Animals That Start with R: Ultimate Guide to Stunning Creatures

The animal kingdom thrives with an abundance of animals that start with R! This comprehensive list of animals digs deep into the fascinating world of creatures great and small, all beginning with the letter R. We’ll encounter roaring predators like the mighty Rhinoceros and cunning Red Fox, alongside playful critters like the mischievous Raccoon and the hopping Rabbit. From the soaring heights of the majestic Red-tailed Hawk to the vibrant colors of the Reef Shark, prepare to be amazed by the diverse adaptations and unique behaviors of animals that begin with R!

Rabbit

Rabbits are fascinating small mammals belonging to the family Leporidae, which also includes hares. They are part of the order Lagomorpha, which includes pikas as well. The term “rabbit” typically refers to all Leporidae species except those in the genus Lepus, which are known as hares or jackrabbits. While Lepus species are precocial, born with fur and good vision, rabbit species are altricial, born hairless and blind. Hares and some rabbits live solitary lives in simple nests above ground, whereas other rabbits are more social, living in groups within burrows called warrens.

Rabbits have a long history of domestication. The European rabbit, for example, has been kept as livestock since ancient Roman times. Selective breeding, which began in the Middle Ages, has resulted in a wide variety of rabbit breeds. Since the early 19th century, many of these breeds have also become popular as pets.

Raccoon

The raccoon, sometimes spelled racoon and also known as the common or northern raccoon, is a mammal native to North America. It is the largest member of the procyonid family, with a body length ranging from 40 to 70 cm (16 to 28 inches) and a weight between 5 to 26 kg (11 to 57 pounds). Its grayish coat is primarily composed of dense underfur that provides excellent insulation against cold weather.

Raccoons, one of the fascinating animals starting with R, are easily recognized by their highly dexterous front paws, distinctive facial mask, and ringed tail. These features are significant in the mythologies of Indigenous peoples throughout the Americas, reflecting the raccoon’s prominent role in their cultural narratives. Curious for more? Read the full article here!

Raccoon Dog

Nyctereutes is a genus of canids that includes only two living species, both known as raccoon dogs: the common raccoon dog (Nyctereutes procyonoides) and the Japanese raccoon dog (Nyctereutes viverrinus). These animals are easily identified by their short snouts, round skulls, and the specific shaping of their molars, particularly the ratio between M1 and M2. Nyctereutes species are primarily opportunistic carnivores, consuming a varied diet that includes small mammals, fish, birds, and insects, as well as occasional plants, particularly roots. Their dietary habits are largely influenced by the environmental conditions in which they live.

Racer Snake

The Racer Snake refers to several species within the Colubridae family, known for their speed and agility. Common species include the North American Black Racer (Coluber constrictor) and the Eastern Racer (Coluber constrictor flaviventris). These snakes are found across various regions in North America, from forests and grasslands to suburban areas.

Racer Snakes, one of the fascinating animals that start with R, are slender and can grow up to 3 to 6 feet in length. Their coloration varies with species, but many, like the Black Racer, have smooth, shiny scales and a solid black or dark gray body, while others may exhibit different hues and patterns. They have large eyes and excellent vision, aiding in their hunting prowess.

Radiated Tortoise

The radiated tortoise (Astrochelys radiata) is a species of tortoise in the family Testudinidae. Native to southern Madagascar, it is most abundant in this region but can also be found throughout the island. Additionally, it has been introduced to the islands of Réunion and Mauritius. Adult radiated tortoises typically have a carapace length of 26 to 38 centimeters (10 to 15 inches) and weigh between 2.5 to 8.8 kilograms (5.5 to 19.4 pounds), with males generally being larger than females.

The radiated tortoise, one of the fascinating animals that start with R, exhibits the classic tortoise body shape, characterized by a high-domed carapace, a blunt head, and elephantine feet. Its legs, feet, and head are predominantly yellow, except for a variably sized black patch on top of the head.

Ragamuffin

The Ragamuffin is a breed of domestic cat that was originally considered a variant of the Ragdoll cat but was recognized as a separate breed in 1994. Ragamuffins are known for their friendly personalities and thick, luxurious fur. Physically, they feature a rectangular, broad-chested body with a short neck and heavy bones, giving them a “substantial” body type. The breed’s head is broad and shaped like a modified wedge, with a moderately rounded forehead, a short to medium-short muzzle, and a distinctive nose dip. Their muzzle is wide and characterized by puffy whisker pads.

Ragdoll

The Ragdoll, one of the fascinating animals that start with R, is a breed of cat recognized for its distinct colorpoint coat and striking blue eyes. It is a large and weighty breed with a semi-long, silky soft coat. Ragdolls are known for their exceptionally floppy and calm nature, a trait believed to be inherited from the Persian and Birman breeds. There is some debate about whether this characteristic results from a genetic mutation or is an instinctive reaction from being carried by their mother as kittens.

As one of the largest domesticated cat breeds, fully-grown female Ragdolls weigh between 8 to 15 pounds (3.6 to 6.8 kg), while males are significantly larger, weighing from 12 to 20 pounds (5.4 to 9.1 kg) or more. It can take up to four years for a Ragdoll to reach its full mature size.

Raggle

The Raggle, a hybrid breed from a Rat Terrier and a Beagle, typically stands 10 to 15 inches tall and weighs 10 to 20 pounds. These dogs often have a short, smooth coat in various colors like black, white, brown, and tan. Known for their energetic and playful nature, Raggles are intelligent and curious, enjoying activities that engage them both mentally and physically. They inherit a strong hunting instinct and keen sense of smell from their Beagle parent. While generally healthy, they can be prone to hip dysplasia, ear infections, and allergies. Raggles respond well to positive reinforcement training but can be stubborn, requiring consistent and patient guidance.

Rainbow Boa

The rainbow boa (Epicrates cenchria) is a species of boa native to Central and South America. This species is found in lower Central America, specifically in Costa Rica and Panama, and extends further south into various regions of South America. The rainbow boa is typically orange, brown, or reddish-brown, with a paler belly and distinctive black markings, including three parallel stripes on the head, rings down the back, and lateral blotches with a crescent over them. There is considerable natural variation in their appearance, which can be further enhanced by selective breeding. Rainbow boas generally reach a length of 4 to 6 feet.

Rainbow Grasshopper

Dactylotum bicolor, commonly known as the rainbow grasshopper, painted grasshopper, or barber pole grasshopper, is a species in the family Acrididae. Native to the United States, Canada, and northern Mexico, this grasshopper is known for its aposematic (warning) coloration. Males typically grow to about 20 mm (0.8 inches) in length, while females reach about 35 mm (1.4 inches). Dactylotum bicolor, one of the fascinating animals that start with R, is predominantly black with striking reddish and yellowish markings, a pale green prothorax, and pale green wingpads. The hind leg’s tibia features six to eight spines. Notably, this species does not develop wings and is unable to fly.

Rainbow Kribs

Pelvicachromis pulcher is a freshwater fish belonging to the cichlid family, native to Nigeria and Cameroon. This species is highly popular among aquarium enthusiasts and is commonly known as kribensis, though it also goes by other names such as krib, common krib, red krib, super-red krib, rainbow krib, rainbow cichlid, and purple cichlid. In the wild, male Rainbow Kribs can reach a maximum length of approximately 12.5 centimeters (4.9 inches) and weigh up to 9.5 grams (0.34 ounces). Females are smaller and more deep-bodied, growing to a maximum length of 8.1 centimeters (3.2 inches) and a maximum weight of 9.4 grams (0.33 ounces).

Rainbow Shark

The rainbow shark (Epalzeorhynchos frenatum) is a freshwater fish species from Southeast Asia, belonging to the family Cyprinidae. It is also known by various other names, including ruby shark, red-fin shark, red-finned shark, rainbow sharkminnow, green fringelip labeo, whitefin shark, and whitetail sharkminnow. Rainbow sharks are native to the basins of the Mekong, Chao Phraya, Xe Bangfai, and Maeklong rivers in Indochina.

Rainbow sharks, one of the fascinating animals that start with R, have elongated bodies that can be black, dark blue, or bright blue. They feature a pointed snout and a flat abdominal area, with fins that range in color from red to orange-red. A distinctive brief stripe runs from the gill cover to the eye and mouth. Male rainbow sharks are typically thinner than females and have black lines along their tailfins, as well as brighter overall coloration. These fish can grow up to about 6 inches (15 cm) in length.

Rat

Rats are various medium-sized, long-tailed rodents found throughout the order Rodentia. The most well-known species are the black rat (Rattus rattus) and the brown rat (Rattus norvegicus), collectively referred to as the Old World rats or true rats. These species originated in Asia and are generally larger than their relatives, the Old World mice, though they rarely weigh over 500 grams (17.5 oz) in the wild.

The characteristic long tail of most rats serves several key functions. Studies on various rat species have identified three primary roles for this structure: thermoregulation, aiding in the regulation of body temperature; minor proprioception, helping the rat sense its body position in space; and a nocifensive-mediated degloving response, a defensive mechanism to escape predators by shedding the skin of the tail when caught.

Rat Snakes

Rat snakes are members of the subfamily Colubrinae within the family Colubridae, which also includes kingsnakes, milk snakes, vine snakes, and indigo snakes. Like nearly all colubrids, rat snakes pose no threat to humans. While they were long believed to be completely nonvenomous, recent studies have revealed that some Old World species possess small amounts of venom, though the amount is negligible and harmless to humans.

Rat snakes, one of the fascinating animals that start with R, are popular pets among reptile enthusiasts, with the corn snake being one of the most favored pet reptiles. These snakes are known for their docile nature and ease of care, making them suitable for both novice and experienced reptile keepers.

Rat Terrier

The Rat Terrier is an American dog breed known for its history as a farm dog and hunting companion. They share much of their ancestry with small hunting dogs known as feists. Commonly found on family farms in the 1920s and 1930s, Rat Terriers are now recognized by the United Kennel Club (UKC) and the American Kennel Club (AKC), though they are still considered a rare breed.

Rat Terriers typically weigh between 10 to 25 pounds (4.5 to 11.3 kg) and stand 10 to 18 inches (25 to 46 cm) at the shoulder. The miniature variety, defined by the UKC as 13 inches (33 cm) and under, has gained popularity as a house pet and companion dog due to its smaller size and adaptability to indoor living.

Rattlesnake

Rattlesnakes, one of the fascinating animals that start with R, are venomous snakes belonging to the genera Crotalus and Sistrurus within the subfamily Crotalinae, also known as pit vipers. As vipers, rattlesnakes are predatory and occupy a wide range of habitats, where they hunt small animals such as birds and rodents. They are native to the Americas, ranging from southern Canada to central Argentina, with most species found in arid regions. The majority of rattlesnake species are concentrated in the American Southwest and Mexico.

Rattlesnake venom is hemotoxic, meaning it destroys tissue, causes necrosis, and disrupts blood clotting (coagulopathy). This potent venom enables them to effectively subdue their prey and defend themselves from potential threats.

Red Ackie Monitor

The Red Ackie Monitor (Varanus acanthurus acanthurus), also known as the Spiny-tailed Monitor, is a small to medium-sized lizard native to the arid regions of northern Australia. Typically reaching 24 to 28 inches in length, including their long, spiny tail, these monitors are distinguished by their vibrant reddish-brown coloration, which helps them blend into their rocky desert habitats.

Red Ackie Monitors are diurnal and highly active, spending much of their time basking in the sun and hunting for insects, small mammals, and other invertebrates.

Red Aphids

Red aphids, such as the red variety of the oleander aphid (Aphis nerii), are small, sap-sucking insects that feed on a wide range of plants, including oleander, milkweed, and other ornamentals. These aphids are typically bright red or orange, which makes them easily recognizable against the green foliage of their host plants.

Aphids are known for their rapid reproduction, with females often giving birth to live young without mating, a process known as parthenogenesis. This allows aphid populations to explode in a short period, leading to significant plant damage.

Red Deer

The red deer (Cervus elaphus) is one of the largest deer species, with males known as stags or harts and females referred to as does or hinds. This species inhabits most of Europe, the Caucasus Mountains region, Anatolia, Iran, and parts of western Asia. The red deer, one of the fascinating animals that start with R, is the fourth-largest extant deer species, following the moose, elk, and sambar deer. As a ruminant, the red deer eats its food in two stages and possesses an even number of toes on each hoof, similar to camels, goats, and cattle. European red deer have relatively long tails compared to their Asian and North American relatives.

Red Diamondback Rattlesnake

The Red Diamondback Rattlesnake (Crotalus ruber), also known as the Red Diamond Rattlesnake, is a venomous pit viper found primarily in the southwestern United States and parts of northwestern Mexico. Known for its distinctive reddish-brown coloration, the Red Diamondback can grow to an average length of 3 to 5 feet, though some individuals may reach up to 6 feet.

This rattlesnake has a series of diamond-shaped patterns along its back, edged with white, which provide excellent camouflage in its arid, rocky habitat. It prefers coastal scrublands, deserts, and chaparral environments, often sheltering under rocks or in burrows to escape the heat of the day.

Red Drum Fish

The Red Drum Fish (Sciaenops ocellatus), also known as Redfish or Channel Bass, is a highly prized game fish found primarily in the coastal waters of the Atlantic Ocean and the Gulf of Mexico. Recognizable by their reddish-bronze hue and distinctive black spot near the tail, these fish can grow up to 60 inches in length and weigh as much as 90 pounds, although the average size is smaller.

Red Drum, one of the fascinating animals that start with R, are known for their powerful fight when hooked, making them a favorite among recreational anglers. They inhabit various environments, from brackish estuaries and tidal creeks to shallow coastal waters, where they feed on a diet of crustaceans, small fish, and marine invertebrates.

Red Finch

The Red Finch, commonly referred to as the House Finch (Haemorhous mexicanus), is a small, adaptable songbird native to North America. The males are easily recognizable by their bright red plumage on the head, throat, and chest, which contrasts with their brown-streaked back and wings. Females, however, are more subdued in color, sporting a mostly brown and streaked appearance. These finches are highly social and can be found in a variety of habitats, including urban areas, forests, and deserts.

House Finches are known for their cheerful, warbling song, which males use to attract mates and defend their territory. Their diet primarily consists of seeds, fruits, and buds, and they are frequent visitors to backyard bird feeders.

Red Fox

The red fox (Vulpes vulpes) is the largest of the true foxes and is one of the most widely distributed members of the order Carnivora. It is found across the entire Northern Hemisphere, including most of North America, Europe, and Asia, as well as parts of North Africa. The species is listed as least concern on the IUCN Red List. Red foxes are very agile, capable of jumping over fences as high as 2 meters (6 feet 7 inches) and are also good swimmers. Vixens typically have four pairs of teats, although it is not uncommon for them to have seven, nine, or even ten teats. The testes of male red foxes are smaller than those of Arctic foxes.

Red Kite

The red kite (Milvus milvus) is a medium-large bird of prey belonging to the family Accipitridae, which includes other diurnal raptors such as eagles, buzzards, and harriers. This species primarily breeds in Europe, although it formerly bred in parts of west Asia and northwest Africa. Red kites measure 60 to 70 cm (24 to 28 inches) in length, with a wingspan of 175 to 195 cm (69 to 77 inches).

Males weigh between 800 to 1,200 grams (28 to 42 ounces), while females are slightly heavier, weighing between 1,000 to 1,300 grams (35 to 46 ounces). Known for their elegance, red kites soar with long wings held at a dihedral angle and a distinctive long, forked tail that twists as they change direction.

Red Knee Tarantula

The Red Knee Tarantula (Brachypelma smithi), also known as the Mexican Red Knee Tarantula, is a striking species native to the Pacific coast of Mexico. Known for its distinctive and vibrant coloration, this tarantula boasts black legs adorned with bright red or orange bands around the knee joints, contrasting with its dark body and carapace.

Red Knee Tarantulas, one of the fascinating animals that start with R, are relatively large, with a leg span reaching up to 6 inches (15 cm). They inhabit dry scrublands and deserts, where they spend much of their time in burrows or under rocks. These tarantulas are nocturnal and primarily feed on insects, small mammals, and other invertebrates, using their venomous fangs to subdue prey.

Red Nose Pit Bull

The Red Nose Pit Bull, a variant of the American Pit Bull Terrier, is distinguished by its copper-red nose, red or amber eyes, and matching red coat, setting it apart from other Pit Bull varieties. Originating from the Old Family Red Nose (OFRN) strain in Ireland, these dogs were initially bred for their strength, agility, and tenacity in bull-baiting and other forms of blood sports. Today, Red Nose Pit Bulls are celebrated for their loyalty, intelligence, and affectionate nature, making them beloved family pets when properly trained and socialized.

Red Panda

The red panda (Ailurus fulgens), also known as the lesser panda, is a small mammal native to the eastern Himalayas and southwestern China. It features dense reddish-brown fur with a black belly and legs, white-lined ears, a mostly white muzzle, and a ringed tail. The red panda has a head-to-body length of 51 to 63.5 cm (20.1 to 25.0 inches) and a tail length of 28 to 48.5 cm (11.0 to 19.1 inches). It weighs between 3.2 and 15 kg (7.1 and 33.1 pounds). Adapted for climbing, the red panda has flexible joints and curved semi-retractile claws, allowing it to navigate trees with ease.

Red Paper Wasp

The Red Paper Wasp (Polistes carolina) is a striking species native to the eastern United States, easily identifiable by its reddish-brown color and slender body, which can reach up to an inch in length. These wasps are known for their characteristic nests, made from chewed wood fibers mixed with saliva, creating a papery texture. The nests, often found hanging from eaves, tree branches, or other sheltered locations, consist of open combs where the wasps rear their young.

Red Paper Wasps, one of the fascinating animals that start with R, play a crucial role in ecosystems as both pollinators and predators. They help control pest populations by feeding on caterpillars and other insects, which they chew up and feed to their larvae.

Red Racer Snake

Masticophis flagellum, commonly known as the coachwhip or the red racer snake, is a species of nonvenomous colubrid snake endemic to the United States and Mexico. These slender snakes have small heads, large eyes with round pupils, and vary greatly in color, often reflecting the natural camouflage of their habitats. Coachwhips are widespread across the southern United States from coast to coast and are also found in the northern half of Mexico. Adult coachwhips typically measure between 127 and 183 cm (50 to 72 inches) in total length, including the tail, with the record-sized specimen, an eastern coachwhip, reaching 259 cm (102 inches) in length.

Red Spitting Cobra

The red spitting cobra (Naja pallida) is a species of spitting cobra native to Africa. This medium-sized cobra typically measures between 0.7 and 1.2 meters (2.3 and 3.9 feet) in length but can occasionally reach up to 1.5 meters (4.9 feet) in rare instances. Known for its striking appearance, the red spitting cobra is usually bright salmon-red with a broad black throat band and distinctive subocular teardrop markings. These terrestrial snakes are fast and alert. Adult red spitting cobras are primarily nocturnal, while juveniles tend to be more active during the day.

Red Squirrel

The red squirrel, also known as the Eurasian red squirrel (Sciurus vulgaris), is a species of tree squirrel. It has a typical head-and-body length of 19 to 23 cm (7.5 to 9 inches), a tail length of 15 to 20 cm (6 to 8 inches), and a weight of 250 to 340 grams (9 to 12 ounces). Both males and females are the same size. The Eurasian red squirrel is somewhat smaller than the American eastern grey squirrel, which has a head-and-body length of 25 to 30 cm (10 to 12 inches) and weighs between 400 and 800 grams (14 ounces to 1 pound 12 ounces).

Red Star Chicken

The Red Star Chicken, also known as the Red Sex Link, is a popular hybrid breed prized for its egg-laying abilities and friendly disposition. Developed by crossing specific parent breeds for desirable traits, Red Stars are known for their prolific egg production, often laying around 300 brown eggs per year. They have a distinctive appearance with reddish-brown feathers and are typically medium-sized, making them suitable for backyard flocks and small farms.

Red Tail Boa

The Red Tail Boa or boa constrictor (scientific name also Boa constrictor), commonly known as the common boa, is a species of large, non-venomous, heavy-bodied snake frequently kept and bred in captivity. Depending on the locality and the availability of suitable prey, it can reach lengths from 3 to 13 feet (0.91 to 3.96 meters). The coloring of boa constrictors can vary greatly depending on their geographic location, but they generally have a base color of brown, gray, or cream, with brown or reddish-brown “saddles” that become more pronounced towards the tail.

Red Wolf

The red wolf (Canis rufus), one of the fascinating animals that start with R, is a canine native to the southeastern United States. Its appearance is typical of the genus Canis and is generally intermediate in size between the coyote and gray wolf, although some specimens may overlap in size with small gray wolves. Adult red wolves measure 136–165 cm (53.5–65 inches) in length, including a tail of about 37 cm (14.6 inches). Their weight ranges from 20 to 39 kg (44 to 85 lbs), with males averaging 29 kg (64 lbs) and females averaging 25 kg (55 lbs).

Red-Bellied Black Snake

The red-bellied black snake (Pseudechis porphyriacus) is a species of venomous snake in the family Elapidae, indigenous to Australia. First described by George Shaw in 1794, it is one of the most commonly encountered snakes in eastern Australia. The red-bellied black snake typically measures around 1.25 meters (4 feet 1 inch) in length. It has glossy black upperparts, bright red or orange flanks, and a pink or dull red belly. While not aggressive and generally retreating from human encounters, it can attack if provoked.

Red-Bellied Woodpecker

The red-bellied woodpecker (Melanerpes carolinus) is a medium-sized woodpecker belonging to the family Picidae. It primarily breeds in the eastern United States, with its range extending from Florida in the south to Canada in the north. Adult red-bellied woodpeckers are mostly light gray on the face and underparts, with distinctive black and white barred patterns on their back, wings, and tail.

Adult males have a red cap that extends from the bill to the nape, while females feature a red patch on the nape and another above the bill. These woodpeckers measure 22.85 to 26.7 cm (9.00 to 10.51 inches) in length, have a wingspan of 38 to 46 cm (15 to 18 inches), and weigh between 2.0 to 3.2 ounces (57 to 91 grams).

Red-Billed Quelea Bird

The Red-billed Quelea (Quelea quelea) is a small passerine bird native to sub-Saharan Africa, known for its immense flocks that can number in the millions during the breeding season. These birds are characterized by their predominantly brown plumage, with males developing a red bill and face during the breeding season, giving them their name. They inhabit a wide range of habitats, from savannas and grasslands to agricultural areas, where they feed primarily on seeds, grains, and occasionally insects.

The Red-billed Quelea, one of the fascinating animals that start with R, is one of the most abundant bird species in the world, forming large, synchronized flocks that can cause significant damage to crops, particularly cereal grains.

Red-Eared Slider

The red-eared slider, or red-eared terrapin (Trachemys scripta elegans), is a subspecies of the pond slider (Trachemys scripta), a semiaquatic turtle in the family Emydidae. The carapace of the red-eared slider can grow to more than 40 cm (16 inches) in length, although the typical length ranges from 15 to 20 cm (6 to 8 inches). Females of the species are generally larger than males. Red-eared sliders typically have a lifespan of 20 to 30 years, although some individuals can live for more than 70 years.

Red-Eyed Tree Frog

Agalychnis callidryas, commonly known as the red-eyed tree frog, is a species of frog in the subfamily Phyllomedusinae. It is one of the most recognizable frogs and is native to forests from Central America to northwestern South America. This species is known for its vibrant coloration, featuring a bright green body with blue and yellow stripes on the sides. It has a white underside, brightly colored red and orange feet, and is named for its distinctive bright red eyes. A unique aspect of the red-eyed tree frog’s coloration is its exceptionally high reflectance in the near-infrared spectrum.

Red-Footed Tortoise

The red-footed tortoise (Chelonoidis carbonarius) is a species of tortoise native to northern South America. These medium-sized tortoises typically average 30 cm (12 inches) in length as adults but can grow to over 40 cm (16 inches). They have dark-colored, nearly black, “loaf”-shaped carapaces (top shell) with lighter patches in the middle of each scute (shell segment) and a somewhat lighter-colored plastron (underbelly). The tortoise’s dark limbs are adorned with brightly-colored scales, ranging from pale yellow to vivid or dark red, which is the feature that gives them their name.

Red-handed Tamarin

The golden-handed tamarin (Saguinus midas), also known as the red-handed tamarin or Midas tamarin, is a New World monkey belonging to the family Callitrichidae. This species is native to wooded areas north of the Amazon River in Brazil, Guyana, French Guiana, Suriname, and possibly Venezuela. The golden-handed tamarin’s body measures 20.5–28 centimeters (8.1–11.0 inches) in length, and including the tail, it measures 31–44 centimeters (12–17 inches). It weighs between 400–550 grams (0.88–1.21 pounds).

Red-Headed Vulture

The red-headed vulture (Sarcogyps calvus), also known as the Asian king vulture, Indian black vulture, or Pondicherry vulture, is an Old World vulture primarily found in the Indian subcontinent, with small, disjunct populations in parts of Southeast Asia.

This medium-sized vulture measures 76 to 86 cm (30 to 34 inches) in length, weighs between 3.5 to 6.3 kg (7.7 to 13.9 pounds), and has a wingspan of about 1.99 to 2.6 meters (6.5 to 8.5 feet). The red-headed vulture is characterized by its prominent naked head, which is deep-red to orange in adults and paler red in juveniles. Its body is black with a pale grey band at the base of the flight feathers.

Red-Lipped Batfish

The red-lipped batfish or Galápagos batfish (Ogcocephalus darwini) is a fish with unusual morphology found around the Galápagos Islands and off the coast of Peru at depths ranging from 3 to 76 meters (10 to 249 feet). This species is closely related to the rosy-lipped batfish (Ogcocephalus porrectus), which is found near Cocos Island off the Pacific coast of Costa Rica. The red-lipped batfish, one of the fascinating animals that start with R, is most notable for its bright red lips. These fish are not good swimmers and instead use their highly adapted pectoral, pelvic, and anal fins to “walk” on the ocean floor.

Red-Shouldered Hawk

The red-shouldered hawk (Buteo lineatus) is a moderately sized raptor. This bird’s breeding region includes the eastern parts of North America, the coastal regions of California, and stretches into northern and northeastern-central Mexico. While it typically remains in its habitat year-round, hawks from the northernmost parts of its range tend to migrate south, primarily to central Mexico. Male red-shouldered hawks are between 38 and 58 cm (15 to 23 inches) in length and average around 550 grams (1.21 pounds) in weight. Females are slightly larger, measuring between 47 and 61 cm (19 to 24 inches) and averaging 700 grams (1.5 pounds). The wingspan of these hawks ranges from 90 to 127 cm (35 to 50 inches).

Red-Tailed Cuckoo Bumblebee

Bombus rupestris, commonly known as the Red-Tailed Cuckoo Bumblebee, inhabits most parts of Europe, excluding Iceland. In the Balkan region, it thrives in mountainous and alpine areas, extending north from Central Greece, and it can also be found in Turkey. Females are significantly larger than males, measuring between 20 to 25 mm (0.79 to 0.98 inches) in length, while males typically reach up to 16 mm (0.63 inches). This bumblebee species is characterized by its black color with orange-red coloring on the last abdominal segments. They are commonly found in flower-rich environments such as meadows and hedgerows.

Red-winged blackbird

The red-winged blackbird (Agelaius phoeniceus), a member of the Icteridae family, is prevalent across most of North America and a significant portion of Central America. The species derives its name from the striking red shoulder patches, or epaulets, seen on the primarily black adult males when they are in flight or displaying. When at rest, the male also exhibits a pale yellow wingbar.

Females are smaller, measuring 17–18 cm (6.7–7.1 inches) in length and weighing 41.5 grams (1.46 ounces), compared to males, who are 22–24 cm (8.7–9.4 inches) long and weigh 64 grams (2.3 ounces). These distinctive markings are crucial for territorial defense, with males boasting larger spots proving more successful in driving away non-territorial rivals and prevailing in aviary contests.

Redback Spider

The redback spider (Latrodectus hasselti), commonly referred to as the Australian black widow, is a highly venomous spider thought to have originated in South Australia. The adult female is easily identifiable by her rounded black body adorned with a distinctive red stripe on the top of her abdomen and a red or orange hourglass-shaped marking on the underside. Female redback spiders typically have a body length of about 10 millimeters (0.4 inches), whereas males are significantly smaller, measuring only 3–4 millimeters (0.12–0.16 inches) in length. Curious for more? Read the full article here!

Redbone Coonhound

The Redbone Coonhound, one of the fascinating animals that start with R, is a hunting dog breed developed in the United States. Known for its proficiency in hunting small game such as raccoons, opossums, and squirrels, the Redbone Coonhound is also adept at pursuing larger prey like bears and cougars. This breed boasts a lean, muscular, and well-proportioned physique, characteristic of the coonhound subgroup. It features long, straight legs, a deep chest, and a head and tail carried high with pride during hunts or shows. The Redbone Coonhound is notable for its uniformity in size and appearance compared to other coonhound breeds.

Redcap Chicken

The Redcap Chicken is a distinctive breed known for its striking appearance and dual-purpose capabilities. Originating from England, these chickens are prized for their unique crest of red feathers atop their heads, which gives them their name. They have a robust build with glossy black plumage contrasting against bright red combs and wattles. Redcaps are known for their friendly temperament and adaptability to various climates, making them favored among backyard poultry keepers. They are good layers of white or tinted eggs and also provide flavorful meat, making them a versatile choice for small-scale farming and enthusiasts seeking attractive, productive birds for both eggs and meat.

Redear Sunfish

The redear sunfish (Lepomis microlophus), commonly known as the shellcracker, Georgia bream, cherry gill, chinquapin, improved bream, rouge ear sunfish, and sun perch, is a freshwater fish belonging to the Centrarchidae family. Native to the southeastern United States, this fish closely resembles the bluegill but is distinguished by its coloration and slightly larger size. The redear sunfish, one of the fascinating animals that start with R, features faint vertical bars extending downward from its dorsal fin. It has a dark upper body and a yellow-green underside. Males are noted for a cherry-red margin on their operculum, while females exhibit orange coloring in the same area.

Redhump Eartheater

The redhump eartheater (Geophagus steindachneri) is a type of eartheater cichlid native to the freshwater regions of northwestern South America. This fish thrives in water that is slightly acidic to neutral, with a pH ranging from 6.5 to 7.0, and at temperatures typically between 24 to 26 °C (75 to 79 °F). It is a stenohaline species, meaning it is exclusively found in mainland freshwater habitats. Redhump eartheaters exhibit immediate maternal mouthbrooding behavior. They mature relatively quickly, allowing for easy sex determination even in subadults. Males are distinguishable by their prominent red nuptial hump and their larger size compared to females.

Redstart

The Redstart bird, a small migratory songbird belonging to the Muscicapidae family, is admired for its vibrant plumage and energetic behavior. The most well-known species, the Common Redstart (Phoenicurus phoenicurus), exhibits striking sexual dimorphism: males boast a bright orange-red tail, black face, and grey upper parts, while females are more subdued in their brownish coloration. Redstarts, one of the fascinating animals that start with R, are typically found across Europe and Asia, breeding in woodlands, gardens, and orchards, and migrating to Africa for the winter. They feed on a diet of insects, spiders, and berries, often catching their prey in mid-air with agile, acrobatic flights.

Redtail Catfish

The redtail catfish, known scientifically as Phractocephalus hemioliopterus, is a substantial species of South American pimelodid, or long-whiskered catfish. It can grow up to approximately 1.8 meters (5 feet 11 inches) in length and weigh around 80 kilograms (180 pounds). However, such sizes are exceptionally rare, with most individuals reaching an average length of 1.1 to 1.4 meters (3 feet 6 inches to 4 feet 6 inches). These striking catfish feature a brownish back, yellow sides, and distinctive orange-red dorsal and caudal fins, which give them their common name. Due to their potential size, redtail catfish are highly prized by anglers as game fish.

Reef Shark

Reef sharks, encompassing several species like the Caribbean Reef Shark (Carcharhinus perezii) and the Grey Reef Shark (Carcharhinus amblyrhynchos), are typically found in warm, shallow waters near coral reefs. These medium-sized sharks, usually ranging from 5 to 8 feet in length, play a crucial role in maintaining the health of reef ecosystems. They are characterized by their streamlined bodies, rounded snouts, and distinctive dorsal fins.

Regal Jumping Spider

Phidippus regius, also known as the regal jumper or regal jumping spider, is a species of jumping spider native to parts of the United States and the Caribbean. It holds the title of the largest jumping spider in eastern North America. Adult male regal jumping spider typically measure around 12 mm (0.47 in) in length, but their size can range from 6 mm to 18 mm (0.24 to 0.71 in). The first pair of legs in larger males are notably larger and feature a distinctive black and white fringe. The spider’s opisthosoma is black with several white markings on its dorsum, including a basal band, a central triangular spot, and two posterior oval spots.

Reindeer

Reindeer, also known as caribou in North America, (Rangifer tarandus), are remarkable mammals adapted to the harsh climates of the Arctic and Subarctic regions. These sturdy animals are distinguished by their large, branching antlers, which both males and females possess – the only deer species where this occurs. Reindeer are uniquely adapted to their environment; their thick, insulating fur provides warmth, while their broad, concave hooves act as snowshoes to traverse snowy landscapes and dig for lichen, their primary winter food source. Migratory by nature, reindeer undertake some of the longest overland migrations of any terrestrial mammal, traveling up to 3,000 miles annually.

Repenomamus

Repenomamus, one of the fascinating animals that start with R, is a genus of gobiconodontid mammals, ranging in size from that of an opossum to a badger, and includes two species: Repenomamus robustus and Repenomamus giganticus. These species are known from fossils discovered in China, dating back to the early Cretaceous period, approximately 125 to 123.2 million years ago. Adult Repenomamus were comparable in size to a Virginia opossum. A complete specimen had a body length, excluding the tail, of 41.2 cm (16 in) and an estimated skull length of 10.6 cm (4.2 in). Additionally, another partial specimen had a skull measuring 11.2 cm (4.4 in).

Reticulated Python

The reticulated python (Malayopython reticulatus) is a species of python found in South and Southeast Asia. Renowned as the world’s longest snake, it ranks as the third heaviest after the green anaconda and Burmese python. The IUCN Red List classifies it as least concern due to its broad distribution. This python features smooth dorsal scales arranged in 69–79 rows at midbody. It also has deep pits on four anterior upper labials, on two or three anterior lower labials, and on five or six posterior lower labials.

As the largest snake native to Asia, the reticulated python has been extensively studied in southern Sumatra. Research on over a thousand wild individuals revealed a length range from 1.5 to 6.5 meters (4 feet 11 inches to 21 feet 4 inches) and a weight range from 1 to 75 kilograms (2 pounds 3 ounces to 165 pounds 6 ounces).

Rex Rabbit

The term “Rex Rabbit” is used informally to describe one of at least eight breeds of domestic rabbits. The Rex breed, originating in France in 1919, is distinguished by its plush, velvety fur. The characteristic “rexed” fur is due to a specific genetic mutation, which breeders now selectively encourage in Rex rabbit varieties.

Nowadays, Rex Rabbits, one of the fascinating animals that start with R, are popular as pets, show rabbits, and are also used for their fur and meat. They are particularly favored in the fur industry for garments and toys because their fur lacks the protruding guard hairs that other breeds have, which usually require shearing and plucking post-tanning to mimic other types of animal furs.

Rhamphosuchus

Rhamphosuchus, meaning “Beak crocodile,” is an extinct genus of gavialid crocodilians. This ancient reptile existed during the Pliocene epoch, with its fossils discovered in the Siwalik Hills of Pakistan and India, as well as the Sindh region of Pakistan. Traditionally, many paleontologists believed Rhamphosuchus to be one of the largest, if not the largest, crocodilians ever, with estimates suggesting lengths of 15 to 18 meters (49 to 59 feet). However, more recent research indicates that it may have been smaller, measuring between 8 and 11 meters (26 to 36 feet) in length, thus not holding the title of the largest known crocodilian.

Rhea

Rheas, also known as the South American ostrich, are medium-sized ratites native to South America. These large, flightless birds have grey-brown feathers, long legs, and extended necks, resembling ostriches. The greater rhea (R. americana) can have large males reaching up to 170 cm (67 inches) in height at the head, 100 cm (39 inches) at the back, and weighing as much as 40 kg (88 lbs). The lesser rhea is smaller, standing about 100 cm (39 inches) tall. Although flightless, rheas possess large wings spanning up to 250 cm (8.2 feet) which they spread while running to help with balance and maneuverability, much like sails.

Rhesus Macaque

The rhesus macaque (Macaca mulatta), commonly known as the rhesus monkey, is a species of Old World monkey. There are between six and nine recognized subspecies, which are categorized into two groups: those derived from China and those from India. Typically, these monkeys have a brown or grey coat, measure 47–53 cm (19–21 in) in body length, and have a tail that is 20.7–22.9 cm (8.1–9.0 in) long. They generally weigh between 5.3–7.7 kg (12–17 lb). Native to South, Central, and Southeast Asia, the rhesus macaque boasts the broadest geographic distribution of any non-human primate.

Rhino Beetle

Dynastinae, commonly known as rhinoceros beetles, form a subfamily within the scarab beetle family (Scarabaeidae). They are also referred to by specific names like Hercules beetles, unicorn beetles, or horn beetles, depending on the group. There are over 1,500 known species and 225 genera of rhinoceros beetles. These beetles are among the largest, with some species growing over 15 centimeters (6 inches) in length. Despite their size, they are completely harmless to humans as they cannot bite or sting. Additionally, some species are reputed to be able to lift up to 850 times their own body weight.

Rhino Viper

Bitis nasicornis or rhino viper is a viper species within the genus Bitis, part of the subfamily commonly referred to as “puff-adders.” This species inhabits the forests of West and Central Africa. Known for its vivid coloration and distinctive nasal “horns,” Bitis nasicornis is also called the butterfly viper, river jack, among other names. Like all vipers, it is venomous.

This species is large and stout, with a total length (including the tail) ranging from 72 to 107 cm (28 to 42 inches). According to Spawls et al. (2004), an exceptional specimen might reach up to 120 cm (47 inches), although the average length is typically between 60 and 90 cm (24 to 35 inches).

Rhinoceros

A rhinoceros, often shortened to rhino, belongs to the family Rhinocerotidae, which includes five living species and numerous extinct ones. These large, odd-toed ungulates are among the remaining megafauna, with adults weighing at least one tonne. Rhinos, one of the fascinating animals that start with R, are herbivores with relatively small brains for their size, weighing between 400 and 600 grams (14 to 21 ounces). They possess one or two horns and have a thick, protective skin measuring 1.5 to 5 cm (0.59 to 1.97 inches), composed of collagen layers arranged in a lattice structure.

Rhode Island Red Chicken

The Rhode Island Red Chicken is an American breed of domestic chicken and serves as the state bird of Rhode Island. This breed was developed in Rhode Island and Massachusetts during the late nineteenth century. Traditional Rhode Island Reds have plumage that ranges from a lustrous deep red to almost black, with predominantly black tails. Their combs can be either single or rose-comb, both of which are a vivid red, as are their earlobes and wattles. They have a reddish horn-colored beak, reddish bay eyes, and yellow feet and legs, often featuring some red on the toes and sides of the shanks. Industrial strains of this breed tend to be smaller and lighter in color compared to the traditional type.

Rhodesian Ridgeback

The Rhodesian Ridgeback is a large dog breed that was initially bred in Southern Africa. The breed’s appearance standard was established in Rhodesia (now Zimbabwe) in 1922 and has remained largely unchanged through 2019. The breed is easily recognizable by the distinctive ridge of hair along its back that grows in the opposite direction from the rest of its coat. Rhodesian Ridgebacks are noted for their loyalty and intelligence. They tend to be somewhat aloof with strangers, but this should not be mistaken for aggression. A well-tempered Rhodesian Ridgeback will not attack strangers without cause.

Rhombic Egg-Eater Snake

The Rhombic Egg-Eater Snake (Dasypeltis scabra) is a fascinating, non-venomous species found primarily in sub-Saharan Africa. This snake is uniquely specialized for a diet consisting exclusively of bird eggs, which it swallows whole. It can grow up to 3 feet in length and is characterized by its slender body and distinctive, rhombic-shaped patterning along its scales, providing effective camouflage in its natural habitat of savannas, woodlands, and scrublands.

The Rhombic Egg-Eater, one of the fascinating animals that start with R, possesses several remarkable adaptations for its egg-centric diet. Its flexible jaws and reduced teeth allow it to consume eggs much larger than its head. Inside its throat, specialized bony projections on the vertebrae help to crack the eggshells as the snake swallows, after which it regurgitates the crushed shell while digesting the nutritious contents.

Ribbon Eel

The ribbon eel (Rhinomuraena quaesita), also known as the leaf-nosed moray eel or bernis eel, is a unique species of moray eel and the sole member of the genus Rhinomuraena. This eel inhabits sand burrows and reefs in the Indo-Pacific Ocean. In captivity, ribbon eels typically have a lifespan of less than a year, as they often cease eating once placed in home aquariums. However, public aquariums have had more success, with a few reported instances of ribbon eels spawning in facilities in Europe and North America.

Ribbon Snake

The Ribbon Snake (Thamnophis sauritus) is a slender, non-venomous serpent commonly found in North America, particularly in the eastern United States and southeastern Canada. Distinguished by its long, thin body and striking stripes running lengthwise down its back, the Ribbon Snake typically sports three light-colored stripes—yellow or white—set against a dark brown or black background. These snakes thrive in wet habitats such as marshes, ponds, and streams, where they can be seen basking on rocks or logs.

Ribbon Snakes are agile and quick, primarily feeding on small amphibians, fish, and invertebrates. Their diet reflects their aquatic lifestyle, and they are excellent swimmers, often hunting for prey both in and around water.

Rim Rock Crowned Snake

The Rim Rock Crowned Snake (Tantilla oolitica) is a small, elusive species native to the limestone rocklands of southern Florida, particularly within the Florida Keys and parts of the Miami-Dade County. This non-venomous snake, reaching only about 8 to 10 inches in length, is characterized by its slender body, smooth scales, and distinctive black head and nape, which sharply contrasts with its tan or light brown body.

The Rim Rock Crowned Snake, one of the fascinating animals that start with R, primarily feeds on small invertebrates such as insects, spiders, and centipedes, making it an important component of the local ecosystem by helping to control pest populations. Due to its secretive nature, it often hides under rocks, leaf litter, and within crevices during the day, emerging primarily at night to forage.

Ring-billed Gull

The ring-billed gull (Larus delawarensis) is a medium-sized gull. The genus name, Larus, is derived from Latin and historically referred to a gull or another large seabird. Ring-billed gulls breed near lakes, rivers, and coastal areas in Canada and the northern United States, nesting colonially on the ground, often choosing islands as their nesting sites. These gulls have white heads, necks, and underparts, with silver-gray backs and wings. Their relatively short bills are yellow with a distinctive dark ring, and their legs are also yellow. The eyes are yellow with red rims. It takes three years for the ring-billed gull to reach its breeding plumage, with its appearance changing with each fall molt.

Ringed Kingfisher

The ringed kingfisher (Megaceryle torquata) is a large, noticeable, and vocal bird found from the lower Rio Grande Valley in southeastern Texas, through Central America, and down to Tierra del Fuego in South America. Adult males have wing lengths ranging from 184.9 to 211.1 mm (7.28 to 8.31 in), with an average of 196.3 mm (7.73 in). Their tails measure between 110.0 and 129.0 mm (4.33 to 5.08 in), and their bills are 74.9 to 94 mm (2.95 to 3.70 in) long. The ringed kingfisher is characterized by its dark-brown irises, which are consistent across all ages. They possess straight bills that are longer than their heads, along with curved culmens and tomial serrations.

Rinkhals Snake

The Rinkhals (Hemachatus haemachatus) is a distinctive spitting cobra found primarily in southern Africa, with a range extending from South Africa to Zimbabwe and Eswatini. Unlike typical cobras, the Rinkhals exhibits unique behaviors such as thanatosis—playing dead by flipping onto its back with its mouth open and tongue out—to deter predators. This medium-sized snake, averaging 90-110 cm in length but sometimes reaching up to 150 cm, is recognizable by its characteristic banded black and white throat, which it flares as a defensive display.

River Otter

The North American river otter (Lontra canadensis), also known as the river otter or northern river otter, is a semiaquatic mammal native to North America’s waterways and coasts. Adult river otters typically weigh between 5.0 and 14 kg (11.0 to 30.9 lb). They are protected and insulated by a dense, water-repellent fur coat.

River otters, one of the fascinating animals starting with R, have long whiskers that help them detect prey in murky waters. On average, adult males weigh around 11.3 kilograms (25 lb), while females weigh approximately 8.3 kilograms (18 lb). Their body length ranges from 66 to 107 centimeters (26 to 42 inches).

River Turtle

River turtles, belonging to various genera such as Pseudemys, Trachemys, and Podocnemis, are remarkable reptiles inhabiting freshwater ecosystems across the globe. One notable example is the Arrau turtle (Podocnemis expansa), native to the Amazon and Orinoco river basins in South America. This species can grow up to 1 meter in length and weigh over 90 kilograms, making it one of the largest freshwater turtles in the world.

River turtles play a crucial ecological role, contributing to the health of their habitats by maintaining aquatic vegetation and controlling insect populations. They are primarily herbivorous, feeding on a diet of aquatic plants, fruits, and seeds, although some species may also consume small invertebrates.

Roadrunner

Roadrunners (genus Geococcyx), also known as chaparral birds or chaparral cocks, are two species of fast-running ground cuckoos characterized by their long tails and crests. These birds inhabit the southwestern and south-central United States, Mexico, and Central America, often residing in desert regions. While they are capable of flight, roadrunners typically prefer to escape predators by running and can reach speeds of up to 32 km/h (20 mph). Their vocalizations include a slow, descending coo similar to that of a dove and a rapid clattering sound produced with their beaks.

Robber Flies

The Asilidae, commonly known as robber flies or assassin flies, belong to a family of powerfully built, bristly flies characterized by a short, stout proboscis that encloses a sharp, sucking hypopharynx. These flies typically range from medium to large in size, with an average body width of 1 to 1.5 cm (0.39 to 0.59 in), although they can vary from as small as 3 mm (0.12 in) to over 5 cm (2.0 in) in length. Most robber flies have an elongated shape due to their long, tapering abdomens, but there are also species with more compact bodies and broader abdomens.

Robin

The robin, known for its distinctive red breast, is a beloved bird species found across Europe, Asia, and North America. Scientifically classified under the genus Erithacus (Old World robins) and Turdus (American robins), these birds are known for their melodious songs and vibrant plumage, which varies slightly between species.

In Europe, the European robin (Erithacus rubecula) is a small bird with a brownish-orange breast, often seen in gardens and parks, where it forages for insects, worms, and berries. It’s known for its fearless behavior around humans, sometimes approaching gardeners for food or to investigate freshly dug soil.

Rock Bass

The rock bass (Ambloplites rupestris), also known as rock perch, goggle-eye, red eye, and black perch, is a freshwater fish native to east-central North America. Although they resemble smallmouth bass, rock bass are typically smaller in size. Key identifying features include two dorsal fins that are connected, one with spines and the other with soft rays, a large mouth, six anal spines, and red eyes. They also have rows of dark dots along their sides. The mouth is terminal, positioned below the snout, and equipped with small conical teeth for consuming prey. Rock bass, one of the fascinating animals that start with R, typically measure between 6 and 10 inches in length and rarely exceed a pound in weight. Their lifespan is usually between 10 and 12 years.

Rock Crab

Cancer irroratus, commonly known as the Atlantic rock crab or peekytoe crab, belongs to the genus Cancer. This species is found along the eastern coast of North America, ranging from Iceland to South Carolina, and can inhabit depths up to 2,600 feet (790 meters). The carapace of the Atlantic rock crab can reach up to 133 mm (5.2 inches) in width. These crabs are adaptable to a wide range of depths, from areas well above the low tide line to the deep sea.

Rock Hyrax

The rock hyrax (Procavia capensis), also known as the dassie, Cape hyrax, rock rabbit, and sometimes referred to as a coney (as interpreted from certain passages in the King James Bible), is a medium-sized terrestrial mammal indigenous to Africa and the Middle East. These animals inhabit elevations up to 4,200 meters (13,800 feet) in areas with rock crevices that provide refuge from predators.

Rock hyraxes, one of the fascinating animals that start with R, have a squat, robust build, with adults typically measuring around 50 cm (20 inches) in length and weighing approximately 4 kg (8.8 lbs). There is a slight sexual dimorphism, with males being about 10% heavier than females. Their thick fur varies in color, ranging from dark brown in wetter environments to light gray in desert regions.

Rock Python

The African rock python (Python sebae), one of the largest snake species globally, inhabits sub-Saharan Africa’s forests, grasslands, and savannas, ranging from Senegal to Ethiopia and down to South Africa. It ranks among the six largest snake species worldwide, capable of exceeding 6 meters in length and weighing over 90 kilograms. Recognizable by its intricate pattern of dark brown blotches on a lighter background, this python is a formidable predator, preying on mammals, birds, and occasionally crocodiles. Females lay clutches of up to 100 eggs, incubating them with body heat for approximately three months.

Rockfish

Rockfishes, members of the genus Sebastes, are a diverse group of marine fish found in the coastal waters of the North Pacific and North Atlantic Oceans, as well as the southern oceans around New Zealand and South America. They are known for their robust bodies, spiny fins, and vibrant coloration, which can range from red and orange to black and yellow, helping them blend into their rocky habitats. There are over 100 species of rockfish, varying in size from a few centimeters to over a meter in length, depending on the species. These fish are slow-growing and long-lived, with some individuals living up to 100 years.

Rockhopper Penguin

The rockhopper penguins consist of three closely related taxa of crested penguins, which have traditionally been considered a single species but are sometimes classified into three distinct species. These penguins, scientifically known as Eudyptes chrysocome, are among the smaller penguin species, typically reaching a height of about 20 inches or 50 centimeters when fully grown. Northern rockhopper penguins breed in cool temperate climates, specifically on the islands of Gough and Tristan da Cunha in the Atlantic Ocean, as well as St. Paul and Manchester in the Indian Ocean.

Rodents

Rodents, derived from the Latin word “rodere” meaning “to gnaw,” are mammals belonging to the order Rodentia. They are distinguished by having a single pair of continuously growing incisors in both the upper and lower jaws. Rodents constitute about 40% of all mammal species. A key characteristic of rodents is their continuously growing, razor-sharp incisors, which have thick layers of enamel on the front and minimal enamel on the back. Due to their perpetual growth, rodents must constantly gnaw to wear down their teeth and prevent them from growing too long and potentially piercing the skull.

Roe Deer

The roe deer (Capreolus capreolus), also known as the roe, western roe deer, or European roe, is a species of deer. The males of this species are sometimes called roebucks. Roe deer are relatively small, with a body length ranging from 95 to 135 cm (3 ft 1 in to 4 ft 5 in) and a shoulder height of 63 to 67 cm (2 ft 1 in to 2 ft 2 in). They typically weigh between 15 and 35 kg (35 to 75 lb). Populations found in the Urals and northern Kazakhstan tend to be larger, with individuals reaching up to 145 cm (4 ft 9 in) in length, 85 cm (2 ft 9 in) at shoulder height, and body weights up to 60 kg (130 lb).

Rooster

The rooster, also known as a cockerel or cock, is a male chicken belonging to the Gallus gallus domesticus species. Recognizable for its vibrant plumage, including iridescent feathers and a prominent comb atop its head, roosters are iconic symbols of farm life and rural culture worldwide. They play a vital role in poultry farming, primarily as guardians and leaders of flocks, announcing the break of dawn with their characteristic crowing, which can carry for long distances. Roosters exhibit territorial behavior, often engaging in displays of dominance such as puffing out their feathers and erecting their neck feathers (hackles) when challenged.

Root Aphids

Root aphids are small, sap-sucking insects that primarily infest the root systems of plants, where they feed on plant fluids. Unlike their above-ground counterparts, root aphids are less visible and often harder to detect until significant damage is evident. These pests can affect a wide range of plants, including ornamentals, vegetables, and agricultural crops, by weakening root systems and causing stunted growth, yellowing leaves, and reduced plant vigor. Root aphids, one of the fascinating animals that start with R, reproduce asexually for much of the year, producing numerous offspring rapidly under favorable conditions.

Rose-Breasted Grosbeak

The rose-breasted grosbeak (Pheucticus ludovicianus), often referred to as “cut-throat” due to its distinctive coloration, is a large, seed-eating bird belonging to the cardinal family (Cardinalidae). Adult rose-breasted grosbeaks typically measure between 18 and 22 cm (7.1 to 8.7 inches) in length, with a wingspan of 29 to 33 cm (11 to 13 inches), and they weigh between 35 and 65 grams (1.2 to 2.3 ounces). During migration, those measured in the West Indies averaged 43 grams (1.5 ounces), while individuals banded in Pennsylvania had an average weight of about 45 grams (1.6 ounces).

Roseate Spoonbill

The roseate spoonbill (Platalea ajaja) is a sociable wading bird that belongs to the ibis and spoonbill family, Threskiornithidae. This species is a resident breeder in both South and North America. Roseate spoonbills, one of the fascinating animals that start with R, are 71–86 cm (28–34 in) in length, with a wingspan of 120–133 cm (47–52 in) and a body mass ranging from 1.2 to 1.8 kg (2.6–4.0 lb). Their tarsus measures 9.7–12.4 cm (3.8–4.9 in), the culmen measures 14.5–18 cm (5.7–7.1 in), and the wing measures 32.3–37.5 cm (12.7–14.8 in). This gives them an overall elongated appearance with long legs, bill, neck, and distinctive spatulate bill.

Rosy Boa

The Rosy Boa (Lichanura trivirgata) is a non-venomous snake species native to the southwestern United States and northwestern Mexico, inhabiting a variety of arid and semi-arid habitats such as rocky deserts, scrublands, and sandy washes. Known for their docile temperament and manageable size, adult Rosy Boas typically range from 2 to 4 feet in length, with females generally larger than males.

They exhibit a distinctive color pattern, with a base color ranging from light gray to reddish-brown, adorned with three dark stripes running the length of their body, giving rise to their common name. Rosy Boas are ambush predators, feeding primarily on small mammals, birds, and occasionally lizards, which they capture by constricting their prey.

Rotterman

The Rotterman is a crossbreed dog resulting from the combination of a Rottweiler and a Doberman Pinscher. These hybrids typically inherit a blend of characteristics from both parent breeds, including a muscular build, medium to large size, and a loyal, protective temperament. Known for their intelligence and trainability, Rottermans often excel as working dogs in roles such as protection, search and rescue, and police work.

They typically have short coats that are easy to maintain, often displaying colors and markings reminiscent of their Rottweiler and Doberman ancestors. Due to their strong guarding instincts and high energy levels, Rottermans require regular exercise, socialization from an early age, and consistent training to thrive as companion animals or working partners.

Rottle

The Rottle, one of the fascinating animals that start with R, is a designer dog breed resulting from crossing a Rottweiler with a Poodle. Also known as a Rottie Poo or Rottweiler Poodle mix, this hybrid typically inherits a combination of traits from both parent breeds. Rottles often exhibit a medium to large size, varying coat types (which can be curly like the Poodle or short and dense like the Rottweiler), and a range of colors including black, brown, and tan. Known for their intelligence, loyalty, and affectionate nature, Rottles can make excellent family pets and companions. They are usually energetic and require regular exercise and mental stimulation to keep them happy and healthy.

Rottsky

The Rottsky, a crossbreed between a Rottweiler and a Siberian Husky, blends the distinct traits of its parent breeds to create a unique and striking canine companion. These dogs typically exhibit a robust build with a medium to large size, combining the muscular frame of the Rottweiler with the sleek, agile physique of the Husky. Their coats vary but often feature dense, double-layered fur that can range in length and may include colors like black, brown, white, or combinations thereof.

Rottweiler

The Rottweiler is a breed of domestic dog that is classified as medium-to-large or large. Originally known in German as Rottweiler Metzgerhund, meaning “Rottweil butchers’ dogs,” these dogs were primarily used for herding livestock and pulling carts filled with butchered meat to market. The Rottweiler has a medium-length skull that is relatively broad between the ears, with a moderately arched forehead when viewed from the side and a well-developed but not overly prominent occipital bone. The stop is quite pronounced, and the frontal groove is not very deep.

The nose of a Rottweiler is well-developed, broad rather than round, with large nostrils and always black in color. The muzzle should appear proportionate, neither too elongated nor too short compared to the cranial region, with a length-to-skull ratio of about 1 to 1.5. The nasal bridge is straight, wide at the base, and tapers moderately.

Rottweiler Mix

A Rottweiler mix, such as the Labrador Retriever-Rottweiler cross, often referred to as a Labrottie, combines the Rottweiler’s robust build and protective instincts with the Labrador Retriever’s friendly and trainable nature. Labrottie dogs typically exhibit a medium to large size with a muscular frame, inheriting a blend of colors and markings from both parent breeds. Known for their loyalty and intelligence, these hybrids are versatile companions, excelling in roles ranging from family pets to working dogs due to their adaptability and affectionate demeanor. Proper training and socialization from an early age are crucial for harnessing their potential as well-rounded and well-behaved canine companions.

Rough Green Snake

The rough green snake (Opheodrys aestivus) is a nonvenomous colubrid native to North America. While it is sometimes referred to as the grass snake or green grass snake, these names are more commonly associated with the smooth green snake (Opheodrys vernalis). The rough green snake is characterized by its bright green upper body and yellowish belly, providing excellent camouflage in vegetation and making it difficult to spot in the wild, despite being relatively common in its habitat. It has keeled dorsal scales arranged in 17 rows at mid-body and can grow up to 116 cm (45¾ in) in total length, including the tail. The rough green snake is also notably slender.

Rough-Legged Hawk

The rough-legged buzzard (Europe) or rough-legged hawk (North America) (Buteo lagopus) is a medium-large bird of prey. During the breeding season, it inhabits Arctic and Subarctic regions of North America, Europe, and Russia, migrating southward for the winter. This sizable raptor measures 46–68 cm (18–27 in) in length, with a wingspan ranging from 120 to 153 cm (47 to 60 in). Individuals weigh between 600 and 1,660 g (1.32 to 3.66 lb), with females generally larger and heavier than males.

The rough-legged buzzard is carnivorous, predominantly feeding on small mammals, which constitute 62–98% of its diet. Lemmings and voles are the primary prey, comprising up to 80–90% of their diet during certain seasons, although this varies depending on seasonal availability.

Rove Beetle

Rove beetles, one of the fascinating animals that start with R, belong to the family Staphylinidae and are primarily characterized by their short elytra (wing covers) that typically expose more than half of their abdominal segments. Given the large number of species within this family, there is considerable variation among them. Rove beetles can range in size from less than 1 mm to 35 mm (1.4 in), with most species falling within the 2–8 mm range. Their body shapes are generally elongated, though some species are more ovoid. The coloration of rove beetles varies widely, including shades of yellow, red, reddish-brown, brown, black, and iridescent blue and green.

Royal Penguin

The royal penguin (Eudyptes schlegeli) is a penguin species that resides exclusively on the sub-Antarctic Macquarie Island and nearby islands. The International Union for Conservation of Nature (IUCN) lists the royal penguin as Least Concern. There has been some debate over whether royal penguins should be classified as a subspecies of macaroni penguins, as individuals from both groups have occasionally interbred, although this is a rare event. Additionally, instances of mixed-species pairings among different penguin species have been observed in the wild.

Rubber Boa

The rubber boa (Charina bottae) is a species of snake in the family Boidae, native to western North America. It is also referred to as the coastal rubber boa or the northern rubber boa. Among the smaller boa species, adult rubber boas range from 38 to 84 cm (1.25 to 2.76 ft) in length, while newborns measure between 19 and 23 cm (7.5 to 9.1 in). The name “rubber boa” comes from their skin, which is often loose, wrinkled, and composed of small, smooth, and shiny scales, giving them a rubber-like appearance and texture. Their coloration typically ranges from tan to dark brown with a lighter underside, though they can also appear in shades of olive-green, yellow, or orange.

Ruby-Crowned Kinglet

The ruby-crowned kinglet (Corthylio calendula) is a very small passerine bird that can be found throughout North America and is part of the kinglet family. Measuring between 9 to 11 cm (3.5 to 4.3 inches) in length, this tiny bird has a wingspan of 16 to 18 cm (6.3 to 7.1 inches) and weighs only 5 to 10 grams (0.2 to 0.4 ounces). It features gray-green upperparts and olive-buff underparts, along with two distinctive white wingbars and a broken white eye ring. The wingbar on the greater secondary coverts, which is closer to the wing-tip, is notably wider and is bordered by a dark band.

Ruby-Throated Hummingbird

The ruby-throated hummingbird (Archilochus colubris) is a species that typically winters in Central America, Mexico, and Florida, and migrates to Canada and other parts of Eastern North America during the summer for breeding.

This small hummingbird measures between 7 to 9 cm (2.8 to 3.5 inches) in length and has a wingspan of 8 to 11 cm (3.1 to 4.3 inches). Their weight ranges from 2 to 6 grams (0.071 to 0.212 ounces), with males averaging around 3.4 grams (0.12 ounces) and the slightly larger females averaging about 3.8 grams (0.13 ounces). Adult ruby-throated hummingbirds display metallic green upperparts and grayish-white underparts, with nearly black wings. Their bills are long, straight, and slender, measuring up to 2 cm (0.79 inches) in length.

Ruddy Duck

The ruddy duck (Oxyura jamaicensis) is a species of stiff-tailed duck native to North America. These small, compact ducks are known for their stout, scoop-shaped bills and long, stiff tails, which they often hold cocked upward. They have slightly peaked heads and fairly short, thick necks. Male ruddy ducks are distinguished by their blackish caps that contrast with their bright white cheeks. During the summer, males have rich chestnut bodies and bright blue bills, while in winter, they turn dull gray-brown above and paler below, with their bills becoming a dull gray.

Ruddy Turnstone

The ruddy turnstone (Arenaria interpres) is a small, cosmopolitan wading bird. It is relatively small and stocky, measuring 22–24 cm (8.7–9.4 inches) in length, with a wingspan of 50–57 cm (20–22 inches) and a weight of 85–150 grams (3.0–5.3 ounces). The bird has a dark, wedge-shaped bill that is 2–2.5 cm (0.79–0.98 inches) long and slightly upturned. Its legs are fairly short at 3.5 cm (1.4 inches) and are bright orange. Throughout the year, the ruddy turnstone’s plumage features a striking harlequin-like pattern of black and white. During the breeding season, the upper parts are reddish-brown with black markings.

Rufous Hummingbird

The rufous hummingbird (Selasphorus rufus) is a small species of hummingbird, measuring about 8 cm (3.1 inches) in length with a long, straight, and slender bill. Renowned for their remarkable flight abilities, these birds migrate up to 2,000 miles (3,200 kilometers).

Adult males are characterized by a white breast, rufous face, flanks, and tail, with an iridescent orange-red throat patch or gorget. Some males may also display green on their back and/or crown. Females have green upperparts, white underparts, and some iridescent orange feathers in the center of their throats, along with a dark tail featuring white tips and a rufous base.

Russel’s Viper

Russell’s viper (Daboia russelii) is a highly venomous snake belonging to the family Viperidae, native to South Asia. It features a flattened, triangular head distinct from its neck. The snout is blunt, rounded, and slightly elevated. The snake has large nostrils, each located in the center of a large, single nasal scale, with the lower edge of this scale touching the nasorostral scale. The supranasal scale is strongly crescent-shaped, separating the nasal from the nasorostral scale anteriorly. The rostral scale is equally broad and high. The crown of the head is covered with irregular, strongly fragmented scales, and the narrow supraocular scales are single and separated by six to nine scales across the head.

Russell Terrier

The Russell Terrier, also known as the Jack Russell Terrier, is a small and energetic breed known for its intelligence, agility, and bold personality. Originating from England, these terriers were initially bred for hunting foxes by Reverend John Russell in the 19th century. They are characterized by their compact, muscular build, typically weighing between 14-18 pounds (6-8 kg) and standing around 10-12 inches (25-30 cm) tall at the shoulder. Russell Terriers have a short, smooth coat that can come in various colors, often with white as the predominant color and patches of black, tan, or brown.

Russian Bear Dog

The Russian Bear Dog, also known as the Caucasian Shepherd Dog, is a large and powerful breed native to the Caucasus region of Russia. These dogs were historically used for guarding livestock and property, as well as protecting against predators like wolves and bears in the rugged mountainous terrain. Known for their imposing size and strength, male Russian Bear Dogs can weigh between 110-200 pounds (50-90 kg) and stand 25-30 inches (64-76 cm) tall at the shoulder, with females slightly smaller.

Physically, they have a dense double coat that provides insulation against cold temperatures, with colors ranging from shades of gray, fawn, brindle, or white markings. Their broad heads are typically adorned with small, triangular ears that sit high on the skull, contributing to their vigilant appearance.

Russian Blue

The Russian Blue cat, often simply called the Russian Blue, is a breed known for its coat, which ranges in color from light shimmering silver to darker slate grey. These cats feature bright green eyes, pinkish lavender or mauve paws, and a blue-grey-black coat comprised of two layers of short, thick fur. The bluish-gray color is a dilute expression of the black gene. Russian Blues, one of the fascinating animals that start with R, are small to moderate in size, typically weighing between 3.6 to 6.8 kg (8 to 15 lb) when fully grown, with males generally being larger than females. The gestation period for Russian Blue cats is around 64 days.

Russian Tortoise

The Russian tortoise (Testudo horsfieldii), also known by various names such as the Afghan tortoise, Central Asian tortoise, four-clawed tortoise, four-toed tortoise, Horsfield’s tortoise, Russian steppe tortoise, Soviet tortoise, and steppe tortoise, is a threatened species within the family Testudinidae. This species is native to Central Asia, ranging from the Caspian Sea southward through Iran, Pakistan, and Afghanistan, and extending eastward across Kazakhstan to Xinjiang, China.

Russian tortoises are small, with adults measuring between 13 and 25 cm (5 to 10 inches). Females tend to be slightly larger, ranging from 15 to 25 cm (6 to 10 inches), to accommodate egg laying, while males typically measure between 13 and 20 cm (5 to 8 inches).

In conclusion, the exploration of the list of animals that start with R highlights the remarkable diversity and significance of wildlife across the globe. From the resourceful raccoon to the regal rhinoceros, each species contributes uniquely to its respective ecosystem. A deeper understanding and appreciation of these animals underscore the importance of conserving their habitats to ensure their continued existence.