Bats (\u3ci\u3eMyotis lucifugus\u3c/i\u3e)

Despite their ecological value, bats (Myotis lucifugus) are relentlessly and unjustifiably persecuted. Bats, the only mammals that truly fly, belong to the order Chiroptera. Bats in North America are virtually all insectivorous, feeding on a variety of flying insects (exceptions among house bats were noted previously). Most North American bats emit high frequency sounds (ultrasound) inaudible to humans and similar to sonar, in order to avoid obstacles, locate and capture insect prey, and to communicate. Bats often fly about swimming pools, from which they drink or catch insects. Bats use roosting niches that are indoors (human dwellings, outbuildings, livestock quarters, warehouses), semi-enclosed (loading docks, entrance foyers), partially sheltered (porches, carports, pavilions, highway underpasses, bridges), and open structural areas (window shutters, signs). Surface areas on walls, under loose woodwork, between bricks and around other bat entryways often have a smooth, polished appearance. Disturbing sounds may be heard from vocalizations and grooming, scratching, crawling, or climbing in attics, under eaves, behind walls, and between floors. Fecal pellets indicate the presence of animals and are found on attic floors, in wall recesses, and outside the house at its base. Several arthropods (fungivores, detritivores, predators, and bat ectoparasites) are often associated with colonies of bats in buildings. Bats are distinct from most vertebrate pests that inhabit human dwellings because of the potential for transmitting rabies — a viral infection of mammals that is usually transmitted via the bite of an infected animal. Rabies is the most important public health hazard associated with bats. The lethal control of bats, even when there is a proven potential danger to humans, often is subjected to careful scrutiny and interagency coordination

BATS: THEIR PUBLIC HEALTH IMPORTANCE AND CONTROL WITH SPECIAL REFERENCE TO TRINIDAD

This brief review of the public health importance and control of bats is oriented to Trinidad, where, during the past ten years I investigated their zoomedical importance (1). Trinidad is noted for Pawan\u27s classic epidemiological studies of bat rabies (2,3) as well as its bat control program with which I have been associated since its inception in 1934 (4). Further, Trinidad has bat problems, in addition to rabies, which occur in other countries of the world. Although various methods of bat control have been developed in Trinidad, the field is virtually unexplored. Increasingly, bat control is a matter of paramount importance to Trinidad and other countries in Central and South America striving for self-sufficiency in meat and dairy production to feed their expanding populations

VAMPIRE BAT CONTROL: A REVIEW AND PROPOSED RESEARCH PROGRAMME FOR LATIN AMERICA

In Latin America paralytic rabies transmitted by vampire bats is a major cause of death in cattle. This problem becomes more acute as countries attempt to increase livestock production to feed rapidly expanding human populations. Vaccination has been the principal weapon against rabies, however this offers no protection to domestic animals and poultry against daily predation of vampire bats. Established methods of vampire bat control, though limited, have proved effective and should be continued while more effective methods are being developed and tested. Existing methods are discussed in some detail. Of the approximately 200 kinds of bats found in Latin America all could be potential vectors of rabies. The 12 species most frequently found infected with rabies (including the three types of vampires) should receive close ecological study for possible control. They have certain attributes in common: they have been reported rabid; are found in association with vampires; are widely distributed; are found in buildings near domestic animals and people; live in groups; have sharp teeth; fly considerable distances; frequently change their roosts; do not hibernate and are biologically or economically important. Improved vampire bat control must be based on an ecological approach in which all available techniques are combined into an integrated control which will not affect other species of bats. Such an approach could use biological, chemical, physical and regulatory techniques. These cannot be fully developed until basic information is available on two points. First, there must be a thorough understanding of the ecosystem in which the bats live, including population dynamics. Second, the population levels which cause damage must be determined. This information Is lacking for vampire bats. Two other questions must also be answered: first, what are the host preferences of vampire bats throughout their range from Mexico to Argentina? And second, how many vampires inhabit any given area? A precise technique for measuring these numbers is essential to evaluate any control measure. All the countries in Latin America are discussed on a regional rather than a political basis listing special problems to be solved. The vampire bat problems throughout Latin America should be defined. FAO could, if requested, assist these countries in carrying out presently known methods of vampire bat control which could provide immediate relief in limited areas. It could also help to establish priorities of research based on the financial and manpower capabilities of these countries to conduct such research

Bats, their public health importance and control with special reference to Trinidad

This review of the public health importance and control of bats is oriented to Trinidad, since this country is well known for its studies of bat problems, especially rabies, and its bat control program. Bat problems which require control are: bat-associated diseases (viral, spirochetal, fungal, bacterial, and protozoan), vampire bats, and house bats. Present methods of bat control and possibilities for future control are discussed, as this is a matter of importance to Trinidad and other countries in Central and South America. Because of its large variety of bats and location, the small island of Trinidad is a natural laboratory to study bat ecology and evaluate control measures. A list of pertinent references is provided

Natural History of Vampire Bats

The reproductive cycles of bats living in temperate zones are forced into a relatively short time span. As a result, in these bat populations breeding is highly synchronized and reproduction characterized by one birth period per year. Offspring of the common vampire bat, Desmodus rotundus, can be found throughout the whole year, a fact which was first noticed by De Verteuil and Urich in Trinidad and confirmed for other South American regions. In Costa Rica Turner found the highest number of pregnant females during the rainy season and discussed an influence of the hormonal status of the prey cattle on the sexual cycle of Desmodus. Mating occurs frequently with captive Desmodus. In Diphylla sperm heads are substantially broader and more rounded, and the attachment of the head is farther off center than in Desmodus and Diaemus. The cumulus cells of Desmodus resemble the granulosa cells as in most mammals

Natural History of Vampire Bats

The reproductive cycles of bats living in temperate zones are forced into a relatively short time span. As a result, in these bat populations breeding is highly synchronized and reproduction characterized by one birth period per year. Offspring of the common vampire bat, Desmodus rotundus, can be found throughout the whole year, a fact which was first noticed by De Verteuil and Urich in Trinidad and confirmed for other South American regions. In Costa Rica Turner found the highest number of pregnant females during the rainy season and discussed an influence of the hormonal status of the prey cattle on the sexual cycle of Desmodus. Mating occurs frequently with captive Desmodus. In Diphylla sperm heads are substantially broader and more rounded, and the attachment of the head is farther off center than in Desmodus and Diaemus. The cumulus cells of Desmodus resemble the granulosa cells as in most mammals