Wildlife Coordinator, CEMEX-Projecto El Carmen
Maderas del Carmen, Coahuila, México
For the last five years I have been living in the Maderas del Carmen of northern Mexico and working as wildlife coordinator on the large conservation project in that area administered by CEMEX (a México-based cement company which owns 40% of the 500,000-acre Maderas del Carmen). You may remember me from the time several years ago when I worked for Texas Parks and Wildlife and conducted black bear research in the Black Gap Wildlife Management Area in Brewster County. I also responded to calls concerning nuisance bears, resulting in our relocating several bears.
Since black bears are near and dear to me, I began working on a research project on black bear movement and ecology in the Maderas del Carmen. Through previous work in Big Bend National Park conducted by Dave Onorato, it has been determined that the black bears now reestablishing small populations in Big Bend are from Coahuila, Mexico, and have moved across the Rio Grande into Texas.
This movement and reestablishment is very important because rarely does a wildlife species reestablish a population without human intervention. Yet the bears did this themselves. It is a wildlife success story that we can’t take credit for, a remarkable occurrence, and from a species that was extirpated from many states in Mexico about the same time they were extirpated from Texas.
The species was on the brink, and made it on its own, without captures, captive breeding, or transplants from some other area. Today’s population of black bears in the Maderas del Carmen and adjacent mountain ranges is healthy and expanding, but it wasn’t always this way.
Historically the black bear was distributed in nine Mexican states, but now is unevenly distributed in only seven: Coahuila, Chihuahua, Sonora, Tamaulipas, Durango, Zacatecas, and Nuevo Leon, with the largest populations in the Maderas del Carmen, Serranías del Burro, and Sierra del Pino ranges in Coahuila. The bear populations in México and West Texas began declining sharply in the 1940’s and 50’s. Historical documents and reports from old-timers in northern México attribute the decline to uncontrolled hunting, indiscriminate killing, and loss of habitat.
One other factor that may be involved was the effort to eradicate the Mexican wolf, or “lobo.” Poison-laced carcasses and steel traps were used for trapping lobos and it is possible that many black bears also fell victim to them.
In the mid-1950’s, Mexican President Miguel Aleman journeyed to northern Coahuila for his annual bear hunt and didn’t even see a single bear. On his return to México Cit,y he placed a moratorium on all bear hunting in México. This was probably the first attempt to provide some protection for black bears. However, population numbers continued to decline, with a few remnant populations hanging on in the aforementioned mountain ranges in Coahuila.
Since 1986, México has officially listed black bears as endangered in all of their range with the exception of one area in the Serranías del Burro where the population is listed as “special protection,” which is similar to the “threatened” status in Texas.
Black bears are dispersing naturally into the mountain ranges of northern Coahuila and other parts of their historic range; areas from which the bears have been absent for nearly fifty years are now occupied by small numbers of them.
Based on our observations and reports from landowners, ranchers, and agricultural cooperatives or ejidos, current threats to bears continue in the form of illegal hunting (even though the species is listed as endangered), fragmentation of habitats, illegal take in cubs, lack of information on true population size and distribution, unverified depredation reports and inflated depredation reports, lack of law enforcement in remote areas, absence of educational materials, and a lack of a general management plan. Currently there are several research projects being conducted in three states.
In Maderas del Carmen, Assistant Wildlife Coordinator Jonás Delgadillo Villalobos and I are moving into the fourth year of research on black bears. We are currently tracking 38 radio-collared black bears of all ages. The information will be used to further our knowledge of black bear ecology, provide management options, educate people on coexisting with black bears, particularly in the areas where bears have been absent for many years and are now reestablishing small populations. The survival and increase in black bear populations in northern Coahuila will be a contributing factor to the presence of black bears in West Texas.
The project is funded by CEMEX and supported by Bear Trust International (which features the project on its web site: www.beartrust.org). The title of our project is “Population Dynamics and Movement of Black Bears in Northern Coahuila, México.” Our objectives are: (1) the identification of major dispersal corridors from the Maderas del Carmen and determination of mortality factors during dispersal and within the resident population, (2) reproductive rates, (3) sex ratios of resident bears, (4) seasonal movement in relation to food availability, (5) cub survival, (6) habitat use, (7) genetic variability in mitochondrial DNA, (9) diet, (10) cooperative work with ranchers and ejidos to develop safe travel corridors during dispersal, (11) develop educational materials and work with landowners to deal with problem bears, and (12) provide technical support and training to Mexican agency personnel.
Bears are moving back and forth across the border and have been doing this for many years. In some regards the population in Coahuila can be considered the core, with satellite populations in West Texas and adjoining ranges in Coahuila and neighboring states. However, whether these populations can establish themselves and grow will depend largely on people being able to coexist with black bears.
The population of black bears in the Maderas del Carmen is healthy and on the increase; in one day this past summer we observed fifteen bears, none of which was a study bear with radio collars.
Female bears, known as sows, are having litters of two, three and sometimes four cubs. This is encouraging since many years see low cub survival rates. Bears are one of the slowest mammals to reproduce, with females only beginning to breed when they are around four years old. The cubs stay with the sow until they are roughly 18 months old, whereupon the sow literally kicks them out and they are on their own.
These small bears face many problems and have to find themselves a home range that will support them with food, water, and cover, all the while dodging males. Small cubs are at risk of being killed by adult males. The sow must defend her cubs against adult males as well as human intruders. In country that has trees she will vocalize to the cubs and in a flash these tiny bears will be literally flying up a tall pine tree, stopping only when they reach the top. They will stay there until the sow gives them the all clear grunt and as fast as they went up, down they come, tree bark flying.
But desert bears, such as the ones at Black Gap, don’t have the luxury of trees. They have quickly adapted to the low desert: one radio-collared female would move her cubs away from her normal home range when other bears moved into the area; she would return only after the intruding bears had left. This is just one example of how intelligent black bears are in the face of hardships.
When bear populations are healthy, natural dispersal occurs; subadults, especially bears in the one-and-a-half to two-year-old range, will leave their natal home range and move to another area to set up a new home range. Adult females and males will also move to new home ranges, particularly if the country is experiencing drought and natural foods are not in abundance.
One of the hazards that black bears face is the routes they travel when they disperse. Oftentimes they move over many miles of harsh terrain where water and food are scarce. Protection of the vital ecological corridors is important for safe dispersal, not only for bears but for other wildlife species as well.
México has made big leaps in the past ten years in the wildlife conservation arena. Many people are now aware of how important the land and the flora and fauna are and they are willing to work to preserve this natural heritage for future generations. The black bear is an integral part of México, just as it is in West Texas. It is up to us as managers, ranchers, landowners, and concerned citizens to work together to ensure that the black bear remains here and is not lost, as many other species already have been in the past.
Our house in the Maderas del Carmen is located in a remote canyon inhabited by many black bears, which don’t cause us any problems. We see them practically every day. Below our house there is a tinaja that holds water; an old sow that has three cubs this year daily traveled several miles from the mountain down into the canyon for water for herself and the cubs during the hot dry summer. She now is in hibernation with her cubs. Next spring they will emerge in April and by June the cubs will be on their own – a new generation of bears.
It will be up to us to make sure that they have habitat to support
them and that we can coexist with one of the most charismatic mammals
in North America.
Bear walking down road in Coahuila, MX. (Jonas Delgadillo)
Author Bonnie McKinney and Jonas Delgadillo with bear.
(Salvador Villarreal)
The author with a large male bear (Jonas Delgadillo)
