Je was op zoek naar: blackbird (Engels - Wels)

common blackbird
mwyalchen

and its not the blackbird
ei

the blackbird is the most numerous breeding bird in britain.
yr aderyn du yw'r aderyn magu mwyaf niferus ym mhrydain.

it's smaller and browner than a mistle thrush with smaller spotting. its habit of repeating song phrases distinguish it from singing blackbirds. it likes to eat snails which it breaks into by smashing them against a stone with a flick of the head.
mae'n llai ac yn frown na'r fronfraith gyda llai o smotio. mae ei arfer o ailadrodd ymadroddion caneuon yn ei wahaniaethu oddi wrth ganu mwyalchen. mae'n hoffi bwyta malwod y mae'n torri i mewn iddynt trwy eu malu yn erbyn carreg gyda fflic o'r pen.