10 ANIMALS THAT LIVE IN A TRANSITIONAL ENVIRONMENT - BIOLOGY - 2025

Some of the animals that live in a transitional environment are the common bittern, the spotted seal, the Magellanic penguin or the common flamingo. A transition environment, or ecotone, is a space of biological interaction where two or more ecosystems that have different characteristics converge. Some of these ecosystems are, for example, mangroves, coasts, marshes and foothills.

This area is not a rigid line, its limits are not static. On the contrary, it is a dynamic region where countless biological interactions occur, which can affect the population dynamics of the species that live there.

Yacaré. Source: Charles J Sharp

The origin of the transition ecosystem can be natural, such as the cloud forest; an ecological space between the jungle and the forest. It could also be induced by man, as is the erosive process of desertification.

One of the aspects that characterizes this area is its biological wealth. The animals that live there have undergone morphological, anatomical and even behavioral adaptations, thus allowing them to develop fully.

Examples of animals that inhabit transitional environments

Bittern (

Juan Emilio from Las Palmas de Gran Canaria, Spain

This species is a pelecaniform bird belonging to the Ardeidae family, native to the wetlands of Africa and Eurasia. The bittern is a heron with a robust complexion, thus weighing almost two kilograms. In relation to their feathers, they are soft brown in color, with dark stripes.

Its common name is due to one of the calls that this animal uses, similar to the moo that the bull emits. When the Botaurus stellaris is not in the rearing stage, it usually inhabits reed beds, rice fields and reservoirs. It can also live in flooded areas and marshes.

Spotted seal

Pixabay.com

It is a pinniped mammal that is a member of the Phocidae family. Each species has a unique spot pattern in a brownish-black, gray, or tan hue. If the coat is dark, the moles will be light. Instead, the ventral area is white.

The spotted seal could spend several days at sea, being able to swim up to 50 kilometers in search of food. It inhabits the entire coastline of the cold and temperate seas of the northern hemisphere. They tend to rest on the sandy beaches, the rocky shores of the Hebrides or those of New England.

It could also live in sandy intertidal areas, being able to enter the estuaries in search of its prey.

Magellanic Penguin (

Gustavo A. Perez Prado

The Magellanic penguin is medium in size, reaching around 35 to 45 centimeters tall. His head is black. In addition, it has a white stripe that starts at the eye, surrounds the ears and the lower part of the face, joining both lines at the throat level.

At the dorsal level, its feathers are grayish black, unlike the front, which is white. Between the head and the torso it has two black bands, highlighting the inverted horseshoe shape of the lower band.

This species, also known as the Patagonian penguin, is a bird that is part of the Spheniscidae family. The female nests on the coasts and islands of Chilean and Argentine Patagonia and in the Malvinas Islands. During the winter it migrates to warmer waters, thus being able to reach the southeast of Brazil and Uruguay.

Yacaré (

This species is endemic to the tropical and subtropical regions of South America. It has a heavily armored body in the dorsal area, being able to measure up to 3 meters long. As for its coloration, it can be dark olive or black.

The natural habitat of the Caiman yacaré are the rivers, swamps, streams and estuaries of Brazil, Paraguay, Argentina and Uruguay. In addition, it lives in transition regions between temperate forests and subtropical forests.

Red marsh crab (

The American red crab, as this species is also known, can measure up to 15 centimeters. Its color can be from deep red to black, green or brown. In contrast to the rest of the members of his gender, his body looks more elongated than these. On the other hand, the male has longer claws than the female.

This crustacean, belonging to the Cambaridae family, is native to the United States. It lives in ponds and marshes, thus having a great capacity to adapt to various ecosystems.

It has body adaptations that allow it to live for more than 4 months in dry environments. In addition, it could tolerate waters with a certain degree of salinity, something unusual in crayfish.

Common Flamingo (Phoenicopterus roseus)

This bird belongs to the Phoenicopteridae family. It lives in southern Africa and Europe, as well as in the southwest of the Asian continent. In these regions it inhabits saline and brackish lakes and marshes, as well as coastal lagoons, wetlands and on the coast.

It is an animal that can measure from 110 to 150 centimeters, with a weight between 2 and 4 kilograms. Their legs and neck are very long, with a downward curved beak, a characteristic of the species. Its plumage is light pink, although on the wings it could become red. The beak is pink with a black tip.

Chigüire (

The capybara or chigüire is the largest and heaviest living rodent in the world. It has a barrel-shaped body, with a small head. The coat is reddish in color on the upper part, turning yellowish brown towards the lower part.

This animal grows up to 130 centimeters long, weighing around 65 kilograms. A characteristic of the species is that it has slightly webbed feet, thus facilitating its movement in the water and in the muddy terrain where it lives.

It is distributed in almost all of South America, thus covering from eastern Venezuela and Guyana to north central Argentina and Uruguay. It can live close to rivers and lakes. They also tend to live in mangroves and salt marshes.

The highest population density of the chigüire is found in the wetlands of South America, among which are, for example, the llanera region and the alluvial plain to the west of Brazil, known as the Great Pantanal.

Piangua (

The piangua is a white bivalve mollusk, belonging to the Arcidae family. It has an outer coat of a hairy type, with a coloration from dark brown to black. In relation to the shells, they are oval, thick and large.

This species is distributed in the Pacific Ocean, and can be found from Mexico to Peru. It lives buried in the mud, thus covering the intertidal zone to about 5 meters deep. It is found abundantly in swamps and mangroves.

Mangrove oyster (

This bivalve mollusk is typical of the coastal lagoons of Brazil and the Caribbean, representing a great fishing resource for the inhabitants of the area. Inhabits mangrove systems, where it fixes on roots.

This ecosystem, together with the lagoons, offers favorable environmental variability for the development of the mangrove oyster. There, you can form large natural banks.

Swamp deer (

This species is the largest deer in South America, reaching 2 meters in length. One characteristic that identifies it is that the male has a branched antler, which could measure up to 60 centimeters.

In addition to this, its hooves, which are very wide in relation to the size of its body, have interdigital membranes. These help the marsh deer to swim, as well as to move in the middle of the marshy surfaces where it lives.

Currently it is distributed in small and isolated populations in the Paraná River, located in the east-central part of South America. It is also located in Peru, Bolivia and Argentina. Their favorite habitats are humid or waterlogged areas, such as estuaries and lagoons.

References

1. Carmen Gonzalez1, Roberta Crescini1, William Villalba1, Ana Maldonado1, Gladys Vásquez1, Gabriel Soto (2015). Size structure, growth and mortality of Crassostrea rhizophorae in the Restinga lagoon, Isla de Margarita, Venezuela. Scielo. Recovered from scielo.org.ve.
2. Ruggiero, Adriana & Ezcurra, Cecilia. (2003). Biogeographic regions and transitions: Complementarity of analyzes in historical and ecological biogeography. A Latin American Perspective Of Biogeography. ResearchGate. Recovered from researchgate.net.
3. James H. Thorp (2015). Functional Relationships of Freshwater Invertebrates. Science direct. Recovered from sciencedirect.com.
4. Kark, Salit. (2013). Ecotones and Ecological Gradients. Recovered from researchgate.net.
5. David Thorpe (2014). The Importance of Ecotones. Recovered from eoi.es.
6. Pawar, Prabhakar, Al Tawaha, Abdel Rahman. (2017). Species diversity and distribution of marine bivalves from coastal transitional ecosystem of Uran, Navi Mumbai, India. Advances in Environmental Biology. ResearchGate. Recovered from researchgate.net.
7. Pusceddu, C. Gambi, E. Manini & R. Danovaro (2007). Trophic state, ecosystem efficiency and biodiversity of transitional aquatic ecosystems: analysis of environmental quality based on different benthic indicators. Recovered from tandfonline.com.