Capybara in the context of "Cavia"

The Amazon Delta (Portuguese: delta do Amazonas) is a vast river delta formed by the Amazon River and the Tocantins River (through the Pará River distributary channel) in northern South America. It is located in the Brazilian states of Amapá and Pará and encompasses the Marajó Archipelago, with Marajó Island as its largest island. The main cities located in the vicinity are Belém and Macapá, each with its respective metropolitan area.

The Amazon Delta has a tropical climate with high humidity and high temperatures. It has a wet season with frequent flooding and a dry season where the delta dries out. These seasons shape the environment of the Amazon Delta and the life in it, such as the water buffalo for which Marajó Island is well known, three-toed sloth, capybara, giant anteater, giant otter, jaguar and pink river dolphins.

Aquatic mammals and semiaquatic mammals are a diverse group of mammals that dwell partly or entirely in bodies of water. They include the various marine mammals who dwell in oceans, as well as various freshwater species, such as the European otter. They are not a taxon and are not unified by any distinct biological grouping, but rather their dependence on and integral relation to aquatic ecosystems. The level of dependence on aquatic life varies greatly among species. Among freshwater taxa, the Amazonian manatee and river dolphins are completely aquatic and fully dependent on aquatic ecosystems. Semiaquatic freshwater taxa include the Baikal seal, which feeds underwater but rests, molts, and breeds on land; and the capybara and hippopotamus which are able to venture in and out of water in search of food.

Mammal adaptation to an aquatic lifestyle vary considerably between species. River dolphins and manatees are both fully aquatic and therefore are completely tethered to a life in the water. Seals are semiaquatic; they spend the majority of their time in the water, but need to return to land for important activities such as mating, breeding and molting. In contrast, many other aquatic mammals, such as hippopotamus, capybara, and water shrews, are much less adapted to aquatic living. Likewise, their diet ranges considerably as well, anywhere from aquatic plants and leaves to small fish and crustaceans. They play major roles in maintaining aquatic ecosystems, beavers especially.

Porcupines are large rodents with coats of sharp spines, or quills, that protect them against predators. The term covers two families of animals: the Old World porcupines in the family Hystricidae, and the New World porcupines in the family Erethizontidae. Both families display superficially similar coats of rigid or semi-rigid quills, which are modified hairs composed of keratin, and belong to the infraorder Hystricognathi within the diverse order Rodentia. The two groups are distinct and are not closely related to each other within Hystricognathi. The largest species of porcupine is the third-largest living rodent in the world, after the capybara and beaver.

The Old World porcupines (Hystricidae) live in Italy, West and South Asia, and most of Africa. They are large, terrestrial, and strictly nocturnal. New World porcupines (Erethizontidae) are indigenous to North America and northern South America. They live in wooded areas and can climb trees, where some species spend their entire lives. They are generally smaller than their Old World counterparts and are less strictly nocturnal.

Caviidae, the cavy family, is composed of rodents native to South America and includes the domestic guinea pig, wild cavies, and the largest living rodent, the capybara. They are found across South America in open areas from moist savanna to thorn forests or scrub desert. This family of rodents has fewer members than most other rodent families, with 19 species in seven genera in three subfamilies.