Meet the Brazilian cavies family
Capybaras, pacas, agoutis, and guinea pigs are part of a large group called the Cavioidea. In biology, this group is classified as a “superfamily”. Within this superfamily there are 4 smaller families, the most diverse of which is called Caviidae, which we will talk about today.
Cavies
Guinea pigs and cavies belong to the family Caviinae of which three genera are composed, in Brazil two genera are found: Galea and Cavia.
Spix’s yellow-toothed cavy Galea spixii
Originally, four species very similar to each other were described. But through genetic studies it was proposed that there are actually only two, with only G. spixii occurring in Brazil, in the Cerrado and Caatinga biomes — being one of the most abundant mammals of the Caatinga.
It is crepuscular and lives in groups. It feeds on leaves, grasses, branches, tubers and the bark of young trees.
Santa Catarina’s guinea pig Cavia intermedia
There are about nine species in this genus (including the guinea pig), four of which occur naturally in Brazil.
One of the species of this genus is Cavia intermedia. These small rodents were discovered in 1989 in the Moleques do Sul archipelago, in the state of Santa Catarina - the only place where they live. The island where they were found is about 10 hectares in size, but much of the terrain is rocky, leaving only 1 hectare for these animals to survive.
They are one of the rarest animals in the world and their population is estimated to be no more than 50 individuals. With such a small number, there is almost no genetic diversity left - which would normally lead to disease, genetic deformities and extinction of the species. However, the species has managed to overcome this obstacle and the deformities caused by inbreeding no longer exist. The fact that these animals could live so well in such a small group and space was a great surprise to the scientific community.
Although this obstacle has been overcome, such a small population can be quickly decimated if a predator such as a dog or cat is accidentally introduced to the island. As such, it is considered a critically endangered species.
Another subfamily of Cavids found in Brazil is the Hydrochoerinae. This includes the capybaras (Hydrochoerus) and the rock cavies (Kerodon).
Capybaras
There are two species of capybaras: the greater capybara (H. hydrochaeris) and the lesser capybara, which is half the size of the greater capybara (H. isthmius) It is found in Colombia, Venezuela and Panama.
Greater capybara Hydrochoerus hydrochaeris
The capybara is undoubtedly one of the best known animals in Brazil. It inhabits the entire national territory, except for part of the caatinga. Capybaras are the largest rodents in the world, weighing an average of 50 kg (110 lb) and measuring up to 1.2 m (4 ft) long and 60 cm (24 in) tall.
In contrast to other cavids, they have interdigital membranes that make them excellent swimmers. This allows them to spend most of the day foraging for aquatic plants in lakes and rivers.
It is a highly social animal and usually lives in groups of 10 to 20 individuals. It is also an easily adaptable animal that can live in almost any tropical region where there is a large enough body of water for its daily activities - even in dense cities and large metropolises.
Mocós
There are two species of rock cavies, one of which (Kerodon acrobata) can only be found on the border between the states of Goiás, Tocantins and Bahia. It is such a little known species that its conservation status is unknown.
Kerodon rupestris
Rock cavies are slightly larger than cavies, measuring about 40 cm (21 in) and up to 1 kg (1 lb). They are found throughout the Caatinga region in open and rocky areas. They can be classified as generalist herbivores, since they feed on leaves, flowers, fruits, and branch shoots. When the vegetation is dry and sparse, they begin to feed on the bark of trees such as mofumbo, abutuá, and faveleira, managing to jump from branch to branch in search of food.
The Rock cavies are major target for poaching. According to the Red Book of Endangered Brazilian Fauna (ICMBio), their populations have declined by 30% in the last 30 years, and they are extinct in some unprotected areas.
The agoutis, pacas, and pacaranas are somewhat more distant relatives of the capybara. Although they are somewhat similar animals, they belong to different families. They will be introduced later in this text .
Read more:
Revisão Taxonômica do Gênero Galea Meyen, 1832 (Rodentia, Caviidae, Caviinae)
Cavia aperea Brazilian guinea pig
Espécie de preá sobrevive sem variedade genética
Origem e Distribuição Intraparenquimal da Artéria Hepática do Preá (galea Spixii Wagler, 1831)
Filogeografia e citogenética do gênero Kerodon (CUIVER, 1825) (RODENTIA: CAVIIDAE)