Tuesday, July 19, 2005

Redtail questions and answers and a word about Pale Male [Sr.]: Blakeman




A website correspondent writes:

Hello Marie,

I found your website, and I thought you might be able to help me out. I have been observing a pair of Redtails for 2 years now. The first year I watched them build their nest and how sad it was that they did not produce any young. I believe Vultures snatched the young. This year however they did produce and on June 16th a baby fledged the nest. I have pictures and movies from beginning to now. Yesterday I took the picture that is I am sending.

Before I ask my question I have to tell you the [redtail] Mother is no longer around, but she was for about 3 weeks, the Father would bring in the food for the baby and would make the baby come to him which I understand would be teaching him. The baby is flying very well now and the Father has been around (but not much) to bring the food, I have observed that the Father will bring the food and when the baby is near drops it so that she must catch it.

Questions: When will the baby start hunting on its own or even attempt to? She calls out (crying or begging) on a regular basis looking for the Father. How will he teach her hunting skills if he is not around for her to observe.

I have had the best two years watching these hawks and so fortunate that they allow me into their world from a distance. I respect them and never want to interfere with the balance of nature.

I have great respect for John Blakeman, and I know that you are affiliated with him and I know between the two of you maybe you can answer my questions.

Sincerely,

Claire F Rutledge

Wakefield MA

John Blakeman sent in a prompt answer:

Claire,

Several points. If vultures took the young last year, the young birds were almost surely dead before the vultures got them. Red-tails are never preyed upon by turkey vultures. Black vultures (don't know if you have any of those in MA, probably not, as they are a more southern species) can be a bit more aggressive. But unless the eyasses were dead on the nest, the parents would have easily defended the young against the vultures. Let us know if you actually saw vulture predation. Very interesting if it was observed. I've never seen this, nor know of any such events in Ohio.

Secondly, don't be completely certain that the mother has disappeared. In summer, red-tails seem to frequently "disappear." They are still around, but they take hunting perches within tree vegetation, instead of sitting so commonly out on utility poles and fence posts. Last week I drove 60 miles along a four-lane into Cleveland. In fall, winter, and spring, I commonly see anywhere from four to a dozen perched red-tails. Last week: not a single bird. I've noticed this for 30 years. In June through September here in Ohio, red-tails seen sitting out on hunting perches are markedly less frequent. It appears that the population just implodes in summer. But the birds are still there, but just not as visible.

Why? l'm not sure. But it probably relates to availability of food for competent adult red-tails. These birds can capture just about anything they wish, and the roadsides are loaded with populations of plump voles, large field mice. By late morning, most adult red-tails in summer have easily captured two or three voles. They are done hunting and feeding for the day. They can simply go off and sit in the cool foliage of an oak or maple overlooking the landscape. Occasionally I've discovered these somewhat "hidden" birds, as their white breast can sometimes be seen in the foliage

So don't presume that your female is not present. She may start to appear in September and October when days shorten and more time must be spend on the hunt. Remember, red-tails do virtually all of their hunting while sitting on an open hunting perch.

Don't so much lament the loss of the first brood of this pair. This is very, very common. It appears that the vast majority of red-tails, at least in the Midwest and similar regions at the same latitude, fail in their first or second nesting attempts. Success requires that everything must be just so. The nest has to be well-constructed. Incubation must be continuous and attentive. Feeding the eyasses at the start can be problematic for parents who have never done it. In short, most red-tails have to try it out for a year or two before they get it right. After that, they are accomplished parents and will be frequently successful in ensuing years. But you have been watching apparently a typical young pair of red-tails.

Once the eyasses fledge, parents will seldom, if ever, give the food they provide directly to the young. As you've observed, it's dropped nearby, or even trailed along to entice the young to actively pursue the food. Have you seen the parent drop a still-alive animal? This entices the young to not only learn to attack the fleeing animal, but also to learn to kill it. The young have really no idea how to kill a struggling prey animal. Yes, they know that they should grab it. But where? In the head? At the tail? In the belly? The young birds have to learn what works, which is usually a head kill with the powerful talons. But their only instinct is to just grab the moving animal. They will have to learn that a talon puncture or severe squeeze to the head works best.

When will the young bird start hunting on it's own? Primarily only when the parents stop providing daily fare. When will a 16- or 18-year old kid stop spending allowance money and go out and get a real job? Only when Mom and Pop cut off the supply of free money.

And you've heard the forelorned cries of the ever-more neglected fledgling. You will never forget that sound. I hear it frequently out here in the countryside at this time of year. The hungry young red-tail wonders where today's food is. "Where are my parents and those voles they were bringing me last week? I'm HUNGRY!!"

Of course, "I'm hungry" in red-tail language is an incessant high-pitched "wheep, wheep" sort of call. It's just pitiful to hear. There is a mixture of both morbidity and selfishness to it. In late June and July, parents respond to it by providing food. But in late July or early August (at Ohio latitudes), the parents stop the routine and the young are left to their own hunting devices -- which aren't very significant.

This is when the young hawks get into real trouble. In more rustic times, when every farmyard had free-ranging chickens (and exceptionally fine-tasting -- I mean for humans), starving red-tails often couldn't resist these large meal targets. Hence the name "chicken hawk." Virtually all chicken predation was by starving first-summer red-tails.

I call these screaming hawks "wheepers," for their wheeping-sort of vocalizations. These are exactly the birds we falconers trap for the sport. They are easy to capture, and they are so appreciative that we provide the food that their parents terminated. All three of the last red-tails I trapped for falconry had been eating only grasshoppers before I took them into my care. A grasshopper diet portends a gruesome, lethal future for a wild red-tail. Remember, only 40% -- at best -- of red-tails that leave the nest will ever survive the first winter. Before winter, most die from their inability to successfully hunt and kill every day.

How, then you ask, will the young bird learn to hunt? It may not. The majority don't learn these lessons fast enough. And today, the main reason for this, just as it was before Europeans altered the North American landscape, is because young red-tails just don't have many unoccupied areas that they can fly into and find sufficient prey animals to support them. The good areas are already occupied by old, experienced adults. In August, they will drive out any young birds hanging around that compete with adults for food. The birds are dumped out on the street and kicked on their way out of the territory. Then, they've got to learn how to hunt very quickly. If, perchance, they wander into an area with lots of voles, they can learn how to hunt by the time cold nights hit in October. Otherwise, they will starve trying to eat grasshoppers or other inadequate fare.

And this, I believe, is why Pale Male, Sr. came into Central Park. When young and inexperienced, he wandered into this giant, prey-filled landscape in which no self-respecting adult would ever take up nesting residence. But Pale Make did, and the rest is history. In previous times he would have found a vacant, typical rural territory because red-tails were commonly shot, leaving openings for young birds to jump into. But today, very few hawks are shot or illegally trapped, so the countryside is saturated with adults. The young birds, such as the one you are watching, have a very difficult time living to adulthood. It's not the 1930s, 40s, or even the 70s or 80s out there any more. Life for red-tailed hawks is very different that it once was, and we are watching that in Central Park and elsewhere.

Sincerely,

John A. Blakeman