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We capitalized on a regional-scale, anthropogenic experiment?the reduction of black-tailed prairie dog (Cynomys ludovicianus) towns across the Great Plains of North America?to test the hypothesis that decline of this species has led to declines in diversity of native grassland vertebrates of this region. We compared species richness and species composition of non-volant mammals, reptiles and amphibians at 36 prairie dog towns and 36 paired sites in the Panhandle Region of Oklahoma during the summers and falls of 1997, 1998 and 1999. We detected 30 species of mammals, 18 species of reptiles and seven species of amphibians. Comparisons between communities at prairie dog towns and paired sites in the adjacent landscape...
We conducted a natural removal experiment, utilizing a local outbreak of sylvatic plague (Yersinia pestis) as the removal agent, to test the effects of removal of Gunnison's prairie dogs (Cynomys gunnisoni) on plant and nocturnal rodent assemblages in three grassland habitats (ponderosa, pinyon-juniper, and desert grasslands) in northern Arizona. We measured plant cover, rodent abundance, plant and rodent species richness, and plant and rodent composition at three treatment locations: active prairie dog colonies (n=15), inactive colonies (n=15), and control locations (n=15). Only the amount of plant cover differed significantly among treatments. As landscape level heterogeneity among habitat types increased, rodent...
Medium-sized kangaroo rats (Dipodomys spp. Gray) function as keystone species in the dynamics of desert bunchgrasses. We tested the hypothesis that kangaroo rat graminivory leads to reduced grass growth and inflorescence production, and that kangaroo rat grass consumption reflects their preferences for open microhabitats. We excluded kangaroo rats from grasses, and measured tiller loss, leaf and tiller growth and inflorescence production. We recorded the extent of tiller loss in grasses varying in tussock size or the extent of surrounding cover. Consumption of tillers by kangaroo rats was extensive, peaking in late summer. Grasses protected from kangaroo rat graminivory showed elevated leaf and tiller growth and...
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There is growing recognition among ecologists that ecosystem engineers play important roles in creating habitat for other species, but the comparative and combined effects of co-existing engineers are not well known. Here, we evaluated the separate and interactive effects of two burrowing rodents, Gunnison's prairie dogs (Cynomys gunnisoni) and banner-tailed kangaroo rats (Dipodomys spectabilis), on lizards in the Chihuahuan Desert grassland (USA). We found that the mounds and burrow systems of both rodent species provided important habitat for lizards, with lizard abundance being 2 to 4-fold higher on mounds than in adjacent areas without mounds. Kangaroo rat mounds supported greater numbers of lizards than prairie...
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Ecosystem engineering by animals can create new habitats and increase the heterogeneity of the habitat mosaic that in turn can increase plant and animal diversity. Prairie dogs in North America alter both the above- and below-ground structure of the landscape and create novel habitats in grassland ecosystems. The ground-dwelling arthropod community associated with Gunnison's prairie dog modified habitats is compositionally different from that found in the surrounding grassland. Individual arthropod families and species have different distributions in both active prairie dog towns and inactive towns, compared to unmodified grasslands. These different responses to ecosystem engineering increase beta (between-habitat)...
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Animals that modify their environment through engineering and herbivory have important impacts on ecosystems, yet the interactive roles of such species have rarely been studied. We studied the comparative and interactive effects of two burrowing herbivorous rodents, Gunnison's prairie dogs (Cynomys gunnisoni) and banner-tailed kangaroo rats (Dipodomys spectabilis), on vegetation where they co-occurred in a Chihuahuan Desert grassland. We found that their effects remained distinct and, thus, non-substitutable, where they co-occurred. The rodents differentially altered plant community structure relative to their different mound types, herbivory, and spatial scales of disturbance. Vegetation structure and plant species...
Prairie dogs (Cynomys spp.) have been labeled as keystone species because of their influence on biological diversity and ecosystem function. However, the validity of several assumptions used to support keystone status is questionable. We review the strength of the evidence and the magnitude of the prairie dog's effects on ecosystem structure and function. We use this review to reevaluate the keystone role for prairie dogs. Our goal is to encourage sound management of the prairie dog ecosystem by improving the ecological foundation of their keystone status. Our review confirms that prairie dogs affect a number of ecosystem-level functions but that their influence on prairie vertebrates may be less than previously...
    map background search result map search result map Engineering rodents create key habitat for lizards Burrowing rodents increase landscape heterogeneity in a desert grassland Conservation of prairie dog ecosystem engineering may support arthropod beta and gamma diversity Conservation of prairie dog ecosystem engineering may support arthropod beta and gamma diversity Engineering rodents create key habitat for lizards Burrowing rodents increase landscape heterogeneity in a desert grassland