Wood bison population recovery and forage availability in northwestern Canada

Forage availability was assessed to determine sustainable stocking rates for eight broadly defined vegetation types (Treed Uplands, Treed Lowlands, Mixed Tall Shrub/Sedge, Closed-canopied Willow, and Open-canopied Willow, Meadow, Wetland Grass, Wetland Sedge) for use by wood bison (Bison bison athabascae), a threatened subspecies, in the Canadian boreal forest of northern Alberta. Clip plots (n=108) were used to sample peak availability of herbs and current annual growth of Salix spp. in late summer. Graminoid wetlands dominated by Carex atherodes, Carex aquatilis, Carex utriculata, Scolochloa festucacea, or Calamagrostis stricta produced 1975-4575 kg ha(-1) of fair to good quality forage, whereas treed stands produced < 250 kg ha(-1) of forb-dominated forage (>85% content), which was below a published 25% foraging efficiency threshold of 263 kg ha(-1) for bison. Upland forests that dominate the region produced < or = 1 animal unit day (AUD) of forage per hectare in summer. Most forest understory plants were of poor forage value, suggesting the potential sustainable stocking rate of such areas was actually < or = 0.3 AUD ha(-1), with even lower rates during winter due to snow cover. Herbaceous wetlands contained approximately 78 AUD ha(-1) of forage, but were considered largely unavailable in summer because of flooding and soft organic soils that make access difficult. Conversion of prime foraging habitat to agricultural land, forest expansion due to fire control, and a warmer and wetter climatic regime after the mid-1900s likely contributed to a regional reduction in carrying capacity. It is hypothesized that substantial recovery of the wood bison population toward historical levels will be constrained in northern Alberta by the availability of summer forage, and the limited extent of graminoid wetlands that provide winter foraging habitat.     

Reintroduction of the european bison into the forest ecosystem of the Orlovskoe Poles’e National Park

The forest ecosystem of the Orlovskoe Polese National Park has been studied in reference to the reintroduction of a rare species: the European bison (Bison bonasus L.). Preliminary data characterizing the state of forest resources and the populations of ungulates living in the forests, as well as the genetic problems associated with maintaining a viable population of the European bison, are considered.Translated from Ekologiya, No. 2, 2005, pp. 132–137.Original Russian Text Copyright © 2005 by Belousova, Smirnov, Kazmin, Kudrjavtsev.     

Hyperdisease in the late Pleistocene: validation of an early 20th century hypothesis

The hypothesis of disease-related large mammal extinction has new support. A unique pathologic zone of resorption was first noticed in a Hiscock Mammut americanum metacarpal. The pathognomonic zone of resorption was present in fifty-nine (52%) of 113 skeletons with feet available for examination. Metacarpals and metatarsals were most commonly affected. Associated rib periosteal reaction is highly suggestive of tuberculosis and the foot lesions were identical to that documented in Bison as pathognomonic for tuberculosis. Recognizing that only a portion of animals infected by infectious tuberculosis develop bone involvement, the high frequency of the pathology in M. americanum suggests that tuberculosis was not simply endemic, but actually pandemic, a hyperdisease. Pandemic tuberculosis was one of several probable factors contributing to mastodon extinction.     

Bison and elk in the American Southwest: In search of the pristine

Ecosystem managers often use the early historic condition of the fauna in an area as the model for restoration or management. West of the Pecos River in the American Southwest, present-day abundances and distributional ranges of bison and American elk exceed those reported in early historic times. I evaluate several potential causes for the historic scarcity of these animals—inadequate forage, insufficient water, nonhuman predation, disease, and hunting by late-prehistoric humans. Archaeological and ecological evidence suggest that restricted availability of water coupled with hunting by late-prehistoric peoples probably were the most important causes. Perennial water is more widely distributed now than previously, mainly because of water well and water catchment construction. Proliferation of agriculture-based human economies in the region from AD 0–1500 led to rapid population growth of aboriginal peoples, with resulting increased harvests of resources. The likelihood that late-prehistoric humans severely depleted the abundances of large mammals indicates a need to reevaluate the exclusive use of early-historic conditions as the basis for setting goals for ecosystem management. Implications of reintroducing large herbivores to ecosystems are discussed.     

The Ecological Future of the North American Bison: Conceiving Long-Term, Large-Scale Conservation of Wildlife

Abstract:  Many wide-ranging mammal species have experienced significant declines over the last 200 years; restoring these species will require long-term, large-scale recovery efforts. We highlight 5 attributes of a recent range-wide vision-setting exercise for ecological recovery of the North American bison ( Bison bison ) that are broadly applicable to other species and restoration targets. The result of the exercise, the "Vermejo Statement" on bison restoration, is explicitly (1) large scale, (2) long term, (3) inclusive, (4) fulfilling of different values, and (5) ambitious. It reads, in part, "Over the next century, the ecological recovery of the North American bison will occur when multiple large herds move freely across extensive landscapes within all major habitats of their historic range, interacting in ecologically significant ways with the fullest possible set of other native species, and inspiring, sustaining and connecting human cultures." We refined the vision into a scorecard that illustrates how individual bison herds can contribute to the vision. We also developed a set of maps and analyzed the current and potential future distributions of bison on the basis of expert assessment. Although more than 500,000 bison exist in North America today, we estimated they occupy <1% of their historical range and in no place express the full range of ecological and social values of previous times. By formulating an inclusive, affirmative, and specific vision through consultation with a wide range of stakeholders, we hope to provide a foundation for conservation of bison, and other wide-ranging species, over the next 100 years.     

Are bison exotic in the Wrangell-St. Elias National Park and Preserve?

The effect of past distributions of animal populations now extinct in an area from unknown causes is considered relative to their status as exotic or native in national parks. The example is the bison (Bisonbison) on the Copper and Chitina river drainages in Alaska in the USA which was introduced prior to establishment of Wrangell-St. Elias National Park and Preserve. The fossil record suggests that bison were present as recently as 500 years ago in Alaska. The policy of the US National Park Service to maintain natural ecosystems and restrict or eliminate exotic species raises the issue of whether this species should be treated as exotic or native.     

Pyric Herbivory: Rewilding Landscapes through the Recoupling of Fire and Grazing

Abstract:  Our understanding of fire and grazing is largely based on small-scale experimental studies in which treatments are uniformly applied to experimental units that are considered homogenous. Any discussion of an interaction between fire and grazing is usually based on a statistical approach that ignores the spatial and temporal interactions on complex landscapes. We propose a new focus on the ecological interaction of fire and grazing in which each disturbance is spatially and temporally dependent on the other and results in a landscape where disturbance is best described as a shifting mosaic (a landscape with patches that vary with time since disturbance) that is critical to ecological structure and function of many ecosystems. We call this spatiotemporal interaction pyric herbivory (literal interpretation means grazing driven by fire). Pyric herbivory is the spatial and temporal interaction of fire and grazing, where positive and negative feedbacks promote a shifting pattern of disturbance across the landscape. We present data we collected from the Tallgrass Prairie Preserve in the southern Great Plains of North America that demonstrates that the interaction between free-roaming bison ( Bison bison ) and random fires promotes heterogeneity and provides the foundation for biological diversity and ecosystem function of North American and African grasslands. This study is different from other studies of fire and grazing because the fires we examined were random and grazing animals were free to roam and select from burned and unburned patches. For ecosystems across the globe with a long history of fire and grazing, pyric herbivory with any grazing herbivore is likely more effective at restoring evolutionary disturbance patterns than a focus on restoring any large vertebrate while ignoring the interaction with fire and other disturbances .