Sloth bears….and sloths and bears
Sloth bears got their name in 1791 by English zoologist George Shaw, who encountered the bear and believed the species was related to actual sloths since they shared similar traits, naming them “bear sloths”. Shaw named them Bradypus ursinus, which means something like ‘slow feet bear,’ using the family name of three-fingered sloths, the Genus Bradypus.
The sloth bear goes by many different names throughout the region depending on the language, and once Europeans got involved, the name changed once again. Confusion over whether the bear is a bear or a sloth made it challenging for scientists to classify it under the Latin-based binomial naming system. Once it was indeed determined that it was a bear, they changed the Genus but kept the common name, so “bear sloth” changed to “sloth bear.”
The modern scientific name of the sloth bear, Melursus ursinus, combines Greek and Latin elements. “Melursus” is derived from the Greek “melas” (meaning “black”) and the Latin “ursus” (meaning “bear”), referring to the bear’s dark fur. The specific name “ursinus,” from Latin, translates to “bear-like.”
To add more confusion to the subject, the most common name for sloths in Latin America is ‘oso perezoso’, which means, as you might guess, sloth bear.
What can we do to protect both species?
These extraordinary creatures’ continued existence hinges significantly on our actions today. This involves adopting more sustainable farming practices and endorsing conservation initiatives that safeguard the natural habitats of these animals from further degradation.
You can support organizations working with this species, like Wildlife SOS, founded in 1995; it has a strong track record in India for rescuing wildlife in distress, including sloth bears, elephants, leopards, and others. Free the Bears is an organization that works to rescue and rehabilitate bears in various Asian countries.
Four species of ground sloths inhabited the United States at the end of the last Ice Age. These were Jefferson's ground sloth (Megalonyx jeffersonii), Laurillard's ground sloth (Eremotherium laurillardi), the Shasta ground sloth (Nothrotheriops shastensis), and Harlan's ground sloth (Glossotherium harlani). Of these four only two, Jefferson's and Harlan's ground sloths, are found in the midwestern U.S.
Ground sloths were large relatives of the modern two-toed sloths (Choloepus spp.) and three-toed sloths (Bradypus spp.). Unlike modern sloths, which spend most of their time in trees, the ground sloths spent all of their time on the ground. This is fortunate because Jefferson's and Harlan's ground sloth were each about the size of an oxen.
All four species of ground sloth had very large claws. However, all were herbivores. They had relatively small, blunt teeth, which they probably used for browsing on trees and shrubs. The shape of their hip bones indicates that they could stand up on their hind legs. This would allow them to reach high up into trees for the best leaves and twigs.
The picture above shows a reconstruction of Jefferson's ground sloth from the University of Iowa Museum of Natural History.
Metabolisme Rendah
Sloth bisa mencerna makanannya yang hanya sehelai daun selama 30 hari. Sloth memiliki tingkat metabolisme yang lemah dibandingkan mamalia lainnya. Perut yang terdapat empat bilik sudah penuh secara permanen, yang bahkan bisa mencapai 30 persen massa tubuh mereka.
Group of tree dwelling mammals noted for slowness
Sloths are a Neotropical group of xenarthran mammals constituting the suborder Folivora, including the extant arboreal tree sloths and extinct terrestrial ground sloths. Noted for their slowness of movement, tree sloths spend most of their lives hanging upside down in the trees of the tropical rainforests of South America and Central America. Sloths are considered to be most closely related to anteaters, together making up the xenarthran order Pilosa.
There are six extant sloth species in two genera – Bradypus (three-toed sloths) and Choloepus (two-toed sloths). Despite this traditional naming, all sloths have three toes on each rear limb – although two-toed sloths have only two digits on each forelimb.[3] The two groups of sloths are from different, distantly related families, and are thought to have evolved their morphology via parallel evolution from terrestrial ancestors. Besides the extant species, many species of ground sloths ranging up to the size of elephants (like Megatherium) inhabited both North and South America during the Pleistocene Epoch. However, they became extinct during the Quaternary extinction event around 12,000 years ago, along with most large animals across the Americas. The extinction correlates in time with the arrival of humans, but climate change has also been suggested to have contributed. Members of an endemic radiation of Caribbean sloths also formerly lived in the Greater Antilles but became extinct after humans settled the archipelago in the mid-Holocene, around 6,000 years ago.
Sloths are so named because of their very low metabolism and deliberate movements. Sloth, related to slow, literally means "laziness", and their common names in several other languages (e.g. German: Faultier, French: paresseux, Spanish: perezoso, Romanian: leneș, Finnish: laiskiainen) also mean "lazy" or similar. Their slowness permits their low-energy diet of leaves and avoids detection by predatory hawks and cats that hunt by sight.[3] Sloths are almost helpless on the ground but are able to swim.[4] The shaggy coat has grooved hair that is host to symbiotic green algae which camouflage the animal in the trees and provide it nutrients. The algae also nourish sloth moths, some species of which exist solely on sloths.[5]
What is a sloth bear?
A Sloth bear is a type of bear species native to India, Sri Lanka, Nepal, and Bhutan. Known for its long snout and long lower lip used for sucking up insects, it’s officially named Melursus ursinus. Despite the name referring to them as ‘lazy’, sloth bears are anything but lazy!
These bears have a distinctive shaggy black coat with a whitish-yellow ‘U’ or ‘Y’ shaped mark on their chest. And although they share a resemblance, sloth bears should not be confused with the Asian Black Bear (Ursus thibetanus)
What do sloth bears eat?
Despite being in the order Carnivora, sloth bears are myrmecophagous, meaning they consume termites and ants. Occasionally, during monsoon season, they are known to dine on fruit in trees such as mango, fig, ebony, etc., as well as flowers. Termites, ants, beetles, and other insects are also of interest to sloth bears year-round, and they are 95% of their diet.
Aside from digging out mounds, they are capable climbers and can climb trees to knock down honeycombs to collect the honey from the ground.
Scientists study sloth bears around India through GPS collars that communicate through satellites and allow them to collect data from the exact location of the animals at any given time. Scientists have studied and collected data on sloth bear attacks, threats to sloth bears, sloth bear denning, relocation of sloth bears, and sloth bear densities. The sloth bear is the least studied and understood bear in the Indian subcontinent.
Here at SloCo, we similarly study sloths through VHF/GPS collars, backpacks, and data loggers. VHF and GPS collars allow scientists to locate sloths and collect information about the sloth and its habitat.
The overall goal of scientists studying sloths is the same for sloth bears: to ensure long-term survival, conservation, and coexistence.
Bisa Memutar Kepala 270 Derajat
Sloth berjari tiga memiliki keunikan dibandingkan dengan sloth berjari dua. Sloth spesies ini memiliki tulang leher tambahan yang memungkinkan mereka memutar kepalanya hampir seluruhnya atau sekitar 270 derajat.
Taxonomy and evolution
Sloths belong to the superorder Xenarthra, a group of placental mammals believed to have evolved in the continent of South America around 60 million years ago.[6] One study found that xenarthrans broke off from other placental mammals around 100 million years ago.[7] Anteaters and armadillos are also included among Xenarthra. The earliest xenarthrans were arboreal herbivores with sturdy vertebral columns, fused pelvises, stubby teeth, and small brains. Sloths are in the taxonomic suborder Folivora[2] of the order Pilosa. These names are from the Latin 'leaf eater' and 'hairy', respectively. Pilosa is one of the smallest of the orders of the mammal class; its only other suborder contains the anteaters.
The Folivora are divided into at least eight families, only two of which have living species; the remainder are entirely extinct (†):[8]
The common ancestor of the two existing sloth genera dates to about 28 million years ago,[8] with similarities between the two- and three- toed sloths an example of convergent evolution to an arboreal lifestyle, "one of the most striking examples of convergent evolution known among mammals".[13] The ancient Xenarthra included a significantly greater variety of species, with a wider distribution, than those of today. Ancient sloths were mostly terrestrial, and some reached sizes that rival those of elephants, as was the case for Megatherium.[4]
Sloths arose in South America during a long period of isolation and eventually spread to a number of the Caribbean islands as well as North America. It is thought that swimming led to oceanic dispersal of pilosans to the Greater Antilles by the Oligocene, and that the megalonychid Pliometanastes and the mylodontid Thinobadistes were able to colonise North America about 9 million years ago, well before the formation of the Isthmus of Panama. The latter development, about 3 million years ago, allowed megatheriids and nothrotheriids to also invade North America as part of the Great American Interchange. Additionally, the nothrotheriid Thalassocnus of the west coast of South America became adapted to a semiaquatic and, eventually, perhaps fully aquatic marine lifestyle.[14] In Peru and Chile, Thalassocnus entered the coastal habitat beginning in the late Miocene. They presumably waded and paddled in the water for short period, but over a span of 4 million years, they eventually evolved into swimming creatures, becoming specialist bottom feeders of seagrasses, similar to the extant sirenians.[15]
Both types of extant tree sloth tend to occupy the same forests; in most areas, a particular species of the somewhat smaller and generally slower-moving three-toed sloth (Bradypus) and a single species of the two-toed type will jointly predominate. Based on morphological comparisons, it was thought the two-toed sloths nested phylogenetically within one of the divisions of the extinct Greater Antilles sloths.[16] Though data has been collected on over 33 different species of sloths by analyzing bone structures, many of the relationships between clades on a phylogenetic tree were unclear.[17] Much of the morphological evidence collected to support the hypothesis of diphyly has been based on the structure of the inner ear.[18]
Recently obtained molecular data from collagen[8] and mitochondrial DNA sequences[19] fall in line with the diphyly (convergent evolution) hypothesis but have overturned some of the other conclusions obtained from morphology. These investigations consistently place two-toed sloths close to mylodontids and three-toed sloths within Megatherioidea, close to Megalonyx, megatheriids and nothrotheriids. They make the previously recognized family Megalonychidae polyphyletic, with both two-toed sloths and Greater Antilles sloths being moved away from Megalonyx. Greater Antilles sloths are now placed in a separate, basal branch of the sloth evolutionary tree.[8][19]
The following sloth family phylogenetic tree is based on collagen and mitochondrial DNA sequence data.[8]
The marine sloths of South America's Pacific coast became extinct at the end of the Pliocene following the closing of the Central American Seaway; the closing caused a cooling trend in the coastal waters which killed off much of the area's seagrass (and which would have also made thermoregulation difficult for the sloths, with their slow metabolism).[20]
Ground sloths disappeared from both North and South America shortly after the appearance of humans about 11,000 years ago. Evidence suggests human hunting contributed to the extinction of the American megafauna. Ground sloth remains found in both North and South America indicate that they were killed, cooked, and eaten by humans.[4] Climate change that came with the end of the last ice age may have also played a role, although previous similar glacial retreats were not associated with similar extinction rates.
Megalocnus and some other Caribbean sloths survived until about 5,000 years ago, long after ground sloths had died out on the mainland, but then went extinct when humans finally colonized the Greater Antilles.[21]
Perenang yang Baik
Meskipun sloth menjadi hewan terlambat di darat, tetapi saat berada di air, sloth terkenal lebih lincah. Sloth bisa berenang tiga kali lebih cepat dibandingkan saat bergerak di tanah.
Kebiasaan memakan serangga sebagai makanan utama
Dengan anatomi tubuh yang mendukung, beruang sloth termasuk ke dalam jajaran hewan myrmecophagous atau pemakan serangga. Biasanya mereka akan menggali dan menyedot sarang semut maupun serangga untuk memenuhi kebutuhan makannya
Menurut laman Smithsonian National Zoo, 95 persen dari makanan beruang sloth adalah serangga. Akan tetapi, bukan berarti mereka tidak memakan makanan lain. Sesekali mereka memakan buah-buahan maupun tanaman lain ketika berada di alam.
Tak hanya itu, mereka juga beberapa kali kedapatan memanjat pohon untuk menjatuhkan sarang lebah ke tanah sebagai pilihan lain dalam makanan mereka.
Baca Juga: 6 Fakta Beruang Kodiak, Pesaing Beruang Kutub yang Tak Kalah Sangar
Satu-satunya jenis beruang yang menggendong anaknya di punggung secara rutin
Beruang jenis lain memang beberapa kali tertangkap kamera sedang menggendong anaknya di punggung, namun beruang sloth merupakan satu-satunya yang rutin untuk melakukan kebiasaan ini hingga anaknya berusia 7 sampai 8 bulan, lho.
Dikutip dari laman Wildlife SOS, menggendong anak di punggung akan memudahkan induk beruang sloth untuk mengangkut anak-anaknya dari satu gundukan sarang semut atau rayap ke sarang lainnya. Hal tersebut ternyata juga dilakukan oleh beberapa hewan myrmecophagous lainnya, lho.
Tak hanya itu, dengan menggendong anaknya di punggungnya, induk beruang sloth akan semakin mudah untuk melindungi mereka ketika diserang oleh predator lain seperti harimau.
