On 8 March 2010, an electronic report on the state of conservation of the property was submitted by the State Party. The report provides a detailed overview of the status and management of bison, cut-throat trout, and grizzly bears, as well as pressures due to visitors.
a) Bison management
The State Party reports that the Interagency Bison Management Plan (IBMP) has been partially revised to include adaptive management measures, in line with the requests made by the Committee in Decision 32 COM 7B.29. Two areas adjacent to the property have been closed to cattle and opened up to migratory bison. A risk analysis of disease transmission between bison and cattle has been undertaken (including consideration of bison genetics), and ways to improve stakeholder involvement in the IBMP are being considered.
- Progress towards securing bison migration routes: The State Party notes that in 2008-2009 all grazing ceased on Horse Butte peninsula, adjacent to the park’s western boundary, which has opened up this habitat to migratory bison. Moreover, in 2009, the state of Montana signed a 30-year livestock grazing restriction and bison access agreement to remove cattle from the park’s northern boundary at Royal Teton Ranch. The State Party considers that this agreement, and the cessation of grazing at Horse Butte peninsula, should allow progressively larger numbers of migratory bison to use winter habitats along the Yellowstone River, up to 10 miles away from the park boundary.
- Risk analysis of brucellosis disease transmission: The State Party reports that a risk analysis of disease transmission from bison and elk to cattle is ongoing and that the final report is expected in December 2009. The analysis quantifies the risk of brucellosis transmission from bison and elk to cattle, estimates transmission rates within bison and elk populations, and assesses whether vaccination of bison could help mitigate risks and contribute to eliminating this disease. The State Party recalls that in 2000 the IBMP originally proposed to maintain bison genetic-diversity by balancing a population of 3000 animals with brucellosis risk management objectives, which include culling. Recent scientific research on this issue has concluded that maintaining an overall bison population between 2,500 – 4,500 pairs should retain 90-95% of genetic diversity currently present within the Yellowstone population for the next 200 years.
- Enhancing stakeholder involvement in the IBMP: The State Party indicates that a new website now provides up-to-date information on the IBMP’s implementation. Moreover, the IBMP partner agencies have requested advice from the U.S. Institute for Environmental Conflict Resolution on how to enhance stakeholder involvement, and will continue to work with the Institute during 2009-2010 in order to improve the public engagement process.
The World Heritage Centre and IUCN note the State Party’s progress towards opening some areas to bison migration and enhancing stakeholder involvement in the Interagency Bison Management Plan. However, several key wildlife species in the park, aside from bison, have migratory routes that take them outside the property. While the revisions to the Interagency Bison Management Plan and the acquisition of several areas adjacent to the property for bison migration are welcome, there is a need to develop a more detailed understanding of the ecological role that the surrounding lands play in maintaining the property’s values. IUCN and the World Heritage Centre suggest to encourage the State Party to continue its efforts to secure bison migration routes, and to increase its engagement with ranchers surrounding the property in order to keep landscapes open to bison movements, including through easement leases and buyouts to limit the loss of habitat, and also as a means to keep bison separate from cattle.
IUCN notes that there have been no documented cases of brucellosis transmission from unconfined bison to cattle, although transmission from elk to cattle has occurred several times around feed grounds. During the winter of 2009 roughly 30% of the property’s bison population was culled due to concerns about the possible spread of a livestock disease to cattle that graze in areas around the park. A recent study assessing the risk of disease transmission from Yellowstone bison to cattle concluded that culling may be unnecessary, and that more cost-effective management solutions may be appropriate such as buying grazing rights from cattle ranchers in a few adjacent areas or testing all cattle within a special zone around the park.
The World Heritage Centre and IUCN further note that development and other human-caused change to the landscapes surrounding the Yellowstone are affecting the ecological role that surrounding lands play in maintaining the values of the property, including animal movement. They note the importance of continued strengthened cooperation with land owners and land managers within the Greater Yellowstone Ecosystem, and of developing a long-term vision and action plan for integrated management of the property and its surrounding areas.
b) Cut –throat trout
The State Party reports that a scientific expert panel has reviewed the programme to remove invasive lake trout from the property’s rivers. The panel noted that cut-throat trout, and the role they play in the property’s ecosystem, are seriously threatened by the continued expansion of the invasive lake trout population. The panel concluded that the lake trout suppression programme cannot succeed on its present budget and that lake trout removal efforts must be intensified for a minimum of six years. The State Party notes that Yellowstone National Park is in the process of implementing the scientific expert panel’s recommendations by developing a strategy to secure additional funding to support intensified lake trout suppression efforts. Moreover, the State Party indicates that a plan for the preservation and restoration of Yellowstone cut-throat trout will be developed during 2010. This plan will also investigate and address the effects of reduced lake levels, drought and climate change on the recovery of cut-throat trout, as requested in Decision 32 COM 7B.29.
The World Heritage Centre and IUCN welcome the State Party’s efforts to rapidly implement the recommendations of the scientific expert panel on cut-throat trout recovery. They urge the State Party to ensure that adequate funding is secured to intensify lake trout suppression efforts over the next six years. The State Party should be requested to submit a copy of the plan for the preservation and restoration of Yellowstone cut-throat trout as soon as it becomes available, including an indication of the level of funding secured.
c) The risks to grizzly bears from declining whitebark pine
The State Party reports that Yellowstone grizzly bears were returned to Federal Protection under the Endangered Species Act, due to concerns that the effects of global climate change on whitebark pine may seriously affect their population of roughly 600 individuals (the seeds of whitebark pine are an important food source for grizzlies). Since 2000, mountain pine beetles have caused substantial and ongoing whitebark pine mortality, which may be exacerbated by climate change and competition from species like lodgepole pine that are more successful in warmer sites. The State Party notes that past widespread mortality of whitebark pine occurred in the 1930’s and 1970’s (also caused by the native mountain pine beetle), and that during these declines Yellowstone grizzlies switched to other food sources including meat from ungulates, cutworm moths and ant colonies. The State Party notes that while it is not possible to predict how changes in whitebark pine will affect the grizzly population, the greatest threats to grizzly bear survival remain human factors such as roads, the amount of secure habitat available and hunter caused mortality.
The World Heritage Centre and IUCN note that the grizzly bear population is a vital element of the property’s Outstanding Universal Value. While the status of whitebark pine remains of concern, there are indications that grizzlies may be able to switch to other food sources. Given that the Yellowstone grizzly bear population only numbers roughly 600 individuals, IUCN recommends that the State Party review the population’s connectivity with the larger population of bears in the region, as well as the need to further mitigate human-bear conflict, which the State Party acknowledges as one of the major causes of bear mortality.
d) Reducing the impacts of visitation
The State Party acknowledges that continued pressures from high visitor use are a recurring issue. To partly address this, a sustainability programme aimed at reducing the impacts of both visitation and park operations is being implemented, and visitor numbers and impacts continue to be assessed, including winter visitation and the effects of snowmobiles. The sustainability programme, titled Yellowstone Environmental Stewardship (YES), complements the park’s environmental management programme and should help further reduce its ecological footprint. The State Party notes that visitor numbers have stabilised between 2.8 and 3.1 million per year. Concerning winter visitation and the effects of snowmobiles, the State Party recalls that for the past five years, a managed winter use programme has been in place. Snowmobiles continue to be prohibited off roads, must use Best Available Technology (which reduces their emissions by 70-90%), and the number of snowmobile groups and snow coaches has remained constant. The State Party further notes that snowmobiles and snow coach impacts are fairly similar and that they cause few known impacts on bison and elk. An interim winter plan has been completed to guide use during the 2009-2010 and 2010-2011 seasons.
The World Heritage Centre and IUCN note the State Party efforts to manage the large number of visitors to the property. They recommend that the State Party continue to monitor the impacts of visitor use, in particular winter visitation and snowmobiles, and adapt the Yellowstone Environmental Stewardship programme and the winter use plans accordingly.
e) Other conservation issues of concern – the potential decline of wolf populations
IUCN has received reports from NGOs that recent delisting of wolves in Idaho and Montana, which has led to the first public hunting of wolves in decades, has resulted in the shooting of the Cottonwood Yellowstone wolf pack after it left the boundaries of the property. Given that the Yellowstone wolf population’s long-term survival depends on its connection to populations in central Idaho and northwest Montana, the World Heritage Centre and IUCN recommends that the State Party consider how public hunting of wolves in neighbouring public and private land may impact wolf population within Yellowstone National Park and ensure that the Yellowstone wolf population remains stable.