Tuesday, September 11, 2007

Calling On - Weta

I was going to write about the Hairy Marron, the fuzzy crayfish from Australia, but I couldn’t find enough information about it, least of all why it’s hairy. So, this week’s post is about the other arthropod I mentioned in the footnote of the Hunter Slug post.

Image by Gerald Cubitt via ARKive

Wetas are cricket-like insects native to New Zealand and frequent (possibly even preferred) prey of Tuataras. The Poor Knights Weta (Deinacrida fallai) belonging to the genus of Giant Wetas1, is amongst the largest insects in the world. They approach 8 inches in size when mature. As they are flightless, being light is not a concern, and thus, when laden with eggs, they can be heavier than sparrows.

The Poor Knights Islands are two small, uninhabited islands off the coast of New Zealand, apparently named for their resemblance to French Toast. Personally, I don’t see it. The islands are a nature reserve, and the 800 meters around the islands are protected as a marine reserve, and apparently a great diving spot2. The trees on these islands are where these Weta live, moving to the ground to lay eggs. They may also live on another nearby island, as a Giant Weta fecal pellet was found there. Please, don’t ask me how they determined that it was from Giant Weta.

Poor Knights Wetas are nocturnal and herbivorous, and their main defenses lie in being gigantic and spiky. An adult female can lay 200 to 300 eggs per clutch, which appears to be a one-time deal in a two-year lifespan. They’re listed as Vulnerable by the IUCN, even though they don’t seem to be declining. What they’re really worried about is the small size of their distribution, contained to small islands. They're also worried about the risk of a simple introduction of a non-native predator and its effects. The Wellington Zoo in New Zealand has a breeding program, both as a safeguard against extinction, and for public education.

1The genus name, according to Wikipedia, means “Terrible Grasshopper”.
2At least, according to the Tourism Department


Divya said...

very informative

erica anne said...

the poor knights are great for diving and the wetas are very cool, if not a little creepy to encounter in the bush. luckily they aren't all that size!