Eemsmond: not viable eggs

Remember the Eemsmond nestsite?
The female laid her first egg om March 12, and completed her clutch of 4 on March 20. With no breaks incubation went on for 35 days without a hatch. Both parents continued incubation during April, May en June. It was clear that something was very wrong.
On July 1 the 4 eggs were taken from the nestbox.
They were scanned and it turned out that there were no embryo's in either of the 4 eggs. Of course after 103 days of incubation the contents of the egg were in a severe state of decomposition. That's why it is not possible to find traces of sperm. The eggs turned out not to be viable.

We have all seen that the 2 peregrines mated. We think the male peregrine is not a new one. But if he is and still immature, that could be a cause of eggs being not viable. He does not have a band, so it is very difficult to be sure.

There are lots of possibilities that cause not viable eggs.
Peregrine falcons stay fertile until their dying day. And when they are sick which could cause infertility they do not mate and do not lay eggs.

During the DDT crisis many eggs were not viable because of this horrible stuff prevented the fertility of the female. And caused thin eggshell which caused an early death of th embryo.
Enviromental polution is still a serious danger to the Peregrine falcon. New enviromental toxins like Deca-BDE, PCB have already been measured in peregrine falcons in very high dosages, as well as in many other species, humans included.

Beside this there a lot of micro organisms ( virus, bacteria, parasites) which can cause death of the blastoderm before it becomes an embryo. This is visible by a bloodring in the eggcontent. But after such a long incubation and a decomposed content it is impossible to say what caused these egg to be not viable. And that's a shame. We sure would have liked to know what caused this.

Eemsmond: eggs removed.

On March 12 the Eemsmond female laid her first egg. On March 15, 17 and 19 she laid the eggs 2, 3 and 4. She started breeding after she had laid the 3th egg. The first days of breeding where in cold and snowy wheather. But they where sheltered by a warm nestbox. 33 days after she started breeding the first egg should have hatched, that was around April 20. Everywhere in the Netherlands eggs hatched around that date, but not in Eemsmond.
First we thought, give her a few days more, but still no hatch.





If eggs don't hatch within 5-7 days after the estimated date they won't anymore.
In these cases, the couple goes on breeding. From other cases I know they leave after 40-45 days to try again somewhere else. Or just stop breeding and leave.
But not this Eemsmondcouple. They kept on breeding. And they did not seem to be bothered by the fact that something was not the way it should be. They had adjusted to this way of life, and where taking turns breeding day in and day out.





Many people have mailed me about this in the past months. How sad and pity these birds. Have asked to intervene. But please do not project your own psyche and emotions on these birds. The Peregrine falcon is one of the most intelligent birds there are. But they lack the ability to think ahead, to draw conclusions, to be aware of this being sad.
The drama in Richmond for instance was a total different thing. She saw how her eyases died, where sick, where dead in the shell. She was very very aware of the death of her eyases. And that is most stressful thing that can happen to a peregrine falcon. Broken eggs, death eyases are very disturbing and do evoke a behavioural reaction that we could almost qualify as emotions. Just recall the Richmond female. Her behaviour has made a big impression on me. It was very emotional to see her stress and greeve about what was happening with her precious eggs and eyases.




But the Eemsmond couple where not stressed one moment. They just behaved as they should when there are eggs. They seem totally relaxed.
The breeding went on and on and on. Until yesterday. The eggs where removed by the Dutch Peregrine Workgroup and will be available for scientific research.
The Eemsmond couple have broken records for sure. I have never red anywhere that a couple kept breeding for this long. It has actually been 106 days!!!

Eemsmond: still breeding.

This is unique behaviour in Eemsmond. On March 12 the Eemsmond female laid her first egg. On March 15, 17 and 19 she laid the eggs 2, 3 and 4. She started breeding after she had laid the 3th egg. The first days of breeding where in cold and snowy wheather. But they where sheltered by a warm nestbox. 33 days after she started breeding the first egg should have hatched, that was around April 20. Everywhere in the Nerherlands eggs hatched around that date, but not in Eemsmond.
First we thought, give her a few days more, but still no hatch.





If eggs don't hatch within 5-7 days after the estimated date they won't anymore.
In these cases, the couple goes on breeding. From other cases I know they leave after 40-45 days to try again somewhere else. Or just stop breeding and leave.
But not this Eemsmondcouple. They are still breeding. And do not seem to be bothered by it. They have adjusted to this way of life, and take turns in keeping their eggs warm.





Many people have mailed me about this. How sad and pity these birds. Have asked to intervene. But please do not project your own psyche and emotions on these birds. The Peregrine falcon is one of the most intelligent birds there are. But they lack the ability to think ahead, to draw conclusions, to be aware of this being sad.
The drama in Richmond for instance was a total different thing. She saw how her eyases died, where sick, where dead in the shell. She was very very aware of the death of her eyases. And that is most stressful thing that can happen to a peregrine falcon. Broken eggs, death eyases are very disturbing and do evoke a behavioural reaction that we could almost qualify as emotions. Just recall the Richmond female. Her behaviour has made a big impression on me. I did feel a deep compassion for her.





But the Eemsmond couple are not stressed. They just behave as they should when there are eggs. They seem totally relaxed.
It will end. Their hormone level will change and they will leave. They do leave the eggs for a few hours more and more in the past days.
After they have the WSN will collect the eggs for scientific research.

Eemsmond: so sad

48 days ago the Eemsmond female laid her fourth egg and they are incubating their eggs eversince. With the same percistance as the first day they keep turning the eggs.
Not knowing the eggs are not viable they will go on. The sight of the egg keeps the prolactine hormone level up. So they will go on breeding. If anyone took the eggs out in time, they would start a second cluctch. But no one will. So they will have no eyases this year.
Theu will probably stop after about 60 days. The hormone levels will change by the influence of the time of year, the temperature and their own molt cycle.
Nevertheless, the sight of this breeding female among all the eyases everywhere is kind of sad. Next year maybe new chances

Eemsmond: failure

The male is sitting al day on the ledge. He comes in every now and then. It seems like he is telling her, come on it is not going to happen anymore. Let's go and have fun again. Go hunt together and fly through walls of clouds, climb to the highest heights again and feel the air under our wings. Don't sit there but come with me.

But she can not say goodbye to this dream yet. But she has to, the eggs are liveless.

Eemsmond: probable failure

At the Eemsmond nestsite things are not going the way they should. The eggs should have hatched on the 24th of April, give or take 2 days. The eggs are overdue.
They are probably not viable. Both peregrines know something is wrong. This morning the male came in to check everything out. Both male and female will stay incubating until the eggs are about 45 days old. After that they will stay away more and more untill they decide that it is hopeless and will probably leave then.
By then it is to late in the season to start a second clutch.
It would be best to take the eggs out, so the pair can start again, but I'm sure that won't happen.

What is the cause, well it's hard to engage in to speculation. I do not know this couple. Last year 4 eggs where laid from which 3 hatched, and 3 juvi's fledged from this nestsite. Maybe this is a new female who has laid her first clutch. It is always very possible that the eggs are not viable in a first clutch. I cannot imagine that the eggs cooled off to much. They where very careful to keep them warm when the snow came etc. So it is not clear what is wrong.

Eemsmond: something wrong

What is wrong here. The hatchdate was April 24. In the incubationperiod there where no problems. The eggs where never left alone for a long period. Still no pip, let alone a hatch. Are the eggs not viable? The incubation period can be extended to as long as 35-37days when there is a plausible explination. And there is none. So we just have to wait and see.

Eemsmond

No Hatch yet........

Eemsmond: no hatch yet

Eemsmond: no pips yet

Tomorrow it will be 33 days after the last egg has been laid, so we expect the first eyas to make it's great excape some time tomorrow.
It's hard to tell if anything is going on here. So we just have to wait and see.

Eemsmond

Eemsmond is one of the 3 scrapes that will be greeting a first hatch this weekend. So be sure to watch this webcam on saterday for the first signs of excitement when the little hatchlings start screaming from within the eggs.

Eemsmond

Eemsmond

Eemsmond

Only 6 days left. Inside the eggs the embryo's are preparing to get out of the egg. It is of major importance that the head is in the right position. Untill now it's has been resting on the yolksac. Now the embryo is starting to lift it's head to be able to move it underneath it's rightwing with it's bill towards the aircell. The head should be along the long side of the egg. Only in this position it will be able to pip the shell in the right spot and keep pipping and turning to break the shell in two.

Eemsmond

Only 8 more days to go before hatching on April 20!