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Friday, June 17, 2005

Fordham Red-tailed Hawks postscript

Prospect Park Red-tailed Hawks (taken early this year)

(Photo credit - Rob J)

I just received a final report from Chris Lyons regarding the Red-tailed Hawk family at Fordham University in the Bronx:

"Well, Hawkeye and Rose's two (so far unnamed) offspring are now fully fledged members of the NYC Red-Tail population. They left their nest tree either late Tuesday or early Wednesday (I'd suspect the latter), so my prognostication of a Mid-June fledging date was right on the money. This also tends to substantiate my guess that they were roughly a week old when I first spotted them on May 9th. Which means Rose probably laid her eggs about ten days or so after I first saw her sitting regularly in the nest on March 21st. She may not have been spending all those nights in the nest, though. Oh for a cheap, durable, self-installing camouflaged nestcam that can climb trees!

On Wednesday, I only saw one of the young hawks, sitting in an oak that's four trees down from the one the nest is in. The fledgling was calling loudly, and flying from branch to branch, but I saw no sustained flight. On Thursday afternoon, someone reported seeing both fledglings on the ground, just a few hundred yards from the library--he thought they were pretending to stalk prey. The notion that they'd be playing at hunting made sense, but Red-Tails don't do much stalking on terra firma, so I'd guess they were making practice pounces on various inanimate objects, honing their reflexes and coordination.

As I left work on Thursday, I followed the sounds of their calls, and found both of them sitting on top of Martyr's Court (a dormitory, where I've often seen the parents roost), four stories up. Again, I didn't see them fly, but there wasn't much doubt they were well past the jumping from branch to branch phase. One of them didn't so much as perch on top of the building as lie down on the roof-edge, as if still lolling about in the nest.

This morning, coming in to work early (hoping to get some pictures of this play-pouncing), I saw a head sticking up out of the nest. I had to wait a bit, but around 8am, both eyasses got up, stretched their wings, and hopped out of the nest. One of the adults flew overhead, and both called plaintively, hoping for food, but none was immediately forthcoming.

One of them then took a preliminary hop, and flew out over the expansive campus lawn, in the direction of Martyr's Court, where I shortly afterwards saw him perched. A bit awkward compared to the parents, but quite a decent bit of flying overall. The other young hawk was still sitting on a limb nest to the nest when I went in to work. I would assume the primary attraction of returning to the nest, other than the comfort of the familiar, was so that they could snuggle together and stay warm during what had been a rather cool summer night.

It's obviously going to be easier keeping track of these campus fledglings than it was with Jodie and Travis' kids in the dense northwest woods of Van Cortlandt Park last summer.

Neither of the fledglings shows much fear of humans, which is to be expected, given the more trusting nature of young birds in general, and the rather unusual circumstances these particular hawks have grown up in. During the past month, with all kinds of end-of-term events going on, they have had several large tents set up directly under them. Large outdoor cocktail parties with loud music have been conducted at night. I'm told a volleyball net was set up below the tree during graduation weekend, where screaming children played while the chicks either huddled down in the nest, or looked on curiously--wish I'd been there to find out which.

Most people have walked by the tree with little or no awareness of the nest (I've lost count of the number of times I've been asked "What are you looking at?"), but there's been a fair bit of friendly human gawking, and it doesn't seem to have done them a bit of harm. Indeed, it's prepared them for life in the big city, with its unique opportunities and challenges for adult raptors seeking to survive and reproduce.

As a postscript to this now-concluding series of reports, I've been musing about the whole New York City Red-Tail nesting phenomenon in recent months. I don't believe for one minute that it started with Pale Male--he was just the first well-known example of a colonization effort that must have been going on for many years before his birth, and probably had a number of distinct phases.

Long before I'd ever heard of Pale Male, an amateur naturalist named Ray Ramirez told me about a Red-Tail nest he'd seen in High Bridge Park--almost impossible to spot in the dense greenery, except from an elevated vantage point he'd found with some difficulty. He was one of the few people who even knew about it, and those few who knew about such nestings throughout the city probably weren't posting reports and digital photos on the nascent internet, or making reports to NYSARC. I know for a fact that some of the nests I've seen Great Horned Owls use in Van Cortlandt Park over the past decade must have been built by Red-Tails--I didn't see Red-Tails actually using one until last year, when Jodie and Travis picked an area of the park that wasn't inside the golf course, and thus more difficult to access during the warm months. For all I know, Red-Tails had been nesting in Van Cortlandt for the past 20 years. Definitely more than 10 years.

New York City has a lot of suitable parks for nesting hawks--most of them are less suitable for birders, particularly back before the crime rate dropped--and even now, city birders tend to be creatures of habit, sticking to a few well-known locations, where rarities are most likely to be found, and muggers less likely to be encountered.

So the fact that the NYC birding community wasn't aware of these early colonists until Pale Male showed up in what may be the most intensively birded area on the eastern seaboard doesn't mean they weren't there. In all probability, the first settlers were as cautious as any Red-Tail nesting in a wild area, doing their level best to avoid detection, building their nests in places that were difficult to spot (as many still do), and generally keeping as low a profile as possible. However, given the nature of their daily existences, it makes sense that over time they'd lose some of their fear of people, and that each successive generation, seeking unoccupied territories to raise young, would be more willing to consider new possibilities, and tolerate the increased chance of detection by humans.

Pale Male's penchant for pigeons isn't as remarkable as some have thought, either--a fellow Bronx birder told me back in the early 90's that he'd seen Red-Tails ambushing pigeons in the neighborhood. With such a versatile opportunistic predator (I've seen footage of them catching bats in mid-air) the presence of so much meat on the wing could not be ignored--the skills and tactics that were needed in order to exploit this food source were mastered and applied, and passed on to the next generation, ensuring that these Red-Tails would have no trouble feeding their young no matter where they nested. Combined with other abundant urban food sources, such as the gray squirrel, this opened up a huge number of potential breeding territories in the city, as well as a keen rivalry with our urban-nesting Peregrines.

With the collapse of New York's crow population, due to West Nile Encephilitis, the last significant barrier to their breeding success has been removed. Five years ago, Red-Tails could not possibly have nested where Hawkeye and Rose did this past spring. Five years ago, there was a massive pre-roost of American Crows that gathered on the very lawn that the nest tree stands at the edge of. During the winter, hundreds, sometimes thousands of raucously cawing corvids would gather there in late afternoon, before flying over to the Harlem River to roost for the night. If they'd spotted a pair of hawks building a nest in February--well, it's not hard to imagine what would have ensued. Even in the springtime, their numbers were considerable, and their persecution would have been unrelenting.

But I haven't seen a crow so much as caw at any of the hawks since early spring--and that was a Fish Crow, and I haven't seen him in quite a while. I doubt there are any nesting crows on the campus at all now, or in the nearby Bronx Park, and if there are, their numbers are so small as to make a contest of wills with a determined breeding pair of Red-Tails an uneven contest at best.

The only harassment Hawkeye and Rose have had to endure this spring was from Mockingbirds, Starlings, and a trio of falcons--a pair of peregrines and a male kestrel--that materialized on the day Rob came to see the nest. The Peregines skirmished with the adults, the Kestrel briefly buzzed over the heads of the chicks, and I haven't spotted any of them since. Presumably Red-Tails aren't the only raptor species that might play while the crows are away.

The Red-Tailed Hawk didn't colonize the five boroughs of New York City all at once. In my opinion, the invasion came in successive waves, from New Jersey, Westchester, and Long Island. It took them time to learn how to make it here in NYC. But they've got a firm talon grip on the city now. I've had a lot of my co-workers ask me, regarding Hawkeye and Rose, "Will they leave now?" The long answer is that the young will have to leave, and the adults may not use the same nest site next spring. But if I'm in a hurry, I just say "They're not going anywhere. It's their campus now. We just work on it.""

NOTE: The first nesting pair of Brooklyn Red-tailed Hawks that I observed was in Prospect Park during the spring of 1995.

(Photo credit - Rob J)

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