The MigrantMoths of Guanacaste

Abstract

The tropics are subject to seasonal extremes. There are times of year when the weather is harsh, when food is scarce, when there is too much sun, or too much rain. Many tropical animals tough out the hard times by sitting tight and becoming dormant or unreproduclive. But other species get up and move to more hospitable localities. In a tropical dry forest. for example, butterflies, beetles, lizards, monkeys. and birds concentrate in the moist and semi-evergreen lowlands and riparian vegetation during the dry season. Then, when the rains come and the lowland forest understory becomes shaded over, the animals move back onto the sunny hillsides. where the food is. Such local seasonal movements have long been apparent to tropical field naturalists. But we are just beginning to learn about a much more dramatic kind of seasonal migration.