Greater+Bilby

** The Greater Bilby ** ** Hayley Reed ** << Galadi Speciosus (Extinct Animal) ﻿﻿ Water Bilby (Future Animal) >> Known as //Macrotis Lagotis// in Latin and whose name translates to ‘long nosed rat’ in Yuwaalaraay Aboriginal, the Greater Bilby is a strictly nocturnal Australian marsupial. Differed from its thought extinct relative the Lesser Bilby (//Macrotis Lecura//) by its larger size and openly exposed tale end, the Greater Bilby’s weight ranges from 1000-2500 grams in males, and 800-1100 grams in females. All animal species require a certain level of environmental and eco-systematic balance in order for them to survive. //Macrotis Lagotis// the Greater Bilby is no different and has even provided further evidence to support this notion. In previous years, the effects of changes in the Greater Bilby’s natural environment have been displayed in an obvious manner and have in turn led to the dwindling population of the Greater Bilby in Australia. The Greater Bilby and its relative species used to roam freely around the continent of Australia in areas that ranged from the temperate coastal regions, to the vast expanses of dry desert found in the country’s centre. However, the colonization of Australia by the Europeans created a threat to the balanced ecosystem to which the bilby existed in. Livestock that were introduced by the Europeans destroyed much of the grasslands that made up the Greater Bilby’s habitat; the competition for food due to the introduction of rabbits, and the threat of predation from foxes, pushed the bilby population to decrease rapidly. The once free to  roam Greater Bilby, is now broken into fragmented populations in areas such as the reat Sandy and Gibson Deserts as well as the Pilbara and Kimberly regions of Western Australia; the Mitchell grasslands of Southwest Queensland; and the mulga shrub lands and spinifex grasses of the Tanami Desert in the Northern Territory (Refer to Figure 2). In relation to climate, the environments that the Greater Bilby has been forced to inhabit have temperatures that are far from pleasantly climatic. During the day temperatures may exceed 40° Celsius whereas at night, temperatures can drop to under 0° Celsius. As uncomfortable as these temperatures seem to humans, the Greater Bilby has successful adapted to suit the pressures of the extreme temperatures. Some animals that can be found in similar Australian arid environments and ecosystems include the Spinifex Hopping Mouse, Thorny Devil, Kangaroos and Wallabies and Dingoes, as well as several species of invertebrates and birds. The Greater Bilby’s predators in its natural environments include dingoes, feral cats, and of course humans. **Scientific Classification of the Greater Bilby ** **<span style="font-family: 'Georgia','serif'; font-size: 16px;">Kingdom: **<span style="font-family: 'Georgia','serif'; font-size: 16px;"> Animalia
 * <span style="font-family: 'Georgia','serif'; font-size: 16px;">Phylum: **<span style="font-family: 'Georgia','serif'; font-size: 16px;"> Chordata
 * <span style="font-family: 'Georgia','serif'; font-size: 16px;">Class: **<span style="font-family: 'Georgia','serif'; font-size: 16px;"> Mamallia
 * <span style="font-family: 'Georgia','serif'; font-size: 16px;">Infraclass: **<span style="font-family: 'Georgia','serif'; font-size: 16px;"> Marsupialia
 * <span style="font-family: 'Georgia','serif'; font-size: 16px;">Order: **<span style="font-family: 'Georgia','serif'; font-size: 16px;"> Peremelamorphia
 * <span style="font-family: 'Georgia','serif'; font-size: 16px;">Family: **<span style="font-family: 'Georgia','serif'; font-size: 16px;"> Thylacomydae
 * <span style="font-family: 'Georgia','serif'; font-size: 16px;">Genus: **<span style="font-family: 'Georgia','serif'; font-size: 16px;"> Macrotis
 * <span style="font-family: 'Georgia','serif'; font-size: 16px;">Species: **<span style="font-family: 'Georgia','serif'; font-size: 16px;"> M. lagotis

**<span style="font-family: 'Segoe Script','sans-serif';">Adaptations **

**<span style="font-family: 'Georgia','serif'; font-size: 16px;">Structural Adaptation 1: ** <span style="font-family: 'Georgia','serif'; font-size: 16px;">The Greater Bilby’s body has adapted to suit the needs of its environment, and to work cooperatively with its behaviours. This marsupial typically breeds throughout the year, which allows them to take advantage of any good seasonal situations especially in the harsh arid Australian environment. The gestation period of a Bilby is 12 to 14 days. One of the most fascinating features of the Greater Bilby’s reproductive system is its pouch. Most marsupials, such as the kangaroo have forward facing pouches. However this does not suit the behavioural needs of the Bilby, who spends much of its time digging. To protect the bilby in the pouch from dirt and other contaminants, the bilby’s pouch faces backwards. (Refer to Fig. 04) The Common Wombat is similar to the Greater Bilby in which it also has a backwards facing pouch. <span style="display: block; font-family: 'Georgia','serif'; font-size: 16px; line-height: normal; text-align: left;">The environmental pressure that could have pushed for this change in structure is obvious. As the bilby dug, large amounts of soil and debris was being built up inside the pouch. This could have caused the damage to or death of the developing offspring in the pouch, which would have ruined the chances of the bilby reproducing effectively. This adaptation allows for the successful breeding and regeneration of the species.

**<span style="font-family: 'Georgia','serif'; font-size: 16px;">Structural Adaptation 2: **<span style="font-family: 'Georgia','serif'; font-size: 16px;">Another of the Greater Bilby’s important structural adaptations is its extremely powerful forelimbs and sharp claws. Each foot, like humans, has five digits. As stated above, this species of bilby digs tunnels that can be up to 6 feet in depth, in an environment where the ground is extremely hard and dry. The strong forelimbs of this animal help it to dig out copious amounts of dirt and shrubbery, while its sharp claws scrape away the dirt and cut at any hard roots found in the ground. It is known that if a bilby senses a threat nearby, it is able to dig a tunnel in less than five minutes. Furthermore, as the bilby is an omnivore, the sharp claws and strong forelimbs allow the animal to dig plant tubers, roots and fungi from the ground, as well as forage for small insects. Without powerful forelimbs and sharp claws the Greater Bilby would find it difficult to forage for food, and dig the tunnels it needs to in such a fast time period. The pressure for these adaptations came from the environmental conditions in which the bilby inhabited, where protection for this small animal could only be found through taking shelter in a burrow that needed to be quickly constructed. **<span style="font-family: 'Georgia','serif'; font-size: 16px;">Structural Adaptation 3: ** <span style="font-family: 'Georgia','serif'; font-size: 16px;">One of the Greater Bilby’s most interesting structural adaptive features is its large ears (Refer to Fig. 03). As an animal with limited visual capabilities, its large ears help the bilby to detect not only predators, but also prey, which are in the surrounding area. As the prey of the Greater Bilby includes insects and spiders, this particular species must have an extremely developed sense of hearing. Furthermore, the ears act as a type of thermoregulation for the Bilby, helping it to reside in such uninhabitable locations as the desert. The process of thermoregulation occurs in the thin tissue that surrounds the bilby’s ears, where there are a large number of blood vessels. Through the process of vasodilation (where the blood vessels dilate allowing a larger amount of blood to flow through the arteries, the bilby is able to collect the unwanted heat from the body in the blood, and direct this heat towards the expanded blood vessels, where the heat is evaporated. In the scorching desert heat, this adaptation is crucial for the survival of the Greater Bilby. <span style="display: block; font-family: 'Georgia','serif'; font-size: 16px; line-height: normal; text-align: left;">Pressure for adaptation evidentially came from two locations. The first is that the hot climatic conditions of the arid habitats in which the bilbies reside, forced the body to provide a solution to the overheating that would have come with this environment. The ears provided a way for the bilby to control its body temperature. Furthermore, as the eyesight of the bilby was poor, the other sensory organs had to be enhanced in order for the bilby to survive. This proves especially useful during the night, when the nocturnal animal must leave the burrow to forage for food and or find its way around its environment. **<span style="font-family: 'Georgia','serif'; font-size: 16px;">Behavioural Adaptation 1: **<span style="font-family: 'Georgia','serif'; font-size: 16px;">The Greater Bilby’s behavioural characteristics are similar to those of many other small animals. It is strictly nocturnal, leaving the burrow no earlier than one hour after dusk, and arriving home at least one hour before sunrise. There are many reasons why the bilby is nocturnal. Firstly, as a smaller animal, the bilby has limited defence against much of its larger predators. During the day, many animals such as foxes, feral cats, and snakes, as well as humans, are active. As the bilby is quite a conservative and skittish animal, it prefers to avoid contact with these animals, and found it suitable to avoid the day. Also, as the bilby is now find in the hotter, more arid environments of Central and Northern Australia, it must avoid overexertion and overheating further by avoiding the sun and desert heat of the day. During the night, the bilby is able to forage for small insects, as well as seek out appropriate food sources. <span style="font-family: 'Georgia','serif'; font-size: 16px; line-height: normal;">The pressure for this adaptation came from the climatic conditions of the living environment, as well as the potential threat of predators in the vicinity. As most animals are less active at night, the bilby adapted as to avoid these predators, and be able to move in a free manner throughout its environment. **<span style="font-family: 'Georgia','serif'; font-size: 16px;">Behavioural Adaptation 2: **<span style="font-family: 'Georgia','serif'; font-size: 16px;"> One unique behavioural adaptation the Greater Bilby employs is the construction methods it uses to create its home environment. (Refer to Fig. 01) As bilbies are strong and talented diggers, their main form of protection lies in their burrows, and more specifically the way they build them. Unlike most other animals, the Greater Bilby digs its burrow so that it spirals down into a sleeping chamber. This technique makes it harder for predators to get in. These burrows are usually around three meters long, and can be as far as two meters deep. This helps to keep a constant temperature inside the burrow (approximately 23° Celsius). <span style="font-family: 'Georgia','serif'; font-size: 16px; line-height: normal;">This interesting behavioural adaptation may have come into force due to the constant threat of predators in the environment in which the bilby resided. As regulation burrows (burrows that are built straight down into the earth) would have been no obstacle for animals such as foxes to invade, the bilby’s talented methods ensure that the species dwell in a somewhat safer environment. Furthermore, as bilbies keep their young inside the burrow for further development, this behavioural adaptation means that the success rate of reproduction is quite high.

**<span style="font-family: 'Georgia','serif'; font-size: 16px;">Physiological Adaptation 1: **<span style="font-family: 'Georgia','serif'; font-size: 16px;">As an animal that has been forced to live and survive in the arid conditions of the Australian desert, the Greater Bilby has developed an adaptation that could be seen as crucial to it survival. The Greater Bilby does not need to drink water. This animal is similar to another Australia mammal known as the koala, in which gathers and stores all the water it needs from its food sources. The Greater Bilby relies on what’s known as metabolic water, metabolic water is created in cellular respiration when glucose is oxidised and oxygen is reduced inside the animal’s body, to create water. The equation for this occurrence is C6H12O6 + 6 O2 <span style="font-family: 'Times New Roman','serif'; font-size: 16px;">→ <span style="font-family: 'Georgia','serif'; font-size: 16px;"> 6 CO2 + 6 H2O. This water is then used to help keep the marsupial hydrated. <span style="font-family: 'Georgia','serif'; font-size: 16px; line-height: normal;">The main pressure for adaptation, like most of the bilby’s environmental pressures, came from the climatic conditions. In an environment where water is scarce, the bilby does not need to worry about this lack of surface water. This allows the bilby to live almost anywhere in Australia’s arid environments as long as there is a good supply of vegetation and insects. As surface water in arid Australia is minimal, and great competition for water comes from other desert dwellers, the bilby’s adaptation has allowed it to survive in the rough environments in Australia. <span style="display: block; font-family: 'Georgia','serif'; font-size: 16px; line-height: 115%; text-align: left;">To conclude, the Greater Bilby can be seen a species with highly successful adaptive features. However, the main threat to the bilby is by humans as well as introduced animals, where their habitats are destroyed or they are hunted. The Greater Bilby rates as a [|vulnerable] species on the IUCN endangered species list. Conservationists are doing what they can to ensure the Greater Bilby survives, so that the next generations are able to enjoy these species. <span style="font-size: 250%; line-height: 119%; padding-bottom: 2.88pt; padding-left: 2.88pt; padding-right: 2.88pt; padding-top: 2.88pt;">** Bibliography ** <span style="font-family: Georgia,serif; margin-left: 0.5in; text-indent: -0.5in;">123helpme. (2010). //Adaptations of Mammals to Arid Australian Environments//. Retrieved June 19, 2011, from 123helpme.com: http://www.123helpme.com/view.asp?id=37811 <span style="font-family: Georgia,serif; margin-left: 0.5in; text-indent: -0.5in;">ABC News. (n.d.). //Bilby male with young//. Retrieved June 18, 2011, from ABC: http://www.abc.net.au/nature/australasia/ep2_pic1.htm <span style="font-family: Georgia,serif; margin-left: 0.5in; text-indent: -0.5in;">//Bandicoot- The Greater Bilby//. (n.d.). Retrieved June 21, 2011, from Animal Photo Album: http://www.animalpicturesarchive.com/view.php?tid=1&did=4009 <span style="font-family: Georgia,serif; margin-left: 0.5in; text-indent: -0.5in;">BBC. (2008, July). //Greater bilby, dalgyte, rabbit-eared bandicoot, ninu, walpajirri.// Retrieved June 20, 2011, from BBC Science and Nature- Wildfacts: http://www.bbc.co.uk/nature/wildfacts/factfiles/3071.shtml <span style="font-family: Georgia,serif; margin-left: 0.5in; text-indent: -0.5in;">Nimu, B. (1990). About Bilbies. In T. Flannery, //Australia's Vanishing Animals.// <span style="font-family: Georgia,serif; margin-left: 0.5in; text-indent: -0.5in;">Outback Australia. (2005-2011). //Australian Desert Animals- The Bilby//. Retrieved June 20, 2011, from Outback Australia Travel Guide: http://www.outback-australia-travel-secrets.com/australian-desert-animals.html <span style="font-family: Georgia,serif; margin-left: 0.5in; text-indent: -0.5in;">Scribd. (2011). //Thermoreglation- HSC Biology//. Retrieved June 19, 2011, from Scribd: http://www.scribd.com/doc/39854804/9-2-Thermoregulation