Monday, February 18, 2013

A few things I bet you didn’t know about elephants

Elephants are probably the most recognizable animal on the planet, but we never really stop to think about just how unique they are. They are equal parts brain and brawn, and have highly sophisticated social patterns; they display lateral preferences (being left- or right-tusked, for example); they can lift objects weighing almost 800lb (~363kg), and can crack the shell of a peanut without damaging its contents.

Here’s a list of some of the things that make elephants so damned amazing. Despite their familiarity, they are truly alien animals.

They are left- or right-tusked. Their “master tusk” is shorter and more worn than the less-used one.
A left-tusked elephant.
They’re also left- or right-trunked. Elephants only have one trunk (duh), but they seem to show preference in twisting it to one side or the other when grasping objects.

They have an extra “toe.” It’s not a true toe, though. Hence the quotation marks. Much like how pandas have an extra “thumb” to assist them in gripping bamboo, elephants have evolved a false toe to help with weight distribution.

They permanently walk on tiptoe. Though their feet may look big and flat, the bones in their hands and feet are balanced on their toes. The feet get their distinctive rounded shape from pads of fat located just under the bones.
Diagrams showing the bones in the hands and feet of elephants. The weight is balance on the tips of their toes, which are supported by large pads of fat. The bones highlighted in white are the extra "toe" which assists in weight distribution.
They get stressed when their matriarch passes away. A study conducted in captivity showed that stress hormones increased greatly after the passing of a herd’s matriarch. The matriarch is the eldest female in the group, and their age has been shown to be linked to a heightened sense of protection for the herd. (McComb et. al, 2011)

No matter if other females are present, the matriarch’s daughter always inherits the herd. Even sisters are second in line to the daughter of the matriarch. Kind of like the beginning of The Lion King. Be prepared…

They’re self-aware. When they are presented with a mirror, they know they’re looking at a reflection of themselves, not just another elephant. This is a trait found in many highly-intelligent species, including apes and dolphins.
This is Happy, an Asian elephant Elephas maximus. When presented in front of a mirror, Happy was able to touch that white "X" on her own head, rather than on the surface of the mirror, indicating her awareness that she was looking at herself.
Humans are selectively breeding them for shorter tusks. Well, indirectly. As more elephants are being poached for their ivory, males with shorter tusks are becoming more common. We aren’t so much breeding shorter-tusked males as we are selectively killing males with more impressive pairs. Since the mid-19th century, the size of African elephant tusks has halved. (Gray, 2008)

They are extremely interested in the bones and ivory of other elephants. Videos often show elephants “mourning” their dead. While scientists are still unsure the extent to which elephants feel emotion, experiments show that African elephants are much more interested in the bones of others, related or not, than they are to objects such as wood or the bones of other species. (McComb et. al, 2006)
A photo from Douglas-Hamilton et. al's research in Kenya. The collapsed female is Eleanor. You can see another female touching Eleanor with her foot. Other females look on.
They aid ailing members of their species, regardless of familial connection. Unrelated females will rush to the aid of an animal that has fallen. In one study done in Kenya, an individual named Grace helped an elderly female named Eleanor back onto her feet after she had collapsed. Eleanor fell again shortly after and eventually passed on. However, elephants of various different family groups investigated her body, touching it with their trunks and feet, and staying by her side even after her death.  (Douglas-Hamilton, 2006)

Douglas-Hamilton, I., Bhalla, Wittemyer, G., and Vollrath, F. 2006. Behavioural reactions of elephants towards a dying and deceased matriarch. Applied Animal Behaviour Science.

Gray, R.  2008, January 20. Why elephants are not so long in the tusk,

McComb, K., Baker, L., and Moss, C. 2006. African elephants show high levels of interest in the skulls and ivory of their own species, Biology Letters 2, 26–28.

McComb, K., Shannon, G., Durant, S.M., Sayialel, K., Slotow, R., Poole, J., and Moss, C. 2011. Leadership in elephants: the adaptive value of age. Proceedings of The Royal Society B, doi:10.1098/rspb.2011.0168

1 comment:

  1. Decreasing size of Ivory
    For some thousand of years Egypt was a main trade harbour of enterely Nile river. I believe that human selection starts many thousand years before! Carlos Yamashita