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Natal & breeding dispersal of colour-ringing Clanga pomarina in Mecklenburg-Western-Pomerania 2007-2018

Für diese spezielle Auswertung zum Ansiedlungsverhalten nestjung beringter Schreiadler (LSE) im Nordosten Deutschlands flossen folgende Q...

Friday, July 29, 2011

"Harald" and the LSE breeding season 2011

Lots of rain in June-July and no voles in the meadows and fields dominate the Lesser Spotted Eagle (Aquila pomarina) breeding season 2011.
Regionally are available in Mecklenburg-Vorpommern very bad breeding success. Of the approximately 80 breeding pairs, according to recent results, there are around 38-40 juveniles. 
But these young Eagles are still far from fully fledged!
Andreas Hofmann and I ringed till now this year 34 young Eagles in Mecklenburg-Western Pomerania.

This young Eagle "HR" = "Harald" - was slightly malnourished - ringed on 6th July 2011 (2,5 weeks old) - © C. Rohde
3 weeks later - I found the Eagle "Harald" (he is a male) on the ground. He was dropped from the nest with 5,5 weeks and is of course still not fledged. He needed 2,5 weeks more.... "Harald" was still agile and must have been for at least 2-3 days provided with food at the ground of the adult birds (I found a mole). I reacted quickly and built a temporary "nest" on a root plate of a spruce at 1.5 m height.
His weight was a big problem (only 1000g!!). Not enough food in the region. Even if the adults brought food to the new location. Still too little ... In addition, the bird is not safe from predators on the ground. I had to respond the next day. The brood nest in the oak was alone very difficult to reached. 27.07.2011 © C. Rohde.

I built finally on 28.07.2011 this new nest on a spruce tree. "Harald" has during insertion defended - a good sign. A renewed problem is the continuous rain....28.07.2011 © C. Rohde.

Good news - on 30. July - "Harald" look from the spruce nest and is alive (last 24 hours more than 70 mm rainfall)!
I'm so happy...and hopeful! 
Over the next few days I check "Harald" and make new images.
And now, unfortunately, bad news. "Harald" is dead!
Today on 01. August - I found him dead under the nesthe must died shortly after my last inspectionwhere he has still lived and was supplied by the parents at the new nest.
We can certainly philosophize much.
 It is first in the sum of the food scarcity, the strong and continuous rain in the last days and previously rather bad condition of "Harald".

The following things are noticed by ringing in 2011:

  • the weight of the young birds were 10-15% below the long-term average
  • the start of breeding was on average about one week later than usual
  • often no adult birds were present by still small young Eagles (< 4 weeks), both ad. birds had to procure food...
  • not enough availability of voles as the main food, very few alternatives this year
  • heavy and long lasting rainfall in June-July 2011 (reg. ∑ 320-340 mm!!), the critical age of the young Eagles
For comparison: in 2010 there were 80 breeding pairs of LSE with 46 fledged young Eagles in MV (SCHELLER et al. 2010).
What a nice view for this young LSE on the top of the pine (see the nest with LSE in the center), Mecklenburg-Western Pomerania - 18.07.2011, © C. Rohde.