Keith Poulsen, the director of the Wisconsin Veterinary Diagnostic Laboratory, encourages anyone who owns domestic poultry to register their flock with the state, keep a close eye on their birds for signs of sickness and to keep their birds away from wild birds. Envato/Maria_Sbytova

While migration can be a time for avid birders and everyday Wisconsinites alike to catch a glimpse of fun-feathered visitors, poultry farmers’ eyes are watching their own flocks like a hawk for signs of avian influenza.

Sometimes called bird flu, avian influenza can spread to flocks from wild birds like a cold through a booger-infested pre-K class. Farmers do their best to prepare.

“It’s like daycare, but on an international scale,” says Keith Poulsen, director of the Wisconsin Veterinary Diagnostic Laboratory.

In a normal year, only a few isolated cases of bird flu will pop up. So far, though, this years’ strain is classified as having high pathogenicity, meaning it spreads quickly through a flock and can kill nearly 100% of birds within 48 hours of infection.

“One in six people in the northwest part of Wisconsin is involved in the poultry industry,” says Poulsen. “So, if you have a problem that has a significant impact on the industry, animal health measures are hugely important.”

To make matters worse, rather than leaving the state with migratory birds as they headed north this spring, Poulsen warns that this year is the first time the virus instead stuck around. Usually, the virus doesn’t survive the summer. This strain, however, remained circulating in bird and mammal populations at low levels, giving it more time to spread.

So far this year, there have been twice as many infected flocks as there were during the last serious outbreak in 2015. With migratory birds starting to fly south again and bringing more virus back to Wisconsin, that number is expected to rise.

Controlling the recent outbreak of avian flu across the state has been complicated not by big commercial poultry farms, but by the increase in the number of backyard hobby flocks. Envato/juliacherk

For testing centers like the WVDL, monitoring the spread is also made more difficult because of an increase in the number of small, backyard hobby flocks.

With outbreaks on large poultry farms, “typically, when you find a positive flock, you don’t want to take anything off the farm. You want to get rid of all the virus on the farm, clean it and disinfect it, then move on,” says Poulsen. “That’s really difficult when you have small premises scattered all over the state.”

Large poultry operations, he explains, have their own systems in place to handle and neutralize an infection quickly and thoroughly so they can get back to making a product fit for market and robust food supply chain.

Many small hobby flocks, however, aren’t registered with the state, he says, even though it’s technically required. Hobby flock owners also don’t often have the resources like a “chicken vet” to call and ask random questions about poultry care or what signs of sickness to look out for.

The virus has also had time to spread to other species, infecting apex avian predators and potentially upsetting the balance in the ecosystem around the state. The virus has killed raptors like bald eagles and snowy owls and in rare cases has caused neurological damage in mammals like foxes and bobcats.

This spill-over into other populations can happen for a number of reasons, and the WVDL sends every virus-positive sample to a national laboratory for genetic sequencing. Keeping track of the virus in this way allows animal health officials to monitor how it’s changing over time and determine whether it poses a threat to human health.

“Some viruses are very stable; they don’t change very much over time. Influenza is very different,” Poulsen says. “That’s the reason why we watch this very closely.”

For some, migration is an exciting time for bird watching. For poultry farmers and hobby flock owners, it’s a time to be on high alert for avian flu infection in their flocks. Envato/bilanol

Right now, animal health officials are assessing the risk of the outbreak to decide whether they should implement poultry vaccination requirements. But it isn’t a simple decision to make since vaccinations would add to farmers’ production costs and could deter international poultry buyers.

With so many people connected to poultry, Poulsen encourages all flock owners to register their flock with the state. It benefits their own flock, their neighbors’ flocks and the health of the ecosystem.

While it can be difficult to find a veterinarian that works specifically with poultry, there are several associations and resources for smaller flock owners that can help to fill those gaps. Poulsen names a few: the Wisconsin Poultry and Egg Association, the National Poultry Improvement Plan and the Wisconsin 4-H Poultry Project.

Poultry owners should watch their flocks for warning signs like sudden death without clinical signs of illness, sluggishness and lower egg yields. Infected birds may also experience swelling or discoloration of their head, comb, eyelids, wattles or legs. Poulsen says flock owners should also report any dead birds to the Wisconsin Department of Agriculture, Trade, and Consumer Protection animal diseases reporting hotline: 608-224-4872 or DATCPAnimallimports@wisconsin.gov.

“Maintain vigilance for your birds,” Poulsen says. “Keep your birds away from wild populations and watch them very carefully.”

Amy Wray doesn’t expect everyone to love bats like she does, but she hopes to help people understand how essential they are to our ecosystem. Illustration by Danielle Lamberson Philipp / College of Agricultural and Life Sciences

Bats are flying throughout Amy Wray’s Twitter account. Her pinned tweet: “Live every week like it’s #batweek.”

What’s Bat Week? Wray, a doctoral candidate in wildlife ecology, is glad you asked. Observed (naturally) Oct. 24–31, Bat Week is an international celebration designed to raise awareness about the need for bat conservation. Wray just got back from the North American Society for Bat Research conference in Kalamazoo, Michigan. It’s a good time to hang (get it?) with fellow bat lovers — and also stock up on bat craft supplies.

“Especially stickers — you can’t have enough bat stickers,” Wray says.

She doesn’t expect everyone to love bats like she does, but Wray hopes to help people understand how essential they are to our ecosystem. What better time than Halloween?

Bat expert Amy Wray, a doctoral candidate in wildlife ecology, in a research lab in Russell Laboratories. Photo: Jeff Miller

Clearly you love bats. Why?

Bats are fascinating creatures  — they are the only flying mammal, they are super intelligent, and they are absolutely adorable. There are a lot of different kinds of bats too: white bats, speckly bats, cuddly bats, bats that catch fish, and even bats that hunt other bats. Sometimes we think of “bats” like they are all one type, when in reality, there are currently 1,411 different species.

When did this adoration begin?

When I was a little kid I was obsessed with the book “Is Your Mama a Llama?” and my favorite part of the story is about a bat, which had a very cute illustration. (Side note: The bat’s name is Dave.) And then, of course, “FernGully.”

“Bats can totally see,” Wray says. “Some fruit-eating bats have very big, puppy-like eyes and they can see well even in the dark. Other bats use echolocation to create a highly accurate sound-based image of the world around them, but those guys can also see.”

Settle it once and for all: “blind as a bat” — true or false?

False! Bats can totally see. Some fruit-eating bats have very big, puppy-like eyes and they can see well even in the dark. Other bats use echolocation to create a highly accurate sound-based image of the world around them, but those guys can also see.

Be honest. Do they want … to suck … my blood?

No! There are only three bat species that are true “vampires” who actually feed on blood. These species also much prefer to snack on animals like cows. It’s also not fair to think that only bats are vampires — insects are much more likely to feed on human blood, and in terms of other blood-feeding animals, there are also birds like the vampire finch (although, vampire finches don’t really bite humans).

What’s the most ridiculous thing you’ve heard about bats?

A new one that I just heard is that if you throw a marshmallow in the air at night, bats will come and catch it. So far, there have been no verified reports of such behavior.

I think the worst myth about bats is the myth that many of them carry rabies. Like most mammals, bats can carry rabies, but it’s actually pretty rare. It’s not a good idea to ever touch a bat without gloves (partly to protect the bat from our germs, too), but by simply treating them (and other wildlife) respectfully there is little risk of contracting diseases from them.

“One thing I really enjoy about bats is that they totally play hard to get,” Wray says. “Studying them has a lot of unique challenges since they are super wily, can be really small, and they’re kind of tricky to find or observe.”

Also, bats do not get stuck in people’s hair. I think this myth comes partly because sometimes if you are sitting outside where bats are foraging, they’re super curious and they may fly somewhat nearby to check out what you’re doing. They may also be foraging around insects that are trying to bite you. However, usually bats are not actually flying that close (it might seem like it because they’re flappy and hard to see). Bats are exceptionally agile, good fliers and they also have incredibly refined echolocation (like, they can “see” a single strand of a spider web or the pattern on a leaf), so they are definitely not going to fly into you.

Why do you think people are afraid?

I think fear usually stems from things that we don’t understand. Bats are kind of mysterious — flying around at night, hiding in small spaces, etc., so I think a lot of people hear myths and misinformation, but may be less likely to see bats up close. For a lot of people, an experience like having a bat stuck in their house, where the bat is going to be super afraid, is their only encounter with them. (If you do have a bat in your house, open a window and they can usually find their way out.) One thing that surprises people a lot is that up close, most bats (including all of the species in Wisconsin) are much smaller and more delicate than you might think they are.

“One thing that surprises people a lot is that up close, most bats (including all of the species in Wisconsin) are much smaller and more delicate than you might think they are,” Wray says.

Are people always giving you bat-related gifts?

The best bat-related gift I ever get is from citizen scientists who send me bat guano and/or data for my research. But in terms of bat-related stuff, people have gotten me some really good gifts like a bat-shaped cookie cutter and some cute bat dog toys. One of my lab-mates also got me some fake eyelashes with bats on them, which I love.

You’re not alone in having a fondness for bats. What do you think bat lovers have in common?

There are a few common threads that I think attract people to bats. First, for anyone curious about the natural world, there are so many different bats that do really interesting things, and yet we have so much to learn about them still. There is a real need for more bat scientists and more people interested in helping them.

Bats also get an unfair reputation as being scary, so they’re great animals for anyone who loves an underdog story. One thing I really enjoy about bats is that they totally play hard to get. Studying them has a lot of unique challenges since they are super wily, can be really small, and they’re kind of tricky to find or observe. Bats are all around us, but we don’t necessarily see them all the time, so it also feels really special to have opportunities to see them up close or even just be around them.

“Like a lot of wildlife, bats don’t really want to mess with people at all, they just want to keep on doing their own batty thing,” Wray says. “If we just leave them alone or handle them appropriately when necessary, there is no reason to be afraid of them.”

I’m sure it’s hard to choose, but do you have a favorite bat?

I have a few favorites, but one of them at the very top of my list is the proboscis bat (Rhynchonycteris naso). These bats are found in Central and South America, and they often roost on trees near the water, sitting in a neat little line, occasionally doing some wiggles. Their faces are outrageously cute in a super goofy way, where it looks like they kind of have an overbite, and it always makes me laugh to look at them.

Tell me again. Why shouldn’t I be afraid?

First step: google “baby flying fox,” then “bat eating banana,” and then “Honduran white bat.” These are the ultimate gateway bats. Like a lot of wildlife, bats don’t really want to mess with people at all, they just want to keep on doing their own batty thing. If we just leave them alone or handle them appropriately when necessary, there is no reason to be afraid of them. Bats also play really important roles in the ecosystem, and a lot of them need our help.

You’ve said a world without bats would be frightening. Why?

Bats are super important for the ecosystem. They do a lot of important things like pollinating plants, promoting forest diversity by dispersing seeds, and controlling insect pests that threaten agricultural systems. There are also so many mysteries about bats that are yet to be discovered, and I think it’s absolutely tragic to lose species before we can even learn about them.

Wray conducts a test with a sample vial of bat guano. Wray is using next-generation DNA sequencing to study the diets of insect-eating bats in Wisconsin. The findings will help her assess the extent to which bats feed on agricultural pests and how the spread of diseases may impact the utility of bats in pest control. Photo: Jeff Miller

A Cooper’s hawk perched on a wire. Known as “perch and scan” hunters, Cooper’s hawks and other woodland hawks are increasingly moving into U.S. cities to take advantage of the buffet of backyard birds drawn to bird feeders. The hawks join a growing list of top wildlife predators making their homes in the city. Sarah MacLean / Project FeederWatch

For the nearly 35 million Americans who faithfully stock their feeders to attract songbirds, an increasingly common sight is a hawk feeding on the birds being fed.

Now, in a new study published Nov. 7, 2018, in the Proceedings of the Royal Society B, a team of Wisconsin researchers documents that woodland hawks — once in precipitous decline due to pollution, persecution and habitat loss — have become firmly established in even the starkest urban environments, thriving primarily on a diet of backyard birds attracted to feeders.

According to the researchers, the birds are doing so well that an increasing number of rural woodland hawks are, in fact, city-bred.

Benjamin Zuckerberg

“Top predators are beginning to use urban areas more frequently and establish breeding populations, and hawks are a nice example of this,” explains Benjamin Zuckerberg, a University of Wisconsin–Madison professor of wildlife ecology and a senior author of the new study. “For hawks, the secret is out: There is a hyperabundance of prey” in the city.

The availability of food — in this instance, backyard birds — is the single most important factor in drawing avian predators such as Cooper’s and sharp-shinned hawks to the city, says Jennifer McCabe, a UW–Madison postdoctoral fellow who led the new study.

As pesticides such as DDT were curbed and new protections from human hunters came into play beginning in the 1960s, populations of woodland avian predators like Cooper’s and sharp-shinned hawks have soared. As populations rebounded, hawks began to move into urban areas and the study concludes that, at least for Chicago, prey availability at feeders significantly influenced colonization and persistence in the city, explains McCabe.

While the new study uses Chicago as its laboratory, the phenomenon of top predators establishing themselves in urban environments is a global trend, say the Wisconsin researchers.

Jennifer McCabe

“Across the world stories are popping up about predators expanding into cities,” says McCabe. “Bear and cougars in the U.S., leopards in India, and red foxes in Europe, to name a few.”

The new study depended on more than 20 years of citizen science data gathered by participants in the Cornell Lab of Ornithology’s Project FeederWatch, where people who feed birds document avian activity in their backyards.

“Project FeederWatch is the perfect program for this kind of research because you can use that information not only to document hawks, but also their prey,” says Zuckerberg of the landmark citizen science project.

Quintessential woodland predators, Cooper’s and sharp-shinned hawks are what wildlife biologists call “perch and scan” hunters, sitting quietly on a tree branch and swooping in when a meal comes within striking distance. “Bird feeders,” says Zuckerberg, “are like buffets. It is an easy meal.”

The new insight from the Wisconsin study is that for the hawks it is all about food. Once established in cities, the urban environment and the absence of trees made little difference.

“I was surprised that tree canopy cover was not important in colonization by these woodland hawks,” McCabe says. “However, they aren’t nesting in the winter, meaning they are more concerned about their own survival and not raising young. So it makes sense that food availability would be so important.”

“For hawks, the secret is out: There is a hyperabundance of prey” in the city.

Benjamin Zuckerberg

Using 20 years of Project FeederWatch data from 1996 to 2016, McCabe and her colleagues portray a steady advance of the predators from outlying rural areas to the hardened center of Chicago, a pattern that also occurs in many other North American metropolitan areas and also in Europe, where sparrow hawks have aggressively colonized urban landscapes.

One other surprising finding, according to McCabe and Zuckerberg, is that prey size did not seem to be an important factor. The informed assumption, says McCabe, was that larger prey would be preferred menu items for the hawks.

“Prey biomass wasn’t an important driver of colonization or persistence,” she notes. “Much of the literature states, at least for Cooper’s hawks, that they prefer larger-bodied prey like doves and pigeons. Perhaps these hawks are cueing in on the sheer number of birds and not particular species.”

An important take-home message, says McCabe, is that cities, which in the United States are adding an estimated 1 million acres of urbanized land each year, are increasingly important wildlife habitat: “Don’t discount urban areas as habitat. The more we know about which species and what landscape factors allow those species to colonize and persist in urban areas, the better we can manage wildlife in an ever-developing world.”

Funding for this research was provided through NASA’s Citizen Science for Earth Systems program (grant no. NNX17AI68A).

“If you want to preserve the muriquis, exactly what do you need to know?” asks Leandro Jerusalinsky, one of the authors of a report published today (Dec. 13, 2017) in the journal PLOS ONE. “This was the essential question, focusing on identifying population trends and conservation priorities.”

“Where do you need to go, and what numbers or qualities do you need to focus on?” adds Jerusalinsky, who leads the National Action Plan for the Conservation of Muriquis at Brazil’s National Center for Research and Conservation of Brazilian Primates, linked to the Chico Mendes Institute for Biodiversity Conservation.

A southern muriqui in its natural habitat. “The two muriqui species live in one of the five most biodiverse hotspots in the world,” says researcher Karen Strier. © Pró-Muriqui Association (used with permission)

“We think this may be one of the most comprehensive efforts to analyze the data monitoring needs for ensuring the survival of an endangered animal,” says first author Karen Strier, a professor of anthropology at the University of Wisconsin–Madison, who has observed muriquis in Brazil for 35 years. “The two muriqui species live in one of the five most biodiverse hotspots in the world — for both plants and animals, but the southeastern Atlantic Forest is the center of Brazil’s economy and population, and so this habitat has long been chopped up by development.”

At most, 2,300 muriquis survive in the wild, including fewer than 1,000 members of the northern species, and an estimated 1,300 for the southern species. “Monitoring demographic trends is essential for management programs, including translocations,” explains co-author Fabiano de Melo, a professor in the forestry engineering department at the Federal University of Viçosa.

Map shows location of northern muriqui (red) and southern muriqui (blue). Circles show specific locations of remnant populations. Karen Strier and co-authors, PLOS ONE

Ensuring that the species survives requires an accurate picture of the different populations, says co-author Mauricio Talebi, professor of primatology and conservation at the Federal University of São Paulo, Diadema campus. “One of the problems we have is that if monitoring uses different methods, the results are not comparable. When we worked on the national action plan for muriquis, we identified gaps. There are big differences in habitat conditions for the northern and southern species, but we still need a standard monitoring system for the various locations.”

Monitoring the health of an endangered species can entail much more than just counting individuals or breeding pairs, says Strier. “Population counts at particular sites and in total don’t require a big labor force, but we are usually interested in other factors, such as genetic uniqueness or geographic importance: Could this site be used to make a corridor linking isolated populations to enhance genetic diversity?”

More monitoring can answer more questions, Strier says. “If you want to understand past or future changes in demographics, or why a population is growing or declining, you will also want to know the sex ratio and what proportion of females are carrying babies. This takes more time, and more expertise.”

Muriquis are an affectionate primate, without hierarchy or aggression. Photo: Pablo Fernicola

Strier, who leads one of the longest field studies of primates in the wild, calls muriquis “the most amazing primates in the world. They have a very low rate of aggression, and have been called ‘hippie monkeys.’ Females are independent and promiscuous, males don’t dominate them, and there’s no real hierarchy among males or females. They spend a lot of time hugging and socializing.

“If you are aiming at avoiding extinction, you need to ask a lot of important questions,” says Strier. “Are you trying to reach the highest genetic diversity? The highest demographic probability of success?”

Monitoring plans must also take feasibility into account, since some places, through topography or ownership, are impossible to get to. Decisions can be problematic if they are made on the fly or based on incomplete information, Strier says.

Another factor that plays a role in monitoring decisions is sites that are on the fringe of species’ habitat. Outliers in terms of altitude or longitude may be the first to die as climate changes. But a relatively cool and underpopulated site today could become an important refuge as climate warms.

Through the work of Strier and a growing number of Brazilian researchers, the plight of the muriquis has become clear, and the primate has emerged as a charismatic animal in desperate need of help, with both species now listed as critically endangered.

“Interest in muriquis has been growing,” says Talebi. Already, he says, the ideas in the monitoring framework are starting to guide his work program of monitoring the southern muriqui.

The same is true for de Melo, who is experimenting with technology, including the use of thermal cameras mounted on drones, to count northern muriquis.

A baby muriqui in Brazil’s Atlantic forest. Photo: Pablo Fernicola

One key factor, called “implementability,” focuses on access, and while some sites are closed to researchers, Talebi says some private landowners have been establishing muriqui reserves.

Muriquis are also getting help from the recovery of landscapes that were converted to farms and then abandoned decades ago, says Strier. “Seeing the resilience of nature makes me more determined than ever. We can’t reverse past assaults to the planet, but we can do everything we can to stop them and give the animals and plants a chance to come back.”

Strier sees the thoughtful processes detailed in the new study as a foundation for a new generation of scientists. “If somebody wants to know how to promote muriqui preservation, this study would be a roadmap. It gives you an idea where to start, and where to focus. We hope it will also serve as a template for scientists concerned with other endangered animals.”

Funding for this project came from Chico Mendes Institute for Biodiversity Conservation, Doctum College Teaching Network, Caratinga, Minas Gerais, Brazil, and Conservation International.

That’s why scientists, investigating an outbreak of respiratory disease in a community of wild chimpanzees in Uganda’s Kibale National Park, were surprised and dismayed to discover that a human “common cold” virus known as rhinovirus C was killing healthy chimps.

“This was an explosive outbreak of severe coughing and sneezing,” says Tony Goldberg, a professor in the University of Wisconsin–Madison’s School of Veterinary Medicine and one of the senior authors of a report documenting the event. The report was published online today (Dec. 13, 2017) in the journal Emerging Infectious Diseases.

“It was completely unknown that rhinovirus C could infect anything other than humans,” says Goldberg, referencing a two-year-old chimp named Betty, who succumbed to the virus and whose body was quickly recovered and autopsied after her death. “It was surprising to find it in chimpanzees, and it was equally surprising that it could kill healthy chimpanzees outright.”

This 2-year-old chimp named Betty succumbed to a human common cold virus in Uganda. The opportunity to retrieve Betty’s body before it decomposed or scavengers set in was critical to making the discovery. Photo: Richard Wrangham

The outbreak occurred in February of 2013 and affected most of the chimps in the community. During that time, five chimps out of a community of 56 died, including Betty; the other animals that died were adults up to 57 years old. The findings, says Goldberg, are a cautionary tale about human interactions with wild apes. In Africa, people encounter chimpanzees and other apes when human settlements expand into ape habitats, through activities like tourism and research, and when apes leave the forests to raid crops.

Rhinovirus C is one of three rhinovirus species, each causing respiratory disease in humans. But rhinovirus C is notably more severe than its relatives, rhinoviruses A and B. Although the virus had likely been infecting people for several thousand years, it was unknown to science until 2006, when it was discovered using new DNA sequencing technologies.

In people, rhinovirus C infection can be especially severe in children, notes James Gern, another senior author of the study and a professor of allergy and immunology in the UW School of Medicine and Public Health. Gern’s lab was the first to grow rhinovirus C in the laboratory where it could be studied. Gern’s lab also described the receptor that the virus uses to infect cells of the respiratory system.

UW–Madison epidemiologist Tony Goldberg investigating primate disease in Africa. He was dismayed to discover that a human common cold virus was killing healthy chimps. Photo: Ronan Donovan

“In general, this virus seems to affect young children the most,” says Gern, whose lab performs high-throughput viral diagnostics, processing thousands of human samples annually. Gern explains that the genetics of the receptor — which serves like a lock-and-key mechanism that allows the virus to enter and infect a host cell — influences who is likely to be most affected by the virus. Some people have a version of the receptor that makes them highly susceptible to the virus while others have a different version that makes them resistant. For some people (young children, in particular) rhinovirus C infection can be a precursor or complicating factor for asthma.

“Chimps seem to be genetically predisposed to have problems with this virus,” Gern says. “The virus found in Betty was one that looked like it came from a human, and the level of virus in the lung was comparable to what we see in children.”

The authors were also able to examine the DNA of the chimps in Uganda using fecal samples, and they looked at published chimp genomes from across Africa. Goldberg says it was sobering to see that every chimp had the receptor that makes cells exquisitely sensitive to rhinovirus C.  “There’s a species-wide susceptibility of chimps to this virus,” says Goldberg.

Ann Palmenberg, a UW-Madison professor of biochemistry and an authority on cold viruses, says the genome of the virus obtained from Betty shows that the virus came from a human host. “We expected to see changes all over the genome, but it is not a chimp-adapted virus.”

Palmenberg, also a senior author of the study, says the virulence of the virus, with about a 9 percent mortality rate, was remarkable. “That’s why kids with the CDHR3 high-risk mutation are at increased risk for being hospitalized with severe respiratory illness.”

The findings, says Goldberg, are a cautionary tale about human interactions with wild apes.

Goldberg, who has worked in Uganda for years tracking viruses in animals, says outbreaks of respiratory disease in wild chimpanzees are not uncommon, but for the most part they go undiagnosed. In the few cases where causes have been identified, other viruses unrelated to rhinovirus C have been in play.

“In most cases, we don’t find out what it is. We’re thinking that rhinovirus C might be a major, missed cause of disease outbreaks in chimps in the wild,” Goldberg notes.

Unlike other viruses known to cause respiratory disease in chimps, though, rhinovirus C is not typically found in feces and may have been overlooked in the past.

Finding rhinovirus C as the cause of the 2013 outbreak in Uganda was part good luck, says Goldberg. The opportunity to retrieve Betty’s body before it decomposed or scavengers set in was critical. So, too, were Goldberg’s colleagues at Harvard and the University of New Mexico, who run a long-term chimp study in Kibale and can identify all the chimps in the community. This, plus the fact that a Ugandan veterinarian was on hand with the proper tools to obtain and secure samples through a post mortem in the field, made the discovery possible, he says.

From On Wisconsin magazine: The Disease Detective

While California spotted owls (left, adult; right, juvenile) typically perch and roost in smaller trees like this incense cedar, their nest trees are often several feet in diameter. Photo: Danny Hofstadter

Logging of the largest trees in the Sierra Nevada’s national forests ended in the early 1990s after agreements were struck to protect species’ habitat.

But new research reported Dec. 6 in the journal Diversity and Distributions by University of Wisconsin–Madison ecologists shows that spotted owls, one of the iconic species logging restrictions were meant to protect, have continued to experience population declines in the forests.

Department of Forest and Wildlife Ecology graduate student Gavin Jones, Professor Zach Peery, senior scientist R. J. Gutiérrez, and their colleagues say the owls in the area may still be paying an “extinction debt” that was created by historical logging of large trees. These large, old trees the owls rely on are slow to grow back, meaning the owl population could still be showing the effects of logging that ended decades ago.

Researchers in Zach Peery’s lab track spotted owl movements using mini-GPS tags fastened to a backpack harness system. Here, Gavin Jones checks the fit of a newly mounted tag. Photo: Sheila Whitmore

Compared to nearby national parks, which were never extensively harvested, national forests in the area were more extensively logged until the 1992 restrictions on harvesting large trees and logging near owl habitat took effect. The new study shows that spotted owl populations are stable in national parks. But in the more recently logged national forests, the researchers suggest historical logging of the largest trees may be contributing to the continued declines in owl populations they observed.

Diagnosing causes of decline is difficult, says Peery, and factors responsible for owl declines are likely complex. “Other factors we didn’t measure could have contributed to declines too, including contamination of owl prey from rodenticides used as part of illegal marijuana cultivation,” he adds, which has been recently observed in other species in the region like the Pacific fisher, a weasel relative. However, the researchers say owl declines were consistent with observations expected in forests with a deficit of large trees.

The findings could indicate parallels among other species and other habitats around the world. The results also have the potential to inform policy decisions about how to continue protecting sensitive habitats, since existing regulations may require more time to pay off in bolstering species’ populations.

Owls may still be paying an ‘extinction debt’ that was created by historical logging of large trees that ended decades ago.

“The spotted owls’ habitat contains the most economically valuable trees,” says Jones, who is the lead author of the new study. He explains that the ideal spotted owl habitat includes trees that could be more than 6 feet wide and hundreds of feet tall. These giants are often centuries old.

Combined with the owls’ long lifespan, the slow regrowth of very large trees means that population declines caused by habitat loss may both take time to appear and last long after protections are put in place. That lag between cause and effect is termed an “extinction debt.”

California spotted owl nest sites are typically characterized by large trees and a closed canopy. Photo: Danny Hofstadter

To determine whether spotted owls were paying off this debt, Peery’s group traveled to four sites that included three national forests — which had been logged — and two national parks, Kings Canyon and Sequoia, which were left intact. Beginning in 1993, after logging restrictions were established, they surveyed the number of owls each season. That requires a bit of performance from the researchers.

“We wander through the woods at night hooting to ourselves,” Jones says of the surveys they conduct, which attract owls with vocalizations. They can then band individual owls they encounter to track them from season to season. Jones was only 4 years old when the surveys began. “I’m the beneficiary of decades of work,” he says. They also used satellite information to determine the area covered by trees and relied on a new set of data on the size of trees recorded by other scientists.

While the habitat was stable in the once-logged national forests as a result of habitat retention guidelines implemented by the U.S. Forest Service, these areas are characterized by a large-tree deficit. Jones and his colleagues found that the owl populations in these areas had continued to decline — evidence of an extinction debt. In contrast, the nearby national parks hosted stable owl populations, even though their habitat wasn’t actively improving. High-quality owl habitat was about four times more common within owl sites in the national parks as in the national forests.

“We wander through the woods at night hooting to ourselves,” Jones says, which attracts owls with vocalizations. They can then band owls they encounter to track them from season to season.

“There is a shortage of very large, old trees that support spotted owls that take decades to centuries to regenerate,” explains Jones. “Owl populations could stabilize in their forests with a large-tree deficit, but it will take time to regrow the trees they rely on.” He says spotted owls aren’t unique in their plight. “Any species can continue to experience decline after you remove habitat,” he says.

The takeaway, says Jones, is that stabilizing, and even increasing, spotted owl populations might require more than just halting habitat loss. It likely requires restoring the large, ancient trees they rely on to the landscape — and patience.

The study was financially supported by USFS Region 5, USFS Pacific Southwest Research Station, Sierra Nevada Adaptive Management Project (SNAMP), U.S. Fish and Wildlife Service, California Department of Fish and Wildlife, California Department of Forestry and Fire Protection, the Sierra Nevada Conservancy, the University of Minnesota Agricultural Experiment Station, and the University of Wisconsin–Madison.

People who rely on tube feeding, called “enteral nutrition,” often suffer bloating, cramping and gastrointestinal infection, with symptoms that range from annoying to painful to life-threatening.

In experiments with mice, the company’s cranberry derivative has improved key markers for immune response, suggesting that it could help people who must obtain nutrition through feeding tubes — often due to swallowing problems related to cancer, neurological disease, surgery or developmental delay.

Christian Krueger

“About 450,000 people in the United States who rely on tube feeding live at home,” says Christian Krueger, a Synesis co-founder and director of the Reed Laboratories in the Department of Animal Sciences at UW-Madison. “Although they are our initial market, others in medical facilities may also benefit.”

Tube feeding relies on simplified formulas that are easy to ingest, but fail to provide stimulation and variety to the gastrointestinal system, Krueger says. In a mouse study of the gastrointestinal tract published in 2013, Krueger, Jess Reed, a professor of animal sciences, Ken Kudsk, a professor of surgery, and graduate student Joseph Pierre showed that their formula improved the barrier function of mucus and the immunologic activity of the gut-associated lymphoid system.

Overall, says Krueger, “we saw improved immune regulation and signal processing.”

Mucus is a gel that coats the interior lining of the respiratory and gastrointestinal tracts, physically preventing dangerous microbes from contacting cells. “Mucus also contains immune components,” says Krueger, “so if bacteria try to colonize, these components identify them as pathogenic and recruit immune cells to attack. So mucus offers multiple levels of defense.”

The idea was sparked about six years ago when Kudsk, a trauma surgeon at the William S. Middleton Memorial Veterans Hospital in Madison, presented a seminar on the effects of feeding trauma patients through an intravenous or gastric tube. “He noticed that those on IVs were more susceptible to respiratory infections, but when he put the same solution into the stomach, they became less susceptible,” says Krueger. “There is communication between the intestinal and the respiratory immune systems.”

Innovation in enteral feeding

Microscopic images compare the wall of the small intestine after mice were fed food, liquid diet (enteral nutrition), or liquid diet supplemented with tannin. Adding tannins to enteral nutrition counteracts the negative effects of enteral nutrition alone on density and size of the goblet cells that line the small intestine and absorb nutrients from food passing through. Tannin also improves the function of the gut barrier, an immune defense against infection.
Courtesy of Christian Krueger/Synesis

Microscopic images compare the wall of the small intestine after mice were fed food, liquid diet (enteral nutrition), or liquid diet supplemented with tannin. Adding tannins to enteral nutrition counteracts the negative effects of enteral nutrition alone on density and size of the goblet cells that line the small intestine and absorb nutrients from food passing through. Tannin also improves the function of the gut barrier, an immune defense against infection.
Courtesy of Christian Krueger/Synesis

Microscopic images compare the wall of the small intestine after mice were fed food, liquid diet (enteral nutrition), or liquid diet supplemented with tannin. Adding tannins to enteral nutrition counteracts the negative effects of enteral nutrition alone on density and size of the goblet cells that line the small intestine and absorb nutrients from food passing through. Tannin also improves the function of the gut barrier, an immune defense against infection.
Courtesy of Christian Krueger/Synesis

Company co-founder Reed was intrigued that route and type of food had large effects on the gut immune system — and beyond. Knowing that plant chemicals called tannins could interact with the lining of the stomach and intestine, he began the train of research that led to Synesis’s innovation in enteral feeding. Tannin can be derived from many plant structures, including fruits or seeds.

Many plant-based compounds that are not regarded as essential nutrients can be beneficial, Krueger says. “The plant-derived tannin extract is causing the intestine to go on alert. If it sees the same set of simple compounds every day, as happens with conventional enteral formulas, it is not ready for a challenge. If it sees novel things, the guards are forced to pay attention: Is this good or bad?”

The company’s product will be considered a “medical food” by the Food and Drug Administration, Krueger says. “Medical foods are prescribed by a doctor, but they are not prescription drugs.” Although their regulation is more stringent than for conventional foods, it is far below pharmaceuticals, especially since the added tannin will meet the “generally recognized as safe” standard.

“In most cases, these patients have enough problems. We want to make the process of getting necessary nutrition more pleasant, and less troublesome.”

Christian Krueger

Synesis has interviewed hospital dietitians and nutritionists who oversee patients on tube feeding. “They tell us that nothing on the market includes our class of patented compounds, and that they would advocate for them with doctors and patients. Nutritionists understand that nearly everybody should be eating fruits and vegetables, which are part of a healthy diet but are lacking in liquid diets. We believe that adding tannin is a major step toward that more complete diet.”

Synesis maintains offices in Wisconsin Rapids and is jointly owned by BNK Enterprises, also of Wisconsin Rapids, and Complete Phytochemical Solutions of Cambridge.

Synesis was one of 13 finalists in the 2017 Governor’s Business Plan Contest. The path forward includes an application for funding from the Small Business Innovation Research or Small Business Technology Transfer programs. Krueger says Synesis next plans to conduct a small trial of people living at home who need enteral nutrition.

Within 18 months, Krueger says, the plant derivative could be challenging patient immune systems to put up a more active defense against pathogens, leading to significant improvements in quality of life and reductions in mortality. “In most cases, these patients have enough problems,” he says. “We want to make the process of getting necessary nutrition more pleasant, and less troublesome.

“We aim to produce results that are better than what’s on the market. Our goal is to improve health and quality of life.”

The dressing is now cleared by the FDA as a class II medical device, for prescription and over-the-counter use.

Like many dressings now used to treat burns and other persistent wounds, Microlyte Ag contains silver to kill bacteria – but in much smaller quantities.

“Silver is an excellent antimicrobial agent,” says Agarwal, a co-founder of the company in the Madison suburb Fitchburg, “as it is active against a broad range of bacteria and yeast. But the large silver loads found in conventional silver dressings can be toxic to skin cells. Our dressing uses as little as 1 percent as much silver as the competition, and yet the tests we submitted to the FDA showed that Microlyte kills more than 99.99 percent of bacteria that it contacts.”

This chronic pressure sore on an Irish wolfhound received conventional treatment for more than three months at the UW-Madison School of Veterinary Medicine.

Fourteen days after application of Microlyte, the sore is closed and well on its way to healing. Photos: Imbed Biosciences

That kill ratio even appeared in tests against some of the nastiest hospital-acquired superbugs, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus.

Microlyte overcomes a key problem with existing dressings: stiffness. Under a low-power microscope, a wound has bumps and fissures — hiding places for bacteria. The Microlyte dressing inherently adheres to moist surfaces and is so flexible that it drops into the fissures, leading to the sweet combination of greater destruction of bacteria at much lower doses of silver.

Microlyte has several other advantages, Agarwal says. It retains moisture yet is ultrathin and breathable, allowing oxygen to reach the wound and gases to exit, all factors that promote healing. The slow release of the silver means the dressing can remain in place for at least one day. And because the material is a hydrogel (a water-based gel), it can simply be rinsed off as needed before replacement.

Experience with animals shows that the ultra-thin dressing simply sloughs off as the wound heals. All of these advantages should reduce the need to change dressings, which can be so painful that sedation is needed, especially for children.

“Reducing or eliminating dressing changes reduces the pain that the patient experiences,” says co-founder Michael Schurr, chair of general surgery at the Mountain Area Health Education Center in Asheville, North Carolina, and adjunct professor of surgery at the University of North Carolina. “It also reduces costs in supplies and reduces the burden to the health care system that supplies visiting nurses to do the dressing changes.”

“We are seeing in a limited number of cases that it does provide us with a remarkable new tool for dealing with chronic wounds” in dogs and cats treated at the UW-Madison School of Veterinary Medicine, says Jonathan McAnulty, chair of the Department of Surgical Sciences. “We certainly have no reason to think that this will be different with humans,” adds McAnulty, who is also a company co-founder. “The principles are the same, and a lot of the problems are the same.”

Imbed’s Microlyte dressing is applied to a wound on a pig. The ultra-thin dressing conforms to the wound, bringing the antimicrobial silver into direct contact with bacteria. Photo: Imbed Biosciences

The dramatic closure of wounds that have resisted months of conventional treatment “suggests that chronic bacterial contamination of the wound surface, even when it looks relatively healthy, is a significant factor inhibiting healing in many cases,” McAnulty says. “Once we treat with our dressing, we start to see very dramatic closure of these wounds.”

McAnulty says he’s starting to use Microlyte earlier in treatment. “Certainly it seems appropriate for prevention of infection as well as treatment.”

The ultra-thin dressing material was invented in the lab of Nicholas Abbott, a UW–Madison professor of chemical and biological engineering, when Agarwal was a postdoctoral fellow and where he is now an honorary associate scientist.

The dressing will compete in the $2 billion market sector of “advanced wound dressings,” which are used to treat diabetic ulcers, venous ulcers, burns, bedsores and other difficult wounds.

Imbed has 10 employees. The company is developing other ideas for wound treatment and discussing commercial-scale production of Microlyte. Currently, it plans to reach the market through licensing agreements with hospital suppliers.

Research reported in this press release was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under award number R44AR061913.