Clash of eagles – Antoni Kasprzak, Poland. Winner, behaviour – birdsThe winter in Poland had been particularly cold and snowy, making it difficult for the eagles to find prey. So when Antoni found a dead moose hit by a train, he knew it would be the ideal bait. A struggle broke out between an adult and an immature white-tailed eagle. The older bird won, forcing the loser to wait its turn for more than an hour

Photograph: Antoni Kasprzak/PR