SCAVENGERS: CHARACTERISTICS AND EXAMPLES - BIOLOGY - 2024

The scavengers are those that feed on dead organisms. These species play a very important role within ecosystems. First, they contribute to the natural cycle of organic matter.

Second, and no less important than the previous one, they help to "clean" the environment of corpses that, if not eliminated, could cause serious problems, such as the proliferation of viruses and bacteria, among others.

Osprey. Source: Juan Carlos Noreña Striped hyena. Source: Dr. Shamshad Alam

In natural habitats there are very few obligate scavengers. This could be due to the difficulty in finding with the necessary regularity the sufficient quantity of carrion that allows them to base their diet exclusively on this type of diet.

In addition, the constant movement through the territory in that search would imply a huge expenditure of energy. Consequently, the vast majority of scavenger species are facultative, thus complementing their diet with the consumption of live species, such as the great white shark.

Examples of scavengers

Birds

The bearded vulture

This bird belongs to the Accipitridae family. Its weight can vary between 5 and 7 kilograms, measuring a maximum of 3 meters.

Among the characteristics of this species are its long and narrow wings and its diamond-shaped tail. The head is covered with feathers, contrary to the rest of the members of its genus.

The name of this vulture is associated with its eating habit. The bearded vulture is an osteophagus species, whose diet consists almost exclusively of bones.

Once the crows and other vultures have consumed the soft parts of the dead animal, Gypaetus barbatus begins to feed on the bones and shells. If these are very large, it takes them with its beak and takes flight. When it reaches a great height, it releases them. Thus, by breaking with the collision against the rocks, it can consume them.

In addition to bones, it eats scraps of meat, tendons, and fat. If it is a dead turtle, first it breaks its shell in the same way, and then it consumes its meat.

The Andean condor (

Condor

This South American bird, which belongs to the Cathartidae family, lives in the Andean Cordillera and on the coasts near the Atlantic and Pacific oceans.

It is a non-marine species, black in color, on which the white feathers located around the neck and in some areas of the wings stand out. As for the head, it has no feathers, presenting a reddish coloration. As an adult, it can grow to 1.42 meters tall, weighing between 11 and 15 kilograms.

The diet of the Andean condor is based on dead animals. When this bird has visualized the carrion, it will fly over it for a long time or perch where it can see it. When it finally descends, it begins to consume the animal for the soft parts.

The black vulture

The black vulture inhabits parts of southern Europe, the Middle East, and much of Europe.

Vultures feed on the remains of dead animals and are never too picky about what's left. They have been known to shed meat, skin, and even feathers, leaving only the skeleton of the animal.

The big crow

The large crow is a passerine bird in the Corvidae family. Its distribution covers the entire northern hemisphere.

The male measures between 52 and 69 centimeters, weighing a maximum of 1.7 kilograms. Its feathers are black, with iridescent reflections in purple and bluish tones. In relation to the beak, it is black and strong, with a slight curvature.

On the other hand, it is an opportunistic and omnivorous animal. Your diet may vary depending on where you are and the seasons.

For example, crows that have their nests near the roads feed on animals that have been the victims of vehicular attacks. Those who live in Alaska get half of their food from the predation of small rodents. The other half comes from dead animals, like caribou.

In Idaho, an agricultural region of the United States, the large raven consumes large amounts of cereals, supplementing this diet with grasshoppers and carrion from birds and cattle.

Marabou storks

From the eastern hemisphere, they travel with vultures and hyenas, and eat fish, reptiles, and other dead animals.

Mammals

The demon of Tasmania (

This marsupial is a member of the Dasyuridae family. It currently lives almost exclusively in Tasmania, an island located in southern Australia.

As for its body, it is stocky, with a large head, a short neck, and a tail that measures around half its body length. The Tasmanian devil's skin is black, with white spots on the back and neck.

The devil, as this species is also known, has a very strong bite. It can open its jaw between 75 and 80 degrees, thus allowing it to shred bones and tear meat.

Contrary to what one might think, this animal is not a good predator, rather it is an opportunist that feeds on a higher proportion of dead animals than those that could hunt. Likewise, it has a great ability to detect carrion, even digging up the corpse.

The black-backed jackal

The black-backed jackal is a mammal that is part of the Canidae family. In adulthood, it can weigh between 10 and 15 kilograms, having a maximum body length, including the tail, of approximately 1.20 meters.

The characteristic feature of this animal, associated with its name, is the black stripe that starts at the back of the neck and ends in the tail. This stands out from the base color of its coat, a reddish brown tone.

Its habits are nocturnal, being able to walk long distances in search of small insects, reptiles or mammals. However, it is a scavenger animal. Because of this, it is usually together with vultures and hyenas devouring the corpses of large African mammals, such as the leopard, the lion and the cheetah.

The striped hyena (

This carnivorous mammal belongs to the family Hyaenidae. It is widely distributed in Africa, Pakistan, India, and the Middle East.

In relation to its size, the weight is approximately 40 kilograms, reaching 1 meter long. Their fur is grayish brown, with black lines, oriented diagonally at the extremities and longitudinally at the sides of the body.

The striped hyena has a dark mane, which runs from neck to tail. In this, the fur is very dense and white.

One of its most outstanding characteristics is the strength of its jaws. Thanks to this, it can break bones and tear the skin of corpses, which are an important part of their diet.

The diet of the Hyaena hyaena consists of wolf, cheetah, lion and tiger carrion, among other mammals. It can also hunt and kill a wide variety of invertebrate and vertebrate animals, as well as consume eggs, fruits, and vegetables.

Fishes

The Mediterranean moray fish

This fish, belonging to the Muraenidae family, lives in the Mediterranean Sea and the Atlantic Ocean.

The Roman eel, as this species is also known, has an elongated body, measuring up to 150 centimeters and weighing around 15 kilograms. Its body lacks scales, the skin being gray or dark brown, with some small spots.

This species does not have pectoral fins. In relation to its mouth, it is robust and contains long, pointed teeth.

As for its diet, it uses its sense of smell to hunt fish and cephalopods. However, it is also a scavenger, being able to consume remains of other dead fish.

The White shark (

White shark, Carcharodon carcharias, cartilaginous fish. Taken and edited from: Terry Goss.

The white shark is a cartilaginous fish that is part of the Lamnidae family. It lives in the warm and temperate waters of the vast majority of the planet's oceans.

The length of its body can range between 5 and 7.4 meters, thought from 1.75 to 2 tons. Contrary to the name by which it is known, this animal only in white in the ventral area. The dorsal part is usually bluish or grayish.

The mouth is large, rounded, presenting an arc shape. The teeth are serrated, wide and triangular. These allow you to grab, tear, and cut your food. Behind the pair of rows of main teeth, you have two or three more lines of constantly growing teeth.

The diet of the white shark that lives in the Mediterranean is based on bluefin tuna, turtles, cetaceans and the monk seal, among others. In addition, it consumes carrion, especially that which comes from the carcasses of whales that have been adrift.

The mapurito (

This freshwater fish, belonging to the Pimelodidae family, is distributed in Colombia, Bolivia, Brazil, Venezuela and Peru.

Its size is approximately 40 centimeters. On both sides of the body and on the adipose fin it has black spots, which stand out against a gray or dark brown body coloration. In contrast, the belly is white. As for the fins, they do not have spines and all, except the adipose, are black.

One of the characteristics of this species is its flattened teeth, which are arranged in the mouth in two rows.

The speck, as Calophysus macropterus is also known, is opportunistic and scavenger. It usually feeds on the fish that are caught in the nets and on the waste from the fishery, such as offal and meat remains. Likewise, it could consume some crustaceans, fruits or seeds.

Insects

The American cockroach (

The American cockroach, of African origin, is an insect that is part of the Blattidae family.

Its coloration is reddish, reaching up to 40 millimeters, with the females being larger than the males. It has wings, the length of which exceeds the abdomen. These allow you to perform short-distance flights, a maximum of two meters.

Generally, the diet of the red cockroach, as Periplaneta americana is also known, is based on spoiled food. Thus, it can eat food scraps, dead animals, damaged fruits, among others.

To obtain the proteins it needs, they could ingest, apart from insect carcasses, animal skin and even human nails and hair.

The earthworm (

This annelid is one of the members of the Lumbricidae family. Although it is native to Europe, it is currently distributed in the rest of the continents.

The length of its body ranges between 9 and 30 centimeters, its diameter being no greater than one centimeter. Its body is segmented into rings, thus being able to reach up to 180. The color of the body can be brown, pink or reddish brown. Contrary to this, the belly is usually more yellowish.

The earthworm lacks teeth. However, they have a very efficient digestive system, made up of a sucking mouth, pharynx, gizzard, and intestine. They have a very voracious appetite, thus being able to eat 90% of their weight daily.

As scavengers, they feed on decomposed materials, such as fallen leaves, small animals, fungi, among others.

Flesh fly

This insect can measure up to 2.5 centimeters, thus being larger than the house fly.

It has a black body, covered with hair. On the thorax it has longitudinal gray or white stripes, while the abdomen may have square spots or transverse lines. The eyes are compound and large, of an intense red tone.

They are scavengers, feeding mainly on decomposed matter, especially meat. This species usually appears quickly on a dead animal, where the female can deposit numerous eggs. Within a few hours, the larvae emerge, feeding on the spoiled meat.

Reptiles

Komodo dragon (

The Komodo dragon is the largest lizard known worldwide. As for the size, it can measure up to 3 meters, with an approximate weight of 70 kilograms.

They have a robust body, covered in scales. In the adult state, it is grayish red or brown. The tail is muscular and strong, almost the same length as its body. It has about 60 serrated teeth in its mouth, which are 2.5 centimeters long.

Their diet is based on the carrion of birds, mammals and some invertebrate animals. However, it can hunt, ambushing its prey.

The Orinoco alligator (

This animal, endemic to the Orinoco river basin, belongs to the Crocodylidae family.

It has a flat and robust body, covered dorsally with osteoderms. The belly and the sides lack these bony plates. In terms of size, females are smaller than males. These come to measure approximately 4.5 meters.

The coloration presents 3 patterns, all with a white belly. Thus, they may have a clear back and sides and others may have black spots. Also, some species are black or dark gray.

The Orinoco caiman is an opportunistic carnivore, consuming fish, frogs, birds, reptiles, and mammals. They frequently incorporate carrion into their diet.

The painted turtle

This freshwater species is part of the Emydidae family. She is a native of Argentina, Uruguay and Brazil.

It has a hydrodynamic shell, green in color. The females are characterized by having yellow drawings, while the males have them in an orange tone. Their toes are webbed, with small, sharp nails. In terms of size, the females are larger than the male, measuring approximately 32 centimeters.

The tiger river turtle, as this species is also known, is omnivorous. Their diet is based on birds, aquatic plants, amphibians and carrion.

References

1. Ameera Mills. (2018). What Are Scavenger Animals? Animal wised. Recovered from animalwised.com.
2. Wikipedia (2019). Scavenger Recovered from en.wikipedia.org.
3. Steve Boyes (2018). Top 25 Birds that Scavenge. National Geographic. Recovered from blog.nationalgeographic.org.
4. Kevin Beck (2018). What Animal Is the Scavenger in a Food Chain? Recovered from sciencing.com.
5. Encyclopedia Britannica (2019). Scavenger. Recovered from britannica.com.
6. Mosquera Guerra, Federico. (2017). Impacts of Calophysus macropterus fisheries a risk to public health and the conservation of river dolphins in Colombia. Moments of Science. Research gate. Recovered from researchgate.net.