| Marsh deer | |
|---|---|
 | |
| Male marsh deer | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Family: | Cervidae |
| Subfamily: | Capreolinae |
| Genus: | Blastocerus Wagner, 1844 |
| Species: | B. dichotomus |
| Binomial name | |
| Blastocerus dichotomus (Illiger, 1815) | |
 | |
| Geographic range: Red=Former; Yellow=Present | |
The marsh deer (Blastocerus dichotomus) is the largest deer species from South America.
It is found in Argentina, Bolivia, Peru, Brazil, Uruguay and Paraguay. Formerly found in much of tropical and subtropical South America, it ranged east of the Andes, south from the Amazon rainforest, west of the Brazilian Atlantic rainforest and north of the Argentinian Pampa. Today it is largely reduced to isolated populations at marsh and lagoon zones in the Paraná, Paraguay, Araguaia and Guapore river basins. Small populations also occur in the southern Amazon, including Peru where protected in Bahuaja-Sonene National Park. [3] [4] [5] It is listed as a vulnerable species by the IUCN and is protected under CITES Appendix I. [1] Ths is the only species in the genus Blastocerus.
The latter half of its scientific name refers to the forked antlers.
Marsh deer resemble the North American mule deer or blacktail deer. They possess very large ears lined with white hairs, red-gold to tawny brown fur, blackish eyes and long dark legs. The hair turns darker during winter. There are also white marks on the hips and around the eyes. The legs are black below the tarsal as is the muzzle. The tail is of a paler reddish tone than the rest of the body on its upper part and black on the under part. The head-and-body length is 153 to 200 cm (5.02 to 6.56 ft), while the tail adds a further 12–16 cm (4.7–6.3 in). The height at the shoulder can range from 100 to 127 cm (3.28 to 4.17 ft). [6]
The hoof, which is large in relation to the body, has elastic interdigital membranes which are useful for swimming and walking on marshy surfaces. Only the males possess antlers which are ramified and reach a length of 60 centimetres (24 in). An adult typically grows to a weight of 80 to 125 kg (176 to 276 lb), although an occasional big male can weigh up to 150 kg (330 lb). [7]
They are solitary animals or living in groups with less than 6 individuals with only an adult male. Their main predators are the jaguar and the puma.
The marsh deer lives only in marsh areas, notably the Pantanal and Chaco, in which the level of water is less than 70 cm (28 in) deep. They are swift swimmers. The marshes with their high vegetation density protect them from predators and provide them with food. These deer also have a small migratory pattern, they follow the water levels between the dry season and flooding season. With the fluctuation in water levels, they are able to find new food sources that the water uncovers during the dry season. Some freshwater ponds on the Pantanal Wetland, Brazil reported low densities of individuals dictating that those ponds are not able to support large populations of marsh deer. [8]
Since marsh deer live near aquatic habitats, they eat a majority of their diet in aquatic plants. A study was conducted and they found 40 different species of plants in which they ate. The main food component was Graminae which took up 22% of their diet, Pontederiaceae took up 12%, Leguminosae was about 11%, and the rest was filled in with Nymphaeaceae, Alismataceae, Marantaceae, Onagraceae, and Cyperaceae. They also enjoy eating aquatic flowers and shrubs that grow in the swamps and the floating mats. [9] They can be best classed as a grazer-browser for food. Their diet also changes between the dry season and the flood season.
Usually the rutting season coincides with the dry season but can change from animal to animal. They may use this to their advantage for breeding or finding mates because the densities of marsh deer are significantly higher on the Rio Negro marshland boundary during the dry season compared to the less dense, more distributed population during the flooded season. [8] Gestation lasts approximately 271 days. [10] The offspring (normally one per female, though occasionally twins are born) are born between October and November. The infant deer are whitish which becomes more adult-like after a year.
The natural predators of the marsh deer – the jaguar (locally called onça or yaguaraté) (Panthera onca) and the puma (Puma concolor)— have almost completely disappeared from its habitat. The former major threat was poaching for its antlers, but this is somewhat under control. Destruction of its habitat presents nowadays the major threat to marsh deer. The Yacyretá Dam altered an area in which several hundred individuals lived and the draining of marshes for farmland and cattle farming threaten hundreds of hectares every year in Argentina and Brazil. Contagious diseases from cattle are also a problem, though it has been shown that the deer is not affected by brucellosis. In October 2018, Argentina established the Ciervo de los Pantanos National Park to help protect this species. [11]
The jaguar is a large cat species and the only living member of the genus Panthera native to the Americas. With a body length of up to 1.85 m and a weight of up to 158 kg (348 lb), it is the biggest cat species in the Americas and the third largest in the world. Its distinctively marked coat features pale yellow to tan colored fur covered by spots that transition to rosettes on the sides, although a melanistic black coat appears in some individuals. The jaguar's powerful bite allows it to pierce the carapaces of turtles and tortoises, and to employ an unusual killing method: it bites directly through the skull of mammalian prey between the ears to deliver a fatal blow to the brain.
The yacare caiman, also known commonly as the jacare caiman, Paraguayan caiman, piranha caiman, red caiman, and southern spectacled caiman, is a species of caiman, a crocodilian in the family Alligatoridae. The species is endemic to Argentina, Bolivia, Brazil, and Paraguay. Brown in color and covered with dark blotches, males grow to a total length of 2–3 m and weigh around 40–50 kg (88–110 lb); while females grow to 1.4 m long and about 15–20 kg (33–44 lb). Typical habitats of this caiman include lakes, rivers, and wetlands. Its diet primarily consists of aquatic animals, such as snails, and occasionally land vertebrates. Mating occurs in the rainy season and eggs hatch in March, with young fending for themselves as soon as they hatch. The yacare caiman was hunted heavily for its skin to use for leather in the 1980s, which caused its population to decrease significantly. However, trading restrictions placed since have caused its population to increase. Its population in the Pantanal is about 10 million, and it is listed as least concern on the IUCN Red List.
The Pantanal is a natural region encompassing the world's largest tropical wetland area, and the world's largest flooded grasslands. It is located mostly within the Brazilian state of Mato Grosso do Sul, but it extends into Mato Grosso and portions of Bolivia and Paraguay. It sprawls over an area estimated at between 140,000 and 195,000 km2. Various subregional ecosystems exist, each with distinct hydrological, geological and ecological characteristics; up to 12 of them have been defined.
The giant otter or giant river otter is a South American carnivorous mammal. It is the longest member of the weasel family, Mustelidae, a globally successful group of predators, reaching up to 1.8 m. Atypical of mustelids, the giant otter is a social species, with family groups typically supporting three to eight members. The groups are centered on a dominant breeding pair and are extremely cohesive and cooperative. Although generally peaceful, the species is territorial, and aggression has been observed between groups. The giant otter is diurnal, being active exclusively during daylight hours. It is the noisiest otter species, and distinct vocalizations have been documented that indicate alarm, aggression, and reassurance.
The Humid Chaco is tropical grasslands, savannas, and shrublands ecoregion in South America. It lies in the basin of the Paraná River, covering portions of central Paraguay and northern Argentina, and with a small portion of southwestern Brazil and northwestern Uruguay. The natural vegetation is a mosaic of grasslands, palm savanna, and forest.
The Pampas deer is a species of deer that live in the grasslands of South America at low elevations. They are known as veado-campeiro in Portuguese and as venado or gama in Spanish. It is the only species in the genus Ozotoceros.
The Grande Sertão Veredas National Park is a national park located on the border between the states of Minas Gerais and Bahia, Brazil.
The Ilha Grande National Park is located on the border between Paraná and Mato Grosso do Sul states in Brazil. The park was created in 1997 to protect the biological diversity of the upper Parana River area.
Noel Kempff Mercado National Park is a national park in northeast Santa Cruz Department, Province of José Miguel de Velasco, Bolivia, on the border with Brazil.
The yellow anaconda, also known as the Paraguayan anaconda, is a boa species endemic to southern South America. It is one of the largest snakes in the world but smaller than its close relative, the green anaconda. No subspecies are currently recognized. Like all boas and pythons, it is non-venomous and kills its prey by constriction.
The maguari stork is a large species of stork that inhabits seasonal wetlands over much of South America, and is very similar in appearance to the white stork; albeit slightly larger. It is the only species of its genus to occur in the New World and is one of the only three New World stork species, together with the wood stork and the jabiru.
The plumbeous ibis, also formerly called the blue ibis, is a large distinctive ibis species endemic to parts of central South America.
The purplish jay is a species of bird in the family Corvidae. It is found in northern Argentina, Bolivia, southern Brazil, Paraguay and southeastern Peru. Its natural habitats are subtropical or tropical dry forest, subtropical or tropical moist lowland forest, and heavily degraded former forest.
The Pantanal Matogrossense National Park is a national park in the state of Mato Grosso at the border to Mato Grosso do Sul, Brazil.
Guaporé Biological Reserve (Portuguese: Reserva Biológica do Guaporé is a biological reserve in the state of Rondônia, Brazil, on the border with Bolivia.
Taiamã Ecological Station is an ecological station in the Mato Grosso state of Brazil.
The Chiquitano dry forests is a tropical dry broadleaf forest ecoregion in Bolivia and Brazil. The ecoregion is named for the Chiquitano people who live in the region.
San Matías Integrated Management Natural Area is a protected area in Bolivia located in the Santa Cruz Department.
Pomacea lineata is a species of a freshwater snail with gills and an operculum, an aquatic gastropod mollusk in the family Ampullariidae, the apple snails.
Cantão is a tropical forest ecosystem located in the central Araguaia river basin, the southeastern edge of the Amazon biome, in the Brazilian state of Tocantins. It is one of the biologically richest areas of the eastern Amazon, with over 700 species of birds, nearly 300 species of fish, and large populations of endangered species such as the giant otter and the black cayman. About 90% of the Cantão ecosystem is protected within Cantão State Park.
Media related to Blastocerus dichotomus at Wikimedia Commons
Data related to Blastocerus dichotomus at Wikispecies