Friday, March 2, 2012

Here today, gone tomorrow, here again the day after tomorrow

 Australia is, in my opinion, one of the weirdest places on Earth. In the good old Northern Hemisphere, marsupials are a minor annoyance you sometimes squish with your car, while in Australia, marsupials can land you in the hospital. In America, our large mammals stroll sedately across our amber waves of grain; in Australia they bounce across vast deserts. Here in PA, we have solid, dependable native species like earwigs, bumblebees, and ladybugs. Australia contains an insect so massive its nickname is "tree lobster". This insect and another, Nothomyrmecia, both have both played peek-a-boo with scientists over the years, but their discovery stories couldn't be more different.
             In 1918, British soldiers had to crash-land on Howe's island, losing one crewmember to the sea and several black rats to the island. Unfortunately, these rats thrived off of the tree lobsters, and quickly ate them into presumed extinction by 1920. In 1960 though, some climbers on nearby island Ball's Pyramid claimed to have see a few recently dead tree lobsters. As exciting as the reemergence of an extinct species was, it wasn't until 2001 till scientists actually went to look at Balls Pyramid, because the insects are nocturnal and the climb is dangerous at night. Their daring paid off: Nick Carlile and a local ranger found 24 tree lobsters on one bush. After a prolonged fight with the authorities, four were removed to start a breeding program at the Melbourne Zoo which now has over 700 individuals (for the full story of the breeding program's struggles, see here). Now, the triumphant tree lobsters faces trouble from Howe Island residents on its reintroduction. Rats still live on the island, causing concerns that history will just repeat itself. Also, look at these things.
Tree lobster, courtesy of Wikipedia
I wouldn't suddenly want this introduced into my backyard either.
             Nothomyrmecia is a different story. It had a slightly later discovery time, 1931. And discovery is perhaps a generous term: a couple specimens were collected by amateur naturalists in West Australia and shipped off to England, but they didn't bother record their collection site, which was quite a bother when Nothomyrmecia turned out to be a living link in the evolution of ants from wasps.
Nothomyrmecia (courtesy of Wikipedia), kicked out of both the ant and wasp family portraits

In fact, Nothomyrmecia wasn't rediscovered until 1977, when Dr. Bob Taylor launched an expedition to Western Australia in a last-ditch effort to find the ant again. Their truck had mechanical problems and broke down near Poochera, where they were forced to camp for the night. As only a true scientist would in these circumstances, Dr. Taylor did a little insect survey around their campsite that night and found: Nothomyrmecia crawling on a tree trunk, over one hundred miles and 46 years from its original collection site. To this day, Nothomyrmecia have never been seen in Western Australia.
      To me, the most interesting part of these Australian insect stories is the contrast in human involvement. Tree lobsters rose and fell with humans: without us, they would never have been eaten to almost extinction, but nor would their numbers have rebounded through a heroic breeding program effort. In contrast, we wander in and out of Nothmyrmecia's life. We don't even really know where their range is, what their numbers are, or how their population has changed over time, just vaguely that they do exist in Australia.

No comments:

Post a Comment