HATCHING PROCESS
3-29-20 Pip 1:15:54pm
We have all been able to observe the miracle of nature while watching the hatching on SWFEC. Throughout the night the eaglet has been going through the hard process of hatching. We were able to see the first view of a pip at 7:15:48 this morning. At around 12:20pm we observed some blood in the egg around the pip area.
While we are not sure what has caused this blood we can share some information regarding the hatch. During the hatch process the chick has to switch its respiration and blood circulation. After it breaks the shell it absorbs the rest of the yolk and the blood vessels.
Blood vessels that haven't dried up yet may still attach the shell to the chick, and prematurely pulling of the shell can cause excessive bleeding. We usually do see some sign of blood inside of the egg shell after the hatch.
But I think most of us have never seen this much blood during a hatch - so it is understandable we all have questions. We can only hope that all will go well for this eaglet during the hatching process. But we would be remiss if we didn’t remind everyone that not all eaglets survive the hatch.
This information on hatching comes from from Nick Fox (Understanding the Bird of Prey, 1995) on hatching:
"About 72 hours before hatching, the egg starts an ordered sequence of events which are critical. The chick must progress from allantoic respiration to lung breathing, retract its yolk sac and hatch.
[The allantois is part of the membrane surround the embryo -- it is the mechanism of the exchange of oxygen in and carbon dioxide out until the chick's lungs begin to function just before hatch, and it collects metabolic wastes that are discarded after hatch.]
"At the time when the air cell is beginning the 'draw down' the complexis hatching muscle at the nape of the chick's neck becomes swollen with lymph and twitches spasmodically. The twitching movement extends throughout the whole body of the chick causing it to straighten briefly.
These unbending movements press the chick tight against the eggshell and force the beak upwards. On the upper ridge of the beak is the small egg tooth which eventually penetrates the inner shell membrane into the air cell. Once the beak is into the air cell, the chick is able to start breathing air into its lungs although it is still dependent on allantoic gas exchange. With its lungs in operation it is able to cheep and this is a sure sign that breathing has started.
"With continuous rebreathing, the air in the air cell becomes high in carbon dioxide and this stimulates the hatching muscle to further activity. With more faint tapping and pressure from the chick, the shell wall gives way and a slight lifting of a fragment of shell becomes visible. This is called 'starring.'
This allows a small amount of fresh air into the air space and the chick usually becomes quiet for some hours. Working sporadically, the chick then begins to break up an area around the pip and also splits the air cell membrane much further so that, on candling, it can be seen to occupy most of the air cell and is much looser inside the shell. Gradually the chick enlarges an opening and the beak and egg tooth come into view.
"The chick may rest at this point for a further twenty-four hours. During this time the lungs and airsac system are becoming fully functional and gradually take over total responsibility for gas exchange. The blood circulation in the allantois slowly shuts down.
"Once the allantois has shut down, the chick starts to rotate inside the shell. Within about fifteen minutes the chick circles about half to two-thirds around the egg, industriously cutting out the shell as it goes. Soon it is able to push up the cap with its shoulders and kick itself free of the shell, leaving the membranes and excreted uric acid waste behind.
The allantoic blood vessels quickly fall away from the navel. By one or two days after hatching the hatching muscle has reduced in size and is no longer swollen with lymph. The total time from pip to hatch in birds of prey varies considerably from about 30-70 hours but is usually complete within 50 hours."
HATCHING PROCESS
3-29-20 Pip 1:15:54pm
We have all been able to observe the miracle of nature while watching the hatching on SWFEC. Throughout the night the eaglet has been going through the hard process of hatching. We were able to see the first view of a pip at 7:15:48 this morning. At around 12:20pm we observed some blood in the egg around the pip area.
While we are not sure what has caused this blood we can share some information regarding the hatch. During the hatch process the chick has to switch its respiration and blood circulation. After it breaks the shell it absorbs the rest of the yolk and the blood vessels.
Blood vessels that haven't dried up yet may still attach the shell to the chick, and prematurely pulling of the shell can cause excessive bleeding. We usually do see some sign of blood inside of the egg shell after the hatch.
But I think most of us have never seen this much blood during a hatch - so it is understandable we all have questions. We can only hope that all will go well for this eaglet during the hatching process. But we would be remiss if we didn’t remind everyone that not all eaglets survive the hatch.
This information on hatching comes from from Nick Fox (Understanding the Bird of Prey, 1995) on hatching:
"About 72 hours before hatching, the egg starts an ordered sequence of events which are critical. The chick must progress from allantoic respiration to lung breathing, retract its yolk sac and hatch.
[The allantois is part of the membrane surround the embryo -- it is the mechanism of the exchange of oxygen in and carbon dioxide out until the chick's lungs begin to function just before hatch, and it collects metabolic wastes that are discarded after hatch.]
"At the time when the air cell is beginning the 'draw down' the complexis hatching muscle at the nape of the chick's neck becomes swollen with lymph and twitches spasmodically. The twitching movement extends throughout the whole body of the chick causing it to straighten briefly.
These unbending movements press the chick tight against the eggshell and force the beak upwards. On the upper ridge of the beak is the small egg tooth which eventually penetrates the inner shell membrane into the air cell. Once the beak is into the air cell, the chick is able to start breathing air into its lungs although it is still dependent on allantoic gas exchange. With its lungs in operation it is able to cheep and this is a sure sign that breathing has started.
"With continuous rebreathing, the air in the air cell becomes high in carbon dioxide and this stimulates the hatching muscle to further activity. With more faint tapping and pressure from the chick, the shell wall gives way and a slight lifting of a fragment of shell becomes visible. This is called 'starring.'
This allows a small amount of fresh air into the air space and the chick usually becomes quiet for some hours. Working sporadically, the chick then begins to break up an area around the pip and also splits the air cell membrane much further so that, on candling, it can be seen to occupy most of the air cell and is much looser inside the shell. Gradually the chick enlarges an opening and the beak and egg tooth come into view.
"The chick may rest at this point for a further twenty-four hours. During this time the lungs and airsac system are becoming fully functional and gradually take over total responsibility for gas exchange. The blood circulation in the allantois slowly shuts down.
"Once the allantois has shut down, the chick starts to rotate inside the shell. Within about fifteen minutes the chick circles about half to two-thirds around the egg, industriously cutting out the shell as it goes. Soon it is able to push up the cap with its shoulders and kick itself free of the shell, leaving the membranes and excreted uric acid waste behind.
The allantoic blood vessels quickly fall away from the navel. By one or two days after hatching the hatching muscle has reduced in size and is no longer swollen with lymph. The total time from pip to hatch in birds of prey varies considerably from about 30-70 hours but is usually complete within 50 hours."