The Cozumel raccoon also called the pygmy raccoon, is a critically endangered species of raccoon

Procyon (genus)

Procyon is a genus of nocturnal mammals, comprising three species commonly known as raccoons, in the family Procyonidae. The most familiar species, the common raccoon , is often known simply as "the" raccoon, as the two other raccoon species in the genus are native only to the tropics and are...

 endemic on Cozumel Island

Cozumel

Cozumel is an island in the Caribbean Sea off the eastern coast of Mexico's Yucatan Peninsula, opposite Playa del Carmen, and close to the Yucatan Channel. Cozumel is one of the ten municipalities of the state of Quintana Roo...

 off the coast of the Yucatan Peninsula

Yucatán Peninsula

The Yucatán Peninsula, in southeastern Mexico, separates the Caribbean Sea from the Gulf of Mexico, with the northern coastline on the Yucatán Channel...

, Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

.

The pygmy raccoon goes by a variety of common names. This raccoon is also known as the dwarf raccoon, Cozumel Island raccoon, Cozumel raccoon, and Cozumel raccoon-bear.

Classification

Clinton Hart Merriam

Clinton Hart Merriam

Clinton Hart Merriam was an American zoologist, ornithologist, entomologist and ethnographer.Known as "Hart" to his friends, Dr. Clinton Hart Merriam was born in New York City in 1855. His father, Clinton Levi Merriam, was a U.S. congressman. He studied biology and anatomy at Yale University and...

 first described the Cozumel raccoon as morphologically

Morphology (biology)

In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....

 distinctive from its mainland relative, the common raccoon subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 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 raccoon

Island raccoon

The term island raccoons is used as a generic term for five subspecies or species of raccoon endemic on small Central American and Caribbean islands, such as Cozumel and Guadeloupe...

s 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

Crab-eating raccoon

The Crab-eating Raccoon is a species of raccoon native to marshy and jungle areas of Central and South America . It is found from Costa Rica south through most areas of South America east of the Andes down to northern Argentina and Uruguay...

 in the third edition of Mammal Species of the World

Mammal Species of the World

Mammal Species of the World, now in its 3rd edition, is a standard reference work in zoology giving descriptions and bibliographic data for the known species of mammals.An updated Third Edition of Mammal Species of the World was published late in 2005:...

. An archaeological study showed that Maya

Maya civilization

The Maya is a Mesoamerican civilization, noted for the only known fully developed written language of the pre-Columbian Americas, as well as for its art, architecture, and mathematical and astronomical systems. Initially established during the Pre-Classic period The Maya is a Mesoamerican...

 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

Pleistocene

The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

, so that the species is unlikely to be older than 122,000 years. Data from molecular clock

Molecular clock

The molecular clock is a technique in molecular evolution that uses fossil constraints and rates of molecular change to deduce the time in geologic history when two species or other taxa diverged. It is used to estimate the time of occurrence of events called speciation or radiation...

 studies implies a divergence date from the common raccoon of anything between 26,000 and 69,000 years ago.

Description

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 cm (22.8 to 32.3 ) in total length, including the 23 to 26 cm (9.1 to 10.2 ) tail, and weigh between 3 to 4 kg (6.6 to 8.8 ). This represents an example of insular dwarfism

Insular dwarfism

Insular dwarfism, a form of phyletic dwarfism, is the process and condition of the reduction in size of large animals – typically mammals – when their population's range is limited to a small environment, primarily islands. This natural process is distinct from the intentional creation of dwarf...

, 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

Sexual dimorphism

Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...

, 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 (184.6 sq mi) in area, lying off the east coast of the Yucatan Peninsula

Yucatán Peninsula

The Yucatán Peninsula, in southeastern Mexico, separates the Caribbean Sea from the Gulf of Mexico, with the northern coastline on the Yucatán Channel...

 in Mexico. Cozumel Island supports several other carnivores including the dwarf coati (Nasua nelsoni) and dwarf gray fox (Urocyon cinereoargenteus). Islands usually lack terrestrial mammals, especially carnivores making the pygmy raccoon and the others unique.

On the island, the raccoons inhabit a range of habitats, but are primarily limited to the mangrove

Mangrove

Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...

 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

Punta Sur

Punta Sur marks the southern point of Cozumel and is part of the Parque Punta Sur, a ecological park that covers the reefs, beaches, lagoons, and the low forest of the surrounding area...

ecological park at the south end of the island.

Behavior

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 (165.6 acre) 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.

Diet

The habitat specificity of pygmy 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 most of their diet. In fact, over 50% of their diet is made of crabs. 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. Being that crabs comprise the majority of the food they eat, this could be the reason their distribution is so limited. They stay near the water where crabs are abundant.

Morphological specializations

A large amount of research has been performed to determine whether the pygmy 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, reduced teeth, and “that 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 pygmy raccoon is development of Cozumel 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.

Conservation actions

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 pygmy raccoons.

Glatston also urged researchers to continue examining the species to assure that the pygmy is a distinct species from its mainland sister taxon.