Friday, October 19, 2007

Another Cardinal story from Bob Levy


Marie, this is the same adult female cardinal that appeared in your October 13th story “Another Bad Hair Day.” She looks much better. I trust you think you do too!


I came upon Mama Castle foraging with her youngest fledgling in Central Park’s Shakespeare Garden. Mama Castle and I are well acquainted so it was not at all unusual for her to rush toward me when I whistled. She stopped on the top of a rock waiting for the peanut she expected I would provide. When she received it she took it to her previous perch and called out. Her fledgling rushed to her side. Then Mama Castle stretched her neck toward the excited juvenile and placed the food in her beak. But as the photo demonstrates when Mama Castle pulled back I saw that she was still holding the peanut which I had expected the fledgling to have eaten. Mama Castle held onto the food as her fledgling resumed begging.

This was repeated three more times with the same results. Why? I assumed that the piece of food might be too large. Until now Mama Castle had always crushed the peanuts into smithereens for this youngster. Clearly smithereens were not on today’s menu. The fifth time Mama pressed the food into the juvenile’s beak she held on to it for a second only to drop it. Her mother picked it up and put it into her daughter’s beak again. At last the fledgling held it firmly. She took it to the base of a shrub where she ate it under the cover of leaves.

Meanwhile Mama Castle had rushed back toward me. About four feet away she “spoke”. I understood. My reply was to toss another peanut to her but she treated this one differently. Instead of delivering it to the fledgling whole she broke it into pieces that were small but decidedly not smithereens . Then she returned to the rock and called out. Her daughter joined her and performed the process as if she had been doing it this way all her life. She readily crushed and swallowed the smaller chunks of food her Mama passed to her. When it was consumed Mama Castle approached me again and the scene was reprised.

What was going on here?

I believe this was a kind of Northern Cardinal table manners training session. Mama Castle had been teaching her daughter how to to eat without her having to jam food down her throat which, if you seen it, is standard operating procedure with younger fledglings. The lesson appeared to have been learned because I later saw the fledgling successfully retrieve, break up and eat a peanut unassisted, This scenario continued for a few more minutes until the fledgling abruptly raced off. Mama Castle faced me for a few seconds almost as if she were wondering what to do next: go after her daughter or collect more food. But her decision was foregone conclusion. She bolted after her fledgling and that was the end of my training session.

Thursday, October 18, 2007

Unusual bird for Central Park

Marsh Wren - October 17, 2007
Photo by David Speiser

David writes:

Marie, Today's Marsh Wren in the Oven gave me spectacualr looks just before it flew off. All of a sudden it started to flit around and it perched in the reeds, then it was off. It didn't fly too far so it still might be around. I'm glad the Central Park birding community alerted me to this non-frequent visitor to the Park. David

PS from Marie: I was at the Ladies Pavilion yesterday morning at about 7:30 a.m with the Early Birders when I came upon an excited Natural History Museum group who had just seen this marsh wren.
Alas, though we hung around for quite a while, searching, we didn't get to see it, and did a considerable amount of regretting. When David's fabulous photo arrived I felt that I'd finally seen it after all.

Wednesday, October 17, 2007

Purple Finches a'plenty

male Purple Finch

female Purple Finch
Photos by David Speiser 10/16/07

David writes:

Marie, The last few days in CP have brought an unprecedented number of Purple Finches, at least for the 10 years I've been birding the Park. Bright males as well as female types have been from the Maintenance field, to Tanner's Spring to the Wildflower Meadow. I hope more Winter Finches are on their way soon. David

PS from Marie

For non-hotshot birders:
Roger Tory Peterson gives some hints about telling a purple finch from the much more common house finch.

1. The purple finch is like a sparrow dipped in raspberry juice. The male house finch is much brighter red.

2. The house finch has dark stripes on sides and belly. The purple finch doesn't have them.

Tuesday, October 16, 2007

more on Lola's kestrel from Blakeman and O'Brien

photo courtesy of palemale.com

James O'Brien writes:
Young kestrels are known for being uncautious by remaining exposed for long periods of time. If you look at the streaking on the breast, this is a young female. I have several pix of young kestrels being picked off by red tails, apparently they take a small percentage of young kestrels...not to worry though, kestrel populations are doing exceptionally well in the city. As always, I have some pix on the blog, http://yojimbot.blogspot.com




John Blakeman adds a note:

Readers should be aware of a significant new lethal element in the lives of American kestrels, at least in wooded and urban areas. Until recently, kestrels were among the most common diurnal raptors in the eastern half of North America. But every recent account shows a declining trend for this formerly frequent species. The population trend line for the American kestrel in many areas is decidedly plunging.
This time, it’s not poaching or trapping, the major killers in the 19th and first half of the 20th centuries. Nor is it bioaccumulating pesticides, which decimated bald eagles, ospreys, and peregrine falcons. Now, it’s another hawk doing the dastardly deeds. It’s “natural,” in a sense.

In recent years, with the termination of widespread spraying of DDT, another fine diurnal raptor has restored itself to high population levels, even probably to numbers never seen before, even in presettlement times.
In the last decade Cooper’s hawks, Accipiter cooperii, have exploded in number. Formerly, as all the older field guides relate, Cooper’s hawks were wary of human disturbance and confined their activities to remote forests and woodlots. The bird eats small birds almost exclusively, and because these prey species had eaten DDT-dazed insects, Cooper’s began to be poisoned. Their reproductive capacities plummeted and these bird-hawks become uncommon.

No longer. The species has erupted. At first, it re-colonized and re-populated its traditional forest habitats. But these habitats became saturated and adults drove off the copious young each year. Most starved, for lack of available prey.
But among all populations (look at the folks walking down a Manhattan or Ohio street), there are always a few “on the edge,” individuals that do not comport to conventional behaviors. So it was with Cooper’s hawks. A few disregarded their innate fears and wariness of humans and they flew right into small towns and started to feed profligately on the abundant, human-provided small birds there. In residential areas everywhere, including the residential boroughs of New York City, people set out bird seed and attract flocks of sitting sparrows, blue jays, mourning doves, and other attractive Cooper’s hawk prey.

Today, Cooper’s hawks breed in local residential neighborhoods, parasitizing the dickey birds on local feeders. Cooper’s hawks are everywhere today.
And sadly, they also pluck off American kestrels. Eyass kestrels, when they leave their nests, are barely capable of flight. A neighborhood Cooper’s hawk simply can't resist the plucking of three or four young kestrels in the first week of their lives.
In recent years, ever fewer young kestrels were able to survive their first summer. Like so many other birds, they became Cooper’s hawk sustenance.

As adults naturally die off, the kestrel population is not being adequately replaced. In my area, an Eagle scout built and erected a number of kestrel nest boxes. Ten years ago, at least half of these would have been occupied in the first spring. These boxes have been up for two years now and not a single kestrel has been seen.

The rise of Cooper’s hawks numbers has resulted in the plummeting of American kestrels where the two species co-exist.

Is this natural? Would this occur if people didn't artificially feed and concentrate song birds at bird feeders? Are backyard bird feeders contributing to the decline of American kestrels. In part at least, this must be so.

Nature is a complex web of interacting forces and processes, not all of which can be anticipated.
–John Blakeman

PS In regard to yesterday's posting of Lola with a kestrel in her talons, reader Karen Anne Kolling commented:

Girls rule.

Monday, October 15, 2007

Lola catches a kestrel

photo courtesy of palemale.com 10/13/07
[click on photo to enlarge]

Yesterday, frequent correspondent Sally Seyal wrote in with a question for John Blakeman:

On Lincoln's site today [10/14/07] he has a photo of Lola with a kestrel in her talons. I would be interested to know what Blakeman thinks about this. I know they catch birds with regularity but a Kestrel seems a much more difficult prey to snag than a pigeon, perhaps I am not giving pigeons enough credit! Perhaps she used the around the corner stalking technique!
Thanks.
Today John Blakeman replied:

Marie,

The photo of the kestrel in the clutches of the big red-tailed hawk on PaleMale.com was, at the least, unexpected. Red-tails don't frequently capture other raptors, especially ones as aerially adroit as the kestrel.

How might this have occurred? Red-tails are intellectual hunters, pre-calculating the probabilities and possibilities of their hunts. If it were spring, I would imagine something along the lines of the following, a scenario we've observed here in Ohio.

We've noted that many Ohio red-tail nests in May have the red epaulet feathers of consumed male redwing blackbirds, which are very similar in size to kestrels. It seemed impossible for a big, lumbering red-tail to repeatedly catch fast-flying little blackbirds. But how this was done is remarkable, and revelatory of the intellect of the red-tail.

Each day a red-tail would fly over a hay field that had a number of redwing blackbird nests, prompting a resident male redwing to ascend into the air and attempt to drive off the hawk who was spying the blackbird's females on the nests below. On the hawk's first pass over the field, the redwing stayed some distance away from the hawk, but nonetheless boldly escorted it out of the field's airspace.

The next day, the hawk resumed its flyover, and the defending male redwing became once again incensed at the hawk's passage. It flew another, albeit closer, harassing flight.
By the third or fourth day, the redwing become hazardously emboldened, and it got very close to the unresponsive hawk, thinking that it was pushing the hawk away. But hawk had this all figured out. It had lured the blackbird ever closer on each daily flyover, and finally just snatched the blackbird out of the sky when it got too close.

The hawk deliberately lured the blackbird into its talon's range by the daily flyovers. Pretty clever, these red-tails. With thousands of acres of hay fields, with thousands of spring-nesting redwing blackbirds, this was an easy and productive method to pluck defending male blackbirds out of the air.

Perhaps Lola's kestrel made the same mistake. Perhaps once each day the hawk would fly close to the falcon's perch, and it flew closer to the hawk each day. By failing to attack on early flights, the red-tail can lead the falcon or blackbird to think that it simply won't attack, that it will simply fly on past. Then, as the smaller bird got too close, the big hawk flips over and instantly plucks the smaller bird from the air.

Of course, that scenario works pretty well in spring time, when territories and young are being defended. In early autumn, however, this is not likely to be the case. Frankly, I can't explain how the kestrel let itself be captured by the red-tail. Most likely, it was incapacitated or injured in some way and became a vulnerable and visible target for the hawk.

Regrettably, I killed a kestrel one time. I was driving down a rural road at less than 50 mph, and noticed a kestrel perched on a low utility wire up ahead. It was flipping its tail back and forth, in typical kestrel fashion. But just as I began to pass by the perched falcon, it inexplicably dropped off into the air and flew right into the path of my windshield. The bird bounced over the car, and in the rear view mirror I saw the hapless falcon roll to a thoroughly dead stop in the middle of the road.

I stopped and went back to see if the falcon could be resuscitated. It had broken its neck and was dead. I tossed its carcass off into some roadside vegetation and quietly pondered the briefest lamentation.

The prey list of Central Park red-tails continues to expand. This is one I would never have expected. In this particular case, I think it was more a defect of the kestrel than the hunting prowess of the hawk that explains the sobering observation.

--John Blakeman