Selasa, 7 Oktober 2008

"a spring in my step"

leaping indri lemurs

springy sifaka lemurs

Top two pics: baby gibbons. Bottom: indri, siamang


There seem to be many parallels between the indri and the siamangs. The abundance of liana vines in island SE Asia for siamangs to swing (brachiate) and the lack of liana vines in Madagascar for the Indris may be why clinging and leaping was adopted among the Indris. Both tend to walk/skip bipedally rather than quadrupedally, and both have enlarged laryngeal air sacs likely indicating past vertical floating in tidal forests.

Inhabits montane and coastal rainforest from sea level to 1800 meters (6). Indris are active during the day and are most at home in the trees, where they feed on leaves, flowers and fruit, but they do occasionally descend to the forest floor to cross small treeless areas or to eat soil (4) (6). On the ground they cannot walk on all fours and so move around on their back legs, standing upright and holding their arms outstretched for balance, skipping in a unique fashion through the forest (6). The indri is one of the most endangered species of lemur on Madagascar, and one of the most threatened primates in the world (4). They live by the coast, where forests have become so fragmented that they are almost too small to sustain viable populations (6).

Except a narrow strip at the eastern coast most of their natural habitat, the rainforest, is destroyed. Indris are amongst the most endangered species.

Even if you are luckily you meet Indris it's more likely to hear their voices instead of seeing them up in the trees. Their voices are said to be amongst the loudest within the animal kingdom. Indris live in family groups and they use their voices to mark their family range.

They give birth to just one young at a time. The young Indri stays in the family for a long time, even if there are younger siblings. Indris are very similar to gibbons concerning these behaviours. Other characteristics of Indris are their large ears, the long hands and the very short tail whereas most other prosimians have long tails. They belong to the few prosimian species which are active during the day; most of the other prosimians are nocturnal animals.

Why is the indri that endangered? Most of the Indri's natural habitat is destroyed by now and the Indri isn't able to adapt to other habitats than the rainforest. The destruction was caused by the growing number of human inhabitants and their need for soil to plant rice which is the common food on the island. Madagascar is a poor country and the methods of planting rice are not very efficient. Conservation societies worked out a masterplan together with the government of Madagascar to use the soil more efficiently, hoping that no more rainforest areas are destroyed in the future.

When elephants weep


Early humans from Africa to Asia: Speed walking or a stroll along the beach?

Speed walking? Wouldn't they all resemble each other cranially very strongly if
that were the case? There's a lot of cranial differentiation, indicating long term separations between groups geographically.

from 2002

Ok one more entry, about what singles typically are looking for in a prospective mate: "This could explain why women are drawn to indicators of resource and future investment, while men are more likely to look for youth and waist-to-hip ratio - signs of reproductive potential and the ability to tolerate the stresses of childbirth". h/t Ed Yong link: the cost of having children

That doesn't sound very romantic, does it? So analytical. Oh well, that's life.

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