Passage: They are highly vigilant and not easy to observe.  However, their faeces is commonly found in Yushan National Park.  At dawn and dusk, they graze and browse in the woods singly or in small numbers.  They generally eat the leaves below the shoulder height, or vines, ferns, shrubs, or herbs on the ground. In addition, they need to absorb salt and they can be observed licking minerals deposited on cliffs or rocks.Taiwan serows can jump as high as 2 m and run as fast as 20 km per hour.  Among all mammals in Taiwan, they are the best high jumpers.  They can be found at an elevation as low as 50 meters, but are mostly seen at 1000 meters and as high as 3500 meters.  Their habitats include conifer forest, mixed broad-leaved forests, and the steep slopes of bare rocks and gravel cliffs. They are sometimes spotted on top of Nanhu Mountain (南湖大山), Hsuehshan (雪山), Yushan (玉山), and Siouguluan Mountain (秀姑巒山).  They also live in the Taroko National Park. Their hoofs separate to two sides and can easily hold on to rocks on steep slopes.  They are also good tree climbers.  They are solitary and territorial. They use tears to smear branches or stones as markers.

Question: How high are they most commonly found?
1000 meters