Emu Hide and Seek and Naturally Occurring Magnetic Particles in Beaks

Emmie the Emu

Being starved for bird company and the chance to try and figure out why they do what they do, I've nine birds at home and none here, I decided to go and visit Emmie today.

Now I've been attempting to win Emmie over but this bird is no sucker. I've come bearing tasty chopped Romaine lettuce, bitty carrots, last time I even brought giant meal worms.

Forget it.

Emmie is having none of it.

When I appear for a visit he struts off in the opposite direction, neck crooked towards the rear onto his back and head crooked forward in the direction in which he's going. Off he goes sometimes at a coquettish trot, only to peep out from behind his emu house or a tree.

I've read that Emus are extremely curious, so today I've decided not to pay the least bit of attention to him and pay attention to everything else I can think of.

I puttered around. Took photographs of rocks, farm machinery, distant grain elevators. Worked the mud out of the treads of my shoes with a stick. Unwrapped gum and put it in my mouth. Whistled Who's Afraid Of The Big Bad Wolf, thumpity, thump. I hear emu feet.

I look at Emmie who may be pretending to be a bush, neck crooked, blending in while still being able to see just what it is I am up to.

Okay what now?

I make sure the camera is ready, quickly scuttle over, trying to skirt the mud, and scrunch behind a very short evergreen. Camera up. Emmie's head pops up. Click. Gotcha.

Emmie the Emu as a bush.

Has Emmie the Emu been attempting to get me to play a game of Emu hide and seek? I walk right at an angle toward Emmie. He walks left and goes behind his emu house. I go behind a fat tree.

When I peek out. There he is. Well I assume the rest of him is there. All I can see is one eye, half a forehead and half a beak appearing from the other side of his house.

I disappear behind my tree, then skitter over toward a new one, slipping in the mud and going down.

After getting back to my feet disgusted at the condition of my clothes, I remember Emmie. He has come out from behind his house as this obviously is something not to be missed. He is standing stock still next to a tree trunk looking through the wire at me with one eye. (first photo)

Now the question becomes, am I actually winning him over the least little bit or does he really think I think he's a tree?

Neither, I'm betting he's hoping against hope, that I'll take another header into the mud.

Donegal Browne

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AND NEXT....

THEY HAVE WHAT????

After trying to figure out just exactly how they do it for hundreds of years. Humans may have finally figured out at least part of why Homing Pigeons can find their way home so unerringly!

Many thanks to Kentaurian, long time hawk watcher and science guy, who sent in the fascinating news.

Do homing pigeons really have a natural three axis magnetometer in their beaks?

(Yes, I know the bird above is not a pigeon; it's Doorstep Dove. She's standing-in as I couldn't find a pigeon today. But she and many other birds may well have a magnetic triangulating system as well.)

PhysOrg.com Published: 11 hours ago, 11:23 EST, March 14, 2007 Study:

Iron minerals in birds' beaks may serve as a magnetometer. It has long been recognized that birds possess the ability to use the Earth’s magnetic field for their navigation, although just how this is done has not yet been clarified. However, the discovery of iron-containing structures in the bills of homing pigeons in a new study by Gerta Fleissner and her colleagues at the University of Frankfurt offers a promising insight into this complex topic.

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The article will be published online mid-March in Springer’s journal _Naturwissenschaften_. In histological and physicochemical examinations in collaboration with HASYLAB, the synchrotron laboratories based in Hamburg, Germany, iron-containing subcellular particles of maghemite and magnetite were found in sensory dendrites of the skin lining the upper beak of homing pigeons.

A dendrite is a branched extension a nerve cell (neuron). This research project found that these dendrites are arranged in a complex three-dimensional pattern with different spatial orientation designed to analyze the three components of the magnetic field vector separately. They react to the Earth's external magnetic field in a very sensitive and specific manner, thus acting as a three-axis magnetometer. The study suggests that the birds sense the magnetic field independent of their motion and posture and thus can identify their geographical position. The researchers further believe that this ability is not unique to homing pigeons as they expect that the ˜pigeon-type receptor system might turn out to be a universal feature of all birds.

Equally, this concept might not only exclusively apply to birds, since it has been shown that many animals display behavior that is modified or controlled by the Earth magnetic field. The meaning of these minute iron oxide crystals goes farther than their amazing ability to help pigeons home. Research into how they work has caught the interest of nanotechnologists concerning their potential application for accurate drug targeting and even as a data storage device.

The main problem, however, lies in their synthetic production. According to Gerta Fleissner and her colleagues, "Even though birds have been producing these particles for millions of years, the main problem for scientists who want to find benefits from their use will be the technical production of these particles".

http://www.physorg.com/news93090188.html Source: Springer

Blakeman on Cold Weather and Eggs and What Is That Big Bird?

Photograph Donegal Browne

Eldest of the Cathedral Nest

Yesterday, with the weather taking a turn for the worse Katherine Herzog, a faithful daily visitor to the Hawk Bench who's been contributing her observations, thankfully as I'm enmeshed in taking care of rather unpleasant family business in Wisconsin, asked me to send her weather and eggs question off to John Blakeman, the Ohio Red-tail expert.

Here's Kat's question-

Today the temperature is supposed to plummet and they're predicting rain and snow (up to half a foot) for the next couple of days. I thought PM and L had escaped that wrath of winter weather but at least the clutch is complete and the eggs are not as vulnerable as when they had just been laid?? That's the question I have for John Blakeman: Are the eggs more vulnerable (softer?) when they first come out; and are therefore more susceptible to damage when the weather is severe...cold, wind and snow. Or are they impervious to radical temperature/weather changes?

And John Blakeman's answer-

Donna,

As bad as the weather might be for humans and other un-feathered creatures who have to purchase and don weather-fighting appurtenances, the hawks are well-provisioned for whatever weather might happen. How many times since the Pleistocene (the Ice Age) has there been cold, thick snows in March?

No problem. The feathers of the hawks easily accommodate the weather, and the eggs are tucked in those feathers and touch the warm naked brood patch on the female's belly. As bad as the weather might be for us, for the eggs it will be nicely warm and cozy up in the nest.

And because they are new eggs, the cold weather---should it cool the eggs for a period----will have no effect. First, the eggs are the strongest right now, with a full thickness of shell. As the eyass grows in the egg it produces carbon dioxide, as do we. This soaks into the watery fluids of the egg and forms a dilute carbonic acid, which in the next four weeks will slowly react and consume much of the egg shell. This weakens it, allowing the baby hawk to poke through the egg at the proper time, a process called pipping.

We are a long from that. Now, the egg is strong and firm, allowing the mother (and sometimes the father) to carefully roll the eggs every hour or so. This keeps all of the internal membranes properly suspended. Unrolled eggs don't grow properly and die (a concern with the pigeon prongs, which might keep the eggs from rolling naturally within the nest bowl).

Actually, raptor breeders know that freshly laid eggs can be stored for a few days, even a week or so, at 40 degrees F without harm. The female does this in the nest by sitting higher on her first eggs, keeping them somewhat cool and retarding embryonic development. When the last egg is laid (the second or third where the parents have sufficient food -- just one often in my rural Ohio areas where corn and soybeans predominate and retard mouse and vole populations), the female hunkers down for the beginning of full incubation with the warm brood patch in contact with the eggs.

This process of starting true incubation at the same time for all of the eggs helps assure all of the eyasses will be the same size during growth, allowing a somewhat equitable distribution (or grabbing) of food. This doesn't often happen in golden eagles, where one eaglet almost always grows earlier and faster than its sibling. The larger eaglet always then just kills and consumes the lessor bird. Golden eagles only fledge one eaglet because of this Cain and Able conflict, regardless of the amount of food the parents bring to the nest. Fortunately, it's not so with our less greedy red-tails.

It doesn't matter what the outside temperature or snow mass might be. Against the female's brood patch, all is well.

But nest watchers are likely to note disconcerting periods of apparent inattention as the adults are away from the nest for up to a half hour. We are not sure on this, but it appears the periodic 15- or 20-minute periods of egg cooling are beneficial. As the egg cools down to, say 70 degrees from the 100-degree+ incubation temp, oxygen can diffuse into the egg at the reduced temperatures. Periodic cooling is probably very important.

So don't be alarmed when the nest is left unattended for short periods in the coming weeks.

Somehow, it all works.

--John Blakeman

What is that BIG bird?

It's was yet another chaotic day of attempting to make order and rational sense out of chaos. Seemingly impossible sometimes but we just have to keep on trying.

I wondered why there had been so few pigeons and doves around the grain elevators. It seems the state has elected to allow a hunting season for them for, as I've heard it said, people don't like them sitting on their churches. (Forget me, Francis of Assisi would be utterly mortified. )

So the soft gentle coos, the morning low note in bird song is mostly missing and has been replaced by more and more and more Starlings making their various strident noises. The Grackles have started to come through and with them various Blackbirds, I even heard a Red-wing today, but mostly it has been hundreds of thousands of Starlings darkening the sky, scavenging the corn fields bare, and mobbing the grain elevators.

I'm once again motoring down the road between the town where I stay and the nursing home where my mother currently lives watching these immense clouds of Starlings and thinking of how few woodpeckers and other cavity breeders I've seen this year. The sun is low in the sky creating that golden light so beautiful on the buildings of Fifth Ave which I am not there to see, and I'm also morosely thinking about how all those Starlings were hatched in cavities where a native bird might have laid eggs. And even more morosely thinking about the fact that I've not seen one Bald Eagle yet this year though Wisconsin is number three for Bald Eagle population in the U.S. I'm definitely as they would say around here, "down in the dumps".

When suddenly far far, we're talking way down the road, I see in the sky...what? A Red-tail flapping? Looks kind of big and kind of wrong. Two ducks almost neck and neck flying in unison. Not a chance.

I'm trying to zoom up there before whatever it is, is lost in the trees, when the bird, as if on cue, rounds it's wing tips down to brake, veers towards me, the sun hits it, and zap, sizzle, the body gleams gold and by golly that's a bright white head! I veer over myself onto the shoulder far faster than I should have and watch this marvelous bird drop her talons and glide in a slow balletic descent across the river.

Another set of thoughts cross my mind. Okay, so now the balance of nature is off with too many Starlings, we humans can be such idiots, but given my druthers I'll take that over not enough Eagles.

Donegal Browne

Pale Male and Lola Have a Late Dinner and The Guy Blowing Up His Pants

Wed, March 14,'07 - Warm, partly sunny - 60's F, 2:30 - 6pm
(Central Park NYC-Hawk Bench):
Just when you think you know something about the Hawks, they do something different...just to show you who's boss. I went to Central Park at 2:30pm and waited, and waited, and waited for Lola to be relieved by Pale at the nest.

Pale had replaced Lola for incubation duty for at least an hour in the morning hours, as told to me by Ric Davis....but when would he return?

The hours rolled on and finally at 5:45pm as the light was fading and dark clouds replaced blue skies with the imminent promise of rain....Pale comes flying in to the rescue with a partially consumed pigeon in his talons....Lola immediately consumed the morsel in the nest, not as I had previously opined that she would not eat at the nest thus keeping her nest parasite-free.

Perhaps since the light was fading she decided to keep the meal and devour it at the nest. Who knows? And she's not talking....only indicating that they have a rhyme and reason known only to themselves.

Katherine

I have noticed that early in the brooding phase that Lola does tend to eat on the nest, quickly and with purpose and then gets right back to sitting the eggs. Once again we may be coming across an arc of hormones that first becomes strong enough to get a hen to the nest, an urge forceful enough to keep her there until she's finished laying plus a little longer before it completely ebbs so she doesn't suddenly find herself laying another egg over on Stovepipe while she's having dinner. An experienced mother like Lola might know if there were another egg being created to be laid but a inexperienced young mother wouldn't. Once or twice a year I find a perfect fresh egg of any number of species in a bird bath or on the ledge of a platform feeder where a young hen has stayed too long from the nest and poof...an egg pops out. Those hens with the strong "stay-on-the-nest-til-it's-done hormones" were the ones who had more eggs to hatch, and therefore a better change of progeny that lived to reproduce. The gene for the strong staying put hormone was a biological advantage.

Particularly for individuals of a species in which Dad is capable of delivering breakfast, lunch, and dinner. D. B.

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STORRS LAKE
Chapter 2

The other day when I was out looking for the guy who was shooting in the wildlife area at Storrs Lake, I rounded a curve and saw all this stuff sitting in the middle of the lake. Now remember that it was 70 degrees and sunny. The other side of the lake was full of paddling birds and this side was awash with water in any number of places. Good grief, did somebody really want a fish that badly that they'd be willing to risk going through the ice for an icy swim?

Or had whoever already gone through the ice? There's a thought



Nope, there he was a good ways off from his equipment and...
What is he doing?


Well, after grilling a number of my cousins later, I found that what he was doing was inflating his life-preserver pants.
Life-preserver pants?

Who knew? Well, probably lots of people who ice fish, but then again we don't do all that much ice fishing in New York City.

Donegal Browne