Habitat and Ecology
Pygmy Raccoons are mainly nocturnal, although it is not uncommon to see them during daylight (Cuarón et al. 2004, García-Vasco 2005). Generally it is a solitary mammal, which could sometimes form family groups (Cuarón et al. 2004, Jones and Lawlor 1965).
The Pygmy Raccoon is an omnivorous species, with preference for crabs but followed by fruits, insects, crayfish, and small vertebrates (McFadden et al. 2006, Martínez-Godinez 2008). The relevance of the different food items varied importantly between seasons and sites, and following major changes in habitat quality due to hurricanes (McFadden et al. 2006, Martínez-Godinez 2008).
The Pygmy Raccoon is particularly vulnerable to introduced pathogens and diseases such as mange, rabies and dog distemper from exotic animals (Cuarón et al. 2004, McFadden 2004, Mena 2007). The parasites Eimeria nutalli, Placoconus lotoris, Capillaria procyonis, Physaloptera sp., a mite in the family Listrophoridae, and a trematode in the family Heterophyidae have been collected from P. pygmaeus individuals (McFadden et al. 2005). The identification of Toxoplasma gondii in some Pygmy Raccoons suggests a recent spillover from domestic cats (McFadden et al. 2005). It has been identified that the Pygmy Raccoon has been exposed to infectious canine hepatitis, canine distemper and feline panleukopenia viruses (McFadden et al. 2005, Mena 2007).
Genetic information indicates that Pygmy Raccoon individuals share the same mtDNA haplotypes, suggesting a recent population bottleneck that might be related to the founder effect (McFadden et al. 2008).
IUCN Red List Assessment
Red List Category
Red List Criteria
Criterion C: Small population size and decline
Number of mature individuals is less than 250: based on the estimates of population size including juveniles [323-955], and the fact that it has been estimated that 59% of the population corresponds to mature individuals, we estimate a number of mature individuals that ranges from [192-567]. Following the precautionary principle of using the lower limits, the population size of mature individuals is much less than 250 mature individuals.
C2: a continuing decline on the population size due to the effects of introduced species and
(a i). Less than 50 mature individuals in all subpopulations: The average estimated population size and standard error for all pygmy raccoon subpopulations is 27.8 ± 5.5 individuals.
(a ii). At least 90% of mature individuals in one subpopulation subcriterion is not met because abundance estimates range from a low of 16 individuals (95% CI= 13-20) to a high of 48 individuals (95% CI = 39-79).
(b) Extreme fluctuations in the number of mature individuals due to the effect of hurricanes (in this part of the Caribbean hurricanes occur on average once every 8 years).
In addition, the species meets criterion B to be listed as Endangered:
Criterion B: Geographic range
B1: Extent of occurrence of 478 km² is much less than 5,000 km².
B2: Area of occupancy is much less than 500 km² (if the EOO is 478 km² the AOO must be less than this value);
(a) less than 5 locations [1 location];
(b) continuing decline in number of mature individuals due to the effect of introduced alien taxa to the island;
(c) extreme fluctuations in the number of mature individuals due to the effect of hurricanes.
- 1996Endangered(Baillie and Groombridge 1996)
- 1994Insufficiently Known(Groombridge 1994)
- 1990Insufficiently Known(IUCN 1990)
- 1988Insufficiently Known(IUCN Conservation Monitoring Centre 1988)
The species is severely impacted by hurricanes and already depressed populations from a variety of human threats make it increasingly difficult for populations to recover following natural disasters. After major hurricanes, the density of pygmy raccoons can decline at a particular site by as much as 60% and the proportion of juveniles in the population can diminish significantly (Copa-Alvaro 2007). The impact of hurricanes may vary among regions or vegetation types on the island (Copa-Alvaro 2007).
The expansion and widening of the road system is fragmenting the vegetation of the island in at least three areas (Cuarón et al. 2004, de Villa-Meza et al. in press). The widening of roads is potentially increasing their barrier effect and exacerbating their impact on the conservation of Pygmy Raccoons and other native species (de Villa-Meza et al. in press). Most cases of Pygmy Raccoon mortality documented since 2001 have been the result of animals being run over by cars on the island's highways (García-Vasco 2005).
Alien invasive predators, such as Boa constrictor, as well as domestic and feral dogs, may have an important impact on the Pygmy Raccoon population and it is confirmed that feral dogs predate on them (Martínez-Morales and Cuarón 1999, García-Vasco 2005, Bautista 2006). Additionally, introduced carnivores to the island could easily become a source of parasites and pathogens that could potentially affect negatively Pygmy Raccoon populations (Cuarón et al. 2004, McFadden et al. 2005, Mena 2007). The introduction of congeners from the mainland (P. lotor), usually for pets, is a risk of genetic introgression and a potential source of parasites and pathogens (Cuarón et al. 2004).
Hurricanes are the main natural threat recognized for the Cozumel biota (Cuarón et al. 2004, Perdomo 2006, Barillas 2007, Copa-Alvaro 2007). In the case of the pygmy raccoon, hurricanes cause drastic population decline, reduction in the proportion of juveniles, and cause injury and facilitate pathological change (Copa-Alvaro 2007, Mena 2007). The frequency, magnitude and duration of hurricanes in the Caribbean Basin is increasing (CITA), so they are an issue of major concern as there may be a synergistic effect with anthropogenic disturbance.
Hunting and collection of Pygmy Raccoons as pets is currently not an important threat.
The Cozumel raccoon goes by a variety of common names including the dwarf raccoon, Cozumel Island raccoon, and Cozumel raccoon-bear.
Clinton Hart Merriam first described the Cozumel raccoon as morphologically distinctive from its mainland relative, the common raccoon subspecies Procyon lotor hernandezii, in 1901. Since then, other scientists have generally agreed with Merriam's assessment, especially Kristofer Helgen and Don E. Wilson, who have dismissed this classification for the other four island raccoons in their studies in 2003 and 2005. Therefore, the Cozumel raccoon was listed as the only distinct species of the genus Procyon besides the common raccoon and the crab-eating raccoon in the third edition of Mammal Species of the World. An archaeological study showed that Maya from Cozumel used raccoons of reduced stature, which suggests that the size reduction of this raccoon is not a recent phenomenon.
No true fossils of the species are known, although skeletons have been found at some archeological sites on the island. Cozumel island itself separated from the mainland during the late Pleistocene, so that the species is unlikely to be older than 122,000 years. Data from molecular clock studies implies a divergence date from the common raccoon of anything between 26,000 and 69,000 years ago.
Merriam described the Cozumel raccoon as being markedly smaller, both externally and cranially and easy to distinguish from the common raccoon because of its "broad black throat band and golden yellow tail, short posteriorly expanded and rounded nasals and peculiarities of the teeth". Its reduced teeth point to a long period of isolation.
Apart from its smaller size and more rounded snout, the Cozumel raccoon is similar in appearance to the common raccoon. The fur over the upper body is buff-grey ticked with occasional black hairs, while the underparts and legs are pale buff in color. The top of the head lacks the buff tinge of the rest of the body, and has a grizzled grey coloration, contrasting with the white fur of the muzzle and chin, and with the black "mask" pattern around the eyes. A line of brownish-grey fur runs down the middle of the snout, joining the "mask" patterns on either side. The tail is yellowish, with six or seven black or brown rings that become fainter on the underside. In males, the scruff of the neck has a patch of relatively bright, orange fur.
Adults range from 58 to 82 centimetres (23 to 32 in) in total length, including the 23 to 26 centimetres (9.1 to 10.2 in) tail, and weigh between 3 to 4 kilograms (6.6 to 8.8 lb). This represents an example of insular dwarfism, and the animals are, on average, about 18% shorter and 45% lighter than the subspecies of common raccoon found on the local mainland, P. lotor shufeldti. Cozumel raccoons also exhibit sexual dimorphism, with the males being around 20% heavier than the females.
Distribution and habitat
According to the IUCN Red List, they are considered critically endangered. In fact, they report that only about 250–300 individuals are left on the planet. These raccoons are so extremely endangered because of their small geographic range. They are endemic to Cozumel Island, an island around 478 square kilometres (185 sq mi) in area, lying off the east coast of the Yucatan Peninsula in Mexico. Cozumel Island supports several other carnivores, including the dwarf coati (Nasua narica nelsoni) and dwarf gray fox (Urocyon sp.). Islands usually lack terrestrial mammals, especially carnivores making the Cozumel raccoon and the others unique.
On the island, the raccoons inhabit a range of habitats, but are primarily limited to the mangrove forests and sandy wetlands in the northwest tip of the island. However, they have also been captured in semi-evergreen forests and agricultural lands surrounding these preferred habitats., and in the Punta Sur ecological park at the south end of the island.
Relatively little is known about the group size of the raccoons. They are primarily nocturnal and solitary animals, but may sometimes form family groups possibly consisting of the mother and cubs.
The raccoons live in densities of about 17-27 individuals per km2., and inhabit home ranges of around 67 hectares (170 acres) on average. However, individuals do not appear to defend territories to any great extent, and their close relative, the common raccoon, can exist at very high densities when food is abundant. Although there have been no detailed studies of their reproductive habits, females seem to give birth primarily between November and January, possibly with a second litter during the summer months.
The habitat specificity of Cozumel raccoons is in large part due to the type of foods they consume. Their overall diet consists of crabs, fruit, frogs, lizards, and insects. They are a generalist omnivore, but crabs make up over 50% of their diet. Their diet is somewhat seasonal. During the wet season, fruit and vegetation are more abundant and become a large portion of the raccoons’ diet. Then in the dry season, they begin to consume more of the crabs, insects, lizards, etc. Crabs comprising more than half the food they eat could have an effect on their limited distribution: they stay near the water where crabs are abundant.
A large amount of research has been performed to determine whether the Cozumel raccoon is indeed a separate species from the common raccoon. Cuaron et al. (2004) reported that research conducted by many different scholars concludes that they are separate species. Body size and cranium size have been reported to be smaller in P. pygmaeus, hence the name pygmy. Other morphological differences include a broad black throat band, golden yellow tail and reduced teeth; "these and other characteristics point to a long period of isolation".
Threats to species survival
Island carnivores at the top of the food chain often become extinct soon after the arrival of humans. The main danger to the Cozumel raccoon is development of Cozumel island due to the tourism industry. Because the raccoons are only located in a small coastal area at the northwest corner of the island- an area coveted for development- the effects of habitat loss are especially severe. There are no laws protecting the raccoons and also no land set aside for them.
Newer threats to their survival that have been researched in recent years are diseases and parasites. Cozumel has a population of feral cats and domestic cats and dogs that can transmit diseases to the raccoons. On average, there are about 2 different species present in each host. That is not overall abundance, but simply the absolute number of species found. Some captured raccoons had developed antibodies to certain diseases. Cats are only newly introduced on the island due to humans bringing them as pets.
One conservation approach would be to reduce or even eliminate human impact on the mangrove forests, especially in the northwest corner of the island. This would constitute the halting of development in this area and to establish protected land for the raccoons. This land to be set aside would include the habitat that is crucial to the survival of the species, most importantly the mangrove forests and surrounding semi-evergreen forests.
Another method that could help to restore the populations is captive breeding techniques. If they willingly reproduce in captivity as the common raccoons do, it could be used successfully. Additionally, the arrival of pets, especially feral cats, brought more diseases and parasites that are having a significant effect on the raccoons. The best method of reducing these impacts is to remove as many feral cats as possible. For any conservation action to be successful, conservation personnel will need to find a way to compromise with the tourism industry to save the Cozumel raccoons.
Glatston also urged researchers to continue examining the species to assure that the pygmy is a distinct species from its mainland sister taxon.
- Wozencraft, W. C. (2005). "Order Carnivora". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. pp. 627–628. ISBN 978-0-8018-8221-0. OCLC 62265494.
- Cuarón AD, de Grammont PC, Vázquez-Domínguez E, Valenzuela-Galván D, García-Vasco D, Reid F & Helgen K (2008). Procyon pygmaeus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 2008-01-26.
- Helgen, Kristofer M.; Wilson, Don E. (2005). "A Systematic and Zoogeographic Overview of the Raccoons of Mexico and Central America". In Sánchez-Cordero, Víctor; Medellín, Rodrigo A. Contribuciones mastozoológicas en homenaje a Bernardo Villa. Mexico City: Instituto de Ecología of the Universidad Nacional Autónoma de México. pp. 221–236. ISBN 978-970-32-2603-0. Retrieved 2008-08-09.
- Zeveloff, Samuel I. (2002). Raccoons: A Natural History. Washington, D. C.: Smithsonian Books. p. 45. ISBN 978-1-58834-033-7.
- Helgen, Kristofer M.; Wilson, Don E. (January 2003). "Taxonomic status and conservation relevance of the raccoons (Procyon spp.) of the West Indies". Journal of Zoology (Oxford: The Zoological Society of London) 259 (1): 69–76. doi:10.1017/S0952836902002972. ISSN 0952-8369.
- Hamblin, NL (1984). Animal Use by the Cozumel Maya. Tucson: The University of Arizona Press.
- de Villa-Meza, A. et al. (2011). "Procyon pygmaeus (Carnivora: Procyonidae)". Mammalian Species 43 (1): 87–93. doi:10.1644/877.1.
- Merriam, CH (1901). "Six new mammals from Cozumel Island, Yucatan". Proceedings of the Biological Society of Washington 14: 99–104.
- Goldman, EA; Jackson, Hartley H. T. (1950). "Raccoons of North and Middle America". North American Fauna 60: 1–153. doi:10.3996/nafa.60.0001.
- McFadden, K. W. (2004). "The ecology, evolution, and natural history of the endangered carnivores of Cozumel Island, Mexico.". PhD Dissertation, Columbia University, New York.
- McFadden KW, Sambrotto RN, Medellín RA, Gompper ME (2006). "Feeding habits of endangered pygmy raccoons (Procyon pygmaeus) based on stable isotope and fecal analyses.". J Mammal 87: 501–509. doi:10.1644/05-MAMM-A-150R1.1.
- McFadden, K.W., D. García-Vasco, A. D. Cuarón, D. Valenzuela-Galván, R. A. Medellín, and M. E. Gompper (2009). "Vulnerable island carnivores: the endangered endemic dwarf procyonids from Cozumel Island.". Biodiversity Conservation. Online.
- Cuaron, A.D., Martinez-Morales M.A., McFadden K.W., Valenzuela D., Gompper M.E. (2004). "The status of dwarf carnivores on Cozumel Island, Mexico". Biodivers Conserv 13: 317–331. doi:10.1023/B:BIOC.0000006501.80472.cc.
- Alcover, J.A. and M. McMinn. (1994). "Predators of vertebrates on islands". BioScience 44 (1): 12–18. doi:10.2307/1312401. JSTOR 1312401.
- Cuarón, A. D., et al. (2009). "Conservation of the endemic dwarf carnivores of Cozumel Island, Mexico". Small Carnivore Conservation 41 (1): 15–21.
- Lotze, J.-H. & Anderson, S. (1979). "Procyon lotor". Mammalian Species 119: 1–8. doi:10.2307/3503959.
- Glatston, A.R. (Ed.). (1994). "The red panda, olingos, coatis, raccoons, and their relatives: status survey and conservation action plan for procyonids and ailurids". Gland, Switzerland: IUCN (World Conservation Union).
- McFadden, K.W., Wade, S.E., Dubovi, E.J., and Gompper, M.E. (2005). "A serology and fecal parsitology survey of the critically endangered pygmy raccoon (Procyon pygmaeus).". J Wildlife Diseases 41: 615–617. doi:10.7589/0090-3558-41.3.615.
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