Tropical New World bats, all collected during the expedition. Left, 

 above, Artibeus lituratus, a fruit-eater; upper right, Phyllosto- 

 mus hastatus, a predator which eats insects, lizards, and other 

 small animals; lower right, Trachops cirrhosus, whose diet prefer- 

 ence is frogs. The wartlike bumps around Trachops' mouth may be 

 sensors for determining a frog's edibility. Photos by Barbara L. 

 Clauson. 



Postscript 



Several weeks have passed now since the 1986 Costa 

 Rican Expedition returned back to Chicago, and it is 

 appropriate to ask what was gained, what was learned, 

 what were the products of this expedition? 



Investigation of the immense diversity and evolu- 

 tion in tropical ecosystems represents one of the great 

 frontiers of biological science. Yet, the immediacy of the 

 task is made more urgent by the rapid destruction and 

 alteration of those very tropical ecosystems which re- 

 quire so much study. Among Central American coun- 

 tries, Costa Rica has done a remarkable job of establish- 



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