Friday, May 28, 2010

Red-tail Updates-Survivor at the Cathedral, Briarwood, Emerald Grove Rd Nest, John Blakeman on No Talons, Portmann Ravens, Noah the Nurturing Pigeon

When I looked up and saw only one eyass standing on the rim of the nest, I realized my sense of foreboding about the other eyasses when only seeing one on my last visit became a reality. It is 90 degrees with humidity as high as it can be without droplets falling on you. Any self respecting eyass of this age will be up on the rim attempting to catch the least puff of moving air. The other two were no more.

So the Emeralds had only one jewel left. And Jewel was panting her brains out.

She'd take a second to stare now and again but then she just stood and panted for long moments on end.

Until she suddenly dozed off for a moment.

Woke up, panted, and then did a moment of chest preening. The fluff to fledgling feathers transition is a very itchy one and in this heat no doubt uncomfortable when dealing with all those new prickly pin feathers.

Then a look through her nictitating eyelid.

She folds her legs and gets down onto her haunches.

More panting and preening.

And a cocky stare.

She picks up a stick and drops it.

More panting mixed with a couple of begs. I look but don't manage to see a parent.

More scrutiny.

Then a pace forward to look between the branches.

My way.

Preening with a bit of fiest to it,

Another look between branches.

And guess what? More panting.

What is over there?

Yup I'm still here and I'm beginning to feel the urge to pant myself.

After more of the same I picked up my stuff, without even a whiff of another eyass, and started walking back. I left the area so that Jewel would be fed by her wary parents. I couldn't help wondering what had caused the deaths of the other two. And why were both urban and rural hawks loosing so many eyeasses this season. Frounce would be a very unlikely culprit here, as there are are no dairy herds for miles and miles. and without dairy cows with their comfy barns and daily supple of grain--no pigeons. Unless of course Mourning Doves can carry the protozoan disease.

Could the cause be at least partially, all the chill weather with drenching rain? Could just plain old exposure be a contributing culprit in the eyasses deaths?

Quess who made it BACK to the nest? From Jeff Kollbrunner of

Hi All,

The Briarwood fledgling has returned to the nest this morning. Not sure how long it will stay, this is a very good sign its gaining the strength it needs to explore its new world. This is the first fledgling to return to the nest at this particular location over the years this soon after fledging. It had to fly upward at least 75 feet and a very good distance from the rooftops below where it has been hanging out since May 22nd. There is also many unexpected wind currents/up drafts at that level so landing in the nest is not always easy either.

Have a great Holiday Weekend!

Best, Jeff

5/26, Photo courtesy of Robert B. Schmunk, for more go to--

In from Cathedral Hawkwatcher Mitch Nusbaum--Last Tuesday I was at the Cathedral and yesterday's post of Bloomingdales village show that Survivor is OK.
And from the original blog contributer on Red-tailed Hawks John Blakeman in regard to Isolde's use of beak instead of talons when in contact with the dead eyass on the Cathedral Nest--

You nailed it exactly, regarding the difficulty the haggard had in removing the dead eyass from the nest, without using its feet to grab the eyass carcass.

There is a rather profound (and necessary) behavioral constraint that suppresses the use of feet and talons to grasp anything at the nest. This contrasts so markedly with red-tails' use of their powerful feet in the killing and transport of prey away from the nest.

Remember, these are not thinking birds. Pretty much all of their behaviors are "go through the motions," ritualized actions. Grabbing anything at the nest is likely, sooner or later, to result in the inadvertent grabbing and killing of an eyass. The grasping ritual and response is turned off at the nest.

A close study of how the parents pull prey apart and feed tibbits to the eyasses also shows this. Away from the nest, the haggards use the strength and grasping capabilities of their feet and talons with alacrity. Not so on the nest, where they step delicately and virtually never grasp anything with force or speed.

It would be interesting to learn the cause of the eyass's deaths. I would presume that it was either some rodenticide, or frounce, a microbial infection from a pigeon.

--John Blakeman

Francois Portman had a thought about Isolde's intention--
"Watching it [the video] again, I noticed that the eyass’ body is still limp, hasn’t stiffened up (how long does it take?), so it should have died soon before, maybe the mother was “testing” it and not necessarily removing it! Just a thought.

ps: little Ravens feeding frenzy:
Looks like mam is trying “come and get it strategy” to get them out of the nest, so far they are still glued on it!


I wondered about whether the eyass was freshly dead too.

If I remember correctly, rigor comes on and then dissipates again after a certain amount of time- depending on temperature, the weight of the body, and other variables. So the eyass could have been stiff and then gotten limp again. Though for want of a better word that might be too descriptive for some--it didn't look yucky--

Rigor Mortis, a stiffening of the muscles, usually starts to take place at around 3 hours after someone is dead with full rigor occurring at about 12 hours after death. After the 12 hour mark the rigor slowly ceases and at around 72 hours rigor disappears.

Take into account this is for a human that weighs much more than a hawk and therefore cools more slowly.

I can't remember ever seeing an adult put a beak to an eyass for anything can you? I'm trying to remember ever even seeing an adult help with those pesky pin feathers at the base of the head. I have seen Lola give Pale Male a couple of decisive pokes (closed beak) when it appeared that he had fallen asleep or was unwilling to vacate the nest promptly enough for her when she had come back from a break.

Wait. One of Jr. and Charlotte's eyasses in 2005 hated rain. So at the first drop he'd dig his way under his mother. He'd gotten pretty old for this and may have nicked her with a talon one day, and then it seemed she may have given him a little nip because she appeared to make an abortive hack at him and he jerked backwards. Though maybe her motion was just really scary and he reacted.

Isolde very much looked like she was attempting to lift, I thought. Testing or an attempt to get a response might have initially been a poke I suppose and it escalated?

We're kind of in fresh territory here.

As to the young Ravens, I'm with them. Leaving the nest would be a little like being plucked from a nice cozy bed and breakfast and dumped in the wilderness with a very dull pocketknife you didn't know how to use.

Photo courtesy of Bob Lenham
A sweet find by Robin of Illinois--
Noah, the Homing Pigeon/Rock Dove and the Bunnies
These little bunnies, about 6 days old, were attacked by a dog and orphaned. Two out of the litter of five did not survive, and these three were not doing very well.

Enter Noah—the non-releasable, one-legged homing pigeon/rock dove that we have here in rehab.
Donegal Browne


Sally said...

So glad you have the Jewel to watch! It does seem to have been a generally tragic year for a lot of nests.

However, Kay and Jay of Tulsa have their one eyass busy branching on the cell tower, and so far Portland still has two healthy-appearing eyasses ready to fledge soon, they are "branching" to the railings and other areas of the fire escape the past few days.

Donegal Browne said...

Thanks Sall, I've put your updates on today's mainpage as well.