Echidnas , sometimes known as spiny anteaters, are quill-covered monotremes (egg-laying mammals) belonging to the family Tachyglossidae
The four extant species of echidnas and the platypus are the only living egg-laying mammals and the only surviving members of the order Monotremata. The diet of some species consists of ants and termites, but they are not closely related to the true anteaters of America, which (along with sloths and armadillos) are xenarthrans. Echidnas live in Australia and New Guinea.
Echidnas evolved between 20 and 50 million years ago, descending from a platypus-like monotreme. This ancestor was aquatic, but echidnas adapted to life on land.
Echidnas are named after Echidna, a creature from Greek mythology that was half female and half male snake the animal was considered to have both mammalian and reptilian qualities
Physical characteristics of the echidna
Echidnas are medium-sized, solitary mammals covered with coarse hair and spines. The spines are modified hairs and are made of keratin, the same fibrous protein that makes up fur, claws, nails and horn sheaths in animals.
Superficially, they resemble South American anteaters and other spiny mammals such as hedgehogs and porcupines. They usually have black or brown coloration. Several cases of albino echidnas, with pink eyes and white spines, have been reported
They have an elongated, slender snout that serves as a mouth and nose. Like the platypus, they are equipped with electrosensors, but while the platypus has 40,000 electroreceptors in its beak, the long-billed echidna has only 2,000. The short-billed echidna, which lives in a drier environment, has no more than 400 on the tip of its snout.
They use their electroreceptive beaks to detect earthworms, termites, ants and other burrowing prey.
Echidnas have short, strong limbs with large claws, and are powerful diggers. Their claws on the hind limbs are elongated and curved backward to aid in digging. Echidnas have tiny mouths and toothless jaws.
It feeds by tearing at soft logs, ant hills and the like, and using its long, sticky tongue, which protrudes from its snout, to pick up prey. The ears are slits on the sides of the head that are not normally seen, as they are covered by its spines
The external ear is formed by a large cartilaginous funnel, located deep in the muscle. At 33 °C, the echidna also has the second lowest active body temperature of all mammals, after the platypus.
Despite their appearance, echidnas are good swimmers, having evolved from platypus-like ancestors. When swimming, they expose their snout and some of their spines, and are known to move into the water for grooming and bathing.
Echidnas and platypuses are the only mammals that lay eggs, known as monotremes
The average lifespan of an echidna in the wild is estimated to be about 14-16 years. A female can weigh up to 4.5 kilograms and a male up to 6. The sex of an echidna can be deduced from its size, as males are 25% larger than females. The reproductive organs also differ, but both sexes have a single opening called a cloaca, which they use to urinate, release their feces and mate.
Male echidnas have non-venomous spurs on their hind legs.
The neocortex constitutes half of the echidna’s brain, compared to 80% of the human brain. Due to their low metabolism and accompanying resistance to stress, echidnas are long-lived for their size; the longest recorded lifespan for an echidna in captivity is 50 years, with anecdotal accounts of wild individuals reaching 45 years.
Contrary to previous research, the echidna enters REM sleep, but only when the ambient temperature is about 25 °C (77 °F). At temperatures of 15 °C (59 °F) and 28 °C (82 °F), REM sleep is suppressed.
The first European drawing of an echidna was made in Adventure Bay, Tasmania by the third lieutenant of HMS Providence, George Tobin, during the second voyage of William Bligh’s breadfruit.
what do echidnas feed on?
The diet of the short-billed echidna consists mainly of ants and termites, while the Zaglossus species (long-billed) usually eats worms and insect larvae.
The tongues of long-billed echidnas have sharp, tiny spines that help them capture prey. They have no teeth, so they break down their food by grinding it between the underside of their mouth and tongue
Echidna feces are 7 cm (3 inches) long and cylindrical in shape; they are usually broken and unrounded, and are largely composed of dirt and material from anthills.
what is their habitat?
Echidnas do not tolerate extreme temperatures; they use caves and rock crevices for shelter from harsh weather conditions
They are found in forests and woodlands, hiding under vegetation, roots or debris piles. They sometimes use the burrows of animals such as rabbits and wombats. Echidnas have large, overlapping territories.
The reproductive process of the echidna
The female lays a single soft-shelled leathery egg 22 days after mating and deposits it directly into her pouch
An egg weighs 1.5 to 2 grams (0.05 to 0.07 ounces)[19] and measures approximately 1.4 centimeters (0.55 inches). During hatching, the echidna hatchling opens the leathery shell with a reptile-like egg tooth
Hatching takes place after 10 days of gestation; the young echidna, called a puggle, which is born as a larva and fetus, then sucks milk from the pores of the two milk spots (monotremes do not have nipples) and remains in the pouch for 45 to 55 days, at which time it begins to develop spines
The mother digs a burrow and deposits the calf, which returns every five days to nurse until it is weaned at seven months. The young remain in their mother’s burrow for up to a year before leaving it.
Male echidnas have a four-headed penis. During mating, the heads on one side are “off” and do not increase in size; the other two are used to release semen into the female’s two-branched reproductive tract. Each time she copulates, she alternates the heads in groups of two. When not in use, the penis retracts into a preputial sac in the cloaca.
The penis of the male echidna is 7 centimeters (2.8 inches) long when erect, and its shaft is covered with penile spines, which can be used to induce ovulation in the female.
It is challenging to study echidna in the wild and they show no interest in mating while in captivity. Prior to 2007, no one had ever seen an echidna ejaculate. There have been previous attempts, trying to force the echidna to ejaculate by using electrically stimulated ejaculation in order to obtain semen samples, but this has only resulted in swelling of the penis.
The breeding season begins in late June and extends through September. Males will form lines of up to ten individuals, the youngest echidna last, which follow the female and attempt to mate. During the mating season, an echidna may change lines. This is known as the “train” system.
what dangers do echidnas face?
Echidnas are very shy animals. When they feel threatened, they try to bury themselves or, if exposed, curl into a hedgehog-like ball; both methods use their spines to protect themselves. Strong front arms allow echidnas to continue burrowing while holding on to a predator that tries to pull them out of the hole.
Although they have a way to protect themselves, echidnas still face many dangers. Some of the predators include feral cats, foxes, domestic dogs and goannas. Snakes pose a great threat to echidnas, as they sneak into their burrows and prey on the young spineless young.
Some precautions that can be taken are keeping the environment clean by picking up trash and causing less pollution, planting vegetation for echidnas to shelter, supervising pets, reporting injured echidnas, or simply leaving them undisturbed. Simply holding them can cause them stress, and holding them inappropriately can even cause injury.
