Razorbills, stocky auks of the North Atlantic, spend winters far offshore where they are highly vulnerable to oil spills and chronic oiling from bilge discharge, which destroys their plumage waterproofing and leads to hypothermia.
Oiled seabirds experience acute hypothermia as waterproofing fails, combined with the toxic effects of oil ingestion during preening. Birds beach themselves as they lose the ability to thermoregulate at sea. Rehabilitation is labour-intensive and success rates for oiled auks are modest, typically 30-50%, meaning the majority of oiled birds suffer and die even with intervention.