TECHNIQUES AND GUIDELINES FOR MONITORING NEOTROPICAL BUTTERFLIES

Long-term monitoring of selected species can identify changes in biolo gical diversity, permitting the timely adjustment of management activi ties to reverse or avoid undesired trends. This paper addresses severa l related issues bearing on the development of inexpensive and easily implemented monitoring programs for tropical butterflies. First, we di scuss the use of butterflies as ecological indicators. Next, we presen t field evaluations of butterfly sampling techniques, indicating that: (1) light-gap size greatly affects sampling results in forests and sh ould be of critical concern in site selection and sampling design; (2) baited traps and visual censuses provide complementary data on butter fly abundances; (3) monitoring a subset of locally common butterfly sp ecies can provide data for comparing community composition and relativ e abundance of species in areas where species inventories are incomple te. Drawing on these results, we develop guidelines for designing moni toring programs. These address the formulation of explicit questions t o be addressed through monitoring and the selection of appropriate stu dy sites, study species, sampling techniques, and sampling frequency. A protocol for the ongoing butterfly monitoring program that emerged f rom these studies is appended. The techniques and guidelines presented here are intended to serve as an adaptable model for biologists desig ning monitoring projects to help guide applied conservation efforts in the tropics.