Wednesday, October 18, 2006


Charlie Ridgway, one of the Central Park "star guys" sent in this notice:

This weekend, a mild but pretty flurry of meteors will shoot out of the constellation Orion. The source is Halley's Comet. Although the comet itself is far away, ancient clouds of dust from the comet are nearby, and Earth is about to run through them. The best time to look is Saturday morning, Oct. 21st, just before local dawn.

Tuesday, October 17, 2006

Pale Male & Lola's pair bond

Pale Male and Lola near Model-boat Pond
Photo: Lincoln Karim

An exchange with our Ohio hawk expert, John Blakeman:

Dear John,

A question has been subliminally present in my mind for quite a while, stimulated by Lincoln's pictures of the Fifth Avenue pair sitting together day after day, month after month.

Today the thought surfaced. Why is it that this pair remains so closely bonded long after the breeding season is over? I was under the impression that a redtail pair's bonds weaken once the kids fledge. They may stay in the same vicinity but are unbonded, I had believed, with the male rather timid and respectful of the female if they ever meet, because of her greater size.

The male, I also believed, would deferentially sit on a lower branch, if ever they happened to land on the same tree, etc. Then they would "renew the bonds" in January or so, when the hormones begin to flow, taking courtship flights etc.

Yet this has obviously never been the case with Pale Male and Lola. They don't seem to need renewal. Their bonds remain strong all summer and winter as they spend much time together, perch side by side, work on the nest, and so on. Lincoln's pictures are strong evidence of their continuing pair-bond.

Also, in previous years, with previous mates Pale Male and his mates seemed to go their separate ways, come August. Pale Male was more likely to be seen in CP in the summer, but obviously his mates traveled considerable distances, since two of them were involved in August accidents in New Jersey.

Any ideas?



Your observations and questions are discerning. Here are my thoughts.

Why is the pair so “closely bonded” so long after the breeding season? I'm certain that what you are seeing, the close-by sitting, the incidental tending or perching at the nest, and all of the other bonding (or “bonded”) behaviors are a reflection of the exceptionally suitable living conditions for the pair in Central Park.

I, too, have been amazed at these behaviors. I have never seen a rural red-tail visit a nest site in the non-breeding, off season (from August through November and December). I'm sure it happens out here, but it’s much less frequent than the credible reports from Central Park. The only explanation is that Pale Male and Lola have everything going their way. They want for nothing, particularly the most controlling life history factor, available prey animals. These birds have it made, in spades. They have absolutely everything they need and want in surfeit.

When I first learned of the Central Park red-tails, back in the 90s, I dismissed them as aberrant birds that had to marginally survive on whatever meager habitat offerings the park might offer. I was (ignorantly) certain that a red-tailed hawk in the center of a major city was there only because it was psychologically warped, or otherwise disabled in some manner. I was wrong on all accounts. Central Park provides abundant food for the hawks, in varying forms, from birds (pigeons) to mammals (rats, mice, and squirrels). Nothing is more exciting and gratifying to a red-tailed hawk (or other raptor) than to spot, pursue, capture, kill, and consume a living animal. The Central Park hawks can do this repeatedly, with ease. For a red-tail, this is heaven on earth.

And the tall building nest sites are ideal, even better for the hawks than the conventional tree nests so much lower to the ground.

Another major factor has been convenient and sheltered night roosting spots, particularly in the tall trees in the park. They can sleep down there relatively free from gusting winds.

And except for some wondering peregrines, which the big hawks can fend off, the CP red-tails just don't have any predators or significant harassers. (And no, the crows and other mobbing birds are only inconveniences, incidental to life in the wild.)

Altogether, the Central Park red-tails want for nothing. Life proceeds for them daily in a rewarding, fulfilling, un-hassled way. Of all the vertebrates in New York City, from the smallest shrew or mouse on up to humans ourselves, no other species lives so contentedly and happily. Of all the places red-tailed hawks live in North America, no pairs live better than those of Central Park, of that I'm now certain.

All of this explains the off-season bonding behaviors you noted. In normal wild red-tails, the late summer and autumn season’s activities must first concentrate on self-survival. Finding and defending habitats with sufficient prey is the first behavioral activity. Then, the prey must be spotted, pursued, and killed. That can take most of the day in the wild. In Central Park, rats, squirrels, or pigeons are always available, to be taken at will. Therefore, Pale Male and Lola have hours upon hours of free time, un-devoted to finding and procuring food.

So what are they going to do with themselves with all of that free time? As you've seen, they frequently “hang around” together, sitting on nearby perches. My old, experienced rural red-tail pairs do this throughout the year, too.

For birds that don't migrate, I disagree with the notion that the pair bond weakens or dissolves during the non-breeding months. It just takes a different, more subtle or nuanced style. For pairs that don't migrate to the south in the winter, such as Pale Male and Lola (and the majority of my wild pairs in northern Ohio), the pairs remain bonded throughout the year. As such, there are subtle, residual nesting behaviors in the hawks’ brains. With a full belly (well, crop), these residual nesting behaviors are expressed with incidental carrying of sticks or flights to the nest.

My rural birds have a tougher life, and probably condescendingly snicker at the spoiled rich hawks who have everything in the big city. My hawks have to live an honest life, working hard each day to survive. They can't be hedonistically diverted to breeding and nesting behaviors of any sort except during the breeding season proper. But Pale Male and Lola are living the lives of the red-tailed hawk royalty they are. Simple as that.

PS – Don't make anything of superior or inferior perches. The male sitting beneath or above the female means absolutely nothing to either bird. That’s a terrestrial mammal thing that doesn't connect with the hawks’ understanding of the world, which is far more three-dimensional than understood by earth-bound mammals. These are non-social predators. There is no “dominance” by either the tiercel or the female hawk, in any classic mammalian sense. There is no “alpha” male or female.

–John Blakeman

Monday, October 16, 2006

More about Silver-haired Bats

[illustration op at end]

Since we were lucky enough to have a rare chiropteran visitor in Central Park last Friday -- appropriately it was also the 13th day of the month-- here, from the University of Michigan, Museum of Zoology, is some more information about the Silver-haired bat {Lasionycteris noctivagans]

Life History of the Silver-haired Bat

The scientific name of the silver-haired bat is derived from Greek and Latin words meaning "Night wandering shaggy bat."

The silver-haired bat prefers to forage along wooded streams. [Note: It was found right near Central Park's best known wooded stream, The Gill, at the Azalea Pond]

During the summer, these bats live as single individuals. The bats seen clustered in buildings and other structures are most likely little brown or big brown bats. Silver-haired bats spend the daylight hours in seclusion under bark, in bulky birds nests, woodpecker holes, or other tree hollows.

The coloration of their fur looks as if they have just returned from the hair stylist. The brown-to-black hair appears as if it has just been frosted with silvery tint. The tinting does not extend to the head or neck. Silver-haired bats have been found all across the state [Michigan] during the summer time. During the fall, groups of mixed sexes can be found. Courtship and mating occur during the migratory period. They form winter colonies and hibernate in the southern part of their range. They return again in spring when females give birth to one or two young.

Conservation of silver-haired bats will depend on maintaining clean healthy rivers. Most of their diet depends on insects that spend part of their time in the water. Having a healthy diet, free of contaminants, is a key to reproducing offspring. Maintenance of river flood plain forests will also be important to provide roosting areas for these masters of the evening skies.

PS from Marie: Well, the Gill is not exactly a river, and the Azalea Pond is not exactly a flood plain. Nevertheless, watch where you throw your gum wrappers , and be sure to scoop after your dogs in Central Park. Maybe some day a pair of Silver-haired bats may choose the park to start a family.

[Click on link for a silver-haired bat photo.]