caused neighbouring regions to suffer. The most common fauna are Tasmanian Pademelons (native), possums and small rodents most of which are native. Also decidedly present, but not necessarily seen, are quolls, echidnas, tasmanian devils and wombats. There are also the famous Tasmanian leeches. The track traverses areas of many types of vegetation, including Myrtle Beech forest, Eucalypts forest, Button Grass plains, alpine herb fields, and shrubs and mosses. Birds The park has been identified as an Important Bird Area (IBA) because it provides habitat for 11 of Tasmania's endemic bird species, as well as for the flame and pink robins and the striated fieldwren. The IBA is important as a representative protected area in north-central Tasmania for those species. Buttongrass plains Large segments of the track pass across buttongrass plains, a landscape that is unique to Tasmania. It's been theorised that the extent of buttongrass plains could be due to Aboriginal fire-stick farming before European settlement. Human interactions with wildlife Some wildlife, especially possums, currawongs and quolls have become to associate humans with food and are quite adept at stealing from tents, huts and packs. Although the vast majority of people are against feeding wildlife, during a Tasmanian study 7.4% of people eating lunch in national parks were observed to feed animals in addition to currawongs scavenging food after they left. It's recommended that bushwalkers suspend food from the roof within huts, and store food in rigid containers inside tents as eating human food has caused lumpy jaw in wildlife. Geology The oldest rocks in Cradle Mountain-Lake St Clair National Park are quartzites laid down in Precambrian times, and form a large base tilted towards the SSW and most exposed in the northern half of the track. Later, there was some mineralisation forming tin and copper deposits, and in the Permian Era marine deposits left shellfish fossils and sedimentary layered cliffs at about 900m. In the Jurassic period, dolerite intruded through the crust, forming columns that cap every major mountain range in the national park. North-south valleys were formed as Gondwana broke up, and they were further carved and deepened by glaciers during the last ice age. Cirque glaciers formed around most major peaks, giving Cradle Mountain its iconic shape. Sights The Overland Track is listed as one of the best treks in the world by Lonely Planet and contains "craggy mountains [and] beautiful lakes and tarns". The scenery is