this is an old question already which raised some discussion on this thread but i don't think it got a full and/or definite answers yet.
andu didn't write where these pictures were taken and that is very important to know, like vainamoinen and chimega wrote in their answers. as i am a Finn i naturally saw in these pictures two birds which are common in Finland (and i believe also in Estonia). i think that the upper bird is willow tit (
Poecile montanus, formely know as
Parus montanus) like vainamoinen wrote. another possibility is marsh tit (
Poecile palustris, formerly
Parus palustris). these two look so much alike that one should hear the voice to be sure of the identification. - i think that the question about these two has been discussed on the bird feeder topic every winter.
voices of the willow tit:
http://www.xeno-canto.org/explore?query ... e+montanus
voices of the marsh tit:
http://www.xeno-canto.org/explore?query ... +palustris
i think that the second bird is a yellow hammer (
Emberiza citrinella). - but if these birds were photographed somewhere else than in Northern Europe then i'm not sure at all what they are!