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Published in Fall 2001
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Biodiversity in peril: help for North America’s most wanted species
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With the pace and preoccupations of modern life, we are in danger of becoming indifferent to the threat of extinction hanging over many species in North America, writes Karen Schmidt. An initiative by wildlife agencies in Canada, Mexico and the United States has targeted 17 species of common concern to conservationists in the three countries. As well as increasing the possibilities for collaboration, this program aims at raising public awareness of conservation challenges and biodiversity loss.
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By Karen Schmidt
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My colleague, Hans Herrmann, head of the CEC’s Conservation of Biodiversity program, recently went on a diving trip in the Sea of Cortes. While preparing for the dive, he excitedly told his diving partner about the beauty of the place that they were about to see, how rich in life it was, and how fortunate they were to be diving there.
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Black-tailed Prarie Dog
(Cynomys ludovicianus) |
But a rude shock awaited them: the area had lost all its richness, its magic, its capacity to inspire amazement. Everything was gray and green. Something drastic had happened. Hans suspected the elimination of an important link in the chain of life, a keystone species—most probably a sea cucumber. But what struck him even more forcefully than the vanished beauty was the fact that some of his colleagues were starting to take the changing landscape for granted.
Living in a world of constant noise, traffic and overcrowding, we cope as best we can. We assume that nature will find its way. That it will stand up to the construction of a new shopping mall, or a larger airport. That it will bounce back from intensive fishing or agriculture. But it is now clear that many once-common animals and plants are rapidly losing the battle against disappearing habitat. And it seems we are becoming indifferent to their absence, seduced by the benefits of comfort and efficiency.
But how much we would lose if only a few species of birds remained, if all our coastlines were covered with buildings, if forests and grasslands were completely replaced by farm fields, or if the seas were scraped clean of their wealth of life? Life would be a dull business without the majestic colors, sounds and shapes of North America’s biological diversity.
Species of common concern
Scientists describe life in its multiple forms—genes, species, and ecosystems—as biodiversity, with species being its most common currency, and its most identifiable element. When we speak of loss of biodiversity, or even degradation of ecosystems, we may be referring to the reduction in the population of a single species or a decline
in the number of species. Species put a face on a conservation problem. They also play an important role as biological barometers ("indicator species"), telling us how well or badly an ecosystem is faring.
Our shared species—such as the Leatherback Turtle and Peregrine Falcon—migrate thousands of kilometers, moving across national and state/ provincial/territorial borders without hesitation. Through these shared species and ecosystems, the environments of Canada, Mexico and the United States are intricately linked. Accordingly, action or inaction on one side of a border will have consequences on the living organisms and systems of another. To conserve our biodiversity, then, action must not only be urgent, it must also be concerted.
The CEC and key players from Canada, Mexico and the United States are working to help protect North America’s shared species.
SPECIES PROFILE
Black-tailed Prarie Dog
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Scientific name:
Cynomys ludovicianus
Common name:
Black-tailed prairie dog
Legal status:
Canada: Listed as vulnerable in 1999
Mexico: Listed as threatened
United States: Warranted as threatened
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Range:
Black-tailed prairie dogs range from Canada to Mexico: current range and distribution represents 2% of their historic range
Habitat:
Grasslands, open plains and plateaus
Life Span:
Up to eight years, although after five years mortality is high
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Importance
Burrowing and grazing activities of prairie dogs affect many ecosystem functions and processes, including vegetation structure, plant composition, nutrients available in soil for plants, soil turnover, soil chemistry, energy flows, nutrient quality of plants, and plant succulence. In addition, their colonies provide habitat for many other prairie species, some of which are declining or are in a state of conservation concern, such as mountain plovers, ferruginous hawks, swift foxes and burrowing owls who use their holes for nest sites. Prairie dog colonies are also essential to the survival and re-introduction of the black-footed ferret, North America's most endangered mammal.
Threats
C. ludovicianus is one of five species of prairie dog recognized in North America. Its population prior to European settlement has been estimated at 5 billion. There are three major threats to the species' long-term survival: disease, eradication programs, and habitat loss and fragmentation.
At the beginning of the last century, prairie dogs still covered between 40 and 100 million ha of grassland ecosystems in western North America. By 1961, the area of occupation had declined to about 165,000 ha-approximately a 99% decline in total habitat. Today, prairie dogs exist largely in isolated colonies throughout their former range, with notable concentrations on Tribal and Forest Service lands in the northern Great Plains and in Mexico.
The black-tailed prairie dog has the greatest distribution of all the prairie dog species. Historically, the species existed in vast colonies up to hundreds of square kilometers in size. Today, while colonies continue to persist throughout much of their historic range, they have become fragmented and isolated. This may significantly affect the long-term conservation of the species, and may affect many other species that depend on, or are associated with, prairie dog colonies (including burrowing owls, rattlesnakes, mountain plovers, black-footed ferrets). Black-tailed prairie dogs are the only species of prairie dog occurring in Canada, where they are found in one area of southern Saskatchewan.
The only healthy population of black-tailed prairie dogs known in Mexico is located in Chihuahua, an area of approximately 40,000 ha. This is the largest contiguous black-tailed prairie dog complex in North America, and perhaps formerly extended
into the southern United States. Prairie dogs are rapidly decreasing in Mexico as a result of habitat loss due to conversion of grasslands to croplands, and prairie dog eradication efforts on rangelands. In the United States, black-tailed prairie dogs continue persist as remnant populations across approximately 70% of their historic range. However, eradication programs have significantly impacted them. These programs exist primarily as result of the perceived competition between prairie dogs and livestock.
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The seventeen members of the terrestrial SCCC are:
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– Ferruginous Hawk (Buteo regalis)
– Peregrine Falcon (Falco peregrinus)
– Loggerhead Shrike (Lanius ludovicianus)
– Piping Plover (Charadrius melodus)
– Mountain Plover (Charadrius montanus)
– Nothern Spotted Owl (Strix occidentalis caurina)
– Mexican Spotted Owl (Strix occidentalis lucida)
– Burrowing Owl (Athene cunicularia)
– Golden-cheeked Warbler (Dendroica chrysoparia)
– Whooping Crane (Grus americana)
– California Condor (Gymnogyps californianus)
– Black-tailed Prairie Dog (Cynomys ludovicianus)
– Sonoran Pronghorn (Antilocapra americana
sonoriensis)
– Lesser Long-nosed Bat (Leptonycteris curasoae
yerbabuenae)
– Greater Mexican Long-nosed Bat (Leptonycteris nivalis)
– Black Bear (Ursus americanus)
– Gray Wolf (Canis lupus)
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In February 2000, the wildlife agencies, assisted by the CEC, agreed to work jointly on an initial set of 17 migratory and transboundary species identified as being of "common conservation concern"(SCCC). One of them is the Black-tailed Prairie Dog (Cynomys ludovicianus), profiled opposite. Similarly in March 2001, government, NGOs and academics started to develop a list of Marine Species of Common Conservation Concern (MSCCC).
When people from Canada, Mexico and the United States work together for the conservation of their species at risk, they are multiplying their potential for success, achieving more than they could alone. Working in collaborative and cooperative ways allows us to make better use of existing policies, initiatives, institutions, scientific research and information, and to make better use of limited funds.
It is our hope that the species of common conservation concern
will help raise awareness of the conservation challenges, put a face on habitat destruction, extinction of species, and over-harvesting. They will help us remember what we once had and what we are in the process of losing if nothing is done to change matters. They will help us to avoid becoming indifferent. We want these species to become a face of hope, a face of success.
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Karen Schmidt 
Species of Common Conservation Concern in North America