Monday, February 13, 2017

Snow leopard and Himalayan wolf diets are about one-quarter livestock


Around a quarter of Himalayan snow leopard and wolf diets are livestock, the rest being wild prey, according to a study published February 8, 2017 in the open-access journal PLOS ONE by Madhu Chetri from Inland Norway University of Applied Sciences, Norway, and colleagues.

Killing livestock creates conflicts between top predators and pastoral communities, and is a main challenge for conserving snow leopards, which are endangered, and Himalayan wolves, which are rare. These wolves prefer the open grasslands and alpine meadows that are also frequented by pastoral herders, and snow leopards prefer the steep terrain associated with montane pastures. To assess prey preferences of these carnivores, Chetri and colleagues analyzed DNA and hairs in 182 snow leopard scats and 57 wolf scats collected in the Central Himalayas, Nepal.

The researchers found that in keeping with the predators' habitats, snow leopards preferred cliff-dwelling wild prey such as bharal, while wolves preferred plain-dwelling wild prey such as Tibetan gazelles. In addition, livestock comprised 27% of the snow leopard diet and 24% of the wolf diet. Livestock occurred more than twice as frequently in scats from male snow leopards than in scats from females. Although livestock constitutes a substantial proportion of the predator's diets, little is known about the actual predation impact on the pastoral communities. Hence, the researchers' forthcoming work focuses on estimating livestock mortality rates and identifying factors associated with livestock loss.

Wednesday, February 8, 2017

Brown bears reduce wolf kill rates says USU ecologist


Contrary to popular assumptions, researchers on two continents find wolves kill less often in the presence of brown bears
UTAH STATE UNIVERSITY
IMAGE
IMAGE: IN NORTH AMERICA'S YELLOWSTONE NATIONAL PARK, HUNGRY WOLVES WAIT TO ACCESS THEIR ELK KILL AS BROWN BEARS FEAST ON THE SPOILS. UTAH STATE UNIVERSITY ECOLOGIST AIMEE TALLIAN AND COLLEAGUES REPORT... view more 
CREDIT: DANIEL STAHLER, NATIONAL PARK SERVICE
LOGAN, UTAH USA - If you've ever been elbowed out of the way at the dinner table by older, stronger siblings, you'll identify with wolves competing with larger bears for food. A study by Utah State University ecologist Aimee Tallian and colleagues reveals wolves might be at more of a disadvantage than previously thought.
Tallian is lead author of a paper examining competition between wolves and brown bears on two continents published Feb. 8, 2017, in Proceedings of the Royal Society B[DOI: 10.1098/rspb.2016.2368]. 
"Wolves and brown bears coexist across most of their range," says Tallian, who completed a doctoral degree from USU in 2017. "Although competition between predators such as these is widespread in nature, we know little about how brown bears affect wolf predation."
With colleagues in Scandinavia and North America, Tallian examined how brown bears affected wolf kill rates at study sites in northern Europe and Yellowstone National Park.
"We found an unexpected pattern," she says. "Wolves killed less often in the presence of brown bears, which is contrary to the common assumption that wolves kill prey more often to compensate for loss of food to bears."
Tallian says the consistency in results between the systems on different continents suggests brown bear presence actually reduces wolf kill rate, but the researchers aren't sure why.
They surmise wolves, unlike lynx and mountain lion, may not be quickly abandoning their kills, as bears move in take advantage of the spoils.
"The wolves may be hanging around longer, waiting their turn to gain access to food," Tallian says.
She and her colleagues also wonder if wolves kill less frequently because it takes them longer to find prey.
"We think this may be the case, in the spring, when newborn ungulates make easy pickings for bears," Tallian says. "It may simply take more time for wolves to find calves, when there are fewer of them."
Interactions between apex predators can either relax or strengthen their effect on prey and predator populations, she says.
"The team's results suggest that ignoring such interactions may underestimate the effect competition between predators can have on predator populations," Tallian says. "In addition, it's possible to overestimate the impact of multiple predators on prey populations."

Saturday, January 28, 2017

Machu Picchu in Peru is home to a biologically important species: the Andean bear


A recent wildlife survey led by SERNANP (Servicio Nacional de Áreas Naturales Protegidas por el Estado) and WCS (Wildlife Conservation Society) in the Historic Sanctuary of Machu Picchu in Peru has confirmed that the world-famous site is also home to a biologically important and iconic species: the Andean bear (Tremarctos ornatus).
Funded by the Andean Bear Conservation Alliance, the U.S. Agency for International Development, and the Gordon and Betty Moore Foundation, the year-long survey revealed the presence of Andean bears in more than 95 percent of the 368-square-kilometer study area, which includes the famous Incan ruins of Machu Picchu, one of the most visited places in South America. While it was previously known that Andean bears existed in the sanctuary, the new survey's findings reveal a much wider presence of bears throughout the protected area.
The Historic Sanctuary of Machu Picchu is classified as a World Heritage site by UNESCO (the United Nations Educational, Scientific, and Cultural Organization) and is one of only 35 sites worldwide listed as a mixed natural and cultural site. The findings from this survey are critical for establishing a baseline for future assessments and to plan for the long-term conservation of Andean bears both within and beyond the sanctuary.
"It is amazing that this world famous location is also important habitat for Andean bears," said Dr. Isaac Goldstein, Coordinator of WCS's Andean Bear Program. "The results of the survey will help us to understand the needs of this species and how to manage Andean bears in this location."
With a range stretching from Venezuela to Bolivia, the Andean bear inhabits the mist-shrouded montane forests and upland grasslands of the Andes Mountains and is South America's only native bear species. The Andean bear is sometimes called the spectacled bear due to yellowish or white patches that surround its eyes. The species features prominently in the cultural fabric of the region, yet much is still unknown about the behavior and ecology of the Andean bear.
The survey results also show that the Andean bears of Machu Picchu are not an isolated population, but part of a much larger population connected by montane grasslands that occur over an elevation of 3,400 meters (more than 11,000 feet above sea level). Understanding this connectivity will help wildlife managers to maintain the corridors needed for healthy bear populations. The survey itself is part of a larger effort by SERNANP and its partners to monitor Andean bears across the Machupicchu-Choquequirao Landscape, a large mountainous region containing both archeological sites and natural areas.
Fieldwork to collect data on the presence of Andean bears in the Historic Sanctuary of Machu Picchu was conducted between August 2014 and September 2015. A team of more than 30 trained researchers and park officials looked for signs of bears in a variety of habitats in the Machu Picchu protected area, ranging from Andean rainforest to montane grasslands. The study area was divided into sections 16 square kilometers in size (more than 6 square miles, the typical size of a female Andean bear's range) to evaluate the bear's presence in the protected area. Researchers looked for bear activity such as scat, footprints, and signs of feeding on terrestrial bromeliads (plants native to tropical and subtropical regions) along 166 kilometers (more than 100 miles) of transects throughout the sanctuary.
In addition to finding signs of bears in most of the sanctuary, the research team also determined that the presence of cattle is a potential risk to Andean bears in the sanctuary. The survey results will help inform the effective management of the Historic Sanctuary of Machu Picchu, the most visited protected area in Peru.
WCS has contributed to extensive research on the ecological needs of the Andean bear throughout its range. In 2014, WCS published the document "Andean Bear Priority Conservation Units in Bolivia and Peru" that consolidated information from 25 Andean bear experts on the distribution of the species and recommendations for conservation. In the U.S., WCS's Queens Zoo is home to the only Andean bear exhibit in New York City. Queens Zoo Director and Curator Scott Silver serves as Coordinator for the Andean Bear Species Survival Plan (SSP), a cooperative breeding program administered by the Association of Zoos and Aquariums that ensures genetic variability within accredited zoo populations.

The Eurasian grey wolf, Canis lupus lupus, has spread across Germany


Since the year 2000, the Eurasian grey wolf, Canis lupus lupus, has spread across Germany. For Ines Lesniak, doctoral student at the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW), and her colleagues, a good reason to have a closer look at the small "occupants" of this returnee and to ask the question whether the number and species of parasites change with an increasing wolf population. This was the case, because the number of parasite species per individual wolf increased as the wolf population expanded. Furthermore, cubs had a higher diversity of parasite species than older animals. The good news: wolf parasites do not pose a threat to human health. The results of this study were published in the scientific online journal "Scientific Reports" of the Nature Publishing Group.
In the course of a long-term study of wolf health in Germany, the internal organs of 53 wolf carcasses were studied in detail. They came from wolves which had died in traffic accidents or were illegally killed between 2007 and 2014.
"Whereas tapeworms are recognisable with the naked eye, the identification of single-celled Sarcocystis parasites was a real challenge, since the species of this genus do not differ morphologically," explains Lesniak.
According to their developmental cycle, endoparasites can be grouped into two types: Some, such as many tapeworms, infect their hosts directly. Others, such as Sarcocystis parasites, first live in an intermediate host, the prey animal of the wolf, and reach their final host, the wolf, only if the intermediate host has been consumed by the final host. With the faeces of the final host, these parasites are released back into the environment. Potential prey animals of the wolf feed then on vegetation that was previously contaminated with the parasites. The parasites thereby invade the intermediate host and settle in the muscle flesh. Roe deer, red deer and wild boar are such intermediate hosts in central Europe. When these are eaten by a wolf, the parasites infect the final host -- the wolf -- and reproduce in its intestines.
By applying sophisticated molecular genetic analyses, the scientists identified 12 Sarcocystis species in the wolf carcasses. They also found four tapeworm species (cestodes), eight roundworm species (nematodes) as well as one fluke species (trematode). In order to examine parasite infections also in the wolf's large prey species, the team collected internal organs of shot prey animals from hunting parties.
In Germany, wolves mainly feed on roe deer, but also red deer and wild boars. Small mammals, such as hares, voles or mice, are very seldom "on the menu." The identified parasites provide indirect evidence for this insight, since fox tapeworms were found in only one of the 53 wolves. Fox tapeworms are transmitted by mice and can occur in all canids, but particularly frequently in foxes. "Good news," Lesniak says, because the larvae of fox tapeworms can cause severe diseases in humans.
The scientists found that the infestation of wolves with parasites varied during their lifetime. "Cubs carry many more parasite species than yearlings or adults." According to Ines Lesniak, such variation in parasite species prevalence can be explained by the more robust immune system of older wolves. Wolves, just like any other wild canid -- other than domestic dogs -- are never dewormed, after all.
Wolves that died at the beginning of the study period had a lower parasite diversity than those who died later. "The bigger the population, the more often wolves are in contact with each other and their prey, and the more often they became infected with different parasites," Lesniak summarises the results.
Currently, there are 46 wolf packs settled within Germany. A pack consists of the parents as well as the cubs of the current and the previous year and can comprise up to ten individuals. "Genetic analyses conducted by our cooperation partners for this study show that the ancestors of the Central European lowland population, which nowadays ranges from Germany to Poland, originated from Lusatia in eastern Germany," Lesniak says. This population was probably initiated by individuals who migrated from the Baltic region at the beginning of the millennium and settled between southern Brandenburg and northern Saxony. From there, they began to spread across northeastern Germany and southwestern Poland, a process which continues to this day.
"Wolves are shy, wild animals. Thus, contact between people and wolves is rare," Lesniak emphasises. "Nevertheless, hunters should boil the leftovers of shot game thoroughly before feeding this to their hunting dogs, in order to avoid possible parasite infections," warns Lesniak. It is also essential to regularly deworm hunting dogs in regions occupied by wolves.
Occasionally, it has been reported that wolves come closer to residential areas; sheep farmers are complaining about losses. "It may well be that today's wolves have learnt that it is easier to find food closer to humans -- those, who once eradicated their wolf forefathers" presumes Lesniak. Of course, it is more convenient for a wolf to break into a sheep enclosure than to chase roe deer in the forest. Therefore, the implementation of appropriate protective measures of domestic animals is very important and now also financially supported by the government in Germany.

Wednesday, January 18, 2017

Tigers could roam again in Central Asia


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IMAGE: THIS IS AN ARTIST'S DEPICTION OF A CASPIAN TIGER. view more 
CREDIT: HEPTNER AND SLUDSKIY 1972
Caspian tigers, some of the largest cats that ever lived -- up to 10 feet long and weighing more than 300 pounds -- met a grim end in the middle of the 20th century. 
Until the mid-1960s when they were designated as extinct, they ranged from modern-day Turkey through much of Central Asia, including Iran and Iraq, to northwestern China. The reasons for their extermination are many: poisoning and trapping were promoted by bounties paid in the former Soviet Union until the 1930s; irrigation projects during the Soviet era destroyed the tugay woodlands (a riparian and coastal ecosystem of trees, shrubs and wetlands) and reed thickets that were critical tiger habitat; and the cats' prey disappeared as the riparian habitat vanished. 
But there is a chance that tigers -- using a subspecies that is nearly identical, genetically, to the extinct Caspian -- could be restored to Central Asia.
A study published online in the journal Biological Conservation lays out the options for restoring tigers to Central Asia and identifies a promising site in Kazakhstan that could support a population of nearly 100 tigers within 50 years.
"The territory of the Caspian tiger was vast," said Professor James Gibbs, a member of the research team and a conservation biologist who is director of the Roosevelt Wild Life Station at the College of Environmental Science and Forestry (ESF) in Syracuse, New York. "When they disappeared, the number of nations that hosted tiger populations was reduced by more than half." 
The researchers say introducing tigers in a couple of locations in Kazakhstan won't make a widespread difference immediately but it would be an important first step.
"The idea of tiger reintroduction in Central Asia using the Amur tiger from the Russian Far East as an 'analog' species has been discussed for nearly 10 years. It met with considerable support from the government of Kazakhstan in 2010 during the Global Tiger Forum in St. Petersburg, Russia," said Mikhail Paltsyn, an ESF doctoral candidate who oversaw analytical aspects of the study. 
"But the program needed a strong scientific foundation to evaluate the full habitat potential for tigers and to better explore different possible outcomes of the reintroduction in different scenarios," Paltsyn said. 
In addition to Paltsyn and Gibbs, the research team includes ESF scientists Liza Yegorova, a recent master's graduate; Dr. Igor Chestin, director of WWF-Russia; and Dr. Olga Pereladova, director of WWF Central Asia Program. Paltsyn is a member of the International Union for Conservation of Nature Cat Specialist Group and has served as a consultant with the World Wide Fund for Nature (WWF) and United Nations Development Programme.
The scientists say two factors have combined to raise the possibility of restoring tigers to the Ili-Balkhash region of western Kazakhstan:
    * The breakup of the Soviet Union and introduction of market economies in newly established states has led to the recovery of tiger habitats in some areas as state-sponsored agricultural programs along rivers were abandoned.
    * Recent work in phylogenetics (the study of evolutionary history) indicates Caspian tigers were closely related to Amur tigers that still exist, making Amur tigers a likely "analog" species for restoration of tigers to the region. 
But Paltsyn laid out the challenges that would need to be addressed before tigers start roaming the landscape again. 
"First, it is necessary to stop riparian zone degradation caused by uncontrolled fires. Second, it is vital to restore wild ungulate (broadly defined as a hoofed mammal) populations in the area. That, alone, could take five to 15 years," Paltsyn said. "Third, human safety and socio-economic benefits for local populations need to be addressed to provide a sustainable future for both tigers and people. And, finally, water consumption from the Ili River needs to be regulated in both Kazakhstan and China to support sufficient water level in Balkash Lake for tugay and reed ecosystems - the main tiger habitat. However, WWF and the government of Kazakhstan seem to be ready to deal with all these difficult issues to bring tigers back to Central Asia." 
Tiger reintroduction has support from the Kazakhstan government and local communities because of potential economic benefit from wildlife tourism, small-business growth and employment opportunities at Ili-Balkhash Nature Reserve.
In the study, the researchers analyzed scientific literature that revealed Caspian tigers once lived in an area about 800,000 to 900,000 square kilometers in size (between 300,000 and 350,000 square miles), mostly within isolated patches of riparian ecosystems (land along rivers or streams). Generally, two or three tigers occupied an area that covered about 100 square kilometers (about 40 square miles).
Spatial analyses based on remote sensing data indicated that options for Amur tiger introduction are limited in Central Asia. But at least two habitat patches are potentially suitable for tiger re-establishment, both in Kazakhstan. When the researchers considered current land use and the low density of the local human population, they found the most promising site is the Ili River delta and adjacent southern coast of Balkhash Lake. The river flows from northwestern China into southeastern Kazakhstan; it drains into Balkhash Lake, the 15th largest lake in the world. 
The team identified about 7,000 square kilometers (about 2,700 square miles) of suitable habitat. Population models for animals that tigers typically prey on -- wild boar, Bukhara deer and roe deer -- suggest the area could support a population of between 64 and 98 tigers within 50 years if 40 to 55 tigers are introduced. 
The Amur tiger is apparently the only subspecies that has significantly increased in number in the last 65 years. Scientists estimate some 520 to 540 still live in the wild. Moving some of them from the Russian Far East to the Ili River delta could be enough to eventually establish a wild population in 50 years, and would not harm the Russian population, the study says.
Around the world, similar relocation programs have worked for cat populations. The study says: "... case studies suggest high adaptive potential of big cats to novel environments. We know of no large cat translocation programs that failed strictly due to maladaptation of source population to environment of release."


Wednesday, July 27, 2016

Arguments for removing gray wolves from endangered species protection are incorrect


Researchers from Princeton University and the University of California-Los Angeles who investigated the genetic ancestry of North America's wild canines have concluded that the U.S. Fish and Wildlife Service's scientific arguments for removing gray wolves from endangered species protection are incorrect.
The study, which contradicts conventional thinking, finds that all of the continent's canids diverged from a common ancestor relatively recently and that eastern and red wolves are not evolutionarily distinct species but a hybrid of gray wolf and coyote ancestry. The study will appear in the journal Science Advances.
Gray wolves once ranged across much of the United States but were hunted to near-extinction in the late 1800s and early 1900s. In 1973, the U.S. Fish and Wildlife Service listed the gray wolf under the Endangered Species Act, in part, because its geographic range once included the Great Lakes region and 29 eastern states. Since then, gray wolves have rebounded due to protections, reintroduction and natural repopulation, making wolf recovery in the West one of the most successful efforts under the ESA. Gray wolves also still live in the Great lakes area but not in the 29 eastern states. The red wolf also was protected under the ESA as a distinct species in 1973, but the eastern wolf, which was only recently recognized as a distinct species, is not protected.
The Fish and Wildlife Service will decide this fall whether to remove the gray wolf from protection, drawing renewed attention to the conflict between conservationists, ranchers, hunters and others who see the iconic predator either as a threat or as part of a healthy ecosystem. The agency says the gray wolf should be delisted because the eastern wolf - not the gray wolf - lived in the Great Lakes region and eastern states. Essentially, the presence of the eastern wolf, rather than the gray wolf, in the eastern United States would cause the gray wolf's original listing to be annulled. With the exception of the Mexican wolf, the gray wolf would lose protection from its entire North American range under the proposed rule change.
In their new study, lead author Bridgett vonHoldt, an assistant professor in ecology and evolutionary biology at Princeton, and her colleagues analyzed the complete genomes of 12 pure gray wolves (from areas where there are no coyotes), three pure coyotes (from areas where there are no gray wolves), six eastern wolves (which the researchers call Great Lakes wolves) and three red wolves.
Results showed that eastern and red wolves are not evolutionary distinct species but the result of a relatively recent interbreeding: Eastern wolves are about 75 percent gray wolf and 25 percent coyote, while red wolves are about 25 percent gray wolf and 75 percent coyote.
"We found no evidence for an eastern or red wolf that has a separate evolutionary legacy," vonHoldt says. "These results suggest that arguments for delisting the gray wolf are not valid."
The researchers also conclude that the ESA should protect hybrid species because interbreeding in the wild, thought to be uncommon when the ESA was passed in 1973, has been shown to be common and may not be harmful.
"Our findings demonstrate how a strict designation of a species under the ESA that does not consider genetic admixture can threaten the protection of endangered species," vonHoldt says. "We argue for a more balanced approach that focuses on the ecological context of genetic admixture and allows for evolutionary processes to potentially restore historical patterns of genetic variation."