Why Is Canada’s Wolf Population Splitting Into Two Groups?

by Jason G. Goldman

Chester Starr of the Heiltsuk First Nation knows that the wolves of British Columbia come in two varieties: timber wolves on the mainland and coastal wolves on the islands. Genetic research has finally confirmed what Starr’s tribe has always known.

It was Starr’s “traditional ecological knowledge” that initially inspired Polish Academy of Sciences researcher Astrid V. Stronen and University of Calgary scientist Erin Navid to take a closer look at British Columbia’s wolves. They wanted to see whether the Heiltsuk Nation’s folk knowledge was reflected in the wolves’ genes.

Woolly mammoth DNA may lead to a resurrection of the ancient beast

Technical and ethical challenges abound after first hurdle of taking cells from millennia-old bodies is cleared

Even a well-preserved carcass like this baby woolly mammoth is unlikely to provide viable cells for cloning, as used to create Dolly. Photograph: Aaron Tam/Getty

By Ian Wilmut

It is unlikely that a mammoth could be cloned in the way we created Dolly the sheep, as has been proposed following the discovery of mammoth bones in northern Siberia. However, the idea prompts us to consider the feasibility of other avenues. Even if the Dolly method is not possible, there are other ways in which it would be biologically interesting to work with viable mammoth cells if they can be found.

In order for a Dolly-like clone to be born it is necessary to have females of a closely related species to provide unfertilised eggs, and, if cloned embryos are produced, to carry the pregnancies. Cloning depends on having two cells. One is an egg recovered from an animal around the time when usually she would be mated.

In reality there would be a need for not just one, but several hundred or even several thousand eggs to allow an opportunity to optimise the cloning techniques. The cloning procedure is very inefficient. After all, after several years of research with sheep eggs, Dolly was the only one to develop from 277 cloned embryos. In species in which research has continued, the typical success rate is still only around 5% at best.

Elephant eggs

Photo: Rubén Portas

In this case the suggestion is to use eggs from elephants. Because there is a danger of elephants becoming extinct it is clearly not appropriate to try to obtain 500 eggs from elephants. But there is an alternative.

There is a considerable similarity in the mechanisms that regulate function of the ovaries in different mammals. It has been shown that maturation of elephant eggs is stimulated if ovarian tissue from elephants is transplanted into mice.

In this way it might be possible to obtain a considerable number of elephant eggs over a period of time if ovarian tissue is obtained from elephants that die.

Cells from mammoths are required to provide the genetic information to control development. The suggestion is to recover cells from the marrow of bones emerging from the frozen north of Siberia. However, these cells will degenerate rapidly at the temperature of melting snow and ice. This means that cells in the bones may well become useless for this capacity as they thaw.

The chances of cells being viable would be increased if bones could be recovered from the lowest possible temperature rather than waiting until they emerge from snow. The cells can then be warmed rapidly. Alternatively, the nuclei could be transferred directly into eggs.

The very first stages of embryo development are controlled by proteins that are in the egg when it is shed by the ovary. One for example has a critical role in cell division. Together these proteins have an extraordinary ability to repair damaged nuclei so it may not be strictly necessary for the cells to be viable. It would be best if the mammoth nucleus could be introduced into an egg immediately, by injection of the contents of the damaged cell into the egg.

Research in 2008 found that when nuclei from freeze-dried sheep cells were transferred into eggs, some of the cloned embryos developed for a few days, but not to term. This was a very clear indication of the ability of the egg to repair damaged nuclei. However, freeze-dried cells are likely to be more stable than those that have been frozen with liquid still present. In the case of the mammoth, the cells would likely be killed by large ice crystals formed from the liquid.

Finally, if embryos that developed normally for a few days could be produced, they would have to be transferred to surrogate mothers to develop through pregnancy. Embryo transfer is only carried out routinely in fewer than a dozen species, and the elephant is not one of them. Success in embryo transfer depends upon introducing the embryo to a womb that is in a receptive state. The mechanisms that bring about this state in elephants are currently being defined by research in a number of zoos.

Taken together, it can be seen that there is biological uncertainty about the availability of viable cells, and that several complex techniques would have to be developed for cloning of mammoths to be successful. There is no guarantee that these techniques are even biologically possible. There may be unknown differences between species that would prevent the procedures that we developed in sheep being successful in mammoths.

Copyright: Royal BC Museum

Mammoth stem cells
An alternative ambition would be to try to use mammoth cells to produce stem cells. In several different species it is possible simply by the introduction of four selected proteins to give adult cells the characteristics of embryo stem cells. The four factors give embryo stem cells their unique characteristics and were found to be able to impose these characteristics on skin cells. This type of stem cell can be grown for very long periods in the laboratory while retaining the ability to form all of the tissues of the body.

They would provide extraordinary opportunities to compare mammoth cells with those of elephants. This knowledge would be of fundamental biological interest. It would enable us to begin to answer groundbreaking questions. What are the differences between the cells and tissues of these species? What are the similarities? The mammoth lived in a different climate, so was the metabolism of their cells different? Does this information cast any light on the cause of extinction of mammoths?

Stem cells of this type can also be induced to form gametes. If the cells were from a female, this might provide an alternative source of eggs for use in research, and perhaps in breeding, including the cloning of mammoths.

From a male, they would be sperm, and they might be able to fertilise eggs to produce a new mammoth embryo. It would be interesting to know if mammoth sperm could fertilise eggs of the elephant. If so, would the embryos develop to term to produce a hybrid animal?

Only a small proportion of mixed matings between species produces viable offspring, but the mule is one example and has been used by humans for centuries.

In all of these discussions it is necessary to consider the welfare of the animals. Mammoths lived in cold climates, whereas their current relatives including potential surrogate mothers live in warmer regions.

It would be essential to provide mother and clone with the appropriate environment of temperature, moisture and diet. It would almost certainly be necessary to keep the animals in captivity, so it would be essential to provide as interesting an environment as possible. Ideally this should include other elephants, mammoths or hybrids to provide social interaction for the animal.

So while unlikely at present, the development of some form of mammoth creature or hybrid might be possible in the longer term, the research of which could lead to major biological discoveries and advances.

This is another area of biology where studies of stem cells would be very rewarding. In stem cell research rather than cloning there would also be fewer concerns over animal welfare, or the effect of the animal on the environment. All in all, research to produce mammoth stem cells would be the appropriate choice, and extraordinarily scientifically rewarding, should it be possible to find viable mammoth cells.

Sources:

http://theconversation.com/produce-mammoth-stem-cells-says-creator-of-dolly-the-sheep-16335

http://www.theguardian.com/science/2013/jul/31/woolly-mammoth-dna-cloning

Rare Maned Lionesses Explained

Posted by Christine Dell’Amore

If it looks like a male lion and is perceived as a male lion—well, sometimes it isn’t. That’s the case of Africa’s unusual maned lionesses, which sport a male’s luxurious locks and may even fool competitors.

Though uncommon, maned lionesses have been regularly sighted in the Mombo area of Botswana‘s Okavango Delta (including the individual pictured below), where the lion population may carry a genetic disposition toward the phenomenon, according to Luke Hunter, president of the big-cat conservation group Panthera, which collaborates with National Geographic’s Big Cats Initiative. (The Society owns National Geographic News.)

Hunter said it’s possible that maned lionesses in Mombo are related—including a safari favorite named Martina, which disappeared in 2002. (Learn more about how you can see the maned lionesses at Mombo Camp.)

A maned lioness in Botswana’s Okavango Delta. Photograph courtesy Deon De Villiers.

Such masculine females likely occur when the embryo is disrupted, either at conception or while in the womb, he said by email.

“If the former case, the genetic contribution of the sperm—which determines the sex of the fetus in most mammals—was probably aberrant, giving rise to a female with some male characteristics.

“Alternatively and perhaps more likely, the problem may have occurred during gestation if the fetus was exposed to increased levels of androgens— male hormones such as testosterone.”

If a lion mother had abnormally high androgens during pregnancy, her female offspring may end up “masculinized”—a situation that occurs occasionally in people but which is rarely observed in wild animals.

A maned lioness with a fellow female. Photograph courtesy Ryan Green.

Whatever the case, such lionesses would likely be infertile but otherwise “perfectly capable” of surviving, Hunter noted. (See more lion pictures.)

In fact, their manes may actually be a boon to the pride—for instance, if the female is perceived as a male, she may better defend kills from hyenas or the pride from attacks by foreign males. In the case of the pictured female, Hunter said, it seems like she’s treated as a lioness by the rest of the pride.

“It would be interesting to know if she behaved like a male,” he added. “Two similarly aberrant Serengeti lionesses were outwardly female—they did not have manes, but were almost male-sized, and they challenged and fought unfamiliar males for territories as though they were males!”

Source: National Geographic

See comments on: http://newswatch.nationalgeographic.com/2012/10/09/weird-wild-rare-maned-lionesses-explained/

Is the Dingo Special Enough to Save?

• By LEIGH DAYTON

A startling discovery: Commonly believed to be a breed of wild dog, scientists now consider the dingo to be a species in its own right. Photo: Neil Newitt

When you look at the picture above, what do you see? A wild dog? A strangely colored wolf? Or something entirely different: a dingo? For centuries, scientists have debated whether Australia’s native canine is its own species or merely a type of wolf or dog. Now, based on physical and genetic evidence, a team of scientists is making the case that the dingo is a unique species that deserves protection under Australia’s federal conservation laws. If they can’t convince governments and landholders, the dingo may be doomed.

Wild dingoes live across Australia, in grasslands, deserts, and even wetlands and forests. Archaeological evidence suggests that the animal arrived on the continent at least 3500 years ago as people sailed back and forth from Asia, where it first appeared, then continued to evolve in isolation until the arrival of Europeans and their dogs in the late 18th century. The European naturalists who first heard descriptions of the dingo believed it represented a new species of canine and gave it a species name to match: Canis dingo. Domesticated dogs, on the other hand, are known as Canis lupus familiaris, indicating that they are a subspecies of wolf (Canis lupus).

But over the next 300 years, scientists began to argue about what to call the dingo, given the lack of early physical specimens and the fact that the original classifications were based on nothing more than a painting and description given by Australia’s first governor, Arthur Phillip. Dingoes have continued to change as they bred with settler dogs. Today, Australia’s native canine is most often referred to by scientists as C. lupus dingo, relegating it to a subspecies of wolf based on a notion that dingoes evolved from wolves in Asia. Recent studies suggest that dingoes, dogs, and wolves are cousins, all descended from a distant ancestor.

That classification left University of Sydney wildlife biologist Mathew Crowther unsatisfied, given his experience studying wild dingoes. He believed that conservation and management decisions were not being based on firm evidence. “A dingo is a distinctive thing in Australia,” identifiable by its erect ears, bushy tail, and neck that can arc backward into prime howling position, he says. Still, it’s difficult to tell a dingo from a dingo-dog hybrid, or even a feral dog, because natural variation within dingoes is poorly understood and mating with wild dogs may have altered the genome of living dingoes, Crowther explains.

Being able to define what a dingo is—and isn’t—is increasingly important in Australia. While some scientists argue that dingoes with no dog DNA fill the important niche of apex predator in Australia’s ecosystem by eating feral cats and foxes, ranchers lump dingoes, feral dogs, and dingo-dog hybrids into the category of pests that attack and kill valuable livestock. Current policies in some jurisdictions of Australia aim to exterminate dingo-dog hybrids while conserving dingoes. But without a clear definition of what distinguishes a dingo, it’s hard to manage wild dingoes, dingo-dog hybrids, and free-roaming domestic dogs, says Damian Morrant, an ecologist with James Cook University, Cairns, who was not involved in the new study. He says the work is a “baseline” for developing clear guidelines for identifying dingoes in the wild.

To begin sorting dingo from nondingo, Crowther and his colleagues at the universities of Sydney, New South Wales, and Western Sydney reviewed genetic work conducted by other researchers and began tracking down pre-1900 dingo specimens, which would allow them to study the species before it encountered—and mated with—domestic dogs brought by European settlers. “One of our colleagues went to all the European [natural history] museums: London, Paris, Germany, Oslo,” Crowther explains. The team discovered a range of coat colors on dingoes preserved in the museums: yellow, brown, ginger/red, black, and white. That indicated that these colors are not the product of recent mating with dogs, and that animals boasting them today can be considered pure dingoes.

The researchers also compared the skulls of the dingo specimens with those of wolves and similar-looking domestic dogs such as Australian cattle dogs and collies. While there were overlaps, the dingoes had wider and shorter skulls and no hind leg dewclaws, vestigial toes that don’t touch the ground, which are common among dogs and wolves, the team reported online this week in the Journal of Zoology. Based on these physical and genetic differences, the researchers propose changing the dingo’s scientific name back to Canis dingo, once again classifying it as its own species.

Given the contentious attitudes about dingoes as either top predators or pests, as well as the uncertainty among scientists about their evolutionary past, the paper will “inflame passions across the board,” says Christopher Dickman, a conservation ecologist at the University of Sydney who is not part of the team. And so it has. Although J. William Ballard, an evolutionary geneticist at the University of New South Wales in Sydney, says the study provides a “road map for the debate,” he believes the methodology is weak and the data unconvincing. Still, dingo specialists such as Christopher Johnson, a conservation biologist and ecologist at the University of Tasmania, Sandy Bay Campus, welcome the work. “It places the dingo on firmer biological ground as a distinct [group],” he says.

Crowther and his colleagues acknowledge that they’ve not yet identified “consistent and clear diagnostic features” that characterize all members of C. dingo, but they claim they’ve set limits on physical traits of the species. And for conservation and land managers that’s a start, says Euan Ritchie, an ecologist at Deakin University, Melbourne Burwood. “If it looks like a dingo, smells like a dingo, and acts like a dingo, is that enough” to count it as a dingo?

Sources:

http://news.sciencemag.org/biology/2014/03/dingo-special-enough-save

http://www.smh.com.au/environment/animals/dog-gone-scientists-confirm-the-dingo-is-a-unique-species-20140328-35onp.html#ixzz2xWWMjaAz

Access to the paper: http://onlinelibrary.wiley.com/doi/10.1111/jzo.12134/abstract

Iconic island study on its last legs: genetic rescue needed for Isle Royale’s inbred wolves

by Emma Marris

Rolf Peterson/Minneapolis Star Tribune/MCT/Newscom

Since 1958, ecologists have watched wolf and moose populations on Isle Royale in Lake Superior wax and wane in response to each other, disease and the weather. But for the longest predator–prey study in the world, the wolf is now at the door. Devastated by inbreeding, the wolf population has dropped from 30 individuals a decade ago to just 10 spotted in field counts so far this year, leading the US National Park Service to consider importing new animals for a ‘genetic rescue’.

Now, nature is intervening — and could either save the landmark project without the need for tranquillizer darts and wolf crates, or sound its death knell. As temperatures plummeted last month, Lake Superior froze for the first time in six years. The 24-kilometre ice bridge could let wolves from the Canadian mainland cross to the US island, bringing an influx of genes (see ‘Wolf island’). But project scientists say that the opposite is more likely: free to roam, the last wolves could leave the island in search of mates. 

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That would put an end to a study that has provided textbook ecology lessons for generations. It has shown how predation can structure populations of prey: when wolf numbers plummet, moose populations tend to soar (see ‘Ecosystem in flux’). And it has offered insights into wolf behaviour, moose physiology, the life cycle of moose ticks and how wolves might be driven to form packs to ward off scavengers such as ravens, rather than for any hunting advantage.

Through the decades, the search for cause and effect in the ecosystem has been rendered much easier by isolation from the mainland’s human and animal populations. Occasionally, however, Lake Superior freezes. The very first wolves came to Isle Royale over an ice bridge in the early 1940s, some 30 years after the first moose. The lake froze nearly every year at the beginning of the study, but that has changed. The most recent ice bridge was in 2008; before that, the last one was in 1997, when a wolf that biologists called ‘the old grey guy’ came to the island. He sired 34 pups and provided a rare boost of genes that doubled the population by the mid-2000s.

Whether any wolves have crossed this year’s ice bridge will not be clear immediately. The scientists are conducting their annual population survey, and are flying along the island shore in their Super Cub plane two or three times a week, but snow fills wolf tracks very quickly. If new wolves do arrive, their presence will probably be confirmed in the coming months, when DNA is extracted from faeces samples.

Source: John Vucetich/Rolf Peterson

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John Vucetich, co-leader of the project and an ecologist at Michigan Technological University in Houghton, says that the need for an influx of genes is becoming urgent. In the past two decades, wolf skeletons have displayed spinal deformities that can painfully pinch nerves and affect gait and generally reduce fitness. According to work led by Vucetich and Rolf Peterson, also an ecologist at Michigan Technological University, this might explain why the number of moose needed to support a given number of wolves has increased: the predators’ attacking efficiency may be compromised (J. Räikkönen et al. Biol. Conserv. 142, 1025–1031; 2009).

For Vucetich, genetic rescue is required not so much to maintain the continuity of the study as to preserve the ecosystem. Moose eat balsam fir trees. When the moose population expands, unchecked by predation, fewer fir seedlings can grow large enough to ‘escape’ into the canopy above the reach of moose and reproduce. There is already a missing generation of trees from between about 1910, when the moose arrived on the island, and 1940, when the wolves came. Most of Isle Royale’s balsam firs are thus either older than 100 years and near the end of their lives, or young and short enough to be browsed to death. If the trees do not achieve escape in the next decade or so, says Vucetich, “large portions of Isle Royale are not going to generate balsam fir, which is a really basic component of a boreal forest ecosystem”.

Many scientists familiar with Isle Royale support genetic rescue, especially because human activity has contributed to the current population crash. Climate change has led to the decreasing frequency of ice bridges. Canine parvovirus, probably caught from a domestic dog, caused the wolf population to fall from around 50 to 14 in the early 1980s. And in 2012, three wolves were found dead in an abandoned mining pit. Given this history of human influence, the argument that leaving the wolves alone would be allowing nature to take its course does not sway most ecologists.

David Mech, a US Geological Survey wolf biologist based in St Paul, Minnesota, argues in favour of “watchful waiting”. He says that much can be learned from studying how inbreeding affects population persistence, and that the knowledge would be useful for conservation biologists, who often need to nurture small, inbred populations of endangered species. He is not convinced that the wolves will die out; they have hit low numbers before and bounced back, he notes. And even if they do disappear, new wolves can be brought in quickly.

But Vucetich says that it could be five years before the last wolf dies and scientists confirm its demise, and another five before federal bureaucracies approve a genetic rescue and a pack develops into a predation force. He fears that a decade without significant moose predation would leave the fir trees devastated.

Phyllis Green, superintendent of the Isle Royale National Park, is considering three alternatives: doing nothing; watchful waiting followed by reintroduction if the population hits zero; or genetic rescue. She has not initiated a formal decision-making process, and will not commit to a timeline, but says that she wants to make a decision in consultation with her regional and national directors “before we run out of options”.

She is proceeding cautiously, she says, in part because of the implications of her decision. The mandate of the National Parks Service, as enshrined in a 1916 Act of Congress, is to “conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations”. Generally, this has meant a hands-off approach, but a genetic rescue could set a precedent for interventions to counteract the effects of climate change in other parks.

Green knows that many scientists are in favour of genetic rescue, but she also hears from “wilderness-oriented” advocates who urge her not to intervene. “It is one of the wicked problems,” she says.

Nature 506, 140–141 (13 February 2014) doi:10.1038/506140a

Source: http://www.nature.com/news/iconic-island-study-on-its-last-legs-1.14697

How do polar bears stay warm? Research finds an answer in their genes

New study is part of a broader genomic research program aimed at understanding what makes a polar bear a polar bear

By Charlotte Hsu

“Gene functions that had to do with nitric oxide production seemed to be more enriched in the polar bear than in the brown bears and in the black bears.

A male polar bear. Credit: U.S. Geological Survey, Steven C. Amstrup

A male polar bear walks on pack ice. Credit: U.S. Fish and Wildlife Service, Eric Regehr

A polar bear in Alaska. Credit: U.S. Fish and Wildlife Service, Steve Hillebrand

A polar bear at rest. Credit: U.S. Fish and Wildlife Service, Susanne Miller

Charlotte Lindqvist, assistant professor of biological sciences University at Buffalo led the study, which is part of a larger research program devoted to understanding how the polar bear has adapted to the harsh Arctic environment.

 In the winter, brown and black bears go into hibernation to conserve energy and keep warm.

But things are different for their Arctic relative, the polar bear. Within this high-latitude species, only pregnant females den up for the colder months.

So how do the rest survive the extreme Arctic winters?

New research points to one potential answer: genetic adaptations related to the production of nitric oxide, a compound that cells use to help convert nutrients from food into energy or heat.

In a new study, a team led by the University at Buffalo reports that genes controlling nitric oxide production in the polar bear genome contain genetic differences from comparable genes in brown and black bears.

“With all the changes in the global climate, it becomes more relevant to look into what sorts of adaptations exist in organisms that live in these high-latitude environments,” said lead researcher Charlotte Lindqvist, PhD, UB assistant professor of biological sciences.

“This study provides one little window into some of these adaptations,” she said. “Gene functions that had to do with nitric oxide production seemed to be more enriched in the polar bear than in the brown bears and black bears. There were more unique variants in polar bear genes than in those of the other species.”

The paper, titled “Polar Bears Exhibit Genome-Wide Signatures of Bioenergetic Adaptation to Life in the Arctic Environment,” appeared Feb. 6 in the journal Genome Biology and Evolution.

Co-authors include scientists from UB, Penn State University, the U.S. Geological Survey Alaska Science Center, Durham University and the University of California, Santa Cruz.

The genetic adaptations the research team saw are important because of the crucial role that nitric oxide plays in energy metabolism.

Typically, cells transform nutrients into energy. However, there is a phenomenon called adaptive or non-shivering thermogenesis, where the cells will produce heat instead of energy in response to a particular diet or environmental conditions.

Levels of nitric oxide production may be a key switch triggering how much heat or energy is produced as cells metabolize nutrients, or how much of the nutrients is stored as fat, Lindqvist said.

“At high levels, nitric oxide may inhibit energy production,” said Durham University’s Andreanna Welch, PhD, first author and a former postdoctoral researcher at UB with Lindqvist. “At more moderate levels, however, it may be more of a tinkering, where nitric oxide is involved in determining whether — and when — energy or heat is produced.”

The research is part of a larger research program devoted to understanding how the polar bear has adapted to the harsh Arctic environment, Lindqvist said.

In 2012, she and colleagues reported sequencing the genomes of multiple brown bears, black bears and polar bears.

In a paper in the Proceedings of the National Academy of Sciences, the team said comparative studies between the DNA of the three species uncovered some distinctive polar bear traits, such as genetic differences that may affect the function of proteins involved in the metabolism of fat — a process that’s very important for insulation.

In the new study, the scientists looked at the mitochondrial and nuclear genomes of 23 polar bears, three brown bears and a black bear.

The research was funded by the University at Buffalo and the National Fish and Wildlife Foundation.

 Charlotte Hsu

Media Relations Manager, Architecture, Economic Development, Sciences, Urban and Regional Planning
Tel: 716-645-4655
chsu22@buffalo.edu
Twitter: @UBScience
Pinterest: UB Science

The origin of recently established red fox populations in the contiguous United States: translocations or natural range expansions?

STATHAM, M. J., B. N. SACKS, K. B. AUBRY, J. D. PERRINE, AND S. M. WISELY

Red foxes (Vulpes vulpes) are native to boreal and western montane portions of North America but their origins are unknown in many lowland areas of the United States. Red foxes were historically absent from much of the East Coast at the time of European settlement and did not become common until the mid-1800s. Some early naturalists described an apparent southward expansion of native foxes that coincided with anthropogenic habitat changes in the region.

Alternatively, red foxes introduced from Europe during Colonial times may have become established in the east and subsequently expanded their range westward. The red fox also was absent historically from most lowland areas of the western United States. Extant populations of red foxes in those areas are considered to have arisen from intentional introductions from the east (and by extension are putatively European), escapes or releases from fur farms, or range expansions by native populations.

To test these hypotheses we compared mitochondrial DNA sequences (cytochrome band D-loop) from 110 individuals from 6 recently established populations to 327 native (primarily historical) individuals from Eurasia, Alaska, Canada, the northeastern United States, and montane areas in the western contiguous United States, and to 38 individuals from fur farms
red fox.

We found no Eurasian haplotypes in North America, but found native haplotypes in recently established populations in the southeastern United States and in parts of the western United States. Red foxes from the southeastern United States were closely related to native populations in eastern Canada and the northeastern United States, suggesting that they originated from natural range expansions, not from translocation of European lineages, as was widely believed prior to this study.

Similarly, recently established populations in the Great Basin and in western Oregon originated primarily from native populations in western montane regions, but also contained a few nonnative North American haplotypes. In contrast, populations in western Washington and southern California contained nonnative, highly admixed stock that clearly resulted from intracontinental translocations. Several common haplotypes in these populations originated in regions where fur-farm stocks originated.

Although European red foxes translocated to the eastern United States during Colonial times may have contributed genetically to extant populations in that region, our findings suggest that most of the matrilineal ancestry of eastern red foxes originated in North America.

Statham, M. J., B. N. Sacks, K. B. Aubry, J. D. Perrine, and S. M. Wisely. 2012. The origin of recently established red fox populations in the United States: translocations or natural range expansions?. Journal of Mammalogy 93(1):52-65.
Access to the original paper in pdf: http://www.fs.fed.us/pnw/pubs/journals/pnw_2012_statham001.pdf

Bitter winter, pup survival alter Isle Royale wolf debate

Article by: JOSEPHINE MARCOTTY

Healthy pups and frigid weather change the scientific debate on Isle Royale

In the upper left, the male and female alpha wolves of this pack on Isle Royale rebuke one of their new pups born last year on Isle Royale. Photo: JOHN VUCETICH,

It’s only February, and already it’s been an extraordinary winter for the wolves of Isle Royale.

At least two new healthy pups, and perhaps three, have survived their first perilous months of life — proof that the famous wolves, which number less than a dozen, may not be dwindling after all.

And twice this winter, the bitter cold that has halted shipping across Lake Superior has also created temporary ice bridges across the 20-mile channel between Isle Royale and the Minnesota-Ontario mainland, raising the tantalizing possibility that once again wolves could either leave the island or arrive on their own four feet.

Both developments are likely to only confound a precedent-setting decision that faces the National Park Service: whether to intervene in nature’s course and bring new wolves onto the island in an effort to preserve them and the critical balance between the predators and their primary prey, moose. Conservationists say the decision could establish new policy on managing critical species in national parks everywhere and even change the definition of wilderness as a place where only nature is allowed to rule.

The wolves, which once numbered as many as 50, are at their lowest ebb since researchers first began tracking them in the 1950s and are closely followed by naturalists all over the world. Scientists running the Isle Royale wolf study today, from Michigan Technological University say they fear that even with the new pups, they could die out, largely as a result of inbreeding.

At best, the new pups “might extend the amount of time the population can bump along,” said Rolf Peterson, who has been studying the wolves and moose along with John Vucetich for years.

In a series of e-mails sent from the island this week, Peterson said that even now the number of wolves is too small to keep the moose population in check and the forest ecosystem in balance. Since 2006, moose numbers have more than doubled to nearly 1,000. That’s far less than their peak of nearly 2,500 more than 30 years ago, but the rate of growth is dramatic.

The huge mammals depend on balsam firs, one of the primary species of trees on the island, as a major part of their diet. If they eat too many, then other trees would take over and, in the long run, neither wolves or moose would survive.

But other wolf experts disagree, including David Mech, a wolf expert with the U.S. Geological Survey in Minnesota. Mech said that the wolves’ population is perilously low, but that it has bounced back before, and that the pups are evidence that it can again. Many of the wolves, he said, are only now at the best age for breeding, and this year could see even more and larger litters, he said.

“Those wolves are not nonreproductive,” he said. “In another year or two they could produce some more.”

Precarious

In the meantime, scientists say they provide valuable information on reproduction, genetics and ecology. This week, the prestigious journal Nature weighed in with an editorial.

“A declining island wolf population underlines the influence that humans have on nature,” it read. It points out that the whole system is “highly artificial.” Wolves and moose have been on the island less than 100 years, and in the 1980s the wolf population was nearly wiped out by canine parvovirus, an infection likely brought to the island by someone’s pet. (Dogs are no longer allowed.)

Meanwhile, climate change — also caused by humans — is greatly reducing the chances for the ice bridges that brought wolves to the island in the first place, it said.

Once a near seasonal event, the bridges have become increasingly rare. The last one formed in 2008, when two wolves collared with tracking devices disappeared, perhaps to the mainland. The last bridge before that was in 1997, when a wolf named “Old Gray Guy” appeared on the island and went on to sire dozens of puppies, providing an infusion of new genes that researchers credit with saving the population from demise.

This year satellite images show that two bridges have formed and then been broken again by wind, the latest in early February, said Peterson.

Isabelle’s fate

Isabelle, a five-year-old female, is not attached to either of the two packs on Isle Royale. Photo: ROLF PETERSON

Meanwhile, as humans fret about the wolves’ survival and the meaning of wilderness, Isabelle waits. She is, literally, a lone wolf on Isle Royale and a prime candidate to mate with a new arrival, should one come, or take off across an ice bridge, researchers said.

Isabelle was born in 2008 to one of the two packs on the island, but, as wolves often do, left the pack in 2012 to find a mate. The pickings are few — and all the males are related to her. That inhibits mating in wolves as well as people, Peterson said.

In addition, lone wolves are vulnerable to attacks from breeding packs in the relentless competition for the right to reproduce.

Because she wears a tracking collar, the researchers have been able to follow her lonely and persecuted life. Last year they saw three other wolves chase her to the edge of the water and attack her with all the ferocity they use to bring down a 900-pound moose. They left her wounded and bleeding on the edge of the ice. When the researchers left last winter, they weren’t sure if they would see her again.

“But she has survived,” Vucetich announced on the research study’s blog in late January. “It would not be surprising if she’s learned to kill moose by herself. A wolf that can do so is better than most.”

Isabelle is now 5, a prime age to mate. About one in 10 wolves will strike off on their own and try to start new packs, and some will travel for hundreds of miles in their search. On Isle Royale, however, the wolves are trapped — unless there is an ice bridge.

No one knows what’s in the heart of a wolf, but Peterson said he thinks it’s quite possible, that given the chance, Isabelle will head out. Mech said that as long as there are potential mates on the island, she’s more likely to stay put.

The chances that a wolf would come from the mainland are also very small, researchers said. It’s known to have happened only three times in the island’s history. And today mainland wolves face a treacherous path across roads, yards and urban areas — never mind 20 miles of shifting ice.

Still, the survival of the three pups and the renewed possibility of ice bridges may have bought the National Park Service some time. Phyllis Green, park superintendent, is weighing three options: doing nothing, reintroducing wolves if their numbers hit zero or a “genetic rescue” by bringing a few new wolves to mate with those that are in residence.

Peterson and Vucetich said they favor genetic rescue. And Isabelle, if she had a vote, would likely agree.

Source: http://www.startribune.com/local/245704671.html

The Hearty Ingredients of Canis Soup

By The Dog Zombie | December 27, 2011 |

The wolf is iconic and charismatic. We see him on t-shirts, on posters, and in fantasy novels. Conservationists do battle with ranchers to preserve populations of wolves. The coyote, on the other hand, is neither iconic nor loved. A newcomer to suburbia, he is feared as a suspected predator of cats, small dogs, and even small children. He is rarely seen on t-shirts; his name is not used to designate a rank of Boy Scout.

But now that we have the genetic tools to look at these animals’ genomes, it turns out that many of the populations of coyotes in North America are actually coyote-wolf hybrids, as are many of the populations of wolves. Unable to draw clear lines between these species, biologists have dubbed the populations of hybrids “Canis soup.”

What’s a Canis?

The term “canid soup” has also been used for this mess of wolf, coyote, and even dog genes that we find in some populations of canids. So what does Canis mean, and what is a canid?

These are terms related to the scientific classification of the species in question. Going through the hierarchy, we have Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Carnivora, Family Canidae (canids), and Genus Canis. Wolves, dogs, jackals, and foxes belong to the family Canidae, but only wolves, dogs, and jackals (not foxes) belong to the genus Canis. We call the wolf-like canids “canines” and the fox-like canids “vulpines.”

As foxes do not interbreed with wolves, dogs, or jackals, what we’re talking about here is correctly Canis soup, or perhaps canine soup, but not canid soup.

Is it Canis or is it soup?

The more you dig into wild canines in North America, the more unclear it is where any species lines should be drawn. So who makes up our cast of characters?

The first ingredient in Canis soup is the charismatic North American gray wolf or timber wolf, Canis lupus, sometimes known as Canis lupus lupus to differentiate it from the dog and the dingo, who belong to subspecies. The gray wolf is the largest wild canine, at a 79 pound (36 kg) average weight. (Domestic dogs of some breeds, of course, weigh more than that.) Its coat coloring can vary from white through blond, brown, grey, and black. It is found in the western parts of North America.

Next is the Western coyote, Canis latrans. This animal is also known as the American jackal or prairie wolf, suggesting that there has been some confusion about how to distinguish canine species for some time. The Western coyote is a significantly smaller animal than the gray wolf, weighing in closer to 20 pounds (7-14 kg). Its coat color is less varied than the gray wolf’s, almost always a grey-brown as you see in the image here.

The range of the Eastern wolf or Algonquin wolf, Canis lycaon, is Ontario, Canada. This wolf is smaller than the gray wolf, and has a distinctive grey-red coat with black hairs along its back. We believe that this wolf was the original North American canine, and thatCanis lupus andCanis latransimmigrated over the land bridge from Europe. There’s a lot of debate about the species status of C. lycaon, as many Eastern wolves appear to have significant C. latrans heritage. Some people suggest that the Eastern wolf is in fact a C. lupus/C. latrans hybrid, or, alternately, a subspecies of the gray wolf, C. lupus lycaon.

The Eastern coyote, spreading along the east coast of the United States, is significantly larger than his Western counterpart. It turns out to be a coyote/wolf hybrid, and it has been argued that it should more accurately be called a coywolf. His wolf ancestors seem to beCanis lycaon —  but then again, there is debate about whether C. lycaon is really different from C. lupus at all.

The red wolf or Southeastern wolf is subject to truly intense debate about species status. Is it his own species, Canis rufus? A subset of the gray wolf, Canis lupus rufus? Or a population of Eastern wolf, Canis lycaon? It has a beautiful red coat, and is smaller in size than the gray wolf. Its range was historically the southeastern U.S., but it went extinct in the wild by 1980. A founder population of 19 animals survived in captivity, and a reintroduction project in North Carolina was begun in 1987. Here the red wolf is today enthusiastically interbreeding with coyotes, leaving conservationists to wonder what they are conserving.

The three species of wild canines in North America today, then, are Canis lupus, Canis latrans, and Canis lycaon. But we really have just two soup ingredients, wolf and coyote. There are pure wolves (Canis lupus) and there are pure coyotes (Canis latrans), and there are populations that are mixtures of more or less wolf and more or less coyote (Eastern wolves, Eastern coyotes, and red wolves). There appears to be some dog mixed in there, too. You can think of gray wolf and Western coyote as ingredients, and everything else as soup.

Coyote flavor versus wolf flavor

The 2011 paper “A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids” analyzed the various soup flavors out there and presented their findings in some easy-to-understand charts (below). Here, the different colors represent different amounts of each ingredient. The first chart describes the Eastern wolf, here referred to as the Algonquin wolf, which is mostly gray wolf (green) and joint wolf/coyote (yellow), but also has significant coyote (red). The second chart describes the red wolf; at a glance, it is obvious that the red wolf has a much larger percentage of coyote genes (again, red in this chart). These charts both use τ to denote the number of generations since the most recent admixture with another species.

The two coyote recipes pictured below describe two subpopulations of what I have described as the Eastern coyote; this particular paper considers them split into Northeastern and Southeastern coyotes. At a glance, these populations are mainly pure coyote (red), with big dashes of mixed coyote/wolf (yellow), and small but notable amounts of our friend the dog (dark blue, light blue, and pink).

Wild canine populations challenge us to let go of our obsessive need to categorize. Instead of slotting a canine population into a single species category, we might instead think of it as existing on a spectrum from “wolf-like” to “coyote-like.” A strongly wolf-like canid would be larger, sixty to ninety pounds. It would require a larger range, and would be a deerivore, subsisting off of larger game. It is likely to be a shyer animal, found only in more rural or wild areas. Conversely, a strongly coyote-like canid would be much smaller, fifteen to thirty pounds, with a smaller range. It might eat deer as well as rabbits and et cetera (probably a lot of et cetera, as coyotes are more willing to scrounge than wolves are). It would be more likely to be found in suburban areas, with a greater tolerance for human proximity. A given population of canines might fall anywhere on the spectrum between the two. The fact that a spectrum actually exists is beautifully demonstrated by the Eastern coyote, who has mixed coyote/wolf ancestry, is mid-sized between coyote and wolf, and has a mid-sized range.

What’s your preferred flavor?

Does the intermixture of various ingredients in the formation of soupy populations matter as more than a gee-whiz story? To some people, the answer is very much yes. The conservationists who are committing significant resources to the preservation of the red wolf don’t want to see the wolves that they reintroduce interbreed with coyotes. If the reintroduced wolf population blends into a coyote population, then are these resources actually being spent just to support a bunch of coyotes (who have been doing fine on their own)? At the same time, evidence shows that the founder population of 19 red wolves was already significantly coyotified, and we’re not sure how long it’s been since there have been any pure Canis rufus specimens in North America.

It is, of course, possible to think about the problem without asking for genetics to provide the complete answer for us. The red wolf is a red wolf, a beautiful, iconic animal that has lived in the southeastern United States throughout living memory. We know what the red wolf looks like (and that hasn’t been changing much, no matter what is happening to his genes). We also know that it is important in a particular environmental niche, and that hasn’t been changing much either.

Practically, the mixture of coyote genes into fragile wolf populations may be a good thing. Because coyotes are better at living on smaller ranges and in closer proximity to humans than wolves are, they are better adapted to the realities of North America today. As their genes mix into wolf populations, these populations become demonstrably more robust, more able to tolerate human presence, and able to survive on smaller ranges. It is possible, in fact, that coyote genes are exactly what are eventually going to allow a red wolf population to flourish without human assistance.

Conclusions, if we can make any

Does it matter that some of what we think of as wolves have coyote genes? I think the answer comes down to a cultural perception of the wolf as a romantic and charismatic creature, and of the coyote as a pest. Perhaps any mixture of the two is perceived as diminishing the wolf. A friend of mine once made this analogy: if you have an entire bottle of fine wine, and you pour just a teaspoon of sewage into it, now you have a bottle of sewage. Does any amount of coyote, no matter how miniscule, make the wolf impure, and less worth conserving than it was?

As a culture, I hope we can come to appreciate the strengths that the coyote brings to Canis soup, in its ability to coexist with humans in the modern world. It may be what saves populations of charismatic wolves from permanent loss. As we look at populations of canines in North America, we should learn to say that one is more coyote-like and another more wolf-like, on a spectrum from one flavor of soup to another, and appreciate the benefits of both.

Canis soup has been used before as an example of the blurriness of some species lines and the inadequacy of many existing definitions of a species, but it also provides some interesting insights into the fluidity of canid morphology and behavioral characteristics. How did something as large and wild as a wolf become something as variably-sized and tame as a dog? Moreover, how did this change happen (presumably) without a carefully planned breeding program? Why is it so easy to breed types of dogs with such different behavioral and physical characteristics, especially compared to the much more limited variety of breeds of cat, horse, or cow? The canine genome clearly has the capacity for expression across a startlingly wide array of phenotypes. The evidence of this variety has always been right before our eyes, but we are just beginning to understand its implications.

References:

· Adams J. R., Leonard J. A., Waits L. P. Widespread occurrence of a domestic dog mitochondrial DNA haplotype in southeastern US coyotes. Molecular Ecology. 2003;12:541-546.
· Adams J. R., Kelly B. T., Waits L. P. Using faecal DNA sampling and GIS to monitor hybridization between red wolves (Canis rufus) and coyotes (Canis latrans).Molecular Ecology. 2003;12:2175-2186.
· Hailer Frank, Leonard Jennifer A. Hybridization among three native North American Canis species in a region of natural sympatry. PLoS ONE. 2008;3:e3333+.
· vonHoldt Bridgett M., Pollinger John P., Earl Dent A., et al. A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids. Genome research. 2011;21:1294-1305.
· Way Jonathan G., Rutledge Linda, Wheeldon Tyler, White Bradley N. Genetic Characterization of Eastern ”Coyotes” in Eastern Massachusetts. Northeastern Naturalist. 2010;17:189-204.
· Wilson Paul J., Grewal Sonya K., Mallory Frank F., White Bradley N. Genetic Characterization of Hybrid Wolves across Ontario. Journal of Heredity. 2009;100:S80-S89.
· Zimmer Carl. What Is a Species? Sci Am. 2008;298:72-79.

Images: Gray Wolf (Image courtesy of vargklo at Wikipedia and Flickr); Western Coyote (Image courtesy of Rebecca Richardson at Wikipedia and Flickr); Eastern wolf (Image courtesy Christian Jansky at Wikipedia); Eastern coyote/coywolf (Image fromEastern Coyote Research); Red wolf (image from True Wild Life); Two recipes for wolf flavored Canis soup (vonHoldt, 2011); Two recipes for coyote flavored Canis soup (vonHoldt, 2011)

Source: http://blogs.scientificamerican.com/guest-blog/2011/12/27/the-hearty-ingredients-of-canis-soup/

No genetic flow found in two Tigrina populations leads to a new Tigrina species

Leopardus tigrinus can be found in Eastern Amazonia or the dry semi-arid Caatinga. Project Wild Cats of Brazil

A new species of wild cat in central and north-eastern Brazil has been confirmed, according to a study published today in the journal Current Biology.

This recognition formally separates the two known tigrina species (Leopardus tigrinus and Leopardus guttulus) which, until now, were regarded as one.

According to the authors of the study, Eduardo Eizirik from the Pontifical Catholic University of Rio Grande do Sul and Tatiane Trigo from the University Federal of Rio Grande do Sul, the possibility that these two wild cat populations were two distinct species was considered in the 1960s, but the hypothesis was never tested.

For the first time, scientists are able to assess the two previously-recognised subspecies using molecular markers to analyse their genetic relationship.

The results showed that the housecat-sized tigrina populations are, in fact, completely separate species.

“Our analysis showed strong genetic differentiation between the tigrina populations, with no gene flow between them, indicating that these two populations are actually reproductively isolated and should be recognised as distinct species,” said Professor Eizirik and Dr Trigo.

L. guttulus is found in southern and south-eastern Brazil. Project Wild Cats of Brazil

Click to enlarge

Data on the two tigrina species also revealed a distinct geographical distribution of both populations.

L. tigrinus, found in central and north-eastern Brazil, live primarily in open and dry vegetation (shrublands and savannahs). The southern and south-eastern Brazilian areas, occupied by L. guttulus, are dominated by denser and wetter Atlantic forest-type habitats.

Such distinct habitat conditions provide clues to their different ecological requirements and the adaptive differences that may have been responsible for their evolutionary divergence.

Hybridisation

The findings from this study also revealed the complexity of the relationships between the tigrinas and two other species of neotropical cats (commonly known as Geoffroy’s cats).

The evidence suggests that L. tigrinus’ evolutionary history includes hybridisation and movement of genes between them and the pampas cat, while extreme levels of interbreeding between L. guttulus and Geoffroy’s cats still occur along their contact zone.

Although there is no evidence that this interbreeding is expanding beyond the contact zone, it is clear that hybridisation can and does occur between distinct animal species.

Christopher Johnson, a professor of wildlife conservation from the University of Tasmania, said: “This study hints that hybridisation in the past has accelerated speciation. The acquisition of new genes by hybridisation can be a potent force in the evolution of species, and this could be a neat example where hybridisation in some parts of the range but not others has contributed to splitting of one species into two.

“We used to think that hybridisation between related species was not supposed to happen – by definition, species did not interbreed – but it’s clearly more significant than was realised.”

L. tigrinus. Project Wild Cats of Brazil

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Professor Eizirik and Dr Trigo explained that hybridisation may occur quite frequently in the initial stages of species divergence, and the species involved may hybridise for some time and maintain a hybrid zone at their region of geographic overlap.

However, this may not necessarily lead to their complete admixture or the loss of the genetic and phenotypic integrity of each parental species.

“Currently, there is a strong genetic differentiation between these two cat species in areas farther from the contact zone. Selective pressure must be keeping the two species morphologically, ecologically, and even genetically distinct outside of this contact zone.

“Therefore, at this point, it seems adequate to keep them as separate species and continue to investigate the extent and biological consequences of their hybridisation.”

Implications on conservation

Gerry Ryan, from the University of Melbourne, warned that the evidence for a recent or continuing hybrid zone between the southern tigrinas and Geoffroy’s cats will need closer investigation to determine if any conservation management actions are needed.

“The two tigrina species are listed as one on the IUCN’s Red List of Threatened Species. Now that they are considered to be separate species, they both need to be re-assessed. Each one will be at a higher risk of extinction, than when considered as one species, because smaller numbers automatically increase the risks.

“If the hybridisation is spurred by human-induced habitat alteration, then conservation management actions must be considered. But, given the already extensive gene flow, this may be too late.”

Much more is known about the southern L. guttulus than the northeastern tigrinas. Project Wild Cats of Brazil

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Hamish Campbell, from the University of Queensland, believes that the use of modern genetic techniques is crucial in determining when one species or sub-species should be declared distinct from another, particularly when it comes to managing rare and threatened species.

He explained: “This study is similar to that of the Scottish wildcat (Felis silvestris) which, using molecular techniques, was found to be breeding with feral domestic cats (Felis felis).

“Feral domestic cats are an environmental disaster, devastating native wildlife, while the Scottish wildcat is a rare and ancient species that needs to be conserved. But where do you draw the eradication line? What level of hybridisation is acceptable to declare the species a threat rather than a pest?

“Molecular techniques are helping us to map the evolutionary history of species, but how those findings are applied to the successful management of rare and threatened species is still in its infancy.”

Future studies

According to Gerry Ryan, this case study shows us how modern genetic techniques can help clarify cryptic patterns of species diversity.

“As genetics and genomics continue to advance and be cheaper and faster, we can better understand the complex and dynamic nature of species boundary. We will then need to develop parallel conservation strategies to protect the diversity of life beyond linear concepts, and allow for adaptation and evolution in the face of global climactic change.”

A close-up photo of the enigmatic L. guttulus. Project Wild Cats of Brazil

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Professor Eizirik and Dr Trigo agreed, saying: “Our study has opened new avenues for research, focusing on more in-depth evolutionary, genomic, morphological and ecological questions.

“We intend to further investigate Brazilian northeastern tigrinas which are virtually unknown with respect to most aspects of their biology. Some initial studies on its ecology (diet, feeding habits and habitat requirements) have been done, but information on its population density, habitat use and population trends remain unknown.

“There is also very little information on the ecological segregation between the two species. Thus, we consider studying L. tigrinus a priority for research and conservation actions.”

Source: http://theconversation.com/one-becomes-two-genes-show-brazilian-wild-cat-is-two-species-20793

Free access to the original scientific paper: http://www.cell.com/current-biology/retrieve/pii/S0960982213013213