Snow buntings fight over seeds in Mirabel, Canada. Photographer Mircea Costina says: These little polar birds migrate in winter to the south of Canada and approach the farm areas, where they can find food. At first it looked as if it was some form of courtship between birds but they were fighting for their share. The piece of ice was on the ground; in fact it was some snow melted from the previous day - it seemed to add to the frosty relationship between the hungry birds.  Picture: Mircea Costina / Rex Features