sign in sign up
<<
Home , Mexican prairie dog, Prairie dog

The Dogs of Their Biological Importance And Conservation

Gerardo Ceballos* Jesús Pacheco** s o l l a b e C

o d r a r e G

ine dust that clung to your whole States and Chihuahua and in 1892 and 1894 as the commission set body had been a problem for the Mexico. The scenery was surprising - the monuments that would mark the new Flast part of the long trip, partic - ly beautiful: wide plains dotted with boundaries between the two countries. ularly for those at the end of the caravan. mountains like islands; the fauna, abun - During his work at the San Luis Moun - It was the intense heat, however, s ome - dant and magnificent. He decided to tains camp, he was able to observe mula times as high as 43 degrees Celsius, that camp in a poplar-filled gallery forest near deer, white-tailed deer, peccaries, great had made the journey so hard. Major a seasonal stream, and stay a few days. herds of antelope, bighorn Edgar A. Mearns wiped the sweat from Mearns was the army surgeon in charge sheep, wolves, black and grey bear, beaver his face and was glad to see the San of the health of the American mission of and many other species. How - Luis Mountains on the horizon, the bor - the U.S.-Mexico Inter national Boundary ever, what surprised him the most were der between New Mexico in the United Co mmi ssion. His interest in natural his - the immense prairie-dog towns ( Cynomys tory had prompted him to obtain per - ludovicianus ) stretching for hundreds * Researcher at the UNAM Institute. ** Biologist working at the UNAM Ecology mission from the U.S. government to of kilometers. In the foothills of the San Institute. also collect plants and between Luis Mountains and in the Las Animas

106 Ecology

Valley in New Mexico, he found a town ing the frequent downpours that com - a predator enters the colony, the sen - of millions of prairie dogs, a sight he pletely flood the prairie during the rainy tinel makes a sound like a bark, which would never forget. season. is what gave them their name. This Prairie dogs are gregarious creatures: sound indicates to the predator that they live in groups of thousands and he/she has been discovered and alerts INHABITANTS OF THE even millions, which has an important the other prairie dogs, who quickly run impact on the structure and composi - back to their . A few minutes Prairie dogs are of the squir - tion of prairie vegetation. They have a later, they cautiously peep out of their rel family ( Sciuridae ); they have stocky high degree of social organization; their holes to inspect the horizon and renew little bodies and weigh about one kilo - behavior is one of the most important their activities. Other behavioral traits gram. Mexico is home to two of the factors for their adaptation and survival in volve corporal contact between indi -

five species of this kind of : the s o l l a b e

Mexican ( Cynomys mexi - C

o d r a ) and the black-tailed prairie dog r canus e G (Cynomys ludovicianus ). The is endemic to Mexico and lives in an area of less than 1,000 square kilometers in the states of San Luis Po - tosí, Nue vo León and . The black-tailed prairie dog is the species that has spread the most in the hemi - sphere, living as it does in the area from southern Canada to northern Mexico, where it inhabits exclusively the grass - lands of northwest Chihuahua and north - east Sonora. The prairie dogs’ color varies be tween a yellowish and a reddish grey buff —sprinkled with black hairs here and there— their bellies are lighter and the ends of their tails are black. They are with semi-digging habits, their ability to dig being one of in the great prairies. The colonies, also viduals, whether it be touching noses, their most noteworthy characteristics. called “towns,” are made up of family bodies or occasionally incisors to iden - Their burrows form elaborate tunnels groups usually composed of an adult tify or recognize each other. up to 34 meters long and five meters male, from one to four adult females deep, with a variable number of cham - and their young under the age of two. bers used for different purposes. The These family groups display very aggres - CURRENT DISTRIBUTION earth that they dig out of their tunnels sive territorial behavior vis-à-vis other is accumulated at the entrance to the groups, with the males in constant alert Mearns did not know it, but when he burrows, forming cone-like mounds, to keep other males out of their territory. visited the San Luis Mountains, dense - giving their colonies a very special look. Another aspect of prairie dogs’ gregar - ly populated colonies of prairie dogs still Among other things, these mounds serve ious life is their communication through occupied about 400 million hectares of both as observation posts to detect the different “calls.” This keeps them in . That would change drastical - presence of predators and as barriers contact with the rest of the colony and ly in the following decades. By the 1960s, to protect them from hail and rain dur - also prevents attacks by predators. When their distribution had been reduced by

107 Voices of Mexico • 54 o c e h c a P

s ú s e J

98 percent, and they only occupied about several hours on the road, as the sun or millions-strong, they have a great 600,000 fragmented, isolated hectares began to set, when we had almost lost impact: they change the landscape, in - of prairie lands. By 1980, it had already hope, the landscape began to change. crease environmental hetero geneity, been decades since the last colonies in Little by little the arid brambles began and have an impact on biological diver - Arizona and New Mexico had been exter - to break up giving way to a huge prairie, sity. Their activities, par ticularly digging minated. What had happened to the sprinkled with mounds and countless burrows and destroying high, standing prairie dogs in Chihuahua? The latest prairie dogs. The spectacle was amazing. vegetation, have a direct in flu ence on available reports —from 1972— situated We had found the prairie dogs of Chi - the environment’s physi cal cha racter is - them in the Casas Grandes area, on the huahua, a complex made up of hundreds tics, on the physical and chem ical prop - plains near the San Luis Mountains. of towns and millions of animals. We erties of the s oil, on the hydrological In 1988, we organized an expedition called it Janos-Nuevo Casas Grandes. cycle, on the structure of vegetation, the to Chihuahua to search for them. We We did not know then that we were decomposition of vegetable matter and decided to use Nuevo Casas Grandes as looking at the last great prairie-dog town on the specific interaction of vertebrates a base camp. Grasslands around the city in the hemisphere, a scene out of the and invertebra tes. Prairie dogs are essen - are scanty, most having been turned into nineteenth century. tial for maintaining grasslands and fields for cultivation, which means that imped ing desertification and the inva - very little of the natural environment sion of mesquite, since they destroy survives. Approxima tely 60 kilometers AN ECOLOGICALLY KEY SPECIES both mes quite and other plants that north of Nuevo Casas Grandes is Janos, invade grasslands and that proliferate a town we passed through on the way to Prairie dogs are closely associated with in over-grazed areas. the mountains along a dirt road in terri - prairies and grasslands, which are char - The environmental heterogeneity ble condition. Lost in the labyrinth of acterized by grass and low bush. Their caused by prairie dogs’ foraging and dirt roads, we left several Mennonite towns are usually surrounded by high burrowing activities propitiates colo - towns and collective ejido farms behind. grass and brambles with abundant bush - nization and permanent residence of The landscape was a mix of brambles es. They are considered an ecologically many species of vertebrates and are and different kinds of grass, with key species because when they estab - the basis for maintaining regional bio - scattered as far as the eye could see. After lish themselves in colonies thousands- logical diversity. In the Janos-Nuevo

108 Ecology o c e h c a P

s ú s e J

Casas Grandes Complex, species such and fragmentation of their . This Ceballos, G., J. Pacheco and R. List, “Influence of the prairie dogs ( Cynomys ludovicianus ) as the bison ( Bison bison ), the brings with it a loss in the biological on habitat heterogeneity and mammalian (Taxidea taxus ), the kit fox ( Vulpes velox ), diversity associated with their colonies. diversity in Mexico,” Journal of Arid Enviro n - ments 41 (1999), pp. 161-172. the ( Aquila chrysaetos ), the The fragmentation of these colonies ( Haliaeetus leucocephalus ), makes them susceptible to extinction Hoogland, J. L., The black-tailed prairie dog. Social life of a burrowing mammal (Chicago: the ferruginous ( Buteo regalis ), through disease, in-breeding or natural The University of Chicago Press, 1995). the ( Athene cunicular - catastrophe. The study and preservation King, J. A., “Social behavior, social organization ia ) and the ( Chara - of the prairie dogs of the Janos-Nuevo and population dynamics in black-tailed drius montanus ) are closely dependent Casas Grandes Complex could be the prairie dog towns in Black Hills, ,” Contributions from the Laboratory of on the prairie dog towns. basis for the design and instrumenta - Vertebrate Biology 67 (Ann Arbor, Michigan: tion of management programs suited to University of Michigan, 1955). maintaining the grasslands in the short, List, R., G. Ceballos and J. Pacheco, “Status of the North American porcupine ( Erethizon THE CONSERVATION OF PRAIRIE DOGS medium and long term, which would dorsatum ) in Mexico,” The Southwestern benefit both wild species and Naturalist 44 (1999), pp. 400-404.

Since we found the Janos-Nuevo Casas local inhabitants. The project’s goal is to Manzano-Fischer, P., R. List and G. Ceballos, Grandes Complex prairie-dog towns, we establish a biosphere reserve that would “ birds in prairie-dog towns in Northwestern Mexico,” Studies in Avian have carried out different studies in the permit the conservation of regional bio - Biology 19 (1999), pp. 263-271. area about these animals’ distribution diversity, the preservation of the native Mearns, E. A., “Mammals of the Mexican bound - and ecology with our colleagues Eric and the maintenance of evo - ary of the United States,” United States Natio n - Mellink, Rurik List, Patricia Manzano, lutionary processes. al Museum Bulletin 56 (1907), pp. 1-530. Mario Rollo, Andrés García, Erika Marcé Miller, B., G. Ceballos and R. Reading, “The and Georgina Santos. These studies have prairie dog and biotic diversity,” Conservation FURTHER READING Biology (1994), pp. 667-681. shown that these colonies constitute Miller, B., R. Reading, J. Hoogland, T. Clark, G. the largest remaining prairie-dog com - Ceballos, G., E. Mellink and L. Hanebury, Ceballos, R. List, S. Forrest, L. Hanebury, P. plex in , covering almost “Distribution and conservation status of Manzano, J. Pacheco and D. Uresk, “The role 40,000 hectares. However, this area is prairie dogs ( Cynomys mexicanus and C. of prairie dogs as : A ludovicianus ) in Mexico,” Biological Con ser - response to Stapp,” Conservation Biology 14 diminishing due to the deterioration vation 63 (1993), pp. 105-112. (2000), pp. 318-321.

109