Sunday, January 23, 2005

JOHN BLAKEMAN ON REDTAILS' SPECIAL NEST BEHAVIOR VIS-A-VIS PREY.

JOHN BLAKEMAN ON REDTAILS' SPECIAL NEST BEHAVIOR VIS-A-VIS PREY.

Marie,

A sincere question was raised about placing dead mice or other dietary enticements in the new nest structure, to prompt the pair’s return and re-use of the site. Inasmuch as red-tails normally select mice as their daily fare and consume them with unvarying delight, this approach would seem reasonable. For those of us lured to fine chocolate, we know what a red-tail might do to procure a nice warm mouse, as mice and voles are red-tail chocolates, for sure. I use mice in my red-tail traps when taking birds from the wild for banding and other licensed activities. A red-tail finds it very hard to resist such a choice morsel.

(And don't be alarmed about the licensed trapping of raptors. It’s nothing like the leg-hold traps used for fur-bearing mammals. A mouse is placed in a low cage with small nylon-cord snares along the top. The red-tail’s toes are ensnared as it attempts to grab the mouse inside the trap. Neither the mouse nor the hawk are injured in any way. The process is closely monitored and the hawk’s toes are released from the snares within a minute of capture. She’s not injured, only confused about her inability to fly away from the trap when I quickly approach. And don't even think of trying this yourself. Without proper state and federal permits, it’s absolutely illegal. Secondly, if you don't know how to properly handle a newly-trapped raptor, you are very likely to get a pair of needle-sharp talons buried completely through your hand or any other body part. This is not for the inexperienced.)

Yes, red-tails would be attracted to a fresh mouse, dead or alive. But here’s an important consideration regarding red-tail behavior at the nest. Away from the nest, at least a 100 yards in most cases, red-tails act like red-tails, as cunning and powerful hunters. When motivated, they will spare no effort in taking a targeted prey animal that presents itself before the hawk.

But in the vicinity and at the nest itself, red-tails assume very different behaviors, especially when a hen is sitting, or especially when eyasses are present. By nature, the species quickly grabs and pierces any prey that presents itself, not unlike what a domestic cat would do to a mouse that attempted to run within striking distance of some apartment-dwelling feline. Any carnivore that hesitates to attack in such situations is not going to survive in the wild. Consequently, a hungry red-tail, or one capturing food for eyasses back at the nest, will strike instantly and lethally when prey are closely available.

But how might those behaviors play out on the nest? What if a hungry red-tail landed on the nest rim, and an eyass or two were nodding off in an afternoon’s slumber. Then, an eyass awakes and pops it’s head up. If the adult were to follow it’s normal hunting patterns, it would instantly reach out and grab this new animal movement. The eyass would be killed. Any red-tail that had this natural, unrestrained pouncing behavior at the nest would kill its offspring. Raptorial child abuse of he worst sort. Fortunately, most of those genetic behaviors are now extinct.

To the point. Lola and Pale Male, like all successful red-tail parents, have an inborn restraint of hunting and killing behaviors at the nest. Those of us who have watched red-tails dive onto and kill either mice or rabbits are always astounded to observe their slow, considered, even delicate movements while at the nest. The adults often curl their talons underneath and walk with slow, deliberate steps on the nest, so as not to puncture an egg or young eyass. Likewise, the adults take inordinate care in pulling off tidbits of flesh from animals brought to the nest for the eyasses or incubating adult. I've watched my trained hunting red-tails rip apart food on my gloved fist hundreds of times. The strength and deliberateness of this is always impressive. But equally impressive is the converse delicacy with which they handle both prey and their feet on the nest, all to protect the eyasses.

Here’s the point about the advisability of offering mice or other food items to lure the birds back to the restored nest site. Because of the hunting and killing restraint behaviors the birds have at a nest, the offered food would not be an enticement. The adults would, indeed, recognize the mice as food. But since they didn't capture it at a distance away from the nest, it would not be regarded as quite natural. They would use it, but it wouldn't contribute in causing the birds to use the nestsite. The found food items just wouldn't connect with any of the bird’s experiences. The hawks would make no connection with the usability of the nestsite with the offered food. In short, red-tails don't capture food in a nest, and when they eat or offer it there, they do so with delicate restraint.

I've watched all of this in the captive pair of red-tails I used in captive-breeding trials back in the early ‘70's.

The fact that Pale Male and Lola have been seen periodically at the nest in recent weeks is an extremely strong indication that they will resume normal activities there. If they didn't like what they saw, they would not be visiting the site in early January, when there is little natural tendency to do so.

It’s still too early to be concerned. In my area of northern Ohio (same latitude as NYC), the third week of January is the meteorological low point of winter, with the statistically coldest weather. Soon, things will start to slowly warm (although it’s not increasing temperature, but increasing day-length that gets the breeding hormones flowing). Presently, it’s the depths of winter, so don't be concerned. Red-tail breeding is highly seasonal, and this am not the season, yet.

Just watch. Activity at the nest will take a marked upswing in February, just about the time that you personally notice that days are getting longer. You haven't noticed that yet, and neither have our famous pair. Spring training hasn't even started. It’s still winter. Be patient. Lola and Pale Male are.

It’s good that so many are thinking about, concerned with, and observing the world’s most famous red-tailed hawk pair. All is well. Let’s watch the pairs’ developing new chapter. Nest building will resume, I'm certain. All is naturally aligned.

Sincerely,

John A. Blakeman

Post Script:

When I sent John Blakeman the letter [sent to e-birds by Deslie Lawrence] suggesting a dead mouse be placed on Pale Male's nest site as an enticement, I mentioned that Pale Male and his clan do occasionally avail themselves of dead birds that have collided with a reflective glass window at the Metropolitan Museum. He also had some thoughts about that, which he sent in a sparate e-mail:

Marie,

I forgot to mention that RTs will, indeed, eat newly-deceased birds that have lethally collided with windows. As I mention so often, sitting RTs spend a lot of time surmising everything in the observed landscape, and they notice the feather wisps of dead birds. They also recognize the birds as both tasty and easily procured. I've noted that RTs take particular notice of both feathers and fur in the field. When hunting with my red-tail and we walk past a the kill site of a rabbit consumed by some other predator, my hawk always spots the remnant fur and wants to jump down onto the ground and see if it can find anything edible -- or catchable. The only hint are a few clumps of loose fur. She picks these out from the multitude of dead grass and leaves. Their eyes are primed for fur and feathers, whether they move or not.

Sincerely,

John A. Blakeman