They are odd birds. Their salivary glands are enlarged and are able to glue food under tree bark and lichens. Even perishable food items are scatter-hoarded across their territories. Perhaps stranger yet, this jay breeds in late winter, incubating eggs when temperatures can approach -30 degrees C. These birds don’t even try to breed in the warmer temperatures of May or June. Strickland and Ouellet (2011) further report that global warming may be causing stored food to spoil. As a result, some southern populations of Gray Jays appear to be declining.