Реферат на тему Desert Tortises Essay Research Paper Desert tortoises
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Desert Tortises Essay, Research Paper
Desert tortoises are found on flats, alluvial fans, bajadas and rocky terrain. Historically, flat terrain has lent itself to human. Skewing population estimates towards this gentler terrain. – But evidence exists that desert tortoises also frequent Rocky slopes, perhaps for protection from the desert heat. Soil friability, or its tendency to break apart, is another indicator of Tortoise habitat. Desert tortoises need soils they are capable of digging into for burrows.
Plant species also play a major role in both defining desert tortoise habitat and their diet. Creosote bush, burro bush, Mojave Yucca and black brush generally distinguish desert tortoise habitat. At higher altitudes, Joshua tree and galleta grass (Pleuraphis
rigida) are common plant indicators.
Populations have declined recently in many areas due to two main human attributable reasons: the direct loss of Individuals and habitat degradation / fragmentation. Individual tortoises are lost due to poaching, collection for pets, military Activities, vehicular impact, livestock trampling, disease and raven encroachment. Habitat degradation and fragmentation occur Mainly through the spread of urban sprawl and livestock grazing practices. In addition to a recent encroachment by ravens due To the presence of garbage dumps, desert tortoises also face the threat of a deadly upper respiratory disease in the Western Mojave area. Sadly the desert tortoise’s population is only 20 tortoises per square mile.
Biologists have identified research Needs and recommendations for funding, reviewed research proposals, developed a manual to educate and aid law Enforcement officials and developed a compensation policy for loss of desert tortoise habitat.