thank you to everybody!
i, too, guessed (from my online research - since i know nothing, jon snow ;-)) that the little black hen is a cross and has old english game in her (rather than japanese as the latter is less common around here).
she is a remarkable little bird and a joy to own. she's bouncy and curious and - since she reminds me of a flamenco dancer for some weird reason - i call her esmeralda.
i was also assuming that the brown hen is a bearded d'anvers - hence her name: bardu.
thank you for giving me the full terminology. i was wondering if belgian d'anvers = bearded d'anvers. i guess this clarifies it and means that those names are used interchangeably (?).
for the belgian bantam lovers, here is another snapshot of her, taken this morning in our livingroom:
yes, you read that right. i have moved my 4 bantams inside the house.
the silkies are not very happy in -16 celsius (3.2 F) and the little black hen exposes a large patch of bare skin once her crop is full. so for the next 2-3 months, they will live indoors and alternate between the livingroom during the day - fiercely guarded by my cats...
... and an unheated 'sunroom' at night. (as well as outdoor adventures when the weather cooperates.)
the rest of the flock is still inside the coop - with a radiant heater when the temps drop below -5 (23).
spoiled chickens...