When we think of the color red, mammals are not necessarily the first thing that come to mind. Mammals typically display more muted tones like browns, blacks, grays, and whites in their fur, feathers, or skin. However, there are in fact some mammals that exhibit vibrant shades of red. In this article, we will explore some of the different types of red mammals that exist and examine why red coloration is relatively rare in the mammal world.
What Causes Red Coloration in Mammals?
In mammals, red coloration primarily comes from two pigments: pheomelanin and hemoglobin.
Pheomelanin is a reddish form of melanin, the pigment that also produces darker black and brown tones. It occurs in the fur and feathers of some animals. Higher levels of pheomelanin result in redder hues. This pigment is found across many types of organisms, but mammals with significant amounts of pheomelanin are more rare.
Hemoglobin is the iron-containing protein in red blood cells that carries oxygen. It gives blood its red color. In some mammals, blood vessels located close to the surface of thin skin or membranes produce a reddish tint.
Mammals with Red Fur
Most mammals with truly red fur get their color from pheomelanin. Here are some of the most vivid examples:
Red Pandas
The red panda is a small mammal native to the Himalayas and southwestern China. Their fur is a distinctive rusty red color. The red panda is the only living member of the Ailuridae family. It is not closely related to the giant panda.
| Scientific Name | Ailurus fulgens |
|---|---|
| Average Length | 50-64 cm (head to tail) |
| Average Weight | 3-6 kg |
| Habitat | Temperate forests in the Himalayas |
Red pandas are solitary and mostly herbivorous, eating bamboo leaves, fruits, acorns, and eggs. They are classified as endangered by the IUCN. Habitat loss and fragmentation present the biggest threat.
Red Squirrels
Red squirrels are tree squirrels found across Europe, northern Asia, and North America. There are several subspecies of red squirrel with plumage that ranges from rusty red to orange-brown. In Eurasia, the Eurasian red squirrel is the most common type. In North America, the American red squirrel is widespread.
| Scientific Name | Tamiasciurus hudsonicus (American) Sciurus vulgaris (Eurasian) |
|---|---|
| Average Length | 28 cm (head to tail) |
| Average Weight | 250 g |
| Habitat | Coniferous and mixed forests |
Red squirrels eat conifer cones, seeds, fungi, and tree bark. They are solitary and territorial animals. While still widespread, habitat loss has caused some declines in red squirrel populations.
Red-Necked Wallabies
Red-necked wallabies are medium-sized marsupials that live in eastern Australia. As their name suggests, they have a distinctive red stripe across the shoulders and neck. Their fur is mostly dark gray, but they have reddish ruffs around the neck.
| Scientific Name | Macropus rufogriseus |
|---|---|
| Average Length | 84 cm (head to tail) |
| Average Weight | 13-27 kg |
| Habitat | Forests and woodlands of eastern Australia |
Red-necked wallabies are herbivores that feed at night on grasses, leaves, and bark. They live in small groups sharing home ranges. Wallaby populations are considered stable throughout most of their habitat range.
Mammals with Red Membranes
Some mammals also exhibit reddish skin or membranes due to the presence of hemoglobin showing through thin tissue.
Orangutans
Orangutans are reddish-brown apes native to the rainforests of Borneo and Sumatra. While their fur is more brown than red, their skin has a reddish hue due to blood vessels located close to the surface. This is especially visible on the face, hands, feet, and belly.
| Scientific Name | Pongo pygmaeus (Bornean) Pongo abelii (Sumatran) |
|---|---|
| Average Height | 1-1.5 m |
| Average Weight | 45-100 kg |
| Habitat | Tropical rainforests |
Orangutans are solitary apes that feed on fruits, leaves, bark, honey, insects, and small vertebrates. Their populations have declined severely due to habitat destruction. Both species are classified as critically endangered.
Red Kangaroos
Red kangaroos are large marsupials endemic to the Australian outback. They have thick reddish-brown fur, but are named for the red membrane inside their ears and on their limbs. This color comes from fine blood vessels near the surface of those thin tissues.
| Scientific Name | Macropus rufus |
|---|---|
| Average Height | 1-1.5 m (standing) |
| Average Weight | 55-90 kg |
| Habitat | Grasslands and savannas of inland Australia |
Red kangaroos are herbivores that live in small groups called “mobs.” They can go long periods without drinking water. Their numbers are considered stable across Australia.
Proboscis Monkeys
The proboscis monkey is an odd primate found only on the island of Borneo. The most striking feature is the male’s large, pendulous nose which becomes reddish in color during mating season. This unusual nose gives the monkey its name.
| Scientific Name | Nasalis larvatus |
|---|---|
| Average Height | 66-76 cm |
| Average Weight | 16-22 kg |
| Habitat | Coastal mangrove forests |
Proboscis monkeys are arboreal primates that live in groups by the water. They feed on leaves, fruits, and seeds. Due to habitat loss, they are classified as endangered with decreasing populations.
Conclusion
While most mammals display earthy tones in their fur or skin, there are a number of unique red-colored species. Red pandas, red squirrels, red kangaroos, and others exhibit shades of rusty red and orange in their plumage. Orangutans, proboscis monkeys, and other mammals appear reddish due to the visibility of blood vessels under thin membranes. Overall, red coloration in mammals is linked to high levels of pheomelanin pigments or proximity of hemoglobin-rich blood to the skin surface. Though relatively rare in nature, these crimson-hued mammals provide some vivid exceptions to the typical mammalian color palette.