Only one mountain lion has been known to successfully make it across California’s Interstate 15 from the east side to the west since 2001. The sole male animal, known as M86, may have been the genetic savior for the entire population in the Santa Ana Mountains, at least for now.

According to a study published recently in PLOS ONE, human-related incidents account for more than half of mountain lion (Puma concolor) deaths in the study’s range in southern California. The overall annual survival rate for this population of mountain lions — also known as cougars or pumas — was abnormally low at about 56 percent, despite being considered “specially protected” in the state. In fact, most states that allow recreational hunting of the animals have higher survival rates than the ones observed in the study, according to lead author and TWS member T. Winston Vickers.

The thirteen-year study began as a way to measure the impacts of mountain lions on the endangered peninsular bighorn sheep (Ovis canadensis nelsoni). Over time, the researchers became increasingly concerned with some of the trends they were noticing, so they began to analyze both demographic genetics and survival rates of mountain lions in the Peninsular Mountain Ranges and Santa Anas, a subset of the Peninsulars.

“Our data started suggesting, part way through the study, that the mortality rates or the survival rates were probably lower than we would’ve expected,” said Vickers, an associate veterinarian for the Wildlife Health Center at University of California, Davis. Also alarming, he says, was the fact that most of the deaths were caused by humans. Data gathered during the study proved that in this region, vehicle collisions are the leading cause of death for mountain lions, followed by deaths secondary to depredation permits. Other causes of death included human-induced wildfires, illegal shootings and public safety removals. “We would’ve expected some human induced mortality…but we were surprised to see the vehicle mortalities be so high and even higher than the depredation permits.”

When examined closely, the low survival rates and increasing human-mountain lion conflict can be traced back to one underlying cause: habitat fragmentation.

Habitat fragmentation, as defined by eLS, is “the process by which habitat loss results in the division of large, continuous habitats into smaller more isolated remnants.” Southern California, Vickers explains, has developed in a somewhat sprawling way, leaving finger-like protrusions in the landscape. The primary fragmenting factors for mountain lions in this area are agricultural, human housing development and especially road and highway infrastructure.

Camera traps set up at known or potential highway crossings and telemetry data revealed that it is nearly impossible for mountain lions to cross I-15, essentially cutting off the small Santa Ana population from the rest of the Peninsular Ranges. In busy, high-traffic areas, wildlife passageways are few and far between, and even where there are passageways, animals tend to turn away without crossing. Studies of other animals suggest that wildlife may be affected by sensory factors such as light and sound. Although this is not confirmed in mountain lions, researchers are attempting to learn more about those factors. Lower traffic areas may be more accessible, but could also be far riskier as animals misjudge fast-moving vehicles and end up getting hit.

Had it not been for M86, the gene pool in the Santa Anas might have deteriorated to the point of no return. M86 produced several offspring, one of which, a female, is still alive and now has two offspring of her own. Although one animal may not seem like a lot, his impact can be significant. A similar story about a male mountain lion crossing U.S. Route 101 in the Santa Monica Mountains showed that one animal can make a noticeable difference in the genetic makeup of a small population. Ironically, M86 is believed to have been killed in a vehicle collision.

Vickers says that there are ongoing efforts to create and preserve undeveloped corridors connecting larger habitat areas. Connectivity and natural translocation are the preferred method of mountain lion conservation in southern California, of course, but relocation of genetically unique animals into the population is also being looked at. Relocation was successful for the critically endangered Florida panther when the U.S. Fish and Wildlife Service brought in eight cougars from Texas to spread new genes through the population. Fencing around highways is another strategy that California has adopted from Florida.

“The lesson is look decades down the road…” Vickers said. “There are a lot of efforts still to build and secure more corridors and more land. But the challenges are significant once the land is broken up into smaller parcels.”

Over the past five years, legislation introduced by Congress regarding the Endangered Species Act (ESA) has increased by 600%. Revising the 40-year-old ESA has become a priority for Chairman Rob Bishop (R-UT) and Ranking Member Raúl Grijalva (D-AZ) of the House Natural Resources Committee, who both intend to propose bills updating the act.

H.R. 2109: Endangered Species Litigation Reasonableness Act

The Endangered Species Litigation Reasonableness Act (H.R. 2109) was introduced by Representative Bill Huizenga (R-MI) and referred to the House Natural Resource Committee on April 29. The legislation would alter the court’s ability to award financial reimbursement for the costs of litigation brought forth through the ESA. As it currently stands, courts may award reimbursement to both defendants and plaintiffs in any amount which the court determines as appropriate. The bill would instead have courts only issue reimbursements to the prevailing party. The bill would also cap the reimbursement amount for attorney fees at $125 per hour to be consistent with the Equal Access to Justice Act.

Congressman Huizenga stated when he first introduced the bill in 2014 (H.R. 4318) that “[i]n times of tight fiscal budgets and escalating national debt, taxpayer dollars should be prioritized for the protection and recovery of species. The Endangered Species Litigation Reasonableness Act makes the ESA consistent with current law by placing a $125 cap on the hourly rate of taxpayer-funded fees that may be awarded to attorneys that prevail in ESA cases. This bill makes government more efficient and more effective, by helping focus ESA resources towards species protection and recovery instead of filling the pockets of lawyers.”

Defenders of Wildlife staunchly opposed the bill when it was originally introduced. Defenders claimed the bill sought to prevent citizens from enforcing the ESA on government and industry projects by restricting their ability to recover their litigation costs when they prevailed in court. Defenders asserted the reimbursement cap would make it difficult for citizens to retain counsel as that cap fell below market rates for attorneys.

S. 293: Endangered Species Act Settlement Reform Act

The Endangered Species Act Settlement Reform Act was introduced by Senator John Cornyn (R-TX) with the goal of giving states and other affected parties a voice in settlement processes regarding ESA listing decisions. The bill requires the Secretary of the Interior to provide notice of a proposed settlement to each state and county in which a species involved in the settlement is found. Each state and county must then approve the settlement for it to proceed.

s. 293 would also modify which parties the court may award costs of litigation. Courts would only be able to award reimbursement to defendants after a settlement. If the settlement is a “consent decree”, where neither party admits liability, then both the plaintiff and the defendant would not receive reimbursement.

A consortium of petroleum industry members wrote a letter to Senator Cornyn supporting S. 293. The letter states the bill will improve the framework of the ESA by increasing transparency and accountability during settlement negotiations. They suggest that the bill would allow the Fish and Wildlife Service to properly prioritize their work without being entangled in litigation that forces them to be driven by arbitrary deadlines

The Center for Biological Diversity opposes the bill, saying in a press release that the bill limits the ability of the Fish and Wildlife Service to settle cases by allowing state governments to intervene. By changing the judicial rules on which parties can intervene in lawsuits, the Center asserts the Department of Justice will be unable to settle unwinnable cases and force them to waste taxpayer resources in litigation. They suggest the resulting slowdown from litigation will cause species to be in limbo as they wait for final listing decisions.

S. 293 was referred to the Senate Committee on Environment and Public Works on January 28.

Other ESA-related Legislation

Other bills being considered cover a wide variety of topics, including requiring the Secretary of the Interior to publish online all the scientific and commercial data used as the basis for regulation; requiring the FWS to consider any data submitted by a state, tribal, or county government as the “best scientific and commercial data available”; and requiring the Secretary to consider the cumulative economic effects of listing a species and preventing listing if the effect is too great.

Along with legislation aimed at amending the ESA, many bills have been proposed focusing on the listing status of specific species, including bills to ignore the FWS rule on the Mexican wolf, remove the ‘threatened’ listing of the lesser prairie chicken, and to reissue rules regarding the gray wolf.

These bills have not garnered as much visible support as the previously mentioned bills but are currently being considered by committees in Congress.

TWS and the ESA

In 2005 TWS published a technical review of the ESA, in which solutions to improve the effectiveness of the ESA were identified, and issued its official position statement on the ESA in 2011. TWS has previously opposed Congressional provisions and amendments that aim to legislate the listing and delisting of species, such as riders in the House’s Fiscal Year 2016 National Defense Authorization Act that mandates a ten year delay in a listing decision for the greater sage-grouse.

Sources: E&E News, House Committee on Natural Resources, Center for Biological Diversity

If publicly funded space agencies such as NASA and the European Space Agency (ESA) collaborated with conservation scientists, they would probably be able to globally monitor biodiversity and help stop wildlife decline — but that’s a big “if” according to an article published last week in the journal Nature.

In a related paper, scientists with the Zoological Society of London (ZSL) and the University of Twente in the Netherlands, urge space agencies and conservation scientists to work together to identify measures to help track biodiversity decline around the world. However, this has proven difficult in the past since there has been a lack of agreement between the two parties on which variables to track and how to translate the information into useful data for conservation.

“With global wildlife populations halved in just 40 years, there is a real urgency to identify variables that both capture key aspects of biodiversity change and can be monitored consistently and globally,” said Nathalie Pettorelli, a researcher at ZSL and a co-author of the article, in a press release. “Satellites can help deliver such information, and in 10 years’ time, global biodiversity monitoring from space could be a reality, but only if ecologists and space agencies agree on a priority list of satellite-based data that is essential for tracking changes in biodiversity.”

Publicly funded space agencies including NASA and ESA are already collecting satellite data and providing the public access to it. For example, NASA’s Sustainable Land Imaging program, which launched last year and provides satellite imaging of the earth, will be collecting publicly available data for the next 25 years. Further, individual tree species or animals can be imaged in great detail by WorldView-3, a private Earth-observation satellite owned by DigitalGlobe, a company that owns and operates satellites based in Longmont, Colo.

Scientists also suggest that vegetation or leaf cover can be measured from space to provide information about biodiversity levels as well as forest degradation. However, there is currently no agreed-upon definition of a forest and no solid decision on what constitutes degradation, making it difficult to use this information.

The next step, according to the scientists, is for ecologists and space agencies to work together to create a list of biodiversity variables that can be monitored by satellite. And they believe that if a biodiversity study is done from space after these variables are defined, there will be a much wider range of information than collecting data on individual species.

“So far biodiversity monitoring has been mostly species-based, and this means that some of the changes happening on a global-scale may be missed,” Pettorelli said. “Being able to look at the planet as a whole could literally provide a new perspective on how we conserve biological diversity.

Lead author of the paper and professor at ITC, University of Twente Andrew Skidmore believes that once scientists and space agencies work together, the space technology available can help conservation efforts.

“Satellite imagery from major space agencies is becoming more freely available, and images are of much higher resolution than 10 years ago,” Skidmore said in a press release. “Our ambition to monitor biodiversity from space is now being matched by actual technical capacity. As conservation and remote sensing communities join forces, biodiversity can be monitored on a global scale.”

How Britain Tackles Tuberculosis in Badgers

Contentious, difficult and expensive: words often used to describe a teenager. But, these words are equally, if not more, applicable to the problem of tuberculosis (TB) in animals in the United Kingdom. This disease — caused by the bacterium Mycobacterium bovis — is one of the most pressing animal health problems in the U.K. and a massive headache for the country’s cattle farmers. TB is also a burden to the U.K. taxpayer who funds the majority of its management. Over £100 million ($150 million) is spent annually on TB surveillance, control and research. Yet, despite these efforts, the disease continues to spread and it’s unclear why.

What is clear, however, is that while cattle are domestic reservoir hosts of M. bovis, the European badger (Meles meles) is a wildlife reservoir, and the two can infect each other. Controlling the disease in cattle, which may subsequently also involve controlling badgers, is a contentious issue in Britain. The public reveres this rarely seen nocturnal creature entwined in British folklore and tends to resist efforts to remove the animals, leaving wildlife professionals and cattle farmers with some tough choices. While badgers may be black and white, how to effectively manage TB is a lot more complicated.

Badger Ecology — An Ideal Maintenance Host

A badger is caught in a cage trap as part of an ongoing long-term study of TB epidemiology in Southwest England. Several traps baited with peanuts are placed around the entrances of burrows. Trapped badgers are transported to a sampling barn where they are anesthetized, identified, measured and sampled. After they recover from anesthesia, researchers release the animals back in the woods at the place where they were caught.
Image Credit: Julian Drewe

Tuberculosis has been present in cattle in the U.K. for more than a century. TB infections in humans, mainly from drinking raw milk, was a particular problem before the introduction of pasteurization in the early 20th century. By the early 1980s, TB in cattle had been almost eradicated. This was never fully achieved, however, and the incidence has since increased dramatically. The number of new herd outbreaks has doubled every nine years and the disease continues to spread geographically.

Meanwhile, researchers are doing their best to better understand badger ecology as well as the epidemiology of the disease in wild populations (Delahay et al. 2000, 2013). European badgers are ideal maintenance hosts for TB for several reasons:

They are social and territorial animals, living in stable groups that can range from two to as many as 23 adults. Badgers mark their territories with their distinctive latrines — collections of shallow pits in which they leave their feces. As a result, there are numerous opportunities for TB to spread among badgers whether from inhalation and grooming within the sett (a badger’s den) or through bite wounds during territorial disputes. Infected badgers may develop enlarged lymph nodes with abscesses that discharge bacteria. In addition, badgers can be long-lived — some survive up to roughly 12 years, although many are killed by vehicles long before this — which allows plenty of time for an infected animal to become infectious. Further, badgers with active TB lesions have been known to survive and successfully reproduce for many years.

Typically, conflict arises because badgers tend to live in the same areas of the country where cattle are farmed. Badgers mainly eat earthworms, which are abundant on pastureland. As a result, numerous opportunities exist for the two species to interact and for disease to spread. A recent study found that direct contact between cattle and badgers was rare at pasture, but indirect interactions such as visits to badger latrines by both species were common (Drewe et al. 2013). This might suggest that disease transmission may be more likely via these indirect means, or through other routes such as badgers gaining entry to barns housing cattle or feed stores. We still know very little about how, and how often, M. bovis infection passes between badgers and cattle in either direction, but despite this limited knowledge, researchers and policymakers have implemented several measures to try to manage the disease.

Managing TB in Badgers and Cattle

Current efforts to control TB in badgers focus on culling and vaccination — usually done without testing the animals’ infection status first. Below, we examine available disease management schemes, none of which is widespread.

Culling. Badgers in Britain fall under the Protection of Badgers Act 1992 and the Nature Conservation (Scotland) Act 2004 and, as a result, a specific license is required to shoot them. This might partly explain why the number of badger social groups in England was recently found to have doubled in the last 25 years, suggesting a large population increase.

The key question is, of course, whether culling badgers will lead to a reduction in TB incidence in cattle. A large-scale Randomised Badger Culling Trial, which ran from 1998 to 2006, investigated this very question (Independent Scientific Group on Cattle TB, 2007). Thirty areas each of approximately 100 square kilometers served as intervention (culling) or control sites. The trial unexpectedly found that if badgers were culled after a TB outbreak in cattle, the incidence of the disease among livestock in the area actually increased. Culling badgers before cattle outbreaks occurred reduced TB incidence, but this beneficial effect was offset by an increased incidence of the disease in surrounding un-culled areas. This detrimental effect appears to be due to surviving badgers mixing more and consequently spreading infection — a change in behavior referred to as a perturbation effect (Woodroffe et al. 2008). The trial’s main conclusion was that badger culling cannot meaningfully contribute to the future control of cattle TB in Britain. A subsequent review by a bovine TB eradication group came to similar conclusions in 2010 (Jenkins et al. 2010). Others have since argued that the benefits of culling may last longer than the negative effects.

An anesthetized wild badger is sampled as part of an ongoing long-term study of TB epidemiology in Southwest England. A large population of badgers has been trapped and sampled at this site for over 30 years, with many individuals sampled repeatedly throughout their lives. Here, researchers flush the badger’s trachea with sterile saline to provide a sample for bacteriological culture. The results help determine which badgers may be infectious.
Image Credit: Julian Drewe

Although the general public is strongly against culling, some farmers, vets and politicians support the practice. In an effort to reduce the costs of culling and temper the perturbation effect, Natural England — the government’s adviser on the environment — issued licenses in 2013 and 2014 that authorized badger culls over two areas of at least 150 square kilometers. An independent expert panel appointed to oversee the culls in 2013 concluded they were ineffective because they achieved a cull rate of less than 50 percent. The panel also questioned their humaneness given that more than five percent of badgers took longer than five minutes to die. Politicians in London debated the matter and then voted by a majority of 219 to one in support of a motion stating that these pilot badger culls had “decisively failed.” The government’s response was to continue the culls in 2014, this time without an independent expert panel to oversee them.

In general, badger culling — if done carefully and extensively over many years in targeted areas — might reduce TB incidence in cattle. Whether this could be sustained in a cost-effective and humane way over the long term is questionable.

Vaccination. In order to vaccinate badgers, biologists must first trap them in cages and inject BadgerBCG — a vaccine licensed to reduce TB lesions in badgers — into the animal’s muscle (Brown et al. 2013). This is relatively easy to perform on wild badgers without the need for sedation or anesthesia but is costly in terms of resources. For example, in the last three years, 4,000 badgers have been vaccinated at an estimated cost of over £600 ($900) per badger in one area of Wales (alongside cattle controls). Field trials in a different area of the U.K. indicated an approximately 75 percent reduction in incidence of positive serological tests in vaccinated badgers (Chambers et al. 2010). Further, vaccinating one-third of the adult badgers in an area resulted in a kind of herd immunity with a roughly 80 percent reduction in risk of infection in unvaccinated cubs (Carter et al. 2012). Data is currently sparse on if or how much badger vaccination might reduce TB incidence in cattle.

Vaccination of badgers has its limitations, however. Badgers are not usually tested before vaccination and, as a result, infected badgers may not benefit from vaccination. Because trapping badgers can be difficult and expensive, government agencies are currently developing an oral badger vaccine that can be placed in bait. Although oral vaccination worked well against rabies in many countries, there are some specific challenges associated with TB such as maintaining vaccine efficacy after it passes through the stomach; the cost of getting bait to badgers; and avoiding non-target species (especially cattle, which may subsequently test positive).

Testing. Northern Ireland is currently exploring a “test and vaccinate or remove” approach (TVR), where researchers catch live badgers and test them for TB. Individuals that test negative are vaccinated and released, whereas those that test positive are culled. Theoretically, this should result in less perturbation than a blanket cull. However, current tests for TB in live animals including badgers, cattle and humans are of low to moderate sensitivity, which could lead to many infected animals being released or vaccinated. As a result, this particular method of controlling TB may be limited until test sensitivity is improved.

Exploring Other Options

Over the years, wildlife managers, cattle ranchers and other stakeholders have tossed around a few other potential options to manage TB. Below are some ideas that come with their own set of challenges.

Vaccinating cattle. The European Union currently does not authorize vaccinating cattle against TB, noting that vaccination offers incomplete protection and vaccinated animals may subsequently test positive on the tuberculin skin test, the standard method to test for TB. This latter problem, however, can be overcome by the use of a diagnostic test — referred to as a DIVA test — that can differentiate infected from vaccinated animals. This would then allow cattle vaccination alongside a test-and-slaughter program (Chambers et al. 2014). Although field trials of cattle vaccination are a high research priority, experts estimate that it could take at least another eight years before a cattle vaccine could be deployed as a control measure.

Improving biosecurity. Biosecurity aims to prevent the introduction and spread of TB on farms. Researchers have explored several measures to achieve this including testing and quarantining new cattle, installing electric fences around farms to keep cows from grazing around badger latrines, and building better gates on farm buildings to keep badgers out of cattle feed stores. Although common sense and mathematical models suggest all these efforts should reduce TB incidence on farms, evidence to support this is sparse, and farmer uptake of biosecurity is varied.

Using antibiotics. Treating badgers or cattle with antibiotics is simply not an option. Widespread and long-term prophylactic or therapeutic use of multiple antimicrobials in cattle or wild badgers would be logistically challenging, not to mention the cost and risks of bacteria developing resistance to the antibiotics.

Doing Nothing. Strange as it may seem, there is a case to be made for doing nothing — after careful consideration of the options rather than ignoring the problem and hoping it will go away. Testing and compensating for tuberculosis in cattle consumes over 90 percent of the current U.K. animal health surveillance budget. Perhaps resources could be better targeted on other diseases where they are more likely to have a bigger benefit to health and welfare. However, support for this argument is limited, probably because controlling TB is an entrenched viewpoint, and there are concerns about zoonotic risk and effect on trade.

Future Prospects

There is potential for farmers in the U.K. to take more responsibility for the direction of the national TB management strategy. There’s evidence of success in that approach in countries such as New Zealand where farmers played an active role in controlling TB in brushtail possums (Trichosurus vulpecula). There are some key differences between the two cases, however: In New Zealand, farmers had more say in management strategies compared to farmers in the U.K. and, perhaps more important, the brushtail possum is an introduced species in New Zealand unlike the European badger, which is indigenous and protected in the U.K.

Still, most people agree that a comprehensive and multidimensional approach is needed if TB in cattle is to be effectively managed. This does not, however, necessarily mean that every possible disease control option should be used. Instead, it’s best to carefully assess the potential benefits and costs of each possible solution and choose the best combination, while considering the costs and ethics of any intervention effort. After all, disease control is ultimately a political decision and, even as we continue researching the issue and tackling related complexities, we must remember that TB eradication is a long way off.

Image Credit: Jemima Margo Elveera

Julian Drewe, PhD, is a lecturer in veterinary epidemiology with a particular interest in wildlife health at the Royal Veterinary College in London, U.K. WDA is all wildlife diseases, all conservation, all one health, all the time.

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