moths, though little studied, appear to be susceptible to pesticides used in the alfalfa and wheat fields where they winter, and to global warming, which is altering the alpine zones where bears feed on them.
The natural diet of Yellowstone's grizzlies consists largely of pine seeds and three other foods: spawning cutthroat trout, army cutworm moths and carrion (primarily bison and elk).
Finally, there are the army cutworm moths, which travel in teeming springtime flights hundreds of miles from prairies to Rocky Mountain peaks.
On top of this are concerns that significant global climate change, which many scientists believe has already begun, threatens not only whitebark pine but tundra flowers that produce nectar for Army cutworm
moths, another valuable staple for dozens of bears.
During spring and autumn of 2002, unusually large swarms of miller moths or adult army cutworms
(Euxoa auxiliaris) moved through our study area at Fort Collins, Colorado (Cranshaw, 2006).