Monday, May 01, 2006

Animal of the Week May 1, 2006 -- Probably the rarest mammal in the world

Happy Summer (Or winter for those in the antipodes, if you're non-seasonal, lucky you)

Some animals make me doubt my faith in evolution and wonder whether some prankster has been guiding the development of at least a few species. For example, pandas, on a branch of the family tree sprouted somewhere bears and raccoons (two generally adaptable groups of animals), the ancestors of this large should-be carnivore decided to ditch the meat eating and become veggie. Not only did they choose to foresake highly nutritious viands, but they decided to subsist solely on a diet of a highly un-nutritious grass of which they would eat only selected shoots that appear every few years.

Similarly, river dolphins... in the oceans of the world, dolphin species travel in enormous numbers, sometimes gathering in groups of thousands, frolicking abundantly in vast, clear, fish-packed waters. But on several occasions in Asia and South America a couple of dolphins have looked at the murky silt-choked effluent of major rivers and thought "I know, I'll try my luck". And so, this week's animal of the week, the possibly extinct Lipotes vexillifer (Baiji, Yangtze river dolphin), probably the world's rarest mammal.

Like other river dolphins, Baijis have very poor vision, they use echolocation and their long slightly upturned beak to search for fish in riverbed silt. Never the most abundant animal, commercial and illegal fishing practices along the Yangtze depleted the population, and damming has further adversely affected fish stock; chemical and noise pollution have also made life hard for the baijis. A few years ago, a survey found only 13 individuals, and a preliminary study, the reults of which were released last week, found no signs of these cetaceans. In November this year, a larger study hopes to find some remnant groups... but it looks very likely that the baiji will become the first whale or dolphin to become extinct in the modern era. Various groups are trying to conserve this species, but it seems they may already have lost their porpoise *Hayward gets coat*.

PS, as I was typing last week's AOTW, a couple of hundred yards away London Zoo were preparing to release the news of the virgin birth of four Komodo dragons. Hatched from eggs laid by a female with no male consort for two years, the paternity of these baby dragons remains a mystery. But welcome little Christ-lizards, welcome to Camden!


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