Endangered Species Handbook

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Grasslands, Shrublands, Deserts

Drylands of the World: SOUTH AMERICA: Atacama Desert

     Patagonia, a vast wilderness of grasslands, shrub and desert, is home to a diverse array of unique animals, from endangered members of the camel family to deer and large rodents.  Over the past few hundred years, this wildlife has been displaced by livestock, which are overgrazing and desertifying the region.  The Guanaco (Lama guanaco), a wild relative of the domestic Llama, was once the characteristic animal of Patagonia's grasslands in populations estimated at between 30 and 50 million prior to the arrival of Europeans (Nowak 1999).  In the past 400 years, they have been crowded out of prime habitat by the millions of sheep grazed by ranchers.  Only about 571,000 Guanacos survive, and their numbers continue to decline (Nowak 1999).  In some areas, ranchers kill Guanacos, considering them competitors with sheep for grass.  The species has been eliminated from most of eastern and lowland grasslands, from southern Peru to eastern Argentina south to Tierra del Fuego (Nowak 1999).  In their vast Patagonian range, no large protected areas have been set aside for them (Uhart and Baldi 2000).   One of the few places where one can see these statuesque animals in Argentine Patagonia is the 2,500-acre Cabo Dos Bahias Provincial Reserve on the coast; it is surrounded by ranch land used for sheep grazing (Uhart and Baldi 2000).  In the summer of 2000, 350 to 500 Guanacos were found dead in this small reserve, including entire families with newborn young.  A team of veterinarians from the Wildlife Conservation Society (WCS) flew from New York to determine the cause (Uhart and Baldi 2000).  Preliminary examination of carcasses indicated that the Guanacos had slowly starved to death as a result of being confined to a too-small reserve that was poorly managed and allowed to become overgrazed and desertified; managers had even allowed sheep to graze within the reserve (Uhart and Baldi 2000).  WCS urgently recommended that the reserve be enlarged.
 
     Guanaco family groups are headed by a male who leads four to ten females and young under 15 months (Nowak 1999).  At certain times of the year, groups form herds that may number as many as 100 animals (Dorst 1967).  Males act as sentinels and warn of danger, allowing the herd to escape at high speed, up to 56 km per hour, outrunning a man on horseback (Dorst 1967).  Guanacos are listed on Appendix II of CITES, since their pelt and fur are in commercial demand.
 
     Its close relative, the graceful and beautiful Vicuņa (Vicugna vicugna), inhabits hill and steppe grasslands at high altitudes of the Andes in Peru, Bolivia, northwestern Argentina and northern Chile (Nowak 1999).  Heavily hunted for its extremely valuable fur, it nearly became extinct several times during the 20th century.  The Incan people had traditionally captured Vicuņas alive, shearing them for their wool and releasing them.  Prior to the arrival of the Spanish, these animals numbered an estimated 1 to 1.5 million (Nowak 1999).  From the 17th century onward, the Spanish killed them by the hundreds of thousands, replacing them with domestic livestock in much of their original range.   By the 1950s, only 400,000 Vicunas remained, declining to only 6,000 in 1965 (Nowak 1999).  Since then, conservation measures have brought them back to about 200,000.  Herds are rounded up under current laws, and their wool is sheared.  The soft wool is marketed on a quota basis under CITES regulations from several countries, primarily Peru, but some illegal killing occurs (see Trade chapter).  The populations of Vicuņa need to be guarded very carefully to prevent further decimation of their numbers. 
 
     The Chaco, a mixed savannah-woodland region of Paraguay, Bolivia and Argentina, covers 100,000 square miles wedged between the Pantanal wetlands of southern Brazil, the semi-tropical forests of eastern Paraguay, the Argentine pampas and the Andes to the west.  Prior to the arrival of Europeans, the grasslands were maintained by native peoples who burned vegetation periodically, limiting woodland growth (Bucher and Nores 1988).  Ranches were allocated to European immigrants by the governments of Paraguay and Argentina, and the new immigrants cut woodlands and plowed the grassland for agriculture.  This region, once a wildlife paradise with more mammal species per square mile than the Amazon basin, according to some zoologists' estimates, has become ravaged by misuse (Thigpen 1996).  More than 400 species of birds were native to the thorny brushlands, marshes, forests of ancient oaks, grasslands and deserts (Thigpen 1996). 
 
     In Argentina and portions of Paraguay, overgrazing by livestock has turned savannah into shrub, and agriculture has destroyed more of the Chacoan ecosystem.  This has threatened many species of native wildlife.  The few parks in the region lack adequate staffing to prevent destruction by activities such as illegal grazing.  In recent decades, bird trappers have felled tens of thousands of old oaks and other trees, used by Blue-fronted Amazons (Amazona aestiva) for nesting, in order to obtain the young chicks for the pet trade.  This trade was ended in the early 1990s after undercover investigations and films by the Environmental Investigation Agency documented this cruel and destructive trade, and the United States banned importation of these birds.  Public opinion and the catastrophic decline in wild populations of these parrots forced the Argentine government to stop exports, but in many areas of Argentina, old trees with nesting cavities have now disappeared.  Forests have also been felled to make way for agriculture, which has threatened many kinds of parrots and other hole-nesting birds, such as woodpeckers and the Great Horned Owl (Bubo virginianus) (Bucher and Nores 1988).  Eucalyptus has been planted in many parts of the Argentine Chaco, and this exotic tree has had a deleterious effect on native plants and wildlife.


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