Thursday, April 24, 2008
James River Bridge: 15 days
Our sweeties are getting bigger and stronger. The cams have zoomed out. So we can only see them from a distance. But they are doing very well. Look how they've grown.
They are 15 days old now.
Eyases from day to day
With all the eyases in different stages of development it might confusing about who is where in his transformationprocess. Here once more the developmentprogress in photo's:
Click the pictures to enlarge
Condition 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:
Copyright Froona
All Rights reserved
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:
Copyright Froona
All Rights reserved
Richmond: No hatch yet
Is there a pip? Both peregrines are watching the eggs often. Do they here the eyases singing inside? Hatchdate will be April 25 or 26.
Indianapolis: 2 eyases!
Hatchtable
Again new hatches today: a third eyas in Cleveland- Terminal Tower, a third one in Cobb Island.
Two eyases in Indianapolis ( thank you Veronica), Richmond and Zwolle on the way, same in Brighton. So a lot to enjoy!
Wednesday, April 23, 2008
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