Thursday, March 31, 2011

Brooklyn Owl Update

Great Horned Owls around New York usually begin nesting while there is still snow on the ground. Our Brooklyn pair started incubating eggs on or around February 16th. I had high hopes that, after two failed attempts, this year they would successfully raise a family of owlets. Unfortunately, the odds were against them from the start and, as of last week, they had abandoned their nest.

I had been intentionally keeping the details about their activities a secret, but for obvious reasons, I can now reveal what had occurred over this past winter.

Back in late-December one of the Green-Wood Cemetery Great Horned Owls showed up roosting in Prospect Park. Her mate soon followed. My guess is that heavy snow and ice cover in the cemetery had made locating prey difficult for these nocturnal predators.

On January 11th I went into Prospect Park at dusk hoping to hear them vocalizing, as this is about the time of year that they begin courting. I spotted the female in her usual roost tree and waited for her to wake. At around 4pm she began to stir, first looking around, then stretching out her wings. Ten minutes later she flew from her perch and headed directly to a dead tree that topped off in a hollow depression. It was about 50 yards from her roost. I watched in excitement as she examined the potential nest site. She dropped down inside the cavity. After a moment she emerged then flew to a long horizontal branch on an adjacent tree. It was close enough to the opening that it would be a good spot for branching owlets to fly across to. I was both ecstatic and troubled by the thought of these large raptors nesting in Prospect Park. It would be the first time that Great Horned Owls would be nesting in the park since it opened to the public in 1867. There were also lots of potential problems.

The first problem was its location in relation to an annual Red-tailed Hawk nest. It was actually about 50 yards away from the hawk nest. Once the hawks began working on their nest, would they see the owls and attack them? If the owls had young perched out in the open, would the hawks try to eat them? Second, the roost tree was, unbelievably, right next to the hawk nest...only about 30 feet away and directly above a busy walkway. Another problem with the nest was that, it too, was in a very busy area. It was only about 30 yards from Center Drive, where work vehicles and other unauthorized vehicles frequently speed passed well above the speed limit. If that wasn't bad enough, on the east side of the nest tree is an area in Prospect Park that is notorious for cruising, meaning that there would be a lot of foot traffic after dark.

I don't fault the owls, it was very quiet in that area of Prospect Park while there was snow and ice on the ground. Once the snow melted, people and noise were nearly constant. I checked on her progress from a distance fairly regularly. It was easy to tell when she was on the nest as her tail feathers stuck out from the side of the tree opening, so I didn't have to get very close. One day in early March, I was near the roost tree when the male gave a reassuring "hoo-h'HOO--hoo-hoo" to his mate across the stream.

The last day that she was on the nest was March 17th, around the time eggs would be expected to hatch. Marge was monitoring the area and spotted a couple of things that could have contributed to them leaving the nest and Prospect Park. At one point a family with kids and dogs were walking under the roost tree. For whatever reason, they decided to stop directly beneath the male owl. Marge described several minutes of loud talking, children shouting and dogs barking. She could see that the male was agitated. Then there were all the men walking back and forth in the woods near the nest tree. I won't go into detail as to why they were there. After we determined that the owls were gone I noticed that people had worn a trail through the dirt directly to the base of the owl tree. By the kind of detritus that they left behind, it became clear that there had been a lot of human activity in the darkness below the nest.

So these two magnificent raptors have returned to the relative quiet of the cemetery. I'm probably just projecting, but when I saw the two of them perched together, I thought they looked sad.

1 comment:

Matthew said...

Sigh. There probably just aren't enough big, dead or half-dead trees with the right kind of holes for them to choose from in PP or GW.

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