Some say that "trouble comes in threes," and many would agree that the islands would be better off without the triplicity of duplicity: the Pacific rat, the Black rat, and the Norwegian rat. Their rap sheet is as long as their scaly tails: they carry over forty diseases, cause enormous agricultural damage, and prey on animal and insect populations, including native snails, turtle eggs, spiders and birds. According to the U.S. Fish and Wildlife Service, the removal of rats from Mokoliʻi (Chinamanʻs Hat) saw an increase in wedgetailed shearwater chicks from 0 to 126 the following year. When I had an unwelcome visitation by some rodents not so long ago, I decided to do a little investigative work to see which one of these three was guilty. Turns out the black rat (Rattus rattus) a.k.a. roof rat and tree rat, was the culprit. This expert climber and jumper (leaping up to three vertical feet and four horizontal feet) has bumped the Norwegian rat (Rattus norvegicus) from its top spot as the most common rat living close to humans, particularly if there is a source of water nearby, like a ditch or canal. You can tell the two species apart with a few key characteristics: the black rat is smaller, has a pointier snout, a tail longer than its body, and a more slender haunch. The Polynesian, or Pacific rat (Rattus exulans) is the smallest of the three, and is rarely found near buildings, preferring fields and woodlands at lower elevations. By the way, the tails are interesting, if not very well-liked features of these rascally rodents. Mostly naked and scaly, they are actually very important to the rat for heat regulation and balance.
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Cunning, resourcefulness, and a certain disregard for the rules - all qualities that describe a Slytherin. Add to that the characteristic slink of the mongoose, and I think you'd agree that the Sorting Hat would have put this efficient and stealthy predator in the House known for its Dark Wizards. Brought to Hawaii Island in 1883 via Jamaica, the hope was that they would control the increasing rat populations in the sugar cane fields. And indeed they were efficient ratters, so, off they went, shipped to other plantations on O'ahu, Moloka'i, and Maui. But what lie beyond the cane fields? Lots of ground nesting birds and their delicious eggs. Being an opportunist, and with rats being nocturnal unless in great abundance, the mongooses strayed from the plantations. As early as the 1895 and into the early 1900's, newspaper articles chronicled the concerns and controversies over this dark wizard. The Hawaii Digital Newspaper Project contains a number of articles on the mongoose, including one from the Hawaiian Star in 1911 in which a Kaimuki woman hid out near her hen-house to determine what was causing the loss of her eggs:
"Presently a mongoose glided in emitting a peculiar whistle so efficacious in fascinating her chickens of immature growth but which has little effect on an egg. Approaching the eggs, it took one tenderly in its mouth and coiling its tail round another left the hen-house holding its head and tail high in the air and looking for all the world like a pair of spectacles. Having deposited the eggs in a space between the rocks of a stone wall bounding the premises it returned twice and secured the remainder of the eggs. The woman watched the proceedings entranced... when she had seen the last two eggs disappear she seemed to come to suddenly and when her husband returned related to him in detail what she had seen. He is now busy experimenting with an explosive which will go off on being jarred and which he intends injecting into some egg shells from which the contents have been removed. By this means he hopes to teach the marauding mongooses in his section a lesson they will never forget." With females producing up to three litters per year, with three pups per litter, mongoose populations quickly increased. Everything that moves is fair game for their supper (frogs, lizards, small mammals, birds, insects, slugs, snails) and they'll not hesitate to dine on some things that don't (fruit, plants, eggs). The nene, moli, and Newell's shearwater have been particularly hard hit by their maleficium. And it has been officially confirmed that they are now practicing their Dark Arts on Kaua'i. In May of 2012, a live mongoose was trapped at at the Marriott Kaua‘i Lagoons. And as Severus Snape warns us: "The Dark Arts are many, varied, ever-changing, and eternal. Fighting them is like fighting a many-headed monster, which, each time a neck is severed, sprouts a head even fiercer and cleverer than before." Rhode Island has not disappointed in terms of nature sightings during my holiday visit. I've seen owls, mergansers, red-tail hawks, seals, great blue heron, and yes, even the elusive river otter, Lontra canadensis. I was fortunate enough to spot one many years back, crossing the road with four young, and even as I watched the mom and babies lope hurriedly to the other side, I knew how lucky I was to witness this rare event. While otters have always been present in Rhode Island, their numbers are up due to improvements in water quality as well as an increase in the beaver population, whose activities create more wetland habitats for the otters. This time, I scared one from its hunting spot next to a salt pond. As it scampered on the thin ice along the bank, I realized what a perfect otter habitat this place was, with lots of dense vegetation along the pond providing protection, plenty of food, including fish, mollusks, and crustaceans, and ample places for a burrow. Though they are called river otters, they haunt brackish and saltwater habitats as well as fresh. Members of the weasel family, Mustelidae, they are kin of mink and fishers, other furbearers found in Rhode Island. All possess anal musk glands and use them to communicate and mark territory. They are supremely adapted to the water, with webbed feet, a long streamlined body and tail, and whiskers, (called vibrissae) that help them locate prey underwater. A layer of fat just below the skin and dense fur keep them insulated through the winter - river otter do not hibernate.
They are often solitary, but will engage in playful behavior when with others, sliding down riverbanks on their bellies, and somersaulting through the water. Otters will create what are called "latrine" sites, scraping the ground clean, and building a mound near a prominent landscape feature, such as a large tree. Marking the mound with "spraint" (feces) and musk, otters will use this area for preening, playing, and scenting. These mounds in turn, help conservationists locate and survey otter populations in the state. Rhode Island does right by its otters - it is illegal to take or kill an otter. It is the only state in the Northeast that does not have a trapping season, which makes the chance of seeing one of these beauties all the more likely. And like me, I hope you will be otterly amazed.
Frank Bonaccorso, a bat researcher with the USGS Pacific Island Ecosystems Research Center, has found that the bats on the Big island have favorite trees used for resting or roosting, and while there remains much that is not known about this bat, it does seem that they migrate to higher elevations in the cooler months of the year, then head down to lower elevations in the spring and summer. Just how many bats there are is difficult to determine, but the populations on the Big Island seem significant, with bat sightings occurring island-wide, and in a variety of habitats. The bats occur on all the MHI, with Maui and Kaua'i also appearing to have good populations. Oahu's population does not seems as robust, perhaps due to greater development, and therefore habitat loss. The 'Ope'ape'a adult females give birth to twins in early summer; the pups will remain with her for a couple of months. Long-beaked and sleek, Hawaii's spinner dolphins thrill the lucky onlooker with their aerial acrobatics. Leaping out of the water, they twirl away, making two to five or so spins before loudly splashing back down. Spinning is often repeated several times in a row. And the acrobatic repertoire doesn't end there. They tail slap, do nose-outs, and leap head over tail too. (see video below) But they are the only dolphins known to go for a "spin." What's that all about? Well no one knows for sure, though it's possible that it may be a way to to rid themselves of parasites; or for communicating with the pod; or as a courtship; or maybe it's just for the fun of it.
One thing that researchers have discovered is the daily pattern of the dolphins around the islands. NOAA Fisheries Service reports that they are night hunters, foraging cooperatively to capture squid, shrimp, and fish. According the Polynesian Voyaging Society Website, the spinner dolphins sometimes accompany "a voyaging canoe, riding on the wave at the bow. At night, when they stir up phosphorescent organisms as they swim, they look like glowing torpedoes." Come morning, they swim along the shallow bays for what researchers have termed "rest." During this time, vocalizations and acrobatics taper off and the dolphins swim closing together in a behavior called milling. Dolphins don't sleep the way we do, but what they can do is shut down one hemisphere of their brain at a time. This allows them to remain watchful enough to respond to threats such as tiger sharks. Come the late afternoon, they get ready to resume their evening hunt. Adult spinner females may have several mates and give birth about once every three years, after about a ten to eleven month pregnancy. The Wild Dolphin Organization reports that the calves are born fluke first, and may display fetal folds, or evidence of wrinkling while in the mother's womb. They form strong bonds with mother, and become very active, often seen "playing" with others as they practice, often humorously, their aerial skills. active at dusk and dawn, and are herbivorous. Wallabies have a bipedal (bi-two, ped-foot) form of locomotion, and use their tail mostly as balance. They breed throughout the year, the offspring living in the pouch for about 8 months. So the next time you head down the Like-Like, keep an eye out for the possibility of spotting one of these outlandish marsupials.
That's the translation of: Ilio holo I ka uaua, the name the Hawaiians gave to *Monachus schauinslandi, or the Hawaiian monk seal. This one wasn't frolicking in the seas however; it was hauled up on the beach for a lazy afternoon of sunbathing. We felt lucky to share the beach with this endangered mammal. With a population of around 1000, there are more giant pandas in the wild than there are monk seals in our waters. The majority of the population live in the NorthWest Hawaiian Islands, but there is a population of about 150 in the main islands. Hawaiian monk seals face threats from shark predation, entanglement in marine debris, food limitations, adult male aggression, and human actions.
*Update: May 16, 2014: Recent DNA analysis has placed the Hawaiian monk seal in a new genus: Neomonachus. According to the National Geographic website: "The new branch of the family tree, Neomonachus, means that species of living monk seals are more distantly related than previously thought—and that the stakes for saving the rare creatures are even higher." |
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