FRANCE - POLAND
(GT)
International mission in Poland. October 7-9, 2022
...
Summary of the information:
Arrivals at the nest: extreme dates
- 2018 first bird: 27 March, second 3 April
- 2019 first bird: 26 March, second 1 April
- 2020 first bird: 22 March, second 31 March, average 25 March - 1. April
Date of start of laying:
- three-year average: April 12
- earliest March 30 - latest May 4
Hatching date:
- average May 16
- average incubation period 32 days
Number of chicks hatched:
- average 3.4 chicks per pair with successful laying (number examined clutches: 38)
- hatching success rate: 82.7%
Adult individual stays with chicks for an average of 8 days.
Adult individual ceases to be permanently in the nest on average after 19 days.
The adult no longer spends the night in the nest from 26 days after the hatching of the last chick.
The average number of chicks per successful clutch
- 2.84, ie 81.4% success rate after hatching
Flight of the last young in the nest
- between July 21 and September 6, on average August 9
The pine marten regularly visits the nests when the storks hibernate. No case of predation on eggs or young during the breeding season was recorded during our study.
Between 2017 and 2020, martens visited 65% of nests and hawks 41%. During the monitored period, 17 nests were monitored, with a total of 37 reproductions.
(source:
https://ciconia-nigra-international-exp ... obre-2022/ - also photos

)
EDIT: here you can open big pics
http://forestiersdumonde.org/index.php/ ... obre-2022/