The ability to accurately measure and detect contact between two or more animals is critical to understanding disease transmission risks. In order to collect more accurate contact data among white-tailed deer, researchers at the USDA Wildlife Services’ National Wildlife Research Center (NWRC) built a deer-borne contact detection system (DCDS) consisting of cameras and proximity loggers installed on global position system (GPS) collars. To ensure the DCDS did not alter the behavior of the deer, researchers conducted a preliminary evaluation of potential stress on deer as a result of the device and monitored the deer for five hours immediately following the placement of collars.

Twenty-six adult male deer were fitted with DCDS collars to record their locations, proximity to other equipped deer, and video of deer interactions in southern Texas. From 17 of the 26 collars, researchers documented 16 contacts with GPS, 33 with cameras, and 61 with proximity loggers, resulting in estimated mean daily contact rates of 0.12, 0.29, and 0.66, respectively. Cameras and GPS underrepresented contacts among deer, whereas proximity loggers provided credible estimates for disease modeling.

“The results underscore the importance of accurate detection and contact rates when modeling disease transmission risks,” notes NWRC supervisory research wildlife biologist Dr. Kurt VerCauteren.

Wildlife Services is a Strategic Partner of The Wildlife Society.

Three hundred manatees staged an invasion of a Florida National Wildlife Refuge, forcing the Three Sisters Springs in Florida’s Crystal River National Wildlife Refuge to close Monday. The manatees likely came from nearby Kings Bay according to a story by Business Insider. The U.S. Fish and Wildlife asked the refuge to close down in order to give the animals space and protect them from potentially boisterous tourists, according to the article.

After three weeks of lengthy debate, the Senate voted 62-36 to approve S. 1, a bill allowing construction of the Keystone XL oil pipeline by TransCanada. The pipeline would carry crude oil extracted from tar sands in Alberta over the U.S. border and through Montana, South Dakota, and Nebraska.

The full text of S. 1 is available and contains amendments approved by Congress. Over the course of the debate, the Senate voted on 41 amendments to the bill, many of which would have had impacts on conservation.

After President Obama announced plans to designate an additional 12.28 million acres of land as wilderness in Alaska, Senator Murkowski (R-AK) introduced an amendment that would restrict agencies like the Fish and Wildlife Service to managing areas as wilderness for a maximum of 1 year before congressional approval is needed. The proposed amendment might have led to relaxed restrictions on oil and gas development in vulnerable areas, like the Alaskan National Wildlife Refuge, but did not receive the required 60 votes for approval.

Another amendment would have reauthorized the Land and Water Conservation Fund (LWCF), a 50-year program that expires in September, and would have dedicated a percentage of LWCF funds each year to increasing hunting and recreational opportunity on public lands. While substantial support existed for the amendment, it fell one vote short of the threshold required for approval after three senators changed their vote from ‘yea’ to ‘nay.’

Oil sand production is the primary source of the crude oil that Keystone XL would carry; it is not subjected to the same per-barrel tax, which helps to fund oil spill liability accounts, as more traditional oil development. While the Senate approved a measure acknowledging that the loophole that allows oil sands to be exempt from this tax should be closed, other amendments that would change regulations to impose the tax on oil sands were not approved.

One notable amendment included the recognition of the existence of climate change by the Senate. The amendment was approved 98-1.

The bill will proceed to the House for consideration. The White House has stated that the President plans to veto the bill. Congress can overturn presidential vetoes with a two-thirds vote.

Sources: Environment & Energy Daily (February 2, 2015), Environment & Energy Daily (January 29, 2015), E&E News PM (January 29, 2015), Greenwire (January 29, 2015)

Don’t let the nickname “cat disease” fool you. A recent study in Champaign, Ill. shows toxoplasmosis, a disease spread by cats, is prevalent in semiaquatic mammals, minks (Neovison vison) and muskrats (Ondatra zibethicus) as well.

“Infected cats shed Toxoplasma gondii oocysts in their feces, and these oocysts are picked up by other hosts in the environment,” said Adam Ahlers, University of Illinois graduate student and TWS Associate Wildlife Biologist who led the study published last week in the Journal of Wildlife Diseases. “This is an important finding because animals like muskrats and minks spend most of their time in streams and wetlands and rarely encounter cats, so the parasite is likely transferred via runoff from the surrounding landscape.”

Ahlers and his research team sought out to determine the prevalence of the parasite Toxoplasma gondii in minks and muskrats in order to determine if the parasite is contaminating freshwater watersheds.

“In our region, most of the wetlands have been drained to accommodate agricultural production and urbanization, and natural drainage systems have been altered,” Ahlers said. “With increased tile drainage and loss of natural wetlands, the transfer of T. Gondii oocysts into watersheds from agricultural and urban runoff is likely.”

The researchers predicted that animals positioned in larger watersheds would have higher prevalence rates since they are exposed to drainage from larger areas. Without wetlands to filter out pathogens like T. gondii, the parasite that causes toxoplasmosis, rainwater likely flushes T. gondii oocysts into the watershed via altered drainage systems, Ahlers said.

Ahlers and his team tested 30 muskrats and 26 minks for T. gondii antibodies in central Illinois. They found that 77 percent of the minks tested positive for T. gondii and about 60 percent of the muskrats tested were also infected.

“This was really surprising for us because muskrats are tightly linked to the watershed,” Ahlers said. “We think they are picking up the parasite from contaminated runoff originating from agricultural and urban landscapes.”

Ahlers said muskrats in larger watersheds had higher prevalence rates than those positioned in smaller watersheds. Muskrats are herbivores and likely pick up oocysts while drinking, grooming, or foraging on aquatic vegetation, he said. On the other hand, there was no link between minks and their location in relation to watershed. As carnivores, they may become infected by consuming other infected prey, he said.

The T. gondii parasite rarely discriminates against who it infects, and even humans are exposed to it. Once infected, animals can develop unhealthy behavior changes, Ahlers said.

“In mice, toxoplasmosis causes behavioral changes in the individual,” he said. “Mice that have been exposed to toxoplasmosis seek out cat urine. We don’t know for sure what the effects are in muskrats and mink, but with sea otters, we know that survival is reduced.”

In humans, the infection is linked to miscarriage, autism, depression, schizophrenia, increased suicide risk and decreased learning in children, Ahlers said.

“There are definitely human implications,” he said. “Humans can pick up oocysts by eating infected meat, or if they come in contact with contaminated water. There have been instances of freshwater contamination causing T. gondii infection in humans in Canada and in South America.”

With the study’s implications of increased pathogen in watersheds, it’s clear that not only minks and muskrats are affected, but other wildlife as well.

“Removing natural wetland habitats and altering natural drainage systems may play a big role in the spread of diseases like toxoplasmosis,” Ahlers said. “It is likely facilitating the transfer of T. gondii oocysts into freshwater watersheds.”

Fin whales and other baleen species may not hear each other’s calls through their ears — they may feel it in their bones, according to a new study.

“Bone conduction is likely the predominant mechanism for hearing in fin whales and other baleen whales,” Ted Cranford said in a release. Cranford is a biologist with the San Diego State University and a coauthor of the study released recently in PLOS ONE. “This is, in my opinion, a grand discovery.”

The findings are important to conservation because little has been known about exactly how whales hear the sounds they make across the oceans. That’s until 2003 when a young fin whale (Balaenoptera physalus) washed up on a beach in Orange County, Calif., giving researchers the chance to examine the way their skulls absorb sound. They took the dead whale’s skull and put it into a large X-ray CT scanner originally created to examine rocket motors. They found that the low frequency sounds that fin whales use to communicate are amplified by bone conduction.

A look at the left lateral view of the skull bones in a fin whale (Balaenoptera physalis).
Image Credit: Ted W. Cranford and Petr Krysl

Petr Krysl, a University of California, San Diego engineer and another of the researchers involved in the study, said that humans experience something akin to this when hearing underwater. “We have that experience when we submerge entirely in a pool,” he said. “Our ears are useless, but we still hear something because our head shakes under the pushing and pulling of the sound waves carried by the water.”

While the findings could be used by legislators deciding on potential legislations regulating human noise in the oceans caused by boats or underwater construction, for example, Cranford said that the most important part of the study is that it revealed a long-standing mystery about fin whales — a species listed on the Endangered Species Act.

“What our contribution does is give us a window into how the world’s largest animals hear, by an odd mechanism no less,” he said. “This research has driven home one beautiful principle: Anatomic structure is no accident. It is functional, and often beautifully designed in unanticipated ways.”

Krysl said they will now build on this information to see if it is applicable across other baleen species like blue whales (Balaenoptera musculus) or minke whales (Balaenoptera acutorostrata). “There is a blueprint for multiple species and it is useful to compare across species to gain insight,” he said.