THE COVER


The photographs on the cover (from left to right, top to bottom)
illustrate the scope of research involved in the AID-sponsored Inter-
national Programs of the Denver Wildlife Research Center.

 The common vampire bat has long been a source of economic loss and
 hardship for livestock producers in Latin America. The trans-
 mission of paralytic rabies and possibly other diseases, blood
 loss, myiasis, and reduced production contribute to a multimillion
 dollar problem annually.

 Systemic treatment of cattle, by intraruminal injection of the
 anticoagulant diphenadione, is one of two highly effective, safe,
 and economical means of vampire bat control developed by DWRC
 researchers.

 Rodents cause severe losses of coconuts in almost all countries
 where they are grown. A control method developed by DWRC biolo-
 gists has yielded dramatic results in field tests in Colombia and
 the Philippines.

 Quantification of the magnitude of food losses to vertebrate pests
 on a worldwide basis is meager at best. Most published discus-
 sions of food losses inevitably focus on micro-organisms or
 arthropods and make only passing mention of vertebrate pests. The
 development of reliable survey methods for measuring vertebrate
 damage will result in a greater appreciation of the role of these
 pests in food losses.

 Laboratory research at DWRC by specialists in such fields as wild-
 life biology, toxicology, animal behavior, physiology, statistics,
 electronics, and chemistry play a major role in the development of
 effective and appropriate control technology.

 Vertebrate damage in agriculture involves a variety of crops and
 species of animals, primarily birds and rodents. Direct losses
 occur typically at planting and sprouting, during the milk or
 dough stages (for grains), just before harvest, or under posthar-
 vest storage conditions. Some damage may be mechanical, as when
 crops are trampled or dislodged by animals. Losses may alter the
 food value, as when rats selectively remove the germ from stored
 corn, or may result from contamination with urine, feces, feath-
 ers, or hair.