When I returned home after photographing this female goosander and her brood of 24 ducklings I got around to thinking of the 'logistics' involved in such a large brood size.
Reference's suggest a maximum clutch of 13 at the top end so it's presumed a second female has to have laid eggs in the nest as well, with incubation taking between 30-32 days and only starting proper when the clutch is complete there is ample time for the interloper to perform the act of laying when the resident female is off feeding. Then I got around to thinking of body mass and the area the eggs must have taken up for the female to keep them viable and after witnessing two female Eider ducks last summer incubating almost on top of one another reckoned it feasible that this may have been the case again, against that theory though is the fact only one female is in attendance, so has her maternal instincts been so strong that she has 'mugged' another female and stolen her brood and does this increase the chances of her own progeny surviving? against that theory is that the ducklings are all obviously the same age.
With Grey heron and Mink in the vicinity the odds are stacked against the bulk of this brood surviving, witnessed by an earlier brood of four reduced to two in a matter of days and none seen since.
Comments as always are welcomed on this theory.