Slow Arctic freeze raises risk of polar bear extinction, say scientists

Record absence of ice after freak warm spells denies pregnant bears birthing dens and triggers 'extirpation event' warningA record slow freeze of many regions of the Arctic this winter is making it harder for pregnant polar bears to find birthing dens.The delayed formation of sea ice during autumn has worried biologists, who fear a first "extirpation event" - the local extinction of a species - may be approaching faster than forecast for the most affected populations. Continue reading...