Wednesday, April 25, 2007

Nest Observations

Yes, it's been a while since I posted. Nothing much new with Alice. She's still a bit hooty (she hoots whenever I'm on the phone upstairs at home), and still maintains some interest in her nest. But other than that she's mostly been staying out of trouble.

I've been really busy lately too. Everyone seems to want educational programs with Alice in April and May. Then I did the Crane Count early one morning for the International Crane Foundation ( and also participated in the Western Great Lakes Spring Owl Monitoring Project through Hawk Ridge Nature Reserve ( That involved driving my nine mile route, stopping every mile to listen for owls, three times during March through April.

Oh, and a producer for the Martha Stewart Show contacted me too! They were looking for a photo of a Great Horned Owl using an artificial nesting platform to use on their owl segment that aired this past Monday, but all I could do was direct them elsewhere since my artificial nests have yet to be used!

In between it all I've managed to spend some time observing owl nests and get some more recordings for my Great Horned Owl vocal study. This is tricky to do, since it can't be too windy, rain would be noisy, and it involves staying up all night so I can't have any evening commitments that night or any commitments the next day, since I need to sleep! (I don't do well on the night owl schedule--I'm a morning person.)

In late March I spent a night on a golf course 65 miles from here observing an owl nest. This pair of owls has nested on this particular golf course for at least the past three years. (Photographer Ron Green has spent much time with this family and gives me regular updates, including excellent photos!) They usually use old squirrel nests, since there are no nice stick nests for them to use, and the nest has usually disintegrated by the next year.

For owls that I observe with some regularity, I try to give them names that have some meaning. I know some people find this objectionable, but it provides an easy way to refer to each bird. It's also very helpful since territories move and birds die, so just referring to a bird by location, such as "the Rochester golf course female" will not work long term for individual birds, as you'll find out shortly.

I recently settled on "Foxy" for the female of this pair. She has a nice "foxy" red facial disk typical to Great Horned Owls in this area. Plus to get to the nest, I follow a maze of roads that have names like "Fox Croft", "Fox Chase", and several other confusing "Fox" names.

The male has a more blond facial disk, and Butterscotch kept coming to mind. But it's a long name and didn't really hint at gender. So I shortened it to "Scotch." The name "Tiger" had come to mind, since Great Horned Owls are known as "flying tigers" and he lived on a golf course so there was the Tiger Woods connection. But frankly, his personality did not seem to be anything like that of a tiger. He generally was pretty skittish. So Scotch it is.

Our March visit was pleasantly warm for Minnesota. It only got down into the 40s that night. A Thermarest mat, sleeping bag, wool sweater, long underwear, and winter coat just barely kept me warm until 5 AM. It was worth it, though.

Foxy didn't spend too much time at the nest with her owlets, which I guessed were around two weeks old. I could only see two, but later Ron Green informed us there were three squished into that small, cramped squirrel's nest in a snapped off pine tree. Scotch was on hunting duty, as was Foxy.

Foxy did a lot of squawking throughout the night. This seems to be a contact call with the owlets to let them know she's around. But it also may serve to keep Scotch on hunting duty. Whenever Scotch had some food to drop off, he flew into another tree just above us and hooted. Foxy arrived immediately, squawking. She took the food from Scotch and delivered it to the squawking owlets. Scotch never went to the nest. Apparently females don't let them take food to the kids until they are much older.

At any rate, we got some good recordings and left chilled and exhausted.

On April 16 I got a phone call from Ron Green. The day before, his wife's boss had been out golfing on the course. He stopped over to check on the owl family and found Foxy lying dead at the base of the tree. The kids seemed fine, and Scotch was in attendance.

With a nest in such a public area, foul play could always be a possibility. As could a host of chemicals used on most golf courses. So I sweet talked Ron into picking up Foxy's body and delivering it to me so we could get it necropsied.

A million phone calls and a few days later I had the results. There were many little nodules all over her liver and spleen, both organs were enlarged, and they had ruptured into her body cavity. This apparently is often caused by bacterial and fungal infections. So at least nothing human-induced had happened to her.

But that leaves Scotch with the daunting duty of trying to raise three big owlets with enormous appetites all by himself. They were old enough to accept food deliveries directly from Dad now, and he certainly seemed to be doing his best. But THREE kids? Uff da. One would certainly be doable, but three seems impossible.

So one week later, this past Monday, I spent another night at the golf course. Scotch was doing a high pitched squawking call that seemed to be a contact call with the kids. He didn't do this last year when the owlets were branching, as they were that night. Maybe the male only does this if his mate dies?? Although he made a few quick stops at/near the nest, I don't think he delivered any food (or if he did it was only small stuff, since I never heard any telltale crunching sounds of food being torn up.) One owlet kept up a loud, all-night squawking. The other two only squawked a bit here and there. One never left the nest.

I had my night vision along (courtesy of a grant from the Wilson Ornithological Society), and could see that the owlets seemed perky, and not lethargic. So that was good. But I was concerned they aren't getting enough to eat.

Ron Green had reported three rabbit heads under the nest two days after Foxy died. There were now at least four, along with a duck head, but I can't say that they were all fresh rabbit heads. I suspect three were the same ones Ron had seen earlier. Judging from the pellets on the ground, though, Scotch was focusing his efforts on large prey and skipping that little vole-sized stuff that he catches earlier in the nesting season.

Phone calls to Marge Gibson of the Raptor Education Group ( and Kay McKeever of The Owl Foundation ( didn't offer much hope for the situation. Supplemental feeding would be very difficult since the kids are branching and could leave the tree prematurely if we tried to get food into the nest for them. And they likely wouldn't eat it if we just put it on the ground. Scotch should be keyed in on live prey, but there's a small chance he would find and use food offered up on a platform off the ground.

At any rate, I've got two freezers full of dead gophers that could be used, but we need permission from the golf course to do anything. We may not be able to do anything until the owlets weaken and wind up on the ground.

Who knows how this will turn out. I guess it's a bit like an owl soap opera. Will the owlets survive? If so, how many? When will Scotch try to find a new mate? Will he continue to use the golf course for nesting after losing Foxy this year? Only time will tell.

In the meantime, I've been tipped off to a Great Horned Owl nest only 20 miles from home that's early in the nesting cycle, right next to a little-traveled road, and it even has a single parking spot right under it so I can use my car as a blind! And did I mention the landowner has worked at a state park for 20 years, so he's interested in wildlife? I hope to make some good observations at that nest when time allows.

Above is a photo of Foxy, just before necropsy. Not a great way to remember her, but you can see her facial disk and stripey toes. (The owls I've had contact with around here don't have stripey toes, but Alice does.)