Archive | March, 2014

Conservation Implications for Delimiting Species

Historically, wolves roamed across North America, from coast to coast and Alaska to Mexico. But an aggressive campaign of hunting and trapping in the early 1900s left wolves in very few places where they once lived. Conservationists, scientists, and managers working to recover wolves today face a difficult task: combining historical records, the present-day distribution of wolves, and genetic analyses to determine the kinds of wolves that once lived in different parts of the U.S. This problem is particularly evident in places like New England where wolves were once abundant but are not found today. Occasional interbreeding between wolves, coyotes, and even dogs blurs the boundaries between species and only adds to the challenge.

Biologists now recognize several distinct subspecies of gray wolf (Canis lupus), each of which is adapted to life in a different region of North America. For example there is the lobo of the southwest (C. l. baileyi) and the snow wolf (C. l. arctos) of the arctic tundra. The assortment of gray wolf subspecies also includes a northeastern variety – the so-called “eastern wolf” or Canis lupus lycaon – that was once found throughout the forests of eastern Canada and New England. These eastern wolves are smaller than their western and northern cousins, likely enabling them to efficiently hunt small prey. But not everyone agrees with this assessment. Recently the U.S. Fish and Wildlife Service (Service) argued that the eastern wolf is instead a unique wolf species, dubbed Canis lycaon. The Service contends that eastern wolves are actually more akin to coyotes than to gray wolves, and that gray wolves never lived in the east. But a recent peer review of this science showed that this is not the majority view among biologists.

Are eastern wolves a full species or just a distinct population or subspecies of one of these other canids? Several genetic studies have tried to tackle this question, but the results so far are conflicting. Studies based on DNA that wolf pups inherit from only their mother (and not their father) suggested that eastern wolves may be a distinct species. However, other evidence including an excellent study based on over 48,000 different “markers” (parts of the genome used to tell individuals apart) found that eastern wolves are the result of gray wolf and coyote interbreeding. This hybridization between wolves and coyotes likely began about 600 to 900 years ago and resulted in eastern canids that are about 85% gray wolf and 15% coyote today. Therefore eastern wolves could be a distinct subspecies, a distinct species, or even a group of gray wolf and coyote hybrids. Although the science remains unsettled, most wolf taxonomists and the American Society of Mammalogists disagree with the Service’s position that the eastern wolves and gray wolves are different species.

While the identity of eastern wolves may seem like a mere disagreement among biologists, the issue turns out to have major conservation ramifications. The Service currently plans to strip gray wolves of their endangered species protections throughout most of the country, including in New England. Although no wolves have been found in New England recently, large areas of excellent wolf habitat remain, especially in Maine. But the Service claims that gray wolves (C. lupus) never lived in New England; they say it was eastern wolves (C. lycaon), a new species with no current legal protections. With some taxonomic sleight of hand, the Service cut out the northeast from the historical range of gray wolves, and made it easier for endangered species protections to be removed everywhere. Divide – then conquer.

As you might imagine, the Service’s plan has received considerable criticism. The delisting plan ignores much of the available science and is not the consensus of biologists. As the peer review panel pointed out, even if eastern wolves are a distinct species, gray wolves may have once roamed New England too. Therefore more time is needed – for scientists to sort out the taxonomy of wolves, and for gray wolf populations to recover across their former range – before protections for wolves are removed.

 

Dan Thornhill, Ph.D.

Conservation Scientist

Posted in ESA, Imperiled Wildlife0 Comments

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Earthworm Invasions: Here’s Something to Make us Squirm

An astounding sixty of the 182 total species of earthworms that occur in the United States and Canada come from other lands. Not all of these foreign earthworms are destructive, but about 16 European and Asian varieties do real damage to our native ecosystems. During the Wisconsonian glaciation, native earthworms in North America were severely impacted by the ice sheets then covering much of the continent. In areas north of this glacial boundary, the absence or lowered populations of native earthworms later facilitated the spread of the exotic invaders.

Invasive, exotic species are recognized as a leading cause in species’ declines and extinctions. Exotic species tend conjure up the most conspicuous instances, for example, pythons invading the Everglades or lionfish in the Florida Keys and Caribbean. On a more subtle level, exotic plants and animals often compete with native species and change entire ecosystems, such as when multiflora rose take over wetlands inhabited by bog turtles. Introduced earthworms probably do not even come to mind as an exotic nuisance. Nevertheless, earthworm invasions and their ability to damage ecosystems have become a global problem. Invasive worms have now spread through almost every habitat, including desert oases. Except for Antarctica, they occur on every continent and many oceanic islands.

Usually out of sight, all worms tend to look more or less the same. And earthworms would seem to be a good thing. Gardeners, composters, fishermen, students needing specimens for dissection, and robins feeding young certainly think of worms in positive terms. The role that earthworms play in building and aerating soils is well known. In the early 1880s Darwin demonstrated that worms on just one acre of land could convert living and dead vegetation into 18 tons of productive soil in just twelve months.

Earthworm invasions have depleted herbaceous plants and seedlings, the litter layer, and led to patches of bare soil in this Wisconsin forest. Photo by Scott Loss

Earthworm invasions have depleted herbaceous plants and seedlings, the litter layer, and led to patches of bare soil in this Wisconsin forest. Photo by Scott Loss, Smithsonian Magazine

Under normal conditions it takes microbes and fungi three to five years to decompose a deciduous leaf to the point that it becomes incorporated into the soil. In a forest infested with introduced night crawlers, however, this process takes as little as four weeks. Although organic duff covering a forest floor may take decades to accumulate, duff can be consumed by introduced earthworms in short order. Accumulation of undecayed and decaying litter is an important feature of temperate forest ecosystems. Exotic earthworms decompose this leaf layer more rapidly than their native counterparts, compromising this micro-habitat on the forest floor. Conditions become unsuitable for seed germination and the various creatures dependent on leaf layer for foraging, humidity, and concealment. In addition, the levels of moisture, temperature, pH, and nutrient levels change substantially. Eventually, this redistribution of organic matter and nutrient loss results in declines in native understory plant cover and an increase in nonnative plants. Soils are often exposed as every leaf, small seed, and tiny twig is devoured by the highly-efficient introduced worms. Soil exposure can then lead to erosion.

Many of the harmful invasive earthworms in the United States arrived in the 18th century. They were accidentally introduced in soil surrounding bulbs and rootstocks of plants brought to the New World by Europeans wanting familiar species for gardens and landscaping. In more recent times, additional species of worms were introduced from Europe and Asia, and cultured on worm farms for use as fish bait. The annual global export of earthworms is a multimillion-dollar business. Unlike many of our native species, these exotic worms are tolerant of disturbed habitats and have high reproductive rates.

Invasions of non-indigenous worms harm woodland wildlife. Worms alter the habitat used by ground roosting bats, ground foraging birds, terrestrial salamanders, and invertebrates that inhabit leaf litter. In addition, changes in leaf litter result in loss of mycorrhizal fungi, thereby paving the way for exotic plants. Because most of our native understory requires a deep, rich, and fertile layer of leaf litter for germination, these invasive earthworms threaten woodland ferns and spring wildflowers like bellworts, trilliums, yellow violets and wild ginger. Invasive earthworms have already denuded forests in the Great Lakes. It’s enough to make you squirm…

David S. Lee

Guest blogger

The Tortoise Reserve, White Lake, NC

 

J. Christopher Haney, Ph.D.

Chief scientist

Defenders of Wildlife

Posted in private lands, Public Lands0 Comments

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Failing Report Card on Federal Efforts to Conserve Sage-grouse

Ranging over ten western states, greater sage-grouse have lost nearly half their original habitat, and their populations have experienced long-term declines. In 2010, the U.S. Fish and Wildlife Service determined the bird warranted protection under the Endangered Species Act – a decision that sparked concern among industries like oil and gas development and agriculture, which would prefer to use sage-grouse habitat for their own purposes. The Bureau of Land Management (BLM), and  the U.S. Forest Service as a cooperating agency, set out to improve management plans to support sage-grouse recovery before the Fish and Wildlife Service makes its formal listing decision in 2015. This new planning strategy is intended to update nearly 100 federal land use and management plans with new conservation measures for sage-grouse on 60 million acres of public land. Needless to say, given the inherent conflicts of interest, we were concerned that the needs of sage-grouse might not be prioritized in the planning process.

Today, Defenders released “In the Red: How Proposed Conservation Plans Fail to Protect Greater Sage-Grouse.” This comprehensive report documents how draft plans released under the federal National Greater Sage-grouse Planning Strategy fail to adopt conservation measures required to conserve and restore sage-grouse and their habitat.

Sage-grouse management plans, Defenders of Wildlife

The planning strategy partitions existing sage-grouse habitat up among 15 different management plans. ©Defenders of Wildlife

Greater sage-grouse are one of the best studied species in the West, and we poured over reams of published research and government and scientific reports to identify key strategies to conserve the grouse. We used these conservation measures to evaluate how well BLM’s draft plans would conserve and restore sage-grouse and their habitat.

What we found wasn’t pretty: Many of the conservation measures in the draft plans are biologically or legally inadequate, and must be improved in final plans in order to provide for the long-term conservation of sage-grouse. The plans were also markedly inconsistent, proposing dramatically different conservation measures for sage-grouse range-wide and even between adjacent planning areas. While sage-grouse occur across large landscapes, the planning process was partitioned into 15 different areas, each with its own approach to protecting sage-grouse. Dividing the habitat along these imaginary lines may be helpful from a human perspective, but not really for sage-grouse.

One measure that the BLM utterly failed to implement is designating new reserves for sage-grouse protection. Though the agency analyzed approximately 44 million acres of priority sage-grouse habitat for special designation, they only proposed to designate about 50,000 acres as reserves. This would mean that less than one percent of sage-grouse habitat would be specially protected for the species.

The good news is that federal planners have another chance to adopt effective conservation measures for sage-grouse in the final plans. In fact, most of the draft plans analyzed our key conservation measures, but simply declined to include them in their proposed management schemes. This means that the BLM doesn’t have to start over with the planning process to issue strong final plans for sage-grouse.

Federal lands are key to sage-grouse conservation and recovery. Our report includes recommendations for BLM to ensure that public lands, which contain the majority of remaining sagebrush habitat, contribute to the conservation and restoration of the species. Our recommendations to federal planners include:

  • Finalize the draft plans together in a centralized process that can more effectively address their many deficiencies and resolve their discrepancies so that the 15 final plans implement consistent, adequate, regulatory conservation measures to conserve and restore sage-grouse and their habitat.
  • Conserve essential habitat to support sage-grouse conservation and restoration, and permanently protect the most important areas as sagebrush reserves to serve as strongholds for sage-grouse and other sagebrush-dependent species.
  • Focus habitat restoration on areas most likely to improve habitat quality and connectivity to expand sage-grouse current range and reclaim parts of historic range for use by the species.
  • Account for the effects of climate change on sagebrush habitat by anticipating future habitat and species shifts and supporting habitat resilience to climate change.

Although sage-grouse may be the best-known species in the Sagebrush Sea, they are not the only species of conservation concern : more than 350 other fish, wildlife and plants in sagebrush grasslands are also at risk. Greater sage-grouse are an “umbrella species” for the landscape – by adopting the conservation measures in our report, the BLM can protect sage-grouse and benefit a host of other species dependent on sagebrush habitat. This is a once-in-a-lifetime chance to implement transformative, lasting conservation measures for an entire imperiled ecosystem. Let’s hope we get it right.

 

Posted in Federal Policy, Imperiled Wildlife, Public Lands0 Comments

Lower Klamath National Wildlife Refuge

Strategically Growing the Refuge System

The U.S. Fish and Wildlife Service recently issued a draft “Strategic Growth Policy” for the National Wildlife Refuge System.  The draft policy is intended to guide how the Fish and Wildlife Service will add lands and new wildlife refuges to the refuge system.  This policy is sorely needed and long overdue. As the Service points out in the release of the draft policy, the complexities of modern conservation and its limited budgetary resources require the Service to be strategic in all facets of conservation, particularly when making long-term investments like land protection.

As I point out in my comments on the draft policy, climate change in particular requires the Service to reevaluate its approach to land protection policies.  The National Fish, Wildlife and Plants Climate Adaptation Strategy, co-developed by the Service, states this new challenge well:

“Increasing the number, quality, and size of conservation areas can increase the opportunities for individual species to adapt to climate change, and also make it more likely that native biodiversity will be conserved. Some species’ habitat under climate change may be well outside their current or historic range. Healthy and biologically diverse ecosystems are likely to better withstand or adjust to the impacts of climate change. Increasing the number (redundancy) and distribution of protected fish, wildlife, and plant populations is important for the same reason. Establishing larger and more hospitable conservation areas for species to transition to will also increase opportunities for species to create new assemblages of species that are better able to persist in a dynamic climate.

Arctic National Wildlife Refuge. Image courtesy USFWS

Arctic National Wildlife Refuge. Image courtesy USFWS

Another challenge will be providing corridors between conservation areas so that species can freely move to new locations with suitable habitat. Protecting and restoring large blocks of habitat and using linkages and corridors to develop networks for movement will facilitate connectivity. Riparian corridors, such as floodplains, are useful as a conduit for migratory species and for providing access to water. In addition, appropriate transitory or “stopover” habitat for migratory species can promote biological connectivity between non-physically connected areas.”

The first goal of the Wildlife Adaptation Strategy emphasizes the need for identifying and conserving areas for an “ecologically-connected network” of public and private terrestrial, freshwater, coastal, and marine “conservation areas that are likely to be resilient to climate change and to support a broad range of species under changed conditions.”  In addition, the Wildlife Adaptation Strategy calls for the conservation and restoration of “ecological connections among conservation areas to facilitate fish, wildlife, and plant migration, range shifts, and other transitions caused by climate change.”  This goal was recently adopted by all the Landscape Conservation Cooperative Coordinators: “LCCs support the creation of an ecologically connected network of landscapes, as defined in the National Fish, Wildlife and Plants Climate Adaptation Strategy.”  This should be the overarching goal of the Service’s Strategic Growth Policy, identifying the refuge system’s specific role in achieving this goal across the nation with partners.

The FWS derives its authority for developing this new policy from the 1997 National Wildlife Refuge System Improvement Act which directs the Secretary of the Interior (acting through the Fish and Wildlife Service Director) to “plan and direct the continued growth of the System in a manner that is best designed to accomplish the mission of the System, to contribute to the conservation of the ecosystems of the United States, to complement efforts of States and other Federal agencies to conserve fish and wildlife and their habitats, and to increase support for the System and participation from conservation partners and the public.”

The draft policy excluded the highlighted portions of this provision.  These mandates provide critical direction directly relevant to this policy, and should be incorporated and implemented in the final policy statement.  Importantly, this provision, in its entirety, provides the legislative authorization for the refuge system to support the ecologically-connected network of conservation areas identified in the Wildlife Adaptation Strategy.  In our view, this important provision of law guides the Service to assess the entire “conservation estate” (the existing mix of federal, state, tribal, local, and private conservation lands and waters) and build upon it, focusing on those ecosystems that are not sufficiently protected by our existing conservation network.

Lower Klamath National Wildlife Refuge. Image Courtesy of USFWS

Lower Klamath National Wildlife Refuge. Image Courtesy of USFWS

The draft policy incorporates many important modern landscape-level conservation planning elements into planning for new and expanded refuges.  The policy requires land acquisition planners to explicitly identify conservation targets, look to “national, Regional, State, Landscape Conservation Cooperative (LCC), or species-specific conservation, management, or recovery plans” for science-based management objectives and to help identify priority conservation areas.  The policy also requires projects to identify vulnerability and resiliency to climate change and other stressors and “describe how the Refuge System will mitigate stressors to ensure the project’s resiliency.”  Our comments focused on improving and strengthening the provisions pertaining to these important concepts to provide clarity to refuge land protection planners and ensure they are actually implemented and operationalized to make strategic conservation investments in the refuge system.

As the only federal land system that can administratively create new units, the refuge system has a unique role to play in conserving the nation’s wildlife and ecosystems in the face of climate change, rapid development, and other landscape stressors.  The final Strategic Growth Policy for the refuge system needs to ensure that refuges play this unique role in the most effective way possible.

Posted in Federal Policy, National Wildlife Refuges, Public Lands0 Comments


dotWild is the blog of scientists and policy experts at Defenders of Wildlife, a national, nonprofit membership organization dedicated to the protection of all native animals and plants in their natural communities.

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