Assessment of Potential Cuban Hutia Management at U.S. Naval Base, Guantanamo Bay, Cuba
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Assessment of Potential Cuban Hutia Management at U.S. Naval Base, Guantanamo Bay, Cuba Gary W. Witmer USDA APHIS Wildlife Services, National Wildlife Research Center, Fort Collins, Colorado Martin Lowney and Harold McDaniel USDA APHIS Wildlife Services, Moseley, Virginia Deanna Rees Natural Resources Section, Naval Facilities Engineering Command, Norfolk, Virginia Abstract: The Cuban hutia ( Capromys pilorides ), known locally as the banana rat, is a large rodent native to Cuba. Endemic to the West Indies, most species of hutia are rare or extinct because of over-harvest, exotic species introductions, and habitat modifications by humans. An exception is the U.S. Naval Base at Guantanamo Bay, Cuba, where the Cuban hutia is very common and is responsible for a variety of damage and conflicts. Conflicts with humans include damage to landscaping, gnawing through cables, damage to vehicles, and the accumulation of large amounts of feces in residential areas. Additionally, hutia are primarily herbivores and botanists have documented substantial damage to native vegetation with little subsequent regeneration of many plant species. Current management focuses on population reduction by shooting and some trapping, followed by euthanasia or relocation to remote areas. Although there is little published information on the Cuban hutia, this paper presents a literature review, population survey data (1999-2000), and biological data from a sample of hutia collected in May 2001. It appears that the hutia, the largest native mammal in Cuba, is quite prolific and well adapted to exploit most habitats and plant foods. Some considerations, including advantages and disadvantages, of potential management techniques (habitat modification, exclusion, trapping, shooting, and toxicants) to reduce damage and conflicts with hutia are presented. Finally, several areas of additional data or research needs are identified. Key Words: Capromys pilorides , Caribbean, damage, Cuban hutia, rodent, wildlife management, Cuba Proc. 20 th Vertebr. Pest Conf. (R. M. Timm and R. H. Schmidt, Eds.) Published at Univ. of Calif., Davis. 2002. Pp. 59-66. INTRODUCTION wildlife, and wildlife issues. During the trip, discussions The U.S. Navy requested assistance from USDA were held with Base personnel regarding wildlife damage Wildlife Service’s (WS) Virginia State Office (WS-VA) and management at GTMO. The entire Base property in the management of several non-native invasive (30,000 acres, of which about 20,000 is terrestrial) was vertebrate species (feral cats and dogs, chickens, goats, toured, using the existing road system, to familiarize white-tailed deer, guinea fowl, and pigeons) that posed consulting personnel with the habitats. Cuban hutia were problems (e.g., vehicle strikes, airport hazards, native collected during the course of wildlife population control vegetation damage, and predation on native wildlife) at operations (trapping and shooting) and later necropsied to the Naval Base at Guantanamo Bay (GTMO), Cuba. obtain biological and demographic information on the Several trips to GTMO were made by WS personnel to species. This paper provides the results of a literature reduce those populations. Additionally, high densities of review and population survey, biological data on hutia, a large native rodent (the Cuban hutia, Capromys and a discussion of potential strategies and techniques for pilorides ) caused a variety of damage and conflicts. A hutia management at GTMO. research scientist from the WS National Wildlife Research Center (NWRC) accompanied a WS-VA LITERATURE REVIEW wildlife specialist on a trip to GTMO in May 2001. This Although Cuba has a rich flora and avian fauna, it trip was preceded by visits by university scientists and has few native mammals. Of the 77 native mammalian personnel of The Nature Conservancy who, along with species, >80% are extinct (Woods 1989, Woods and U.S. Navy biologists, documented vegetation damage by Eisenberg 1989). Bats comprise the largest mammalian hutia and provided some information on the status of species group on the island: 33 species have been hutia populations. The objectives of the May trip by WS identified (both living and extinct). Rodents comprise the personnel were to further assess the hutia situation at next most common mammalian species group. GTMO and to recommend possible management Historically, there have been as many as 21 species strategies. WS-VA personnel had made several trips to belonging to 2 subfamilies (Capromyinae and GTMO for hutia control operations before the May trip. Heteropsomyinae), but only 4 species (all Capromys spp.) Before the May trip, a literature review was currently remain (Woods 1989). There is also one rare conducted on hutia as well as Cuban vegetation, habitats, species of insectivore ( Solenodon cubanus ). Human 59 exploitation, habitat modification, and exotic species fur is lighter colored on the underside of the animal. introductions have caused the demise of most species Hutia of various species are, in general, sexually (Woods and Eisenberg 1989, Wing 1989). It is mature at about 10 months. Based on observations of interesting that so many mammal groups (carnivores, captive animals, it appears that females can breed and ungulates, rabbits, marsupials, and most rodent genera) bear young throughout the year, but have a birth peak in that occur in North, Central, and South America are June. Females undergo a 15-16-day estrus and have a absent from the living or extinct species of Cuba; this is gestation period of about 110-125 days. The young are presumably because of the great geographic isolation of very precocial and are fully weaned in about 150 days, the Caribbean Islands (Williams 1989). Most of the although they are sampling vegetation within a few days native mammalian species of Cuba are rare or after birth. Females have a pair of lateral thoracic endangered; of terrestrial species, only the Cuban hutia is mammae on each side that are well hidden in the fur of fairly common, especially in the area of Guantanamo Bay their sides. Females typically have one young during (Alvarez and Gonzalez 1991, Anderson and Jones 1984, their first pregnancy but usually bear 2-3 (range 1-6) IUCN 1982, Nowak 1991, Wilson and Reeder 1993). young thereafter. Hutia may live 8+ years in captivity. It has been already noted that a number of non- Hutia, depending on the species, are usually solitary or native mammalian species occur in Cuba. Some of these found in family groups. were introduced purposefully (cattle, sheep, goats, pigs, The Cuban hutia is primarily nocturnal, spending the chickens, white-tailed deer, and mongoose) while others days in trees, inside hollowed-out tree trunks, in dense arrived accidentally (commensal rodents such as Rattus grass, in rocky areas, or underground in natural openings. spp. and Mus musculus ). We will not address these They forage on a variety of plant parts (bark, stems, species in this report unless they have a bearing on hutia leaves, flowers, fruit) of many species and may consume ecology or management. lizards. Presumably, they do not require free water. Because of the rarity of the Capromyids, most Cuban hutia use a wide variety of habitats from steep, human effort with them involves locating and protecting rocky, ocean cliffs to mud flats to grasslands to forests. populations, including relocation and captive breeding The chief predators of hutia are humans, large birds of programs (e.g., Alvarez and Gonzalez 1991, Brochstein prey, boas, and introduced dogs and cats. The Cuban 1987, Clough 1985). There is relatively little published crocodile may have been a significant predator of hutia, literature on the hutia, and some of what may be available but that species is now very rare in Cuba. Hutia may feed is in Spanish and located in Cuban journals that are not on the bark that they strip from trees and may feed in readily accessible in the U.S. Much of what we know gardens, but are not considered an agricultural pest, about hutia comes from observations of captive perhaps because of their rareness throughout most of populations held at zoos or at universities; furthermore, Cuba. the accounts in mammal books are usually very brief In addition to the general literature summarized (e.g., Anderson and Jones 1984, Nowak 1991, Wilson above, there have been some reports generated on hutia and Reeder 1993, Parker 1990). Most of the research on and other resources of GTMO that provide more specific hutia has been done by Charles Woods of the University information on hutia and their damage. These include a of Florida, Gainesville (e.g., Woods 1982, 1989; Woods Rapid Ecological Assessment (REA) of the entire Base and Howland 1979; Woods and McKeen 1989). (ProAmbiente/The Nature Conservancy 1999), an Unfortunately for resource managers, his research focuses assessment of plant damage (APD) by herbivores at the on species evolution, taxonomy, morphology, and Base (Areces-Mallea 2000), and a hutia population biogeography rather than on ecology, management, and management (HPM) report (Higginson and Howe 2001). species interactions. Lee (1996) provides a good, general An additional report (USFWS 1978) provides text on the natural history of Cuba, but only a very brief background information on fish and wildlife resources account of hutia. He notes that the Cuban hutia is the and their potential management at GTMO but makes no largest native mammal in Cuba and is known to Cubans mention of hutia. as “juntia Conga,” although we found them to be The REA is a lengthy document that reviews the commonly called “banana rats” at the Naval Base. status of all terrestrial and marine resources of GTMO. The following brief account of the biology and Although moderately disturbed in the past by human ecology of the Cuban hutia has been gleaned from the activities, GTMO is considered an important global above citations. The Cuban hutia is the largest of the representative of the arid, tropical ecosystems of the living species of Capromys . Adults average about 4-7 kg Caribbean.