Saturday, April 12, 2008
Heidelberg: eyases on their way!
Watching the nestbehaviour today indicates something is happening inside the eggs. The female was excited, looking at the eggs, wiggeling, looking again, looking around.
32 days ago incubation began. There are 3 eggs. If everything goes well, the eyas(es) will have pipped the membrame to the aircell and has started screaming from inside the egg. Indicating to his sibblings: "I am on my way guys, come on let's hatch together". For the mother it is very exciting. From feeling the little ones move inside the egg, to hearing them is a great bondingprocess, for her as well as for the male.
So in Heidelberg as weel, eyases must be on their way. Maybe another hatch tomorrow....
Columbus Ohio
Well things have settled down here alright. Scout and Orville are incubating 2 clutches. I a way that is right: 4 eggs from 2 clutches. It will be quite a while before we know if we have just 1 or 2 clutches.
De Mortel
In the Netherlands we all are very anxious for these 4 eggs to hatch. For the new resident female S2 this is her very first clutch ever. She herself hatched in 2005 in Seraing. Belgium. Last year she killed the resident female Ma and after a very hard time eventually became a very good stepmother. She managed together with the resident male Pa to healthy fledge the two juveniles Hope and Faith.So in 8 days time her very first eyas will hatch. It will be a day ro remember.
Nijmegen
No intrusions today fortunately. No room left, place is taken intruder, find yourself your own home. Little eyases will be born here in 8 days time.
Oberhausen: meet the parents
A remarkable shot: the Oberhausen couple together at the entrance of the eyrie. Note the size difference between the male and the female. Only recent biologists suggested that this sizedifference is an evolutionary asset. The smaller male is much more agile when hunting, and can because of his smaller size react much quicker on the agility of prey then the larger female.The parts they both play in the nesting season is obvious therefor: she takes care of the hatchlings, while he hunts. In order to keep the eager customers satisfied in the scrape the male peregrine has to kill several times a day. And not every stoop is succesful, only in 30% of every stoop the male succeeds in a kill.
While the courtship is still going on the female makes a cache to store food in. The male hunts, brings home prey. He waits on the ledge till she get's it and takes it away. For offering prey is a major part of courtship. When the female is finished eating she caches it, in a place no other animal can get it. And not to far from the eyrie. When the eyases are born, the male takes the prey to the female, she feeds the hatchlings with it and brings the leftovers to the cache. That way she has always food in storage for the babies.
Derby Cathedral Peregrine Project
With incubation just begun, both peregrines have a long way to go. With all the hatching going on Derby, Harrisburg and Rochester have hatchdays in May. So we will be able to enjoy eyases growing up untill in june. The first ones will fledge in Oberhausen, when the Derby's will only just have hatched. Interesting facts.
Eyases growth and development
Click the pictures to enlargeCondition At Hatching
The peregrine falcon eyases are semialtricial, nidicolous; covered with off-white (prepenne) down. Semi altricial means: Covered with down, incapable of departing from the nest, and fed by the parents. In species like the peregrine falcon we speak of semi-altricial 2, hatch with the eyes closed.
The bill and feet pinkish to pale gray with eyes closed. They weigh about 35–40 g. If eyes open with food-begging first day, they are slitlike. The eyases obtain 2 downy plumages.
Growth and development
At 5 days after hatch, their mass has doubled. The eyas can sit with relative ease, and the open eyes are more round.
At 6–8 days of age the second down (mesoptile or preplumulae) starts to emerge, first on humeral and alar tracts but no down visible on belly at 6 day, although on the legs and belly at 8 days.
Also second down is well out on the wings and looks a bit blueish and sheaths of primaries breaking skin on wings.
By 10 days of age the second down is complete and uniform and outer rectrices are breaking skin. At 10 days, primaries growing at 2–3 mm/d, rectrix sheath not yet split.
At 14 days the second down is dense and long, rectrix sheath about 2 mm and typically ninth primary emerges from sheath.
By day 17 the contour feathers start to push out prepennae and only pale (buffy) tips of rectrices have emerged but growing at about 2 mm/d (since day 13).
By 10 days of age the second down is complete and uniform and outer rectrices are breaking skin. At 10 days, primaries growing at 2–3 mm/d, rectrix sheath not yet split.
At 14 days the second down is dense and long, rectrix sheath about 2 mm and typically ninth primary emerges from sheath.
By day 17 the contour feathers start to push out prepennae and only pale (buffy) tips of rectrices have emerged but growing at about 2 mm/d (since day 13).
At 20 days while still with heavy coat of second down, brown contour feathers are visible on margins of wings, tail, and faintly around the eyes.
By 30 days young appears about half down-covered and half feathered; while side of face well feathered, crown still covered with down.
At 35 days while mostly feathered, large conspicuous patches of down around legs, under wings, and on crown.
At 40 days almost fully feathered with traces of down on crown and under wings and outer several remiges; rectrices not fully grown but bird capable of weak flight.
From my Peregrine falcon website:
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