Grassland fencing threatens the survival of wild ungulates

(Press-News.org) Ungulates like Tibetan antelope, Kiang, wild yak, Przewalski's gazelle, Tibetan gazelle, Mongolian gazelle, roam on the steppes and grasslands of Asia, need large open habitats. For examples, once millions of Mongolian gazelles migrate to the Inner Mongolian steppe in winter and return to steppes in eastern Mongolia and Durian, Russia during the breeding in summer. Hundreds of thousands of Przewalski's gazelles also roam in the Alpine steppe in Qinghai lake drainage (Fig. 1). Those wild ungulates move freely on the grasslands are animal spectacles in Eurasia.

Area of grasslands, including desert grasslands, accounted for 23% of the land area of China. As part of the agricultural modernization, more and more grasslands have been fenced as livestock paddocks. Since 1990s, from Mangzhouli in Northeastern China to Xinjiang in Northwest China, then up to the Tibetan Plateau, people are constructing grassland fences with full speed. Building fenced grassland paddocks is regarded as a mean of modernization of pastoralist system. Until 2002, about 70% of grasslands in the country have been fenced.

Recent study reveals that Grassland fencing threatens the survival of wild ungulates. A report named Impacts of grassland fence on the behavior and distribution range of the critically endangered Przewalski's gazelle on the Qinghai-Tibetan Plateau which explored impacts of grassland fencing on wild animals on grasslands, written by You Zhangqiang, Jiang Zhigang, Li Chunwang and David Mallon, with Jiang Zhigang, Professor of the Institute of Zoology, Chinese Academy of Sciences as the author of correspondence, has been published in Volume 68 of Chinese Science Bulletin in 2013.

The authors studied the grassland fencing on the survival of the endangered Przewalski's gazelle, a species endemic to China. They discovered that the daily moving distance of the gazelle was shorter in grasslands with fences than that in area without grassland fences; the gazelle had shorter feeding bouts than those in grasslands with fences than that in area without grassland fences; gazelles instead of jumping over fences, they often walked along fence lines to search for pass or drilled through the fences. The activity range of the gazelle reduced to 6% or 20 % after the grassland fences were constructed. The fences ever hindered the ability of gazelle to escape from predators, in the study area, gazelles which were strangled by grassland fence or be trapped by fence and then predated by wolf, accounted for 55 or 15-20% of the total population during the study period (Fig. 2).

One of the characteristics of modern animal husbandry is intensivism. When pastoralists settled down in residential area and pastoralism was transformed from intensified animal husbandry, more and more fence lines were built on grasslands. Originally, to build grassland fences is to restrict the movement of livestock and to mark private ownership of grasslands, and to increase the grassland productivity. However, those fence lines chopped the once endless grasslands into pieces, fragmented and reduced the habitat of wild ungulates, blocked the migration route of wild ungulates, for instance, because of grasslands fences, Mongolian gazelle cannot migrate to the steppe in China in winter anymore; thus grassland fence increased the genetic isolation between wild animal populations with an effect greater than those caused by big mountains and lakes. Fenced grassland make the poachers easier to kill wild ungulates, fence lines even strangled or injuries wild animals, affected the survival and reproduction of wild animals.

Now, habitats of wild animals subjected to visible and invisible destructions. Grassland fence belongs to the former whereas over stocking may cause invisible destruction of grasslands. We should consider the management of wildlife and protection of biodiversity in the integrative grassland management plan, and pay special attention to those wild ungulates which need larger habitats. We should make comprehensive grazing animal and wild animal management plan for sustainable development of grassland ecosystem. Otherwise, we will face a wave of wild ungulate extinction on grasslands in Asia.





INFORMATION:

You, Z. Jiang, Z., Li C.，Mallon D. Impacts of grassland fence on the behavior and distribution range of the critically endangered Przewalski's gazelle on the Qinghai-Tibetan Plateau. Chinese Science Bulletin 58: 2262. doi: 10.1007/s11434-013-5844-9.

http://csb.scichina.com:8080/kxtbe/EN/abstract/abstract507883.shtml

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