby. It had the tufts of feathers that give it the name horned, and it wasn’t downy. That was an adult owl. I thought, wait. Didn’t I just see her fly several hundred yards away? Didn’t I just hear them mating? Or did I dream that? What I didn’t dream was the adult owl in the nesting site. That, I have on film. I waited another half hour. The bird in the hole never poked its head up again, and the female didn’t return.
When I got inside, I called the neighbors who live nearest to that Sycamore. Mark told me that he has seen three adults. Oh. Suppose last year’s owlet has stuck around. Suppose it was a female and she’s helping incubate the eggs, while Momma Owl goes off to, shall we say, keep the pair bond strong. That’s several suppositions, but none of them are a far stretch.
When I filmed the owls mating on January 27th, I supposed they didn’t already have eggs. I supposed that owls agree with the ancient popes, that sex is for reproduction and that they wouldn’t copulate after the eggs are laid. Seemed like a reasonable supposition since I couldn’t find any information either way on the internet. But then I learned that Barn Owls do mate after the eggs are laid, so why not Great Horned Owls too?
There’s too much supposing and not enough knowing going on to suit me, but I will be down in those woods almost every afternoon until I figure out what’s really happening.

The Siren’s Call

The Siren's Call

Despite the aching aftermath of my fall Monday, I was lured through the snow to the woods late this afternoon. I went out to feed the birds about 4:30 and heard the male Great Horned Owl calling. Got some nice film and this photo.

Whenever he had the back of his head to me, he would snap it back around to stare if I so much as crunched the snow by shifting my weight. He was probably fifty yards away, but their hearing is phenomenal. Their facial disks help direct sound to their ears. (Those tufts on top of their heads are just feathers, not ears.) One ear is set slightly higher than the other and at a different angle, so that they can pinpoint sound with laser accuracy. They don’t have to figure out where a sound originated. They know. And my little snow crunchy noises would reverberate in his ears as loudly as a telephone book dropped on a hardwood floor.

Do Great Horned Owls copulate after the eggs are laid?

My husband just told me that a birding acquaintance of his told him a couple of years ago about watching a webcam set up on a Barn Owl nest. The camera showed that even after the pair’s eggs were laid, they copulated. The acquaintance, a woman, said that all the women who observed this said something to the effect of: that’s males for you! I mention this not to join in the chorus of complaints but because I said in the film I just posted about Great Horned Owls that they obviously don’t already have eggs because if they did, they wouldn’t be copulating now. They would agree with the ancient popes that sex is for reproduction. (One of my commenters observed that: “I presume the Owl Pope would approve that they’re not enjoying sex too much, with the quickest copulation imaginable.”) But suppose I was wrong about their sexual habits? Maybe they do already have eggs. Hmm.

Great Horned Owlet: Fresh from the Nest

Bird Movies by Jo,

We’ve had a pair of Great Horned Owls nesting in the woods behind our house for the last seven years. Last winter, they had one owlet, and on his first day out of the nest, I filmed him. When he tests those powerful wings, I can almost feel the potential of flight in my own arms. Wouldn’t you love to be him for an hour and REALLY feel your wings spread?

The tree that had their nest was destroyed last May 31st in a tornado, but we’ve been hearing the pair calling to each other every night since they returned in late August. They coo. The male’s call is slower and deeper; the female’s is higher pitched and faster, a little more fussbudgety. Near the nest, the tall cedars that they roosted in every day were also destroyed by the tornado. The nursery is gone and so is Mommy and Daddy’s bedroom. So we wondered if they would look for a different territory. Apparently not. It’s 7:45 p.m., and I’m listening to them as I type. They’ll mate in January, and the young will be born in late February or early March.

You can see all my films on my YouTube channel: Jo Alwood.