Thursday, May 15, 2008

Blakeman on the Riverside Nest Fall, Creepy Coop, the Traxler Park Goslings, and a New Peregrine Cam


RIVERSIDE UPDATE: Lincoln Karim reports that he has taken the two remaining eyasses from the Riverside Nest along with a partially eaten pigeon, also found in the fallen nest, up to Dr. Ward Stone for testing.

The pigeon will be tested just in case it was the carrier of the poison. The poisoning of pigeons and the sale of pigeon poison is illegal in New York City. Though periodically pigeon haters will illegally poison pigeons sporadically in the city just because they feel they are "messy and dirty" as opposed to what pigeons really are. Besides being smart, beautiful, and friendly to say nothing of urban Red-tails main food source, Pigeons are our first line of defense against rats as they are the daytime vacuum cleaners of our streets and sidewalks. Pigeons clean up before dark when the rats come out to feed. The pigeon poisoners either use commercial pigeon poison bought in other areas or make homemade concoctions sometimes containing rat poison.

I know this seems strange but I've done a phase of field notes on rats at night in New York City, proving to my satisfaction that it isn't bird feeding that fuels the furnace of the rat population, and I'm backed up by the rat experts as well, but people don't want to hear that the rat population in any given area is directly linked to the amount of available night time human garbage. What are we thinking? Rats have no problem whatsoever getting through the ubiquitous plastic bags that we now use to contain garbage for pick up.

Unfortunately New York City does not have daytime garbage pickup nor is it mandated that all bagged garbage left on the curb at night for pick up must be left in rat proof containers. Either adjustment would reduce the rat population exponentially and make live much safer for everyone, including urban hawks.

It's seems easier to leave poison around than for people to take responsibility for their leavings until the bill comes due and something or someone not meant to be poisoned, is.


Red-tail expert John Blakeman and blog reader Mai Stewart (in italics) Have a Dialogue--

Hi John,

You're so right, we could have had a disaster had the nest fallen w/ the eyasses in it -- possible injury to the eyasses plus danger from dogs, even people -- but also, there appear to be a number of hawk watchers and friends-of-RTs who frequent RSP, almost a network, so it's quite possible that someone who's responsible and/or knows what to do might have come along or at least alerted someone who knows what to do. I find many New Yorkers can be surprisingly caring. But better not to have to face that situation.

The problem with retrieved, "rescued" half-grown eyasses is that they are impossible to raise in captivity with the hope of releasing them back to the wild. They instantly get imprinted to humans, and fail to learn to hunt, fly, etc. It's just as well that they did not liv I assume the parents would have attacked anyone who'd have tried to help (or dogs investigating) -- as the St. John Divine parents have the workmen?

No, with the eyasses on the ground, out of the nest, the parents are still protective, but usually not to the point of attacking a human on the ground. Once an eyass leaves the nest, especially when it falls to the ground, the birds are much less aggressive. They will continue to try to feed the eyasses, but that's about it.

I thought your first inclination as to the eyasses' demise -- the weather & hypothermia -- was actually most likely, since that Friday had been very cold & wet.

Yes, me too. But in either case, the demise from rat poison, or from the shabby, poorly-placed first-time nest falling out of the tree, the birds' inexperience probably played major roles, certainly in the poor placement of the nest.
Next year, they should choose a more secure location. We see these poorly-constructed and poorly-placed nests frequently with young Red-tail pairs, most of which go on to successes in subsequent years. They learn from these childish "Let's play house (or nest)." routines.

Do we assume that "poison" means rat poison? I don't think the Parks' Dept. puts out poison to kill pigeons. And if so, what, if anything, can be done about it -- there had been stories in the Times about a year or 2 ago of "packs" of rats trolling West End Avenue and Riverside Drive, approaching apt. buildings, a very scary prospect, so perhaps the intensity and frequency of rat poisoning on the West Side, esp. RSP, has been increased.

The poison was almost surely an anticoagulant rat poison, probably containing warfarin, the exact same chemical (in far stronger amounts) as the human drug Coumadin, which is used to prevent clotting. And no, here is little that can or will be done. Anticoagulant rat poisons are among the cheapest and (except for hawks) safest rodent poisons. No heavy metals, no neurotoxins, no appreciably bioaccumulating toxins, etc. In Europe, anticoagulant rodent poisons actually cleared a number of cities of rats. Of course, those were primarily in northern Europe, where attention to the proper disposal of rat food (garbage, etc.) is diligently attended to. Since then, a number of rat populations have evolved resistance to warfarin, making such poisons useless there.

But it didn't affect the RT parents -- Does this mean that they could eventually die from the same cause? Which is worrisome because they seem to have established that particular area as their territory.

No, the parents won't die from this single exposure. Apparently, they didn't eat the single rat with the poison. Only the eyasses got this fed to them.

Also, what did you think about the posting on Donna's website by someone who thought both last year and this that there have been 4 eggs in the Fordham nest -- is this possible?
[Chris lyons theorized the presence of 4 eggs in the last two Fordham clutches. D.B.]

It's very possible that 4 eggs were laid, given the large amount of prey available. This sometimes happens in the West, in areas with abundant ground squirrels. But I don't think there is any record of adults being able to raise 4 eyasses. One or two always die in these situations. It's almost impossible to capture enough prey to adequately feed 4 giant eyasses in the last weeks on the nest.

So much still to think about, and at least we still have viable nests, and nestlings, and can look forward to their growth and fledging. Hopefully, things will be better for PM/Lola and the RSP pair next year.

Although there have been these so-obvious deaths and nest failures, the fact remains that Manhattan and the other boroughs are now loaded with Red-tailed Hawks. I'm not concerned at all. The Red-tails of New York City are here to stay. They've set up housekeeping and are probably creating some unique, local dialect. Along with the rats, the pigeons, and humans, they're real New Yorkers now.

John A. Blakeman

If I hadn't seen her glide into the tree, I likely wouldn't have noticed the neighborhood's resident Cooper's Hawk. She stealthily enters the trees, often with the sun at her back, and predates the bird feeders.

For some reason, her form of creepiness reminds me of the feeling I used to get from the flying monkeys in the Wizard Of Oz when I was a kid.

Meet Daisy and Bill the Canada Geese parents at Traxler Park. I'd seen them along the shore and had gone slightly closer to count the goslings. They steeped into the lake and started going the other direction. Keeping my distance, I followed.
Bill gives me a look and hisses.
Upon hearing the hiss, Daisy gives me a look.

She then leans further into her paddling and picks up speed. Perhaps feeling that he's done his job and scared me off, Bill becomes distracted by a snack in the water.
This allows the gap to lengthen between he and the goslings.
Daisy slows slightly for Bill to catch up. She looks back seemingly to make sure that he has closed up the gap, and then they pick up speed and off they go.

I hadn't realized that the goose would adjust her paddle speed if the gander had lagged. My thought was that it was the gander's job to keep up. But after thinking about it, if he were distracted as in this case, and if there had been a real predator instead of me, and she didn't adjust, the longer duration gap might have given the predator an opening to nab a gosling. It makes perfect sense.

Another of Central Park Photographer Eleanor Tauber's expressive Raccoon moments--She's focused. But is she seeing a dog or a bag of corn curls?

And a friend from Illinois, drew my attention to the wonderful Peregrine eyasses in Allentown.
And here's the Allentown Peregrine cam link--
Donegal Browne


Karen Anne said...

Lincoln had a photograph on his web site sometime within about the last few months of a poison packet of some kind in the park.

I realize that the pigeon or rat could have been poisoned nearby, outside the park, but the question is, who would be putting poison in the park? Some pigeon hater poisoning at random, or does the park management do some of this.

Donegal Browne said...

I didn't see that particular photograph but yes, the NYC Parks have bait boxes within the parks filled with rat poison. Park officials have told us that children, birds, and other animals are unable to access the poison and that this poison is less likely to poison birds second hand. I don't know what the susceptibility to this particular poison in in very young raptors.

Many people are still very uncomfortable with the rat bait policy and would prefer other measures to be used such as scrupulous sanitation across the city but there are also park patrons who are horrified by the sight of a rat and therefore do want the bait boxes placed in the park. Park officials are caught in the middle.

Perhaps education to the public about the possibility however small, it is thought to be, and ramifications of possible accidental poisoning in other creatures would help those that fear rats to be more amenable to other techniques in rat control beyond poisons.

The three eyasses that died, from whatever cause, would have eaten many a rat in their lifetimes, as do the Screech Owls and other raptors that feed in the NYC park system.

Pigeon poisoners are another matter altogether. As I've mentioned before the poisoning of pigeons is illegal in New York City. In the past this has not kept building supers for instance, pressured by their tenants, from poisoning pigeons without giving thought to the ecological secondary effects of their actions.

Nor does it keep those who hate pigeons from sporadically putting food down laced with poison where pigeons feed including parks and sidewalks.

Education, education, education!

Karen Anne said...

It would not only be the park and "nearby" buildings, but there was a mention deep in Lincoln's site in email from various people about a restaurant in a park (it wasn't clear to me if it was in this park) setting out poison, that had apparently killed a number of the feral cats nearby that a feral cat group had been tending.

You probably know this, but I assume this is the type of feral cat group that sets out food for the cats at fixed locations the cats know, waits and takes any remaining food up after they have eaten so as not to cause a rat problem, and catches any kittens for neutering and adoption. These groups also work on neutering the adult ferals; those are often not adoptable and if so are released back and maintained by the daily feedings.