Museum Expeditions

Photo record for the Nicaragua expedition

The Center for Biosystematics on the UC Davis campus is excecuting a survey of the birds and mammals of the Río San Juan Basin. An insect survey is needed to complement the vertebrate surveys. A complete survey of the insects is nearly impossible, so initially a survey of the Lepidoptera will occur, particularly the butterflies and the sphinx moths, as indicators of faunistic richness.

The Río San Juan forms the southeastern boundary between Nicaragua and Costa Rica. Its drainage basin is one of the most entomologically interesting areas in Central America. For most of recent geological time, North and South America were separated by ocean. A continuous land connection between North and South America was completed only about 3.5 million years ago, and the interchange of plants and animals between the two continents continues. One of the last points of the connection to be filled in is the Río San Juan Region of Nicaragua. Even today, a nearly sea level corridor extends across Central America at this point. This region is known to be a barrier to dispersal for many plant and bird groups. The butterfly fauna of Costa Rica, south of this connection is well known. We are interested in an inventory of the fauna of Nicaragua just north of this connection so we can document how much of this relictual barrier remains.

One unintended result of the political unrest in Nicaragua of the 1970’s and 1980’s is that the extractive economies of other Central American countries never really got started. The Río San Juan River basin is the largest extant tract of tropical lowland forest in the region. The unbroken forests of the southwestern corner of Nicaragua stand in stark contrast to the pastures and vast fields of edible palms across the river in Costa Rica. Wise use of the Río San Juan Basin and an understanding of its value to Nicaragua depend upon a thorough knowledge of the biological riches it contains. Costa Rica has invested millions of dollars over the years in an inventory of their biological riches. By contrast, Nicaragua is the poorest nation in Central America and has not been able to do a similar survey. We are hoping to fill that knowledge gap.

Our collecting efforts are based at the Montecristo Resort, which is just upstream of the historic town of El Castillo.