Thursday, July 24, 2008

The Twins Meet the Blue Jay! And a Territory Question

Photos and commentary by Cheryl Cavert

Wanted to share some of the latest sightings of Red Tails in Tulsa. I watched the two Langenheim Twins for a bit this morning as they waited, calling for breakfast, and being repeatedly mobbed and chased by irritable birds and non-friendly humans.

I was told by one person that was outside with their camera, that one had perched near her window but a coworker banged on the window to scare it off and was ready to run outside and chase the other one away too. Then another person chose to take the short-cut across the bridge where the hawk was perched, rather than going a different route around, which scared Viola off the bridge (and he thought she was an owl!!)

Rose, one of our spotters who first brought the Langenheim juveniles on our hawk-radar, has named them Sebastian and Viola.

(Rose also sends us updates! D.B.)

SEBASTIAN GETS MOBBED- incoming, duck!!

Viola cooling off in the grass.
(Remember it was 100 degrees plus in Tulsa, Oklahoma. All pretty lively for such hot weather.)

Viola taking off for a different bridge perch.

Sebastian getting mobbed yet again!
(I wonder if the angry smaller birds ever use the light patch on the hawk's heads as a target? Looks awfully handy to me. D. B.)
From the Tulsa Forum, Catbird had a question about territory--
From Calvorn's site: "In a study commissioned last year by Audubon, pairs of red tails were spotted breeding in nests at 32 locations throughout the city and hawk watchers say they have spotted hundreds of unattached red tails across the five boroughs."
Does this mean that the unattached red tails (juvies??) live / hang out, sort of in between the claimed adult territories?
Some of the unattached Red-tails are juveniles and some are matures without mates or territories as yet. For instance in the winter the Ramble, a wooded section of Central Park, is crawling with RTs, Pale Male and Lola don't care. It isn't breeding season and Central Park has so much prey that there is plenty of food for everyone and more.

During breeding season the unattached will sometimes sneak into other RT territory just to hunt new ground but also they can appear to challenge the pair. There have been several instances in Pale Male and Lola's territory (and I'm sure others but because of location and clear sight lines you can really see what is going on at Fifth Avenue), in which a pair of RTs will appear and there is a pitched battle over the land and nesting site. Pale Male and Lola never have any trouble running them out but you have never heard so many Red- tail battle cries in your life.

There are some portions of the city, where I'm betting Red-tails are sighted and have territory but either they haven't attracted a mate, or they have a mate and nest but no hawkwatchers have as yet nailed down the location. There are parts of town where there are no hawkwatchers living locally, or they aren't in touch, so they are, so to speak, "under the radar"..

I don't believe that the "hundreds of sightings" referred to, were all of different individual birds. I'm sure a number of them were sighted more than once. Territory size differs. Outside breeding season the Red-tails go exploring farther afield. And of course, there are the juveniles who are hanging around waiting to grow up.

In places with a lower prey base and/or seriously cold or snowy weather, Red-tails migrate to more fruitful areas during the off season. John Blakeman tells that country hawks will also, come winter, chase their previous seasons young away from the natal territory when the prey base is low. Sounds mean but it's perhaps better for everyone. It saves wear and tear on the prey population of the natal territory and also gets the youngster into the floating population of RTs that are likely on their way to greener pastures, open territory, and possible mates.
The Manhattan Red-tails, and most probably those in the other boroughs as well, but I can't speak from experience, don't migrate. There is plenty to eat year-round and it usually isn't all that cold. We can't be sure as they aren't banded but there are juveniles in Central Park until the following spring when the adults start paying a good deal of attention to boundary lines. Come Spring the previous year's young either find areas that haven't been claimed or take off for perusing vacations.

Donegal Browne
P.S. For the next two weeks I'll be more out of contact with technology than I'll be in contact with it due to the Pennsic War therefore, just keep sending in your updates and checking for new posts. I'll pop in and post as often as I can!


Karen Anne said...

What's with that coworker? Some people's minds baffle me.

He couldn't share the window? He thought the hawk was going to eat him up? He was asserting human dominion over the earth? He was scared of hawks? I would really like to know...

Karen Anne said...

Wondering about a Hous update?