You can learn a lot about animals by simply watching them. But some secrets can only be revealed in the dark … with an ultraviolet flashlight.

This happens to be the case for pocket gophers, small rodents that live underground in sandy soil. A new paper by University of Georgia researchers found that these feisty, solitary, round-cheeked animals have a special skill that’s only revealed under ultraviolet light: They are biofluorescent, giving off a colored glow when illuminated with UV light.

Published in The American Midland Naturalist, this is the first time biofluorescence has been documented in pocket gophers. J.T. Pynne, a recent Ph.D. graduate of the UGA Warnell School of Forestry and Natural Resources and lead author of the study, said he was inspired to shine a light on the possibility a few years ago, after reading similar studies documenting the phenomenon in flying squirrels and opossums.

“A bunch of people, myself included, were curious about other animals,” said Pynne, now a private lands wildlife biologist with the Georgia Wildlife Federation. So, he turned to Warnell’s collection of animal specimens.

“We tested it on the flying squirrels we had, and sure enough, it worked. So, I said, ‘Well, what else do we have?'” During his time at Warnell, Pynne focused his research on pocket gophers, which are short-tempered and live in underground tunnels. So, he turned his UV flashlight toward those he had on hand. “And it turned out, pocket gophers, flying squirrels and opossums were the only animal specimens that fluoresced. And I’m thinking, of course my strange little animals do this.”

This was in 2019. At the time, identifying organisms that glowed purple, orange or pink under a black light was a bit of a thing in certain scientific circles. What started with the revelation of the flying squirrel snowballed into several other fluorescent discoveries, such as the nocturnal springhare and the platypus. Biofluorescence has also been documented in birds, salamanders, spiders and scorpions, among other organisms, said Warnell professor Steven Castleberry.

A UV light is required for humans to see biofluorescence.

“Just in the past few years, there’s been this uptick of people shining UV light on mammals to see if they glow. So now people have started to ask, why do they fluoresce?” added Castleberry. Whether the fluorescence is a defense mechanism, a communication method, camouflage or simply a trait from earlier eras is anyone’s guess at this point. “There’s some speculation and hypotheses, but nobody really knows the truth.”

Pynne also documented biofluorescence in pocket gophers in the wild, which emit a more intense orange-pink glow. He also tested specimens of other pocket gopher species archived at the Georgia Museum of Natural History, all of which emitted biofluorescence.

While the reason for pocket gophers’ and other animals’ ability to glow under ultraviolet light is still up for debate, Pynne said it can serve as a unique introduction to the animals’ world. With UV flashlights readily available, most anyone can highlight a foraging opossum in their backyard, for example, or watch how different insects light up at night.

“We have known for a long time that arthropods fluoresced. Any time I catch a scorpion or a spider or a millipede and I have my black light, they’re bright blue,” said Pynne, who keeps an ultraviolet flashlight in his backpack whenever he’s exploring new places. “It’s probably more of a cool teaching thing than anything.”

Although pocket gophers, with their long, curved teeth and penchant for burrowing, would rather be left alone, thank you very much.

More information:
J. T. Pynne et al, Ultraviolet Biofluorescence in Pocket Gophers, The American Midland Naturalist (2021). DOI: 10.1674/0003-0031-186.1.150

A new study shows that the frequency of polar vortex disruptions that is most favorable for extreme winter weather in the United States is increasing, and that Arctic change is likely contributing to the increasing trend. Led by Atmospheric and Environmental Research (AER), University Massachusetts Lowell and the Hebrew University of Jerusalem, the study is published in the September 3 issue of Science.

The analysis demonstrates that a relatively obscure weak or disrupted state of the stratospheric polar vortex, where it takes on a stretched appearance rather than the more typical circular appearance, has been increasing over the satellite era (post 1979). Extreme winter weather in the US is more common when the polar vortex is stretched. Both observational analysis and numerical modeling experiments demonstrate that changes in the Arctic, including accelerated warming, melting sea ice and increasing Siberian snowfall, are favorable for stretching the polar vortex followed by extreme winter weather in North America east of the Rockies. Such a chain of events occurred in February 2021, when a stretched polar vortex preceded the destructive and deadly Texas cold wave.

During the past three decades, the Arctic has experienced the greatest climate change of anywhere on Earth, including rapidly rising temperatures, melting sea ice, diminishing spring snow cover, and increasing autumn snow cover. Rapid Arctic warming relative to the rest of the globe is referred to as Arctic amplification. The extent to which these rapid changes in the Arctic are influencing midlatitude weather has become a topic of vigorous debate by climate scientists and popular in the press.

“The publication of the paper is especially timely given the extreme winter of 2020/21: record warm Arctic, low Arctic sea ice, deep Siberian snows, a protracted and complex polar vortex disruption, record-breaking cold in the US, Europe and Asia, disruptive snowfalls in Europe and the US and most notably the record breaking and possibly unprecedented combination of cold and snow in Texas,” said Dr. Judah Cohen, director of seasonal forecasting at AER and lead author of the study.

Cohen adds that “last winter the severe cold wave across Texas heated up the debate as to whether climate change can contribute to more severe winter weather with those arguing for and against. However, studies supporting or refuting the physical connection between climate change and the Texas cold wave and other recent US severe winter weather events don’t exist, until now. The study also provides cautionary evidence that a warming planet will not necessarily protect us from the devastating impacts of severe winter weather.”

The paper presents a physical mechanism of how climate change in general and Arctic change in particular are contributing to more severe winter weather despite an overall warming climate that has not been previously considered. Most theories on the connection between Arctic amplification and mid-latitude winter weather argue that the pathway is either through a wavier Jet Stream or sudden stratospheric warmings, which are the largest and most often studied disruptions to the polar vortex. This study provides compelling evidence that the strongest connection between the Arctic and mid-latitude weather, at least in the US, may be through this lesser known and weaker “stretched” disruption of the polar vortex.

These extreme winter weather events begin when a wave of high pressure between Northern Europe and the Urals and low pressure over East Asia undergoes amplification. Such an amplification can be forced by observed Arctic change during the fall season, and specifically by melting sea ice in the Barents-Kara Seas and heavier snowfall across Siberia. The excess energy from the Eurasian wave bounces or reflects off the polar vortex and is absorbed in a similar North American wave with high pressure over Alaska and the North Pacific and low pressure over eastern North America, causing rapid wave amplification. When atmospheric waves amplify, extreme weather is more likely.

UMass Lowell Environmental, Earth and Atmospheric Sciences Prof. Mathew Barlow, a co-author on the study, added that “the synthesis of both observational analysis and computer model experiments is a particular strength of this study and greatly increases our confidence in the results. The dynamical pathway explored here—from surface climate change in the Arctic up to the polar stratosphere and then back down to the surface in the US—highlights one example of the wide range of impacts that climate change can have.”

Israeli collaborator Prof. Chaim Garfinkel, the Hebrew University of Jerusalem, concludes “There has been a long-standing contradiction between an apparent increase in cold extremes in winter in midlatitudes even as temperatures globally are warming. This study helps resolve this contradiction and highlights that an apparent increase in such midlatitude cold extremes in winter should not be used as an excuse to delay taking urgently needed action to reduce greenhouse gas emissions.”

Provided by
Atmospheric and Environmental Research

Since Charles Darwin’s day, the abundance of life on coral reefs has been puzzling, given that most oceanic surface waters in the tropics are low in nutrients and unproductive.

But now research, led by Newcastle University and published in in the journal Science Advances, has confirmed that the food web of a coral reef in the Maldives relies heavily on what comes in from the open ocean.

The team found that these offshore resources contribute to more than 70% of reef predator diets, the rest being derived from reef associated sources.

Led by Dr. Christina Skinner, now based at the Hong Kong University of Science and Technology, the researchers included collaborators from Woods Hole Oceanographic Institution (USA), Banyan Tree Marine Lab (Maldives) and the University of Bristol (UK).

The team used advanced stable isotope techniques to show that four species of grouper near the top of the food web all rely on offshore resources; this didn’t change between species and was the case on the outside of an atoll and also inside the lagoon, suggesting that the oceanic subsidy is system-wide.

The scientists believe that this offshore energy may be entering the food web through lower-level plankton feeding fish that the groupers are then feeding on. This is likely to be supported by inputs of nutrient-rich deep water, which are little understood.

The findings help explain how coral reefs maintain high productivity in apparently nutrient-poor tropical settings, but also emphasise their susceptibility to future fluctuations of ocean productivity which have been predicted in many climate-change models.

Dr. Skinner said: “The study provides key insights into the nutrition of coral reef ecosystems, especially their dependence on offshore production. Detailed knowledge of food web dynamics is crucial to understand the impacts of anthropogenic and climate-induced change in marine ecosystems.

“The results force us to reconsider how we view coral reefs, and they highlight the extent of the connectivity with the surrounding ocean. If these groupers are mostly reliant on offshore energy to support their feeding, then maybe they won’t be so impacted by the loss of live coral, as many fishery studies have predicted; they may be more resilient.

“On the other hand though, some studies have predicted that ocean production will decline in the future from climate change. If that is the case, and these groupers are reliant on that open ocean energy, they will be impacted by those changes.”

Study co-author, Professor Nick Polunin, from Newcastle University’s School of Natural and Environmental Sciences, added: “Coral reefs are really suffering across the tropics from climate-related disturbances, particularly oceanic warming.

“In spite of its tiny area, this ecosystem is a massive contributor to marine biodiversity and this study highlights how little we know about the food web sources sustaining that exceptional wealth of species it sustains.”

Each year, thousands of migratory mule deer and pronghorn antelope journey northwest from their winter homes in the Green River Basin, a grassland valley in western Wyoming, to their summer homes in the mountainous landscape near Grand Teton National Park.

But to reach their destination, these ungulates must successfully navigate the more than 6,000 kilometers (3,728 miles) of fencing that crisscrosses the region. That’s enough distance to span nearly twice the length of the U.S.-Mexico border.

In a new study, wildlife biologists at the University of California, Berkeley, combined GPS location data of tagged mule deer and pronghorn with satellite imagery of fences to find out just how often these animals encounter fences, and what happens when they do. The results, published on Jan. 7 in the Journal of Applied Ecology, help pinpoint which fences pose the biggest barrier to ungulates trying to access their ideal habitat.

Along with the study, the team is also publishing a software package that will help wildlife managers around the world quickly analyze GPS tracking data to identify fences and other barriers that might be impeding the vital movements of animals.

“We need fences—they help keep livestock safe, can help keep livestock and wildlife separate, and mark property boundaries,” said Arthur Middleton, an assistant professor of wildlife management and policy at UC Berkeley and senior author of the paper. “So, the question becomes, how do you identify which fences are really important, and which are problematic from a wildlife standpoint, and then seek some way to mitigate the impacts?”

Fences don’t always pose an insurmountable barrier to wildlife, and different species find different ways to get around them. Mule deer are willing to jump over fences that are low enough. Pronghorn antelope, however, are reluctant to jump over fences and instead must seek out areas where they can move underneath.

Wenjing Xu, a Ph.D. student at UC Berkeley and lead author of the paper, took these different behaviors into account when creating the software package that compares animal tracking data with fence maps. The program can categorize different types of behaviors that animals might engage in when they encounter a fence, such as quickly crossing over the fence, pacing back and forth along the fence, or turning around and walking away from the fence.

To understand how fences are impacting mule deer and pronghorn, Xu started by painstakingly comparing fencing maps from the federal Bureau of Land Management and the U.S. Forest Service with satellite imagery, adding in fences that were not included in the government surveys. When all the fences were accounted for, Xu was surprised at the sheer amount of fencing in the region.

“The total length of fences is really, really striking, especially with what we know about the different types of wide-ranging animals that live in that area,” Xu said.

Xu then compared these maps to GPS tracking data that collected locations every two hours for 24 tagged female mule deer and 24 pronghorn antelope.

Each year, mule deer encountered fences an average of 119 times, Xu found. Pronghorn antelope encountered fences at more than twice that rate, about 248 times per year. About 40% of these fence encounters resulted in a change in the animals’ behavior.

“Anybody who’s spent time in the West knows you’ll find a lot of fences. But, seeing such frequent encounters, 40% of which result in a failure to cross, is kind of mind-blowing—especially when you multiply those numbers across whole populations and landscapes,” Middleton said.

Some of these fences are currently being used by ranchers to protect livestock or mark property lines. Others are relics of a bygone era when sheep farming was popular in the state, Middleton said.

The best way to mitigate the impact of these fences on animal migration is to remove them, or to replace them with more “wildlife-friendly” fences that mule deer can jump over or that pronghorn can duck under. However, both of these options require money and labor. According to Xu, a recent fencing modification project in Wyoming spent more than $10,000 per mile of fencing to make the fences more permeable to pronghorn.

The software package developed by Xu is able to create maps that highlight the fences that pose the greatest impediment to animal movement, helping to prioritize fences to be modified or removed.

“There is such a strong need for this kind of data,” Xu said. “Modifying fences is really, really expensive, and the amount of fencing that might need to be fixed is just so large. [Wildlife managers] really want to find ways to prioritize their resources.”

Brandon Scurlock, a wildlife management coordinator for the Pinedale region of the Wyoming Game and Fish Department, is working to designate a protected migration “corridor” that connects the summer and winter ranges of pronghorn antelope in western Wyoming. Similar migration corridors for mule deer were established by the state earlier this year.

Scurlock’s team is already using the study results to identify fences that might create barriers along these routes, and prioritize those for modification.

“It’s been interesting noticing the characteristics of some of these fences that this study has pointed out as being not very permeable for Pronghorn,” said Scurlock, who was not a member of the study team. “We recommend the bottom wire of a fence be at least 18 inches above the ground. And, when looking at some of the particularly bad fences that that these methods highlight, we almost invariably see that they have barbed wires that are too close to the ground.”

One option for offsetting the cost of fence mitigation throughout this region, which is part of the Greater Yellowstone Ecosystem, could consist of imposing a small “conservation fee” on visitors to the area’s parks, which include the extremely popular Yellowstone National Park and Grand Teton National Park. Middleton and co-authors, including Berkeley Law professor Holly Doremus, explored the feasibility of this approach in a study published last month in the journal Conservation Science and Practice.

“Fine-scale movement data has helped us see much further into animals’ lives, including the challenges we’ve imposed,” Middleton said. “I hope this work helps open people’s eyes to the scale of fence effects. Our next steps are to better understand the actual biological cost that all these fence-related behavioral changes have on wildlife populations, and find ways to mitigate those effects at a really large scale.”