These beetles appear to cluster at high elevations all over the southwestern United States for reasons that are not clearly understood. Spring and fall are good times to see monarch butterflies in Big Bend National Park. The park lies just west of one of the monarchs primary migration routes and receives many monarch visitors as they fly through here in April en route to summering grounds in the northern U.S. and Canada. In September they fly south to wintering grounds in central Mexico. These black and orange butterflies travel over 1,000 miles on their migratory journey, covering up to 80 miles per day.
Monarchs are only one of many species of moths and butterflies that inhabit the park.
At night look for the black witch moth, one of the largest moths in North America. In the late spring and early summer, people often see tarantula hawks flying low over the ground, searching for tarantulas. The female tarantula hawk stings the spider only to paralyze it, but not kill it. She drags the inert body into her tunnel, lays her eggs on it, and then seals the tunnel shut with pebbles and dirt. The wasp larvae hatch and eat the tarantula s body for a week or two.