Thursday, May 8, 2008

Derby eyases today

MORNINGFEEDING OF THE 4 EYASES AT 8:00





SLIDESHOW



The little one does not get any food here. But that is absolutely no reason for concern. Just before hatching all the leftover yolk has been transported into the digestive system of the hatchling. That offers enough nutrients to last for 48 hours. In it are very important immunoglobulines as well to give the little one a form of immunity until after 2 weeks it's own immunity is coming online. So not to worry. I'm sure it will participate in one of the next feedings.

JUST SO SWEET








FEEDING AT 15:00





AND A SLIDESHOW




AN INTERMEZZO AFTER THE FEEDING





AND A SLIDE SHOW


http://derbyperegrines.blogspot.com/

Rochester: first feeding

Some images of today









and a slide show

Oberhausen: to catch the early pigeon







Beautiful fairytale morningviews from the Oberhausen ledge. Such fine colors, it's amazing. The shadows the light makes on the juvi's is so wonderful. They love wingflapping in the early morning on the ledge. It makes awesome pics. To catch the early bird, that will be a pigeon in this case. I wonder how many have to follow before we will see the first one being properly plucked by one of our juvi's. In a way it is sweet to see how they still are very much eyases although from teh outside they look grown juveniles. They are still children.
When they first fledge they scream for joy and fly and tumble laughing through the skies trying to catch eachothers tail. It's a shame we cannot see that. If you are near a nestsite please try for once to see that live. I's great!

Terminal Tower Cleveland: 16 days old





Zurich





Zwolle eyases: 13 days old





Rome: 2 fierce eyases indeed








These are 2 very fierce eyases. They grumble and fight, they tear prey apart, even pluck already. Especialy the eldest looks like a frightful fighter. Whenever one of the parents arives with prey she tears it from the beak of mostly Vento and runs away with it. Screaming. She mantels the prey and no one gets it from here. Especialy not father Vento who is much smaller than his big daughter. I've seen him trying but he does not manage, so he leaves. The other eyas keeps screaming and wailing to him picking to his chest and claws for food, but big sis has it. As soon as the parent leaves, big sis does allow the other eyas to grab a bite. Both have full crops all the time, so it is no hunger, but the raptor in especialy the eldest.

Brighton Sussex Heights





James River Bridge: 29 days old







The chicks are nearing the midpoint of their transition from down-covered chick to juvenile-plumaged fledgling, and are nearly full-grown in terms of body size and weight.

De Mortel





Oberhausen juvi's and the pigeon







And there she was again. The female came to the daily rescue. The pigeon lay in the back of the scrape. Untouched. The juvi's did some picking but no plucking and lost interest. And went to their daily business: wingflapping and sleeping. Until the female appeared. Help was on the way. The little babies where fed by here and they still love it. What a difference with the Italian eyases. 29 days old and still white. They pluck and tear prey apart, like the raptors they are already. Fierce and frightfull they are the enormous chicks in Rome.
But not here in Oberhausen, 3 very lovely juvi's a long way from the raptor they will eventualy turn into. T

Rhea Mae: first hatch


Photo courtesy of Linda Woods/Canadian Peregrine Foundation




Yesterday Rhea Mae and Tiago became parents of 2 beautiful eyases. Rhea Mae is the 2006 female offspring of Mariah and Kaver of Rochester. Canadian Peregrine Foundation member Linda Woods snapped this shot of one of the adults tending to their fluffy new nestling.

You can watch all the hatching action at the Canadian Peregrine Foundation’s Sheration Centre Nest Webcam!

Rochester: first 3 hatches












Early this morning at 3:53 the first eyas of Mariah and Kaver hatched, the second came shortly after that and in the meantime there are 3 very sweet and adorable eyases in the scrape and 2 eggs. They will no no doubt hatch within the upcoming 24 hours. Mariah is after the first feeding not feeding again and is holding the 2 eggs between her wings. They are screaming within, absolutely, maybe even pipped. It's hard to see. So they will hatch soon.

First feeding and the yoke supply

I received many questions about the first feedings.
In every scrape parents start at a different time with the first feeding. Females who have their first clutch wait a long time before they start. Females however who are experiencend mothers start rather quickly with the first bite of meat. How come this difference. I think it is a matter of instinct versus personal experience. When is the first feeding necessary? There fore we have to take a look at the development within the egg.

In the embryonic development the embryo lies on top of a very big yoke. In the third day of development the extra embryonic membranes are starting to built. The infrastructure within the egg so to speak. Nutrients and oxygen have to be transported from the yoke and oxygen from the outer world to the embryo.
After the gastrulation, the development of the extra-embryonic membranes is the most important event in the early embryonic stages. It's like setting up camp. In the first 2 days oxygen exchange is possible through th eeggshelle. But when the celllayers get thicker the embryo needs a proper circulation from itself to the eggshel to get enough oxygen. And one from his foodsupply - the yolk- to his body.

Evolution has figured out an amazing way to do that.

On the third day of incubation, blood islands begin linking and form a vascular system, while the heart is being formed elsewhere. By the 58 th hour of incubation, the heart and vascular systems join, and the heart begins beating. Two distinct circulatory systems are established, an embryonic system for the embryo and a vitelline system extending into the egg. In later stages of embryonic development, there are two distinct extra-embryonic blood systems. One system, the vitelline system, transports nutrients from the yolk to the growing embryo. from the fourth day on, it oxygenates blood. The other blood system, made of allantoic vessels, is concerned with respiration and the storage of waste products in the allantois. When the chick hatches, both circulatory systems cease to function.







The three extra-embryonic membranes are formed from the primitive germ layers:

The Yolk Sac

The yolk sac surrounds the yolk and draws nourishment from it. Blood islands, which eventually form channels followed by vessels, are derived from the mesoderm. These blood vessels, the vitelline vessels, extend to connect with the ovessels coming off the heart of the embryo. The cells lying next to the yolk become more and more specialized to digest the yolk and pass its nutrients on to the neighboring vitelline circulation and thus to the embryo

The Amnion

Ectoderm and somatic mesoderm surrounding the embryo, form a protective covering over the embryo called the amnion. The inner layer of cells secretes amniotic fluid in which the embryo floats. This fluid keeps the embryo from drying out and helps protect it when the egg is jarred.

The Chorio-Allantoic Membrane

Ectoderm and somatic mesoderm form the chorion which lines the eggshell and performs gas exchange and waste elimination. The allantois is the embryo's connection to the chorion. It appears as a balloon-like structure coming off the hindgut at about day 5. It carries with it the allantoic vessels coming off the heart. The allantois grows larger as the chick grows, wraps around above the chick, and fuses with the chorion. It works together with the chorion to exchange gasses between the embryo and the outside environment. The egg shell is porous and thus allows oxygen and carbon dioxide to pass freely back and forth from the environment to the inside of the egg.
The chorio-allantoic membrane is also responsible for drawing calcium from the egg shell and carrying it back to the chick. Calcium is needed to carry on general metabolism and make bone ( ossification) . For the first 15 days the chick can absorb a sufficient amount of calcium from the yolk. But at around day 15, the formation of bones begins to accelerate and the embryo must draw calcium from the egg shell. The allantois also stores wastes (urine) once the embryonic kidneys begin to function. When the chick hatches, the chorio- allantoic membrane remains attached to the egg shell and is therefore discarded with it.

It is an amazing journey to see what is happening inside the egg. And a true miracle of life.





There is always to much yoke. For 2 reasons. The first is that the mother has put important immunoglobulines in the yoke the eyases have to consume before hatching. Because it's own immuunsystem is not working yet. The way that is developing after hatching is one other fantastic miracle I will certainly tell you about in one of the next posts.

The second is that the eyas needs a foodsupply to last for at least 48 hours. That is because most often there are other eyases hatching and the parents will not leave a hatching egg. Unless it is very late like in Derby. The eyas is very tired from 2 days intensive work getting out of the eggshell. It needs sleep and cuddles up against the warm broodpatch of it's mother or father. But it will start begging as soon as she moves. That's instinctive behaviour. They will do that even if they are not hungry: lift their little heads and scream.



Females in their first clutch act on the collective consious of millions of years of evolution embedded in the brainstem. And handle by the book. But females who have had clutches already follow their own way. And start feeding much sooner. They know best what is good for their hatchlings. Mariah started today about 5 hours after the third one hatched, 10 hours after the first that was. So all the ways are the right ones.

One thing no one ever has to be concerned about is feeding. It's an instinct of every parent, human or avian, to feed it's child. So never worry about that. Peregrines are excellent parents. They are one of the most intelligent avians, they know very well what they're doing. They do have a kind of emotion, they can remember, they even have some kind of compassion where it comes to eyases from themselvers or even adoptive ones.

I have watched many, many peregrines and their feeding behaviour. They are very well aware of which eyas has not had enough. As long as the eyas continues begging it will get food. An eyas that does not beg will even be offered food. The parent animates them eating by chupping, load chupcalls, untill the eayas will turn away when it had enough. And even then the parents tries to feed more. So first feedings will always start within 24-48 hours.

illustration by Janet Sinn-Hanlon

Nijmegen: 17 days of age already







The webcam that watches the ledge is out of order for a couple of days now. We do miss those great blue views. Hope they repair it soon.
The eyases are doing great. They have grown so much. The flight feathers are growing rapidly, and the retrices can be seen as well.

Zurich









After I saw 2 of them I never saw rhem together again, until today. They are amazingly beautiful these 2, transforming rapidly into juvi's. Looking forward to all the flapping and trying on the ledge the upcoming weeks. After watching them a couple of days I'm quite sure they are the same age as the Rome eyases. So 29 days.

Hatchtable

We are coming to the final stages of the hatching for this season. Now that Rochester has hatched we are just awaiting Columbus Ohio around May 13. The hatchtable looks like this.