For the project, researchers teamed up with scientists at the Pontificia Universidad Javeriana in Colombia and officials at . The team hopes that data on small animals’ movements will inform plans to expand the park and connect it to other nearby protected areas.

Previously, it was impossible to collect movement data for hummingbirds and other small animals in the region. The team set up an automated radio telemetry grid in the , a high-altitude region in the Andes more than 10,000 feet above sea level. Their technology generates fine-scale resolution and continuous location estimates for individual animals, collecting in millions of data points that provide information on species’ habitat requirements, movement patterns and seasonal occurrence, all of which are critical for developing landscape-level management practices and avoiding local extinctions.

“Hummingbirds might not get the same buzz that bees do when it comes to the ecosystem services they provide, but they’re hugely important pollinators all the same,” said co-author , a 91̽��doctoral student in biology. “If you think about it in practice, it’s very challenging to protect an animal when you don’t know where or how far it moves each day, or what kinds of habitats it prefers. The fact that these questions are still largely unanswered when it comes to hummingbirds means that there remains a lot of important work to be done!”

The researchers used backpack-like harnesses to attach tiny transmitters to the hummingbirds. Since the birds themselves weigh at most about 10 grams, which is almost as heavy as an Oreo cookie, the transmitters had to be incredibly light – less than 500 milligrams, or the weight of a Tic Tac. The transmitter included a solar panel, providing it power for the bird’s lifetime. In early 2023, the researchers placed tags on 10 adult hummingbirds from two species, Great Sapphirewing and Bronze-tailed Thornbills, and followed the birds’ movements for up to 100 days.

“Through this, we have been able to obtain information on foraging routines, home ranges and seasonality,” said lead author , a graduate student at the University of Aberdeen. “This information increases our understanding about biodiversity in tropical mountains and is also useful to protect these species, as well as their key ecosystem roles as pollinators, in the face of ongoing climate and land use change.”

The study is the first to use automated radio signals in a high-mountain ecosystem to track the movements of animals, according to Rueda Uribe. It is also one of only a handful to try to track animal movements across terrain difficult for humans to trek across. The team plans to compare its findings about high-altitude hummingbird movements to data already collected by the team at the Colibrí Gorriazul Research Center, a separate mid-elevation site in the Andes.

The system prototyped in this study could easily be adapted to learn about small animals’ movements in other ecosystems, which directly impacts communities in the region.

“To know how to best conserve nature, we need to understand it fully, and this is opening the door to heretofore underexplored aspects of these small and elusive animals’ daily choices,” said co-senior author , a 91̽��assistant professor of biology and curator of ornithology at the 91̽��. “This is especially important for the ��á�������� biome, which maintains water sources for other ecosystems down the mountains and for humans as well. It is a tremendous biodiversity hotspot that is comparatively less studied and much more threatened because of climate change and human-driven shifts in land use.”

Other co-authors on the study are María Ángela Echeverry-Galvis, professor at the Pontificia Universidad Javeriana; Pedro Camargo-Martínez of the Chingaza National Natural Park; of Queen’s University Belfast; and and , both professors at the University of Aberdeen. The research was funded by the U.K. Biotechnology and Biological Sciences Research Council, the U.K. Natural Environment Research Council, Walt Halperin Endowed Professorship at the UW, the 91̽��Orians Award for Tropical Studies, the 91̽��Margo and Tom Wyckoff Award, the National Science Foundation, the Rufford Foundation and the University of Aberdeen.

For more information, contact Rico-Guevara at colibri@uw.edu.  

Adapted from a by the University of Aberdeen.

A team led by researchers at the 91̽�� and the National Oceanic and Atmospheric Administration has uncovered key information about what resident killer whale populations are eating. Researchers had long known that resident killer whales — also known as resident orcas — prefer to hunt fish, particularly salmon. But some populations thrive, while others have struggled. Scientists have long sought to understand the role that diet plays in these divergent fates.

“Killer whales are incredibly intelligent, and learn foraging strategies from their matriarchs, who know where to find the richest prey resources in their regions,” said , 91̽��assistant professor of aquatic and fishery sciences, who began this study as a postdoctoral researcher with NOAA’s . “So we wanted to know: Does all of that social learning affect diet preferences in different populations of resident killer whales, or in pods within populations?”

In a published Sept. 18 in the journal Royal Society Open Science, Van Cise and her colleagues report the cuisine preferences of two resident killer whale populations: the Alaska residents and the southern residents, which reside primarily in the Salish Sea and off the coast of Washington, British Columbia, Oregon and northern California. The two populations show broad preference for salmon, particularly Chinook, chum and coho. But they differ in when they switch to hunting and eating different salmon species, as well as the other fish species they pursue to supplement their diets.

Southern resident killer whales are critically endangered, while other populations are growing. This new study will inform conservation efforts for resident killer whales from northern California to the Gulf of Alaska.

“We know that lack of food is one of the main threats facing the endangered southern resident killer whales,” said Van Cise. “We figured that if we could compare their diet to the dietary habits of a healthy and growing population, it might help us better understand how we can steward and protect this vulnerable population.”

While the rivers of Alaska, British Columbia and the Pacific Northwest have historically provided resident killer whales with abundant levels of salmon, humans have recently disrupted this food supply — both directly by polluting waters and building dams that reduce salmon runs, and indirectly by generating noise pollution that interferes with hunting. In addition, in the latter half of the 20th century, resident killer whales — particularly southern residents — were captured and penned in amusement parks, which disrupted their social structure and further reduced their numbers.

This anthropogenic impact has left its mark. While Alaska resident killer whales number in the thousands and the northern resident killer whale population is growing steadily, southern resident killer whale numbers have plateaued at approximately 75 individuals. Recent research has implicated noise pollution from cargo vessels and higher rates of pregnancy failure as factors.

For this study, the team from 2011 to 2021 collected fecal samples from both southern resident and Alaska resident killer whales at various points during the year. The researchers analyzed DNA in the fecal samples to determine what the killer whales were eating. They discovered that the summer diet of Alaska residents included more chum and coho salmon, in contrast to the Chinook-heavy summer diet of a southern resident killer whale.

“Chinook are clearly an important resource for resident killer whales in any population. They’re large and energy-rich, which makes them a delicious and nutritious meal,” said Van Cise. “But what we’ve learned from the Alaska residents is that stable sources of other fishes — chum and coho salmon, even flatfishes like arrowtooth flounder — may be an important nutritional supplement helping this population thrive.”

In recent years the team has obtained more fecal samples outside of the summer months. Those samples revealed an unexpectedly diverse diet for resident killer whales. Sablefish, arrowtooth flounder, lingcod, Pacific halibut and big skate all feature in the diets of these whales, which were previously thought to eat salmon exclusively. The two populations differ in the non-salmon species they choose to supplement their diet, and when they switch among species. These dietary patterns reflect a delicate balance between regional abundance of different fish species, as well as a matriarch’s knowledge of reliable foraging locations.

“The survival of her family depends on whether the foraging sites she knows are reliable from year to year,” said Van Cise.

In both the United States and Canada, resident killer whales have gained fame, particularly the very public plight of southern residents. The team believes that their findings and follow-up dietary studies are key to aiding their recovery.

“While protecting key populations of Chinook salmon will always be vital to supporting the recovery of the endangered southern resident killer whale population, this study has taught us that we might need to think more holistically about how we can conserve the whole ecosystem of fishes that together make up the annual diet of predator populations like this one,” said Van Cise.

Co-authors on the study are M. Bradley Hanson, Candice Emmons and Kim Parsons of NOAA’s Northwest Fishery Science Center; Dan Olsen and Craig Matkin of the Alaska-based North Gulf Oceanic Society; and Abigail Wells of Lynker Technologies. The research was funded by the North Gulf Oceanic Society, the National Fish and Wildlife Federation, Shell, SeaWorld, NOAA, the Exxon Valdez Trustee Council and the U.S. Marine Mammal Commission.

For more information, contact Van Cise at avancise@uw.edu.��

The Salish Sea — the inland coastal waters of Washington and British Columbia — is home to two unique populations of fish-eating orcas, the northern resident and the southern resident orcas. Human activity over much of the 20th century, including reducing salmon runs and capturing orcas for entertainment purposes, decimated their numbers. This century, the northern resident population has steadily grown to more than 300 individuals, but the southern resident population has plateaued at around 75. They remain critically endangered.

New research led by the 91̽�� and the National Oceanic and Atmospheric Administration has revealed how underwater noise produced by humans may help explain the southern residents’ plight. In a published Sept. 10 in Global Change Biology, the team reports that underwater noise pollution — from both large and small vessels — forces northern and southern resident orcas to expend more time and energy hunting for fish. The din also lowers the overall success of their hunting efforts. Noise from ships likely has an outsized impact on southern resident orca pods, which spend more time in parts of the Salish Sea with high ship traffic.

“Vessel noise negatively impacts every step in the hunting behavior of northern and southern resident orcas: from searching, to pursuing and finally capturing prey,” said lead author , a senior research scientist at the UW’s , who began this study as a postdoctoral researcher with NOAA’s . “It shines a light on why southern residents in particular have not recovered. One factor hindering their recovery is availability and accessibility of their preferred prey: salmon. When you introduce noise, it makes it even harder to find and catch prey that is already hard to find.”

Northern and southern resident orcas search for food via echolocation. Individuals transmit short clicks through the water column that bounce off other objects. Those signals return to orcas as echoes that encode information about the type of prey, its size and location. If the orcas detect salmon, they can initiate a complex pursuit and capture process, which includes intensified echolocation and deep dives to try to trap and capture fish.

The team — which also includes scientists at Fisheries and Oceans Canada, Wild Orca, the Cascadia Research Collective and the University of Cumbria in the U.K. — analyzed data from northern and southern resident orcas, whose movements were tracked using digital tags, or “Dtags.” The cellphone-sized Dtags, which attach noninvasively just below an orca’s dorsal fin via suction cups, collect data on three-dimensional body movements, position, depth and other environmental data including — critically — the sound levels at the whales’ locations.

“Dtags are a critical innovation for us to understand firsthand the environmental conditions that resident orcas experience,” said Tennessen. “They open a window into what orcas are hearing, their echolocation behavior and the very specific movements they initiate when they hunt for prey.”

The researchers analyzed data from 25 Dtags placed on northern and southern resident orcas for several hours on specific days from 2009 to 2014. The team’s deep dive into Dtag data showed that vessel noise, particularly from boat propellers, raised the level of ambient noise in the water. The increased noise interfered with the orcas’ ability to hear and interpret information about prey conveyed via echolocation. For every additional decibel increase in maximum noise levels around orcas, the researchers observed:

• An increased chance of male and female orcas searching for prey
• A lower chance of females pursuing prey
• A lower chance that both males and females would actually capture prey

Dtags also recorded “deep dive” hunting attempts by orcas. Out of 95 such attempts, most occurred in low or moderate noise. But six deep-hunting dives occurred in particularly loud settings, only one of which was successful.

The team found that noise had a disproportionately negative impact on females, who were less likely to pursue prey that had been detected during noisy conditions. Dtag data did not indicate the reason, though potential explanations include a reluctance to leave vulnerable calves at the surface while engaging prey in long chases that may not be fruitful, and the pressure for lactating females to conserve energy. Though southern resident orcas often share captured prey with one another, the impact of noise may contribute to nutritional stress among females, which previous research has linked to high rates of pregnancy failure among southern residents.

Reducing vessel speeds leads to quieter waters for the orcas. Both sides of the U.S.-Canada border include voluntary speed-reduction programs for vessels: the , initiated in 2014 by the Vancouver Fraser Port Authority, and , launched in 2021 for Washington state waters. But reducing noise is only one factor in saving southern resident orcas and helping northern residents continue to recover.

“When you factor in the complicated legacy we’ve created for the resident orcas — habitat destruction for salmon, water pollution, the risk of vessel collisions — adding in noise pollution just compounds a situation that is already dire,” said Tennessen. “The situation could be turned around, but only with great effort and coordination on our part.”

Co-authors on the paper are Marla Holt, Brad Hanson and Candice Emmons with NOAA’s Northwest Fisheries Science Center; Brianna Wright and Sheila Thornton with Fisheries and Oceans Canada; Deborah Giles with Wild Orca and the UW’s Friday Harbor Laboratories; Jeffrey Hogan with the Cascadia Research Collective; and Volker Deecke with the University of Cumbria. The research was funded by NOAA, Fisheries and Oceans Canada, the University of Cumbria, the Marie Curie Intra-European Fellowship, the University of British Columbia and the Natural Sciences and Engineering Research Council of Canada.

For more information, contact Tennessen at jtenness@uw.edu.

The overlap between humans and animals will increase substantially across much of the planet in less than 50 years due to human population growth and climate change, according to a collaborative study by scientists at the University of Michigan, the 91̽�� and University College London. The was published Aug. 21 in Science Advances.

By 2070, the overlap between humans and more than 22,000 vertebrate species will rise across nearly 57% of Earth’s land, according to the team.

“This gives us an early warning of where we may expect to see future increases in habitat degradation, human-wildlife conflict or biodiversity loss,” said co-author , a 91̽��assistant professor of biology in the Center for Ecosystem Sentinels. “We especially need to pay attention to forested areas, which is where we project much of the increase in human-wildlife overlap to occur.”

In contrast, less than 12% of land globally will see a decrease in habitat sharing between people and other animals.

Understanding where the overlap is likely to occur — and which animals are likely to interact with humans in specific areas — will help urban planners, conservationists and countries meet their international conservation commitments.

To calculate future human-wildlife overlap, the researchers created an index that combined estimates of where people are likely to live with the spatial distributions of 22,374 species of land-based amphibians, reptiles, birds and mammals.

“The index we created showed that the majority of global lands will experience increases in human-wildlife overlap, and this increasing overlap is the result of the expansion of human population much more so than changes in species distributions caused by climate change,” said lead author Deqiang Ma, a postdoctoral researcher at the University of Michigan.

For the index, they drew information about the spatial distribution of vertebrates from previously published data, which also forecasts where species will live based on their ecological and climactic niches. Their estimates of where people are likely to live were based on projections of economic development, global society and demographics.

“In many places around the world, more people will interact with wildlife in the coming decades, and often those wildlife communities will comprise different kinds of animals than the ones that live there now,” said senior author , an associate professor of environment and sustainability at the University of Michigan. “This means that all sorts of novel interactions, good and bad, between people and wildlife will emerge in the near future.”

The researchers found that areas that have high levels of human-wildlife overlap today — and are predicted to see high overlap in 2070 — are largely concentrated in regions where human population density is already high, including China and India. In addition, they project that human-wildlife overlap will increase in forested areas, particularly in Africa and South America, two continents with high levels of biodiversity threatened by human activity. They predict that median species richness — the variety of species in a given area — will decrease across most forests on both continents.

But preserving biodiversity has real benefits, according to the study. For example, part of their analysis, which was led by Ma, looked at birds that eat insects in agricultural areas and examined where those birds will go under climate change. They found that more than two-thirds of the croplands that will likely experience an increase of human-wildlife overlap by 2070 will see a decline in bird species that can help reduce crop pests. Studies have also shown that scavengers such as vultures and hyenas play critical roles by clearing waste from urban areas and other landscapes, which reduces the prevalence of rabies, anthrax, bovine tuberculosis and other diseases.

“This research can help us identify which human communities, wildlife species and geographies are likely to feel the compounded effects of future societal and environmental changes,” said Abrahms. “For example, not only will certain human communities have to contend with the direct stressors of climate change, but they will also have to contend with shifting human-wildlife interactions as a result. The same is true for wildlife communities.”

Future conservation strategies will have to evolve, especially in regions that previously haven’t seen much human settlement, according to the researchers. In the past, a core conservation strategy was to establish protected areas where human access is restricted. This is becoming harder to implement because there are fewer such places.

“There’s also a significant environmental justice argument around the validity of telling communities that may have lived in a certain area for generations that they have to move,” said Carter. “Our study suggests that with more areas of the world expected to be shared both by people and wildlife, conservation planning will have to get more creative and inclusive.”

Conservationists will need to engage local communities to build interest in helping improve the conservation process. This process may include establishing habitat corridors to connect protected areas or other conservation innovations, such as establishing temporary protected areas during critical periods for wildlife, like breeding seasons.

“We care a lot about which areas can support populations of endangered species, like tigers, and how human communities interact with these species,” said Carter. “In some places it’s going to be really hard to do everything at once: to grow crops and have urban areas and protect these species and their habitats. But if we can start planning now, we have a lot of tools to help us promote sustainable coexistence.”

Co-authors on the study are Jacob Allgeier and Brian Weeks with the University of Michigan, and with University College London. The research was funded by the University of Michigan, the David and Lucile Packard Foundation and the Royal Society.

For more information, contact Abrahms at abrahms@uw.edu.

Adapted from a by the University of Michigan.

Humans drove wolves to extinction in Washington state around the 1930s. Thanks to conservation efforts, by about 80 years later, wolves had returned — crossing first from the Canadian border into Washington around 2008 and later entering the state from Idaho. Since then, wolf numbers in Washington have been steadily growing, raising questions about what the return of this large predator species means for ecosystems and people alike.

In northeast Washington, where wolves have recovered most successfully, researchers from the 91̽�� and the Washington Department of Fish and Wildlife tracked one of their primary prey — white-tailed deer — in part to see what impact wolf packs are having on deer populations. The answer? So far, wolves aren’t having as much of an impact on deer as other factors.

In a published June 18 in Ecological Applications, the team reports that the biggest factors shaping white-tailed deer populations in northeast Washington are the quality of habitat available and a different, long-established large predator in the state: the cougar, also known as the mountain lion or puma. Wolves were a distant third in their impact.

“A big take-away from this study is that wolves are not returning to empty landscapes. These are places with humans and other carnivore species, like cougars, which will affect the impact that wolves can have,” said lead author , who conducted this research for her 91̽��doctoral degree as part of the . “This area has a relatively high human footprint compared to other areas where wolves have been studied. These are not national parks or dense, old-growth forests. They are areas with active logging, farming, ranching and towns. Our findings show that these factors are likely limiting the impact of wolves on one of their primary food sources.”

It’s not that wolves aren’t preying on white-tailed deer. According to the study, they are, just not enough to take a large bite out of the population as a whole.

White-tailed deer are widespread east of the Cascades. The state’s highest-density population of this species lies within the study area, which includes farmland and timber forests in parts of Stevens and Pend Oreille counties in northeast Washington. For the study, researchers radio-collared 280 white-tailed deer, 14 wolves, 50 cougars, 28 coyotes and 33 bobcats from 2016 to 2021. At the time of collaring, the researchers also noted vital statistics, including body condition, age and whether females were pregnant. When collared animals died, the team conducted a mortality investigation, if possible, and attempted to determine the cause of death.

The team, which also includes researchers with Washington State University and the Spokane Tribe of Indians, used the resulting dataset to estimate the growth rate of the white-tailed deer population over the four-year study, and to identify the major factors shaping it. The analysis determined that the white-tail population in the study area was likely stable, or slightly declining, but that wolves were not largely responsible.

The biggest factor impacting the deer population was habitat quality, including the amount of forage available for deer. For white-tailed deer, which are highly adaptable to human activity, foraging sites can range from forests and shrublands to agricultural fields. The study area includes both agricultural land and forests recently harvested for timber, both of which could provide deer with high-caloric density foraging sites, according to Ganz.

After habitat quality, the study found that predation by cougars had a smaller effect on the white-tailed population. Wolf predation had a still smaller impact. Bobcats and coyotes — both medium-sized predators — had a negligible impact on deer numbers.

“Studies like this provide valuable insights about the complexity of these systems and how managing predator and prey populations is challenging and dynamic,” said co-author Melia DeVivo, a research scientist with the WDFW. “It’s important to continue evaluating these systems to understand the impacts of management decisions. Prior to this study, one might have expected that relying solely on wolf management strategies would result in a booming deer population, when it is clearly more complex than that.”

Since their return, the number of wolves in Washington has risen steadily, reaching a minimum of 260 in 2023, according to state researchers. Four wolf packs reside in the northeast Washington Predator-Prey Project study area. The total number of wolves in the study area — about 23 — remained steady overall during the research period.

The team’s findings contrast with studies of long-established wolf populations in protected areas, like Yellowstone National Park, which show a higher impact of wolves on the population dynamics of their prey species. To the authors of this new study, those differences highlight the importance of studying wolves in a variety of habitats.

“This study reminds us that the population dynamics of predator and prey species can vary quite a bit,” said senior author , a 91̽��associate professor of environmental and forest sciences. “Habitat quality, the species that are present and the degree of human activity all affect the impact that large predators like wolves will have. It’s critical to compare different types of sites.”

The paper is part of the Washington Predator-Prey Project, a partnership between the 91̽��and the WDFW to investigate the impact of the wolves’ return on state ecosystems. Additional co-authors are , a 91̽��doctoral alum in environmental and forest sciences; Lauren Satterfield, a 91̽��doctoral student in environmental and forest sciences; biologists Brian Kertson and Benjamin Turnock with the WDFW; , a professor at WSU; Savannah Walker and Derek Abrahamson, both biologists with the Spokane Tribe of Indians; , a 91̽��associate professor of environmental and forest sciences; and , a 91̽��professor of environmental and forest sciences. The research was funded by WDFW, the National Science Foundation, the Rocky Mountain Elk Foundation, and the 91̽��College of the Environment.

For more information, contact Ganz at trganz@uw.edu.

Spending time in nature is good for us. Studies have shown that contact with nature can lift our well-being by . Even brief exposure to nature can help. One well-known study found that hospital patients recovered faster .

Knowing more about nature’s effects on our bodies could not only help our well-being, but could also improve how we care for land, preserve ecosystems and design cities, homes and parks. Yet studies on the benefits of contact with nature have typically focused primarily on how seeing nature affects us. There has been less focus on what the nose knows. That is something a group of researchers wants to change.

“We are immersed in a world of odorants, and we have a sophisticated olfactory system that processes them, with resulting impacts on our emotions and behavior,” said , a 91̽�� assistant professor of environmental and forest sciences. “But compared to research on the benefits of seeing nature, we don’t know nearly as much about how the impacts of nature’s scents and olfactory cues affect us.”

In a published May 15 in Science Advances, Bratman and colleagues from around the world outline ways to expand research into how odors and scents from natural settings impact our health and well-being. The interdisciplinary group of experts in olfaction, psychology, ecology, public health, atmospheric science and other fields are based at institutions in the U.S., the U.K., Taiwan, Germany, Poland and Cyprus.

At its core, the human sense of smell, or olfaction, is a in constant operation. The nose is packed with hundreds of olfactory receptors, which are sophisticated chemical sensors. Together, they can , and that information gets delivered directly to the nervous system for our minds to interpret — consciously or otherwise.

The natural world releases a steady stream of chemical compounds to keep our olfactory system busy. Plants in particular exude , that can persist in the air for hours or days. VOCs perform many functions for plants, such as repelling herbivores or attracting pollinators. Some researchers have studied the impact of exposures to plant VOCs on people.

“We know bits and pieces of the overall picture,” said Bratman. “But there is so much more to learn. We are proposing a framework, informed by important research from many others, on how to investigate the intimate links between olfaction, nature and human well-being.”

Nature’s smell-mediated impacts likely come through different routes, according to the authors. Some chemical compounds, including a subset of those from the invisible realm of plant VOCs, may be acting on us without our conscious knowledge. In these cases, olfactory receptors in the nose could be initiating a “subthreshold” response to molecules that people are largely unaware of. Bratman and his co-authors are calling for vastly expanded research on when, where and how these undetected biochemical processes related to natural VOCs may affect us.

Other olfactory cues are picked up consciously, but scientists still don’t fully understand all their impacts on our health and well-being. Some scents, for example, may have “universal” interpretations to humans — something that nearly always smells pleasant, like a sweet-smelling flower. Other scents are closely tied to specific memories, or have associations and interpretations that vary by culture and personal experience, as research by co-author of the University of Oxford has shown.

“Understanding how olfaction mediates our relationships with the natural world and the benefits we receive from it are multi-disciplinary undertakings,” said Bratman. “It involves insights from olfactory function research, Indigenous knowledge, Western psychology, anthropology, atmospheric chemistry, forest ecology, — or ‘forest bathing’ — neuroscience, and more.”

Investigation into the potential links between our sense of smell and positive experiences with nature includes research by co-author at University College London, which shows that the cultural significance of smells, including those from nature, can be passed down in communities to each new generation. Co-author at Birmingham City University has delved into the associations people have with scents in built environments and urban gardens.

Other co-authors have shown that nature leaves its signature in the very air we breathe. Forests, for example, release a complex chemical milieux into the air. Research by co-author at the Max Planck Institute for Chemistry and the Cyprus Institute shows how natural VOCs can react and mix in the atmosphere, with repercussions for olfactory environments.

The authors are also calling for more studies to investigate how human activity alters nature’s olfactory footprint — both by pollution, which can modify or destroy odorants in the air, and by reducing habitats that release beneficial scents.

“Human activity is modifying the environment so quickly in some cases that we’re learning about these benefits while we’re simultaneously making them more difficult for people to access,” said Bratman. “As research illuminates more of these links, our hope is that we can make more informed decisions about our impacts on the natural world and the volatile organic compounds that come from it. As we say in the paper, we live within the chemical contexts that nature creates. Understanding this more can contribute to human well-being and advance efforts to protect the natural world.”

Other 91̽��co-authors on the paper are , profess of psychology; , a graduate student in the School of Environmental and Forest Sciences; and , a clinical associate professor of environmental and occupational health sciences. Additional co-authors are of Stanford University; at the University of Pennsylvania; Thomas Hummel of the Dresden University of Technology; of the University of California, Berkeley; John Miller of Wildwood|Mahonia; Anna Oleszkiewicz of the University of Wrocław; of Oregon Health and Sciences University; of the Monell Chemical Senses Center; and of Harvard University; and Chia-Pin Yu of National Taiwan University.

For more information, contact Bratman at bratman@uw.edu.

There are 154 national forests in the United States, covering nearly 300,000 square miles of forests, woodlands, shrublands, wetlands, meadows and prairies. These lands are increasingly recognized as vital for supporting a broad diversity of plant and animal life; for water and nutrient cycling; and for the human communities that depend on forests and find cultural and spiritual significance within them. Forests could also be potential bulwarks against climate change. But, increasingly severe droughts and wildfires, invasive species, and large insect outbreaks — all intensified by climate change — are straining many national forests and surrounding lands.

A by a team of 40 experts outlines a new approach to forest stewardship that “braids together” Indigenous knowledge and Western science to conserve and restore more resilient forestlands. Published March 25, the report provides foundational material to inform future work on climate-smart adaptive management practices for land managers.

“Our forests are in grave danger in the face of climate change,” said , an associate dean of forestry at Oregon State University. “By braiding together Indigenous knowledge with Western science, we can view the problems with what is known as ‘Two-Eyed Seeing,’ to develop a path forward that makes our forests more resilient to the threats they are facing. That is what this report is working to accomplish.”

Eisenberg co-led the report team with , a fire ecologist in the School of Environmental and Forest Sciences at the 91̽��.

“Climate change is stressing these forests even as they are considered for their potential role in slowing rates of climate change,” said Prichard. “We want this report to provide not just guidance, but also hope — hope in the practical measures we can take now to promote resiliency and help forests thrive.”

Initiated by interest from the Forest Service on Indigenous knowledge and Western science, the report stems from direction to protect old and mature forests outlined in , signed by President Joe Biden in April 2022. These types of forests, some hundreds of years old, are often dominated by larger trees, with fewer seedlings and saplings. Some management practices over the past century have made many of these forests vulnerable to drought, fire, insects and other stressors, all of which will likely increase with climate change.

The executive order included guidance on strengthening relationships with tribal governments and emphasized the importance of Indigenous knowledge, a theme highlighted repeatedly in the new report. This knowledge includes the time-tested practices of Indigenous stewardship that for millennia shaped forest structure and species composition. Following European colonization, these practices were sharply curtailed by genocide, displacement, and forced assimilation of Indigenous peoples. Western scientists increasingly recognize that Indigenous stewardship practices built and maintained forests that were more resilient and ecologically diverse than today.

Many Indigenous cultures, for example, used a practice called intentional burning — also known as cultural burning — which decreased forest density, promoted healthy understory growth, and hosted a broad diversity of plant and animal life. These practices over time yielded “mosaics” of forests made up of diverse patches of trees varying in age, density, and overstory and understory composition. These “mosaic” forests are less prone to the types of large, severe wildfires that have burned swathes of North American forests this century, according to Prichard.

Other members of the core leadership team for the report are , a senior research ecologist with the Forest Service’s Pacific Northwest Research Station, and , a professor and director of the Center for the Future of Forests and Society at OSU.

“Two powerful ideas we heard from our Indigenous colleagues in developing this are those of reciprocity and the seven generations principle. Collectively, the writing team agrees that we can frame a more sustainable land ethic with these ideas,” said Hessburg. “These perspectives guided our recommendations, which suggest taking from the land and giving back in equal measure, and proactively stewarding these lands with seven generations in mind.”

come from tribal nations, universities, U.S. Forest Service research stations, consulting groups, Natural Resources Canada, Parks Canada, and Tall Timbers Research Station and Land Conservancy.

“Our report is deeper than changes in policy and management — it proposes a fundamental change in the worldview guiding our current practices,” said Nelson. “Our writing team’s cultural, geographic and disciplinary diversity allows for guidance on a shift in paradigms around how we approach forest stewardship in the face of climate change.”

The report may also inform Forest Service work on the proposed national forest land plan intended to steward and conserve old-growth forest conditions.

“We are very interested in understanding how Indigenous knowledge can be used in combination with western science to improve our management of all forest conditions including old growth,” said Forest Service Deputy Chief Chris French. “This report is a big step in improving our understanding of how to do that.”

The report is available for download , along with an interactive map highlighting more than 50 examples of forest adaptation strategies. It was funded by the U.S. Forest Service, the Resources Legacy Fund, the 444S Foundation, the Doris Duke Charitable Foundation, the Gordon and Betty Moore Foundation, and the Wilburforce Foundation.

For more information, contact Prichard at sprich@uw.edu, Hessburg at paul.hessburg@usda.gov, Eisenberg at Cristina.Eisenberg@oregonstate.edu, and the Forest Service press office at sm.fs.pressoffice@usda.gov.

Alaskan waters are a critical fishery for salmon. Complex marine food webs underlie and sustain this fishery, and scientists want to know how climate change is reshaping them. But finding samples from the past isn’t easy.

“We have to really open our minds and get creative about what can act as an ecological data source,” said , currently a postdoctoral researcher at the Peabody Museum of Natural History at Yale University.

As a doctoral student at the 91̽�� in Seattle, Mastick investigated Alaskan marine food webs using a decidedly unorthodox source: old cans of salmon. The cans contained fillets from four salmon species, all caught over a 42-year period in the Gulf of Alaska and Bristol Bay. Mastick and her colleagues dissected the preserved fillets from 178 cans and counted the number of anisakid roundworms — a common, tiny marine parasite — within the flesh.

The parasites had been killed during the canning process and, if eaten, would have posed no danger to a human consumer. But counting anisakids is one way to gauge how well a marine ecosystem is doing.

“Everyone assumes that worms in your salmon is a sign that things have gone awry,” said , a 91̽��associate professor of aquatic and fishery sciences. “But the anisakid life cycle integrates many components of the food web. I see their presence as a signal that the fish on your plate came from a healthy ecosystem.”

The research team reports in a published April 4 in Ecology & Evolution that anisakid worm levels rose for chum and pink salmon from 1979 to 2021, and stayed the same for coho and sockeye salmon.

“Anisakids have a complex life cycle that requires many types of hosts,” said Mastick, who is lead author on the paper. “Seeing their numbers rise over time, as we did with pink and chum salmon, indicates that these parasites were able to find all the right hosts and reproduce. That could indicate a stable or recovering ecosystem, with enough of the right hosts for anisakids.”

Anisakids start out living freely in the ocean. They enter food webs when eaten by small marine invertebrates, such as krill. As that initial host gets eaten by another species, the worms come along for the ride. Infected krill, for example, could be eaten by a small fish, which in turn gets eaten by a larger fish, like salmon. This cycle continues until the anisakids end up in the intestine of a marine mammal, where they reproduce. The eggs are excreted back into the ocean to hatch and begin the cycle again with a new generation.

“If a host is not present — marine mammals, for example — anisakids can’t complete their life cycle and their numbers will drop,” said Wood, who is senior author on the paper.

People cannot serve as hosts for anisakids. Consuming them in fully cooked fish poses little danger, because the worms are dead. But anisakids — also known as “sushi worms” or “sushi parasites” — can cause symptoms similar to food poisoning or a rare condition called if ingested alive in raw or undercooked fish.

The , a Seattle-based trade group, donated the cans of salmon to Wood and her team. The association no longer needed the cans, which had been set aside each year for quality control purposes. Mastick and co-author Rachel Welicky, an assistant professor at Neumann University in Pennsylvania, experimented with different methods to dissect the canned fillets and look for anisakids. The worms are about a centimeter (0.4 inches) long and tend to coil up in the fish muscle. They found that pulling the fillets apart with forceps allowed the team to count worm corpses accurately with the aid of a dissecting microscope.

There are several explanations for the rise of anisakid levels in pink and chum salmon. In 1972, Congress passed the , which has allowed populations of seals, sea lions, orcas and other marine mammals to recover following years of decline.

“Anisakids can only reproduce in the intestines of a marine mammal, so this could be a sign that, over our study period — from 1979 to 2021 — anisakid levels were rising because of more opportunities to reproduce,” said Mastick.

Other possible explanations include warming temperatures or positive impacts of the Clean Water Act, Mastick added.

The stable anisakid levels in coho and sockeye are harder to interpret because there are dozens of anisakid species, each with their own series of invertebrate, fish and mammal hosts. While the canning process left the tough anisakid exterior intact, it destroyed the softer parts of their anatomy that would have allowed identification of individual species.

Mastick and Wood believe this approach could be used to look at parasite levels in other canned fish, like sardines. They also hope this project will help make new, serendipitous connections that could fuel additional insight into ecosystems of the past.

“This study came about because people heard about our research through the grapevine,” said Wood. “We can only get these insights into ecosystems of the past by networking and making the connections to discover untapped sources of historical data.”

Co-authors on the paper are 91̽��undergraduate Aspen Katla, and Bruce Odegaard and Virginia Ng with the Seafood Products Association. The research was funded by the U.S. National Science Foundation, the Alfred P. Sloan Foundation, the Washington Research Foundation and the 91̽��.

For more information, contact Mastick at nataliemastick@gmail.com, Welicky at rwelicky@gmail.com and Wood at chelwood@uw.edu.

, a 91̽�� assistant professor of biology and researcher with the 91̽��, has been named a 2023 Packard Fellow for Science and Engineering, according to an Oct. 16 from the David and Lucille Packard Foundation. As one of 20 new fellows across the country, Abrahms, who holds the Boersma Endowed Chair in Natural History and Conservation, will receive $875,000 over five years for her research.

Abrahms studies how wildlife across the globe are changing behaviors in response to human-caused environmental change. Her research probes both the specific causes and consequences of behavioral changes, like altering migration routes, pursuing different food sources and changing the timing of important life events, such as breeding. She is particularly interested in how climate change is bringing large animals — from whales to lions — into more frequent contact with people. Abrahms and her team have shown that climate change is increasing human-wildlife conflicts globally.

“While we know that climate change is having profound impacts on both ecological and human communities, there is very little understanding of how these effects interact with one another,” said Abrahms. “The Packard Fellowship will allow my research group to push the boundaries of ecology to understand how species’ responses to environmental change are creating unforeseen feedbacks in the complex socio-ecological systems in which we all live.”

For her research, Abrahms incorporates data from diverse sources — including government databases, studies by other research groups and field studies by her own team. Some examples include:

• Using GPS collars to track the movements of large predators in Botswana, including African wild dogs and lions, to understand how environmental conditions shape their behavior and interactions
• Analyzing large, complex datasets on predator demographics collected by the Center for Ecosystem Sentinels that show the impacts of climate change, such as four decades of data on Magellanic penguins in Argentina
• Analyzing data on specific types of human-wildlife interactions, such as whale-ship collisions off the U.S. West Coast, and how these are affected by changing environmental conditions

By analyzing these diverse sources of data and modeling animal behavior, Abrahms and her team have started to pinpoint the causes and consequences of wildlife responses to environmental change and open the door to developing mitigation efforts. For example, Abrahms collaborated on a project to create an online tool that alerts shipping vessels in California’s Santa Barbara Channel and the San Francisco Bay Area if there are whales nearby so that they may avoid collisions.

Studying animals’ different ecosystems can also help scientists try to understand which species may be able to adapt to rapidly changing environmental conditions, which ones may struggle, and why. These studies can alert conservationists to species or ecosystems in need of interventions against specific climate change hazards.

More recently, Abrahms and her team have started to develop new methods for sorting and analyzing large datasets. One project, for example, uses AI tools to help classify behavior from “bio-loggers” — collars that collect behavioral data — as part of ongoing efforts to study climate change impacts on large carnivores in Botswana. Her group is also leading expanded efforts to map whale-ship collision risk globally, especially as whale migration routes and feeding behaviors shift due to climate change.

For more information, contact Abrahms at abrahms@uw.edu.

Since their protection under the Endangered Species Act, wolf populations have been making a comeback in the continental United States. Conservationists have argued that the presence of wolves and other apex predators, so named because they have no known predators aside from people, can help keep smaller predator species in check.

New research shows that in Washington state, the presence of two apex predators — wolves and cougars — does indeed help keep populations of two smaller predators in check. But by and large the apex predators were not killing and eating the smaller predators, known as mesopredators. Instead, they drove the two mesopredator species — bobcats and coyotes — into areas with higher levels of human activity. And people were finishing the job.

The — published May 18 in the journal Science by researchers at the 91̽��, the Washington Department of Fish and Wildlife and the Spokane Tribe of Indians — reports that bobcats and coyotes were more than three times likely to die from human activity, like hunting or trapping, than from the claws and jaws of cougars and wolves.

The findings illustrate how humankind’s growing footprint is changing interactions among other species.

“When cougars and wolves moved into an area, coyotes and bobcats employed a specific strategy to avoid apex predators by moving into more human-impacted regions,” said lead author , a wildlife ecologist and 91̽��associate professor in the School of Environmental & Forest Sciences. “That indicated to us that coyotes and bobcats likely perceived these large carnivores as a greater threat to them than people. But when we looked at causes of mortality for the mesopredators, humans were by far the largest cause of death.”

For the study, researchers used GPS collars to track the activity of 22 wolves (Canis lupus), 60 cougars (Puma concolor), 35 coyotes (Canis latrans) and 37 bobcats (Lynx rufus) across two study areas in north central and northeastern Washington from winter 2017 to summer 2022 as part of the . The study areas — which included portions of Okanagan, Stevens, Spokane, Pend Oreille and Lincoln counties — consisted of national forests; recreational areas for camping, hunting and fishing; and lands dedicated to agriculture, timber harvesting, ranching and residential use.

Tracking data indicated that, when wolves or cougars moved into their region, bobcats and coyotes would shift their movements accordingly.

“Coyotes and bobcats started using areas that had twice as much human influence compared to where they were before the large carnivores moved in,” said Prugh.

Researchers also attempted to determine the cause of death for any tracked animals that died during the study period. They discovered that areas with high human activity were far more deadly to mesopredators than those without a large human presence.

More than half of the 24 coyotes that died over the course of the study were killed by people. Some were shot after preying on livestock. Humans also killed half of the 22 bobcats that died during the study, including several that were attacking chickens.

In general, humans killed between three and four times more mesopredators in this study than wolves or cougars, both of which typically avoid areas with high levels of human activity.

In the short term, human activity poses little threat to the overall populations of bobcats and coyotes, which are two of the most widespread mesopredators in North America. Neither are endangered, and coyotes in particular are highly adaptable to the presence of people.

But not all mesopredator species are as resilient in human areas as coyotes and bobcats, said Prugh. Others reproduce more slowly or may be vulnerable in multiple ways to human activity. Rodent poisons used to keep away pests, for example, can kill fishers, another mesopredator species.

Future studies would need to investigate how mesopredators use space and resources in areas with high human activity, and what the risks of these shifts are to people.

“These are not trivial shifts in territory or space,” said Prugh. “There are real consequences.”

The findings also add a wrinkle to a working theory of wildlife-human interactions called the human shield hypothesis. Under the hypothesis, the presence of predators in a region causes prey species to move to areas with higher human activity. In Yellowstone National Park, for example, elk have at times moved near hiking trails, which wolves and other large carnivores typically avoid.

But the impact of humans in Yellowstone is typically smaller compared to other types of recreational areas or farms, grazing lands and residential developments – leaving some scientists to wonder if humans would be much of a “shield” in those areas.

“In these areas with higher levels of human activity, it was unknown whether a mesopredator would perceive the apex predator or humans as the greater threat,” said Prugh. “Here, we found that bobcats and coyotes perceived their apex predators as the greater threat, but their strategy of avoiding those large carnivores backfired by bringing them into contact with a much more effective predator: us.”

Co-authors are 91̽��postdoctoral researcher Calum Cunningham; former 91̽��researcher Rebecca Windell; Brian Kertson, a biologist with the Washington Department of Fish and Wildlife; , a 91̽��doctoral student in environmental and forest sciences; Savanah Walker with the Spokane Tribe of Indians; and , 91̽��professor of environmental and forest sciences. The research was funded by the National Science Foundation, the Washington Department of Fish and Wildlife and the Australia Fulbright Program.

For more information, contact Prugh at lprugh@uw.edu.