Dr. Victoria Bowes, British Columbia Ministry of Agriculture, June 2013: In the winter of 2011, and again in 2012, an unexpected record number of overwintering Snowy Owls arrived along the southern coast of BC

[…] from the high Arctic already in poor body condition, and over a short period of time many of the weakened birds were admitted to local wildlife rehabilitators. Others […] were found dead or dying. […] The unanswered question was whether or not there were underlying predisposing factors that made these birds more vulnerable. In January 2013, and again in April, a team of investigators assembled […] to examine a total of 49 Snowy Owl carcasses […] the majority of birds in both necropsy sessions were emaciated adult or sub-adult males. An associated finding was carcass pallor accompanied by acute gastric and intestinal hemorrhage […] terminal intestinal hemorrhage has been recognized as a manifestation of severe physiologic stress […]

South China Morning Post, Jan. 20, 2013: […] snowy owls arrive in Vancouver […] worrying bird welfare experts […] The owls perch listlessly […] the second winter in a row that Vancouver has been treated to a visit […] raising concern among experts who say the owls should normally only visit Vancouver every five or so years […] some of the birds are badly emaciated.

Rob Hope, Orphaned Wildlife Rehabilitation Society: Some were suffering from asperogillosis, a breathing problem […] that can be triggered by a weakened immune system or malnutrition. [Owls arrived in] November, earlier than they would normally venture so far south […] “We have been finding a lot in very poor condition by the time they arrive. They are already in a weakened state.”plume_arctic_snowl