Thank-you John Blakeman!! Sarah

thanks a million!!!!!!!!!

I've merely made some very distant comments about the NYC nest situation. I've never even been to NYC, and have never seen the 927 Fifth Ave nest. The real work has been done by the NYC locals who have intelligently prevailed in getting a nest-suporting structure back up on the windlow cornice. I merely made some suggestions regarding its design and some observations on how the birds might respond, based upon my field experiences with red-tailed hawk nests here in rural Ohio and in the West.

Fortunately (For me!) the birds have acted pretty much as I predicted.

But I believe, now, that I was very wrong in thinking that the pair subsisted primarily on ambushed city pigeons. My NY colleagues who have watched the pair have made it clear that the hawks take a lot of rats. Rats are probably their prime food source.

I was also wrong in thinking that the pair would be unlikely to have a nest so high. I've studied RT nests in both Ohio and in Nevada and Idaho, and cliff-nesting RTs in the West seldom park their nests so high.

Makes no difference. The pair is back at the nest and starting to do its seasonal thing.

For those who would like to read about the entire affair, check out the following websites:

http://www.mariewinn.com/disc.htm

(check both the center articles and the right margin ones)

and

wwww.palemale.com

Best wishes to all, especially to Pale Male and Lola, who will resume their remarkable breeding activities along Fifth Avenue.

john, your name is familiar. are you a falconer?

Thanks John you were instumental in my birding I have learned so much from you and I just want to let you know that you are very much appreciated.. thanks Claire

Yes, I'm a falconer specializing -- can you imagine it? -- in red-tails. I'm waiting for the foot of snow here to melt to get back into the field with my female "Savanna." She's eager to get back to chasing bunnies.

you're right about the rats...the whole of fifth ave was absolutely crawling with rats 10 years ago. they are the hawks least challenging prey item--they probably succeed 50% of the time. as for pidgeons, they are very plentiful too but very hard to catch. success is only about 10% for those. so we NY'ers owe those red-tails a double debt, one for cleaning out all the damn rats from central park and one for controlling the pidgeons. on a last note, the rats are also the riskiest for the hawks due to poisoning. two weeks ago a red-tail was found dead from poison at bethesda fountain. just goes to show you that there's still a lot of work to be done in terms of educating people about these wonderful and beneficial birds!

I guess that's why they have so many owls in central park I read that's their favorite food too. Sarah

This is all very interesting. I visited NYC for my first time in Dec. 2003. I wish I'd known about Pale Male at that time so I could have seen the nest.
Thanks to John Blakeman for his postings on this site.
Robin

Don't anyone think that the red-tails will be able to reduce Central Park rats in any useful or significant way. I love red-tails and promote them any way I can. But I won't tell an ecological lie. Red-tails (nor any other hawk or owl) canÂt possibly reduce prey species to any useful or significant level. This un-truth has been used for decades as a reason to keep raptors from being shot. "Hawks control rodent populations!" is the ubiquitous cry.

But in fact, they don't. They can't. How so?

First, let's figure out how many rats Pale Male or Lola (or any other red-tail) could consume in a day. I keep a trained red-tail (for falconry) and I know exactly how many grams of rodent (or other) protein is needed to maintain perfect health. In the summer, when temps are high and metabolic needs low, a red-tail can easily subsist on a single nice rat each day. If Central Park has two adults and two eyasses (offspring) floating around, that's a loss of four rats a day.

And just how many rats do you suppose occupy Central Park. It's not hundreds. It's multiple thousands. And they breed every few weeks or less. In short, there is no way the red-tails can make any discernable dent in the continuously abundant Norway rat population of NYC in general or Central Park proper. Even in spring, when the adults are capturing perhaps two rats a day for each eyass, with three eyasses on the nest that's six rats for the kids, and two each for the parents. That's ten rats a day, maximum. But the birds are also taking pigeons, reducing the pressure on the rat population.

The same thing happens out in the countryside. My wild red-tails in rural northern Ohio have, on average, a 2-square mile hunting territory. Each adult has to capture two or three voles each day in the summer, and five or six in the winter.

Let's say that's an annual average of four voles each day for each of the two resident hawks. That's 2920 voles. Round that off to an annual red-tail take of 3K voles in two square miles. Since vole populations can reach several hundred per acre, and a mile has 640 acres, it doesn't take a calculator to discern that red-tails have in their territories just a whole lot more crawling food specimens than they can ever reduce.

And while the hawks are eating the voles or rats, the rodents are going about their business in rapidly reproducing. Actually, hawk predation on the rodents can facilitate the maintenance of high rodent populations, as for every rodent removed by a hawk, a new slot is opened for a new growing rodent. It might be said that the purpose of hawk predation on rodents is to provide space and food for growing, young voles and rats.

Sorry to poke holes in a universal (but errant) ecological doctrine. It's all in the numbers, and they don't add up. Hawks, owls, (even cats) don't, even can't, control rodent numbers. Only rodent disease, poison, lack of food, water, or shelter can do this.

your point is well taken, rats exist in nyc in huge numbers. the issue is that the hawks, owls, cats and some guy on 110th st who invented "rat baseball" reduce their visibility--which is a huge help. i know they are there but i dont like seeing them and when some huge flying thing occasionally drops from the sky and takes a cousin, they do get the msg!

This is very interesting, although I live in an urban/suburban area I saw my first vole ever last summer 2003 and I was told by my county agent that the best way to control voles is by getting a jack russell dog Then I watched a program on PBS about a sugar cane farmer in Florida who has been setting up barn owl houses because it was the only effective treatment to control rats that eat his crop. He said he even used pesticides, but the barn owl is the most effective. Scroll down a bit on link and you will see the part about barn owls. Also just this morning on the Pennsylvania bird list there was a post from Minnesota on how the great gray owl and hawk owl are coming down from Canada because of the shortage of microtine or meadow voles. (I wish there were a shortage in my yard although I think what I saw was a pine vole) Sarah

Here is a link that might be useful: PBS Nature show on owls

Yes, owls can take more rodents than hawks. But it just stands to reason that if raptors could significantly reduce the food supply they rely on, the rodents, raptors would simply go hungry. If hawks or owls significantly reduced prey species, they would then have to leave the now food-deficient area. That's why all raptors possess and defend territories much larger than the needed food supply.

If raptors reduce their food supply by eating too much of it, they go hungry. That doesn't work in nature.

About the barn owls taking 3000 rats each year from the sugar cane. If there are 100 rats per acre (reasonable, probably higher), then a pair would clean out a 30-acre patch in a year. But barn owls have much, much larger territories. They simply can't consume enough rats to make a difference. Barn owl territories are usually measured in square miles, not acres (640 acres/sq. mi.)

And you've got to consider not just how many rats or voles exist in a specific area, but more importantly, how fast do they repopulate from both invasion and reproduction. Not only do the raptors have to eat more rodents than exist, but they have to eat more than are being reproduced, to cause any rodent population reproduction. Rats breed, well, like rats.

Yes, the current invasion of northern owls is a result of lack of rodent (and other) prey up there. The reduction of the northern rodent populations wasn't caused by owl and hawk predation. Rodent populations got too big and a lack of food and disease caused a populaton crash. This happens frequently in boreal areas. If the owls would have been doing the job that many well-meaning people are sure they do (control rodent populations), things would never have gotten so "out of balance." But these wide, "out of balance" population swings occur commonly in northern areas.

Again, I love hawks and want them to be appreciated and protected. But we needn't appeal today to unfounded romantic population dynamics. Raptors are sufficient unto themselves. No need to create or perpetuate predation myths.

On behalf of those of us in NJ .'Thankyou John'
-stephen