Gray Jays also fed on the peanut butter plastered about the Admiral Road bird feeders in the Sax-Zim Bog. These jays thrive in the bitter cold of Northern Minnesota. They are known as Camp Robbers, because of their fearless raids on anything edible. They hoard food under tree bark, gluing it in place with their sticky saliva. Gray Jays breed in late winter. Eggs are incubated at temperatures as low as -30 degrees. Second broods are not attempted in warmer weather. Gray Jays may be declining at the southern edge of their range as a result of global warming (Strickland and Ouellet 2011).