Liz01 wrote: ↑August 6th, 2018, 6:23 pm
18:22 Gaja again with much little fish
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Email from M.S
1) Start of migration. Departure from nest does NOT mean immediate start of migration. Some birds do but many hang around for quite some time. This can be identified for tagged bird ONLY, all other „data” are speculations. I do not know what the english version of Vikipedia (in general poor source concerning BS) quotes but very likely those can be birds from western flyway – France and Belgium. Even if the figures are correct from the right sources, those birds are very different from eastern flyers (like ours or EE storks are), so cannot be used as a reference concerning thoughts „when will these juveniles start migration?”. Czech birds fly both ways so those data must be devided per flyway before quoting. Another important aspect is extra 1000-1500 km birds from LV and EE shall fly. It adds some time that they require to make it happen.
Data (unpublised so far) from 22 LV storklets that started migration at all (from 27 tagged), the mean age of start of migration is at least 89.7 days, min. 73.4, max 142.2 days. Of those 5 birds that reached age of 1 year, mean age is 90.5 days (Mellene – 92.5, Kate – 85.4, Sarma – 115.2, Raitis – 83.0, Mare – 76.4).
2) Small fish they eat now almost 100% is Neunstachliger Stichling / nine-spined Stickleback (Pungitius pungitius).
EDIT: M.S. both oldest storklets today are 80.6 (now) and 80...., not 81 (2018-08-06)
it was wrong written in the chat
thank you M.S.
And they are all also enough much different in their behaviour.
