Anatomy and physiology
editSlow lorises have a round head and a less pointed snout than the slender lorises.[1] They have large eyes and good night vision. Their tails are either short or absent,[2] while their spine has an extra vertebra, which allows them greater mobility when twisting and extending towards nearby branches.[3] The intermembral index averages 89, meaning the front and back limbs are nearly equal in length. The second digit of the hand is short compared to the other digits, and its sturdy thumb helps to act like a clamp when digits three, four, and five grasp the opposite side of a tree branch. Both hands and feet provide a powerful grasp,[4] which can be held for hours without losing sensation due to the presence of a retia mirabilia (network of capillaries), a trait shared among all members of the lorisine subfamily.[1]
Slow lorises have an unusually low basal metabolic rate. This may be as little as 40% the typical value for placental mammals of their size; comparable to that of sloths. Since they consume a relatively high calorie diet that is available year round, it has been proposed that this slow metabolism is due primarily to the need to eliminate toxic compounds from their food. For example, slow lorises can feed on Gluta bark, which can be fatal to humans.[5]
Predator avoidance
editSlow lorises can produce a toxin which they mix with their saliva to use as protection against enemies. The toxin is similar to the allergen in cat dander.[6] Mothers will lick this toxin onto their offspring before leaving them to search for food. The toxin is produced by glands on the insides of their elbows. The lorises suck it into their mouths and deliver it when they bite or lick.[citation needed] Loris bites cause a painful swelling, but the toxin is mild and not fatal. Cases of human death have been due to anaphylactic shock.[7] If the toxin does not deter a predator, the slow loris will often drop from the branch to the ground and roll into a protective ball.[citation needed]
Cultural refernces
editReferences
edit- ^ a b Ankel-Simons 2007, pp. 80.
- ^ McGreal 2007a.
- ^ Cite error: The named reference
2009Adam
was invoked but never defined (see the help page). - ^ Ankel-Simons 2007, pp. 82.
- ^ Wiens, F.; et al. (2007). "Fast food for slow lorises: is low metabolism related to secondary compounds in high-energy plant diet?". Journal of Mammalogy. 87 (4): 790–798. doi:10.1644/06-MAMM-A-007R1.1.
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(help) - ^ Lee R. Hagey, Bryan G. Fry, and Helena Fitch-Snyder. Talking Defensively - Chapter 12 of Primate anti-predator strategies edited by Sharon Gursky and K.A.I. Nekaris.
- ^ Wilde, H. (1972). "Anaphylactic Shock Following Bite by a 'Slow Loris,' Nycticebus Coucang" (PDF). American Journal of Tropical Medicine and Hygiene. 21 (5): 592–594. ISSN 0002-9637. PMID 5075669.