Bald-faced hornet hydrocarbons serve as a barrier to moisture diffusion and thus prevent dehydration in wasps. Cuticular hydrocarbon profiles vary over species and nests, and so cuticular hydrocarbons are a proposed mechanism for nest-mate recognition. Worker and queen cuticular lipids have similar components, but their distributions differ dramatically, implying that cuticular hydrocarbons also play a role in caste differentiation. The following lipid profiles were determined from specimens collected in the summer and early fall of northeastern Georgia in 1989. The dominant hydrocarbons recovered from the cuticles of workers were n-alkanes and methyl branched and dimethyl branched alkanes with a C27 or a
Red-faced cormorant predators, though river otters may attempt to take them, as will corvids of various species, bald eagles and golden eagles. Gulls and corvids are common predators on eggs and chicks. Red-faced cormorant The red-faced cormorant, red-faced shag or violet shag ("Phalacrocorax urile") is a species of cormorant that is found in the far north of the Pacific Ocean and Bering Sea, from the eastern tip of Hokkaidō in Japan, via the Kuril Islands, the southern tip of the Kamchatka Peninsula and the Aleutian Islands to the Alaska Peninsula and Gulf of Alaska. The red-faced cormorant is closely related to the