December 30, 2008
Just thought I'd pass along something interesting from the Fall 2008 issue of Wings (a publication of the Xerces Society). The Miller Moth (Euxoa auxiliaris) is found in Missouri, but the individuals living on the western edge of the Great Plains migrate into the Rocky Mountains during the summer. Most likely because nectar is more available there than on the hot dry prairie.
These migrating moths are an important food for grizzly bears which can eat an astounding 10,000 to 20,000 moths each day! In a 4-week period, this immense number of small prey items can combine to provide 300,000 calories. The moths are crucial for the bears as they pack on weight for survival during hibernation.
Source: Small Animals That Pack a Big Punch by Scott Hoffman Black and Matthew Shepard. Wings, Fall 2008, p 4-8.