ROCKY MOUNTAIN LOCUST
When did it become extinct?
Th e last sighting of this insect was in 1902.
Where did it live?
Th e native range of this insect was the eastern slopes of the Rocky Mountains, extending from the southern forests of British Columbia through Montana, Wyoming, Idaho, and the western parts of the Dakotas. In some years, the species was able to extend its range to take in one-third of Manitoba, the Dakotas, Minnesota, Kansas, Oklahoma, Missouri, the western half of Nebraska, and the northeastern part of Colorado.
(Rocky Mountain Locust—The Rocky Mountain locust formed enormous swarms, possibly the largest known aggregations of any animal.)
In the late 1800s, much of the United States was a frontier where people sought to realize their American dream, and many of them headed to this continent's vast prairies. The term prairie conjures up images of beautiful, undulating plains stretching as far as the eye can see, but this is not entirely correct. These plains are bitterly cold in the winter and scorching hot in the summer. Add to that an almost constant wind, and you have an unforgiving environment. As if the harsh conditions weren't enough for the settlers, they were also confronted with an insect that swarmed in massive swarms.
The Rocky Mountain locust was small for a locust, with an adult body length of 20 to 35 mm, long wings that extended past the end of the abdomen, and the enlarged back legs that most grasshoppers have. What this insect lacked in individual size, it more than made up for in aggregate size. Locusts, for the most part, live their lives like most other grasshoppers, going about their business without bothering anyone, but their populations can become very dense at times, causing a dramatic change. The locusts change color, their wings expand, and they begin to congregate in swarms.
The Rocky Mountain locust swarms were incredible, and they likely represent some of the largest aggregations of any land animal that has ever existed. A swarm of staggering proportions was observed in Nebraska during the summer of 1874. Dr. A. L. Child of the United States Signal Corps was tasked with determining the extent of the swarm. To do so, he measured the speed of the locusts as they flew by and then telegraphed the results to surrounding towns. The swarm was estimated to be about 2,900 kilometers long and 180 kilometers wide. Observers in Nebraskan towns where the swarm passed said the massive cloud of insects obscured the sun and took five days to pass overhead. This raises the question of how many locusts were in this massive swarm. Estimates are all we have, but it has been calculated that there must have been around 12 trillion insects in this swarm. All of these fl uttering insects weighed somewhere around 27 million tonnes, and if the desert locust of the Old World is any guide, this swarm may have eaten its own weight in food every day just to survive. Fortunately, the Rocky Mountain locust was not picky about what it ate; in the absence of foliage, it would eat bark, leather, laundry, dead animals, and even the wool from a sheep's back. As one might expect, the swarms of mandibles left a trail of destruction, and between 1873 and 1877, the vast swarms of insects caused massive crop damage in Nebraska, Colorado, and other states, estimated at around $200 million.
The Rocky Mountain locust mysteriously vanished around 30 years after these massive swarms left a trail of devastation in their wake. The cause of this insect's extinction has been debated for some time. Some experts have proposed that the species was never extinct and that the locust was actually the swarming phase of a species that can still be found today, a theory that has been proven false. The most likely explanation for this insect's disappearance is that, when not swarming, the locust retreated to the sheltered valleys of Wyoming and Montana, where the females laid their eggs in the fertile soil. These same valleys drew the attention of settlers, who saw their potential for agricultural endeavors and turned the soil over with their horses and ploughs, grazing their livestock on the nutritious grass. These actions destroyed the insect's eggs and developing young, and the Rocky Mountain locust was extinct around three decades after its swarms blotted out the sun.
• Swarming of grasshopper species, such as the Rocky Mountain locust, is thought to be a survival mechanism that allows the insects to disperse into new habitats when conditions worsen, concentrating the nymphs into ever shrinking areas. During their normal or solitary phase, grasshoppers are extremely sensitive to the presence and proximity of other grasshoppers. When things get too cosy, the insects switch from intolerance to attraction, forming so-called nymph bands. The locusts resemble swarming insects and fl y away in search of more space and food.
• Settlers in the locust's native range also killed large numbers of beavers and widened streambeds, causing increased flooding and the death of locust eggs and young in the ground. These settlers also planted alfalfa across vast swaths of land, a plant that the locust disliked. It has also been proposed that bird species from the eastern United States followed the settlers along cottonwood corridors, preying on a massive number of insects, including the locust.
• Female Rocky Mountain locusts excavated a tunnel and deposited their eggs below the surface of the soil, out of sight of most predators, using a pair of tough valves at the end of their abdomens. The eggs were cocooned in a hardened foam egg sac that resembled a stale marshmallow for added protection.
• Some Rocky Mountain glaciers are known as grasshopper glaciers because swarms of Rocky Mountain locusts were driven high up into the mountains by winds, where they died on the glaciers, only to be covered by subsequent layers of snow and ice. As these glaciers thaw, the mummified remains of these insects become visible.
• Despite the fact that the Rocky Mountain locust was abundant, there are surprisingly few specimens in collections. Entomologists at the time saw little point in collecting such a large number of animals because it seemed impossible that an insect forming such massive swarms could ever become extinct.
PIG-FOOTED BANDICOOT
When did it become extinct?
Th e last verifiable specimen was collected in 1901, but it probably survived in remote areas for far longer, possibly until the 1950s.
Where did it live?
Th is marsupial was known only from the plains of inland Australia.
(Pig-Footed Bandicoot—The pig-footed bandicoot was a small, fleet-footed marsupial from the plains of Australia.)
Australia once had a diverse range of animals, including giant marsupials and terrifying reptiles. Scurrying around the big feet of this megafauna, however, were a swarm of small marsupials that evolved to fill the majority of the ecological niches occupied by placental mammals in other parts of the world. To name a few, there were rabbitlike marsupials, tiny mouse like animals, and even a marsupial equivalent of a mole. Some of these animals can still be found today, but many perished along with the rest of Australia's long-gone inhabitants.
One of these animals was the pig-footed bandicoot. For millions of years, this strange little marsupial, no bigger than a kitten, roamed Australia, but it has recently been confined to the arid and semiarid inland plains. The bandicoot's rabbit ears were probably familiar to the Australian Aborigines as it hopped and bounded around the plains.
Perhaps the oddest thing about this marsupial was the four spindly legs that supported its plump little body. It is from the animal’s feet that we get its common name. On its forefeet, there were only two functional toes with hoof like nails, remarkably similar to the feet of a pig, but in miniature. Th e hind limbs were also highly modified as the second and third toe were fused together, and only the fourth toe, which ended in a nail like a tiny horse’s hoof, was used in locomotion. With such highly modified limbs, the pig-footed bandicoot was undoubtedly a running animal, and the gait it used depended on how fast it was moving. When it was skulking around looking for food, the pig foot moved in a series of bunny hops—taking its weight on its forelimbs and pulling its back legs along. When it chose to up the pace, the hind limbs were moved alternately and, according to Aborigines, when it really wanted to move, it stretched out and took to a smooth gallop. Not only was the pig foot quick, but it also had a lot of stamina and could run at full speed for long periods of time. Apart from being very fl eet of foot, the pig foot was also said to be more dependent on plant food than the other types of bandicoot, which are generally insectivorous marsupials. In the wild, they subsisted on grass seeds, but in captivity, they ate a range of food, including lettuce, bulbs, and grasshoppers. It is said that during the hottest part of the day, they would seek refuge from the sun’s rays in a grass nest, only venturing out to seek food and mates in the early evening. If the other bandicoots are anything to go by, the pig foot must have had a very short gestation. Baby bandicoots spend only about 12 days in their mother’s womb—the shortest time for any mammal—and they are also unique for being attached to their mother by a placentalike organ. Th e pig foot’s short gestation probably ended in a very short birth—which, for living bandicoots, is around 10 minutes. Th e tiny babies crept to their mother’s rear-facing pouch, and although there were eight teats in this furry pocket, there were no more than four babies in each litter. After the young had outgrown the pouch, the female left them in a grass nest until they were ready to follow her on forays for food in the warmth of the evening sun.
What happened to the pig foot? Th e last known defi nite specimen was collected in 1901, and even long before this date, it was never considered to be a common species. We do know that it was hunted by Australian Aborigines for its meat, which was regarded as a delicacy, and its tail brush, which was sometimes worn as a decoration. Th e extinction of some of Australia’s other native animals has been blamed on Aborigines, but the pig-footed bandicoot coexisted with the Aborigines for thousands of years. Th e decline and extinction of this unique marsupial coincides with the spread of Europeans through Australia. For thousands of years, Aborigines practiced brush burning to clear land and encourage new plant growth. Many species of smaller marsupial profi ted from this because of the food it provided, not only in terms of fresh plant matter, but also in terms of the smaller animals that were forced out of hiding by the smoke and fl ames. With the arrival of Europeans, all this changed, as the Aborigines themselves were pushed toward extinction. Th e way the Aborigines managed the land ended, and any native animals that had previously benefi ted were faced with some tough times. As the Europeans swept aside the old Aboriginal ways, they replaced them with their own methods of taming the harsh land. They brought modern agriculture and a menagerie of domestic animals, including dogs, cats, foxes, sheep, goats, and cattle. To a seasoned predator, such as a cat or fox, the pig-footed bandicoot must have been a delightful morsel; however, hunting by introduced species was probably only a minor factor in their extinction. Agriculture probably had the greatest effect on this species. Herds of sheep, goats, and cattle grazed the delicate plains of inland Australia, lands that simply could not tolerate the intensive chomping of countless mouths, not to mention the hordes of hooves, which churned the ground into a dust bowl. Not long after Europeans first settled Australia, the pig-footed bandicoot joined the long roll call of extinct marsupials.
• Although the last verifiable pig-footed bandicoot was collected in 1901, interviews with Aborigines indicate that it may have survived until the 1950s in some remote interior areas. Because this animal is so small and shy, there's a chance it's still alive somewhere in inland Australia.
• Gerard Krefft, an Australian zoologist, sought the assistance of Aborigines in locating specimens of the pig-footed bandicoot. He showed them a picture of a pig-footed bandicoot, but it was missing a tail, so after several false starts in which they brought him other bandicoot species, he was overjoyed to see a pair of pig feet. He kept these animals for a while and documented his findings, but when he realised his supplies were running low, he ate them both. This is not the first time science has been defeated by the hunger of a starving pioneer.
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