May 3, 2006
The Mongoose: A Maui Menace
Whenever we plan to visit somewhere, I always look up the local wildlife. So when we headed to Maui, I was ready to check out lots of birds, turtles, fish and a couple rare mammals. I hoped to see a critically endangered Hawaiian monk seal, although I was doubtful we would manage that since there are less than 1500 left.
The Devil-Eyed Snake Charmer
Most of the mammals on Maui, and Hawaii in general, are not native. They were introduced for a variety of reasons, and I've frankly never seen so many feral species in one place. One particular alien species I wanted to check out was the Indian Mongoose. As in Kipling's Jungle Book character Rikki-Tikki-Tavi, the devil-eyed cunning critter is famous for taking on venomous snakes like king cobras. But that's not why the ferret-like mongooses are sometimes referred to as the most dangerous animal in the world. That illustrious title was earned when it became clear that the mongoose is unparalleled when it comes destroying native species. A fact that Hawaiians learned the hard way.
So why, you might ask, would the mongoose be purposefully introduced to the Hawaiian Islands, the endangered species capital of the world? And by that, I'm refering to the fact that Hawaii has more endangered species per square mile than anywhere else on the planet. The answer is simple. The story of how the Mongoose got to Hawaii is a familiar one of greed.
Greed and rats. (Just like the feral cats got there!)
Way back in 1872, some Jamaican sugar planter (rum yum!) got this great idea to introduce the mongoose in order to keep his rat problem under control.
W.B. Espeut got the idea that Indian mongooses might take care of the rat problem in Jamaica if turned loose in the sugar cane fields there. So he sailed across the ocean to Calcutta on a ship called the Merchantman, captured four male and five female mongooses (one pregnant) and brought them back across the ocean to Jamaica.
Twenty years later, in a journal article, Espeut gave the mongooses rave reviews. Besides killing rats, he wrote, "snakes, lizards, crabs, toads and the grubs of many beetles and caterpillars have been destroyed."
It'd Be Amusing If It Wasn't So Sad
Espeut was so successful, he created a new Jamaican export: more mongooses! When the article reached the sugar cane plantations of Hawaii, the farmers saw an answer to all their rat problems. So despite some dissent, the Hawaiian farmers ordered 72 mongooses from the Jamaicans in 1883. The mongooses were raised on the Big Island and spread amongst the islands. Little did they know...
Lana'i and Kaua'i remained mongoose-free, but on the other islands, the introduction of the Indian Mongoose has been a disaster of epic proportions. Mongooses do kill rats, but not the numbers needed to justify their use. Unlike the nocturnal rats, the mongoose is active during the day. So instead of ridding the islands of rats, the mongooses have found many other things to eat instead. Their diet is surprisingly varied. In fact, it appears there's very few things that a mongoose won't eat.
The nature of their foodstuffs depended largely on the opportunities available. An examination of the stomachs of 180 individuals revealed insects, spiders, snails, slugs, frogs, lizards, snakes, birds, eggs of birds and reptiles, all kinds of rodents, crabs, fish and fruits. Members of this species have also been known to catch mammals many times their size, up to the size of hares and even the young of white-tailed deer.
The Indian Mongoose has no natural predators in the Hawaiian Islands and so they have to be controlled using poisoning and trapping. They carry several nasty diseases including rabies and leptospirosis.
Nowadays, mongoose rule every Hawaiian island except Lana'i and Kaua'i, and even there it may only be a matter of time. Recently, mongoose have been sighted on Kaua'i. Almost all the mongooses on the Hawaiian Islands today are descended from those nine original ones brought over by W.B. Espeut from Calcutta.
Where Are All The Birds?
We expected to see lots of tropical birds in Hawaii. Sure, we did see some neat-looking cardinals and lots of cattle egrets. But where were the seabirds - the albatrosses, the petrels, the frigatebirds (I love that word)?
We were told to go to Lana'i, since they don't have mongooses. We didn't see a single sea bird on our entire week-long visit to Maui. This is not really an exaggeration - the total was two in a wildlife refuge surrounded by water.
Two... on an island.
Mongooses love eggs (Shane prefers the term "potential birds"). They throw eggs against rocks to break them open and then eat them. The mongooses have preyed on not just the eggs though, but also fledgling and adult native Hawaiian birds, not to mention endangered sea turtle eggs and hatchlings.
One case that seems to have truly horrified the Hawaiians is that the mongooses like to snack on the Hawaiian State Bird, the Nene, or Hawaiian Goose.
In 1952 the remaining nene population was estimated to be about 30 birds. Current estimates are around 1,300 birds in different populations on the islands of Hawaii, Maui, Molokai and Kauai.
Almost half of the statewide population exists on Kauai, probably due to the fact that predatory mongoose are not known to be established on the island.
What's To Be Done?
Mongooses are even more difficult to get rid of than rats. They're smarter and more agile. The IUCN has listed the mongoose as one of the top 100 worst invasive species, causing $50 million in damages each year in Puerto Rico and the Hawaiian Islands alone, but while some money is spent on combating invasive species, it hasn't been enough in terms of wildlife management and the mongoose has a firm hold on the islands. That $50 mil figure is interesting, but you have to wonder how one would measure species extinction in dollars.
Some people have taken the matter into their own hands, reminding us of the snow monkey (Japanese Macaque) bounty we heard about in Japan. Rumor has it there's a B&B in the Big Island that used to give a free night's stay to anyone who brought in a dead mongoose with treadmarks that matched your car tires... You gotta wonder, did they stop because it was in poor taste or because the frequency of mongoose roadkill made the promotion too costly to the B&B hosts?
Check out our Maui, Hawaii podcast - a video program that highlights this beautiful place!
Posted by sorsha at May 3, 2006 6:33 PM
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