once believed the focuses of her doctoral and postdoctoral work were completely different. 

She completed her doctorate in Botswana, studying how humans were changing large carnivore behavior. After earning her degree, she researched whale migration at the National Ocean and Atmospheric Administration (NOAA). But while Abrahms was with NOAA, a historic heat wave off the West Coast was associated with an unprecedented rise in whales getting tangled in fishing gear. The event reminded her of studying in Botswana, when an extreme drought led to predators killing more livestock. 

“It struck me as important that you have two really different systems, yet in both cases an extreme climate event led to a change in human-wildlife interactions,” said Abrahms, an associate professor of biology at the 91̽��.

Those experiences led Abrahms to study how climate change is affecting human-wildlife interactions and increasing conflict around the world — from polar bear attacks on people to elephant destruction of agricultural areas. Her areas of expertise made her the ideal choice for keynote speaker at the held in Botswana in January.

Abrahms offered a global perspective on how climate change is impacting human-wildlife conflict while also providing specific insight on southern Africa, since she has worked in Botswana since 2011. The roundtable was hosted by the National Assembly of Botswana in partnership with through its program.

“It was really gratifying,” Abrahms said. “As a scientist, we’re often putting papers out and not knowing what reach they will have. You never really know where they’re going to go, if they’re going to go anywhere. To be featured so prominently in this intergovernmental parliamentary workshop was a career highlight.”

The roundtable brought together parliamentarians from Botswana, other African nations, the European Union, and beyond, alongside government officials, civil society leaders, local community representatives, conservation experts and international partners. Attendees focused on identifying solutions to human-wildlife conflicts while ensuring that the interests of citizens, local communities, ecotourism operators and wildlife advocates are reflected in policy.

Abrahms’ speech addressed the global impacts of climate change on human-wildlife coexistence.

She discussed increasing news reports of human-animal conflict, like kangaroos mobbing areas in Australia during droughts, and increased alligator attacks due to hurricanes in South Carolina. Previous research from Abrahms and her team revealed that the warming world is increasing human-wildlife conflicts. Another of her studies found that 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. 

“These issues are definitely getting more attention and when I gave this talk, it resonated,” Abrhams said. “Afterward, there was a panel featuring different parliament members and every single one of them had their own stories of climate increasing conflict in their countries, whether it was from a hurricane or a drought or a heat wave.”

Despite the wide variety of animal species and climate events — floods and hurricanes in Sri Lanka, droughts in Botswana and more — Abrahms was struck by how frequently climate change exacerbated these problems. She was heartened, though, by how many people from around the world came together to share experiences, success stories and challenges.

Some national-level policy recommendations that came out of the roundtable included predictable compensation and insurance mechanisms for when human-wildlife conflicts occur. Experts also suggested land-use planning that recognizes wildlife corridors as well as human needs. Among the other ideas: Investment in community resilience and climate-smart livelihoods, parliamentary oversight and a wildlife coexistence fund. 

Public outreach is also an important piece, Abrahms said.

“That would help people prepare and hopefully prevent some of these conflicts from occurring,” Abrahms said. “Governmental fiscal planning also could help by anticipating that there will be increased strain on a system and extra money could be put into a fund for use during extreme climate events.”

Abrahms left the roundtable impressed with how much the attendees genuinely cared about the environment, as well as their interest in learning from each other and about her work.

“It was a very grounding experience,” Abrahms said, “and it was nice to be part of a policy-oriented audience. There is a huge amount of money and resources and personnel and expertise aimed at alleviating these problems. In that respect, it was uplifting.”

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

The historic Norwegian tall ship Statsraad Lehmkuhl set sail for San Francisco from the Port of Seattle on Monday, marking the end of and another stop on the to support a sustainable future at sea.

The ship, built in 1914, boasts three towering masts and hails from Bergen, Norway. During the inaugural One Ocean Week Seattle, organized by , it docked at Pier 66 to welcome attendees and members of the public aboard to explore and learn.

The drew hundreds of people to Seattle to discuss marine ecosystems, the seafood industry, shipping and renewable energy, and more. 91̽�� scientists joined policymakers, educators and industry leaders to define and address priorities in stewardship and ocean science.

, a 91̽��affiliate professor and research scientist at the Center for Ecosystem Sentinels, served as a panelist on the “Coast to Coast Collaboration in Research” aboard Statsraad Lehmkuhl on Friday morning.

Moore contributed her expertise as a marine mammal ecologist to help launch the in the Pacific Arctic in 2010, leading to an international effort to establish a network of observatories in the Arctic to track ecosystem health amidst physical changes to the region.

The panel, part of a series hosted by , offered a chance to discuss shared goals as melting ice opens the Arctic up to more traffic.

“It was an important opportunity for international collaboration and public engagement regarding rapid ecosystem changes in Arctic, and local, waters,” Moore said.

, a 91̽��professor of mechanical engineering, helped lead a “behind the scenes” lab tour hosted by the , which joins researchers at UW, Oregon State University and the University of Alaska Fairbanks.

During the tour, researchers showcased marine energy monitoring projects at the , including videos and sonar documenting interactions between marine life and tidal energy turbines, sensors to detect underwater collisions, and systems to monitor how much noise is produced by the devices that help harness energy from waves and currents.

“These tools help us identify and minimize environmental effects associated with harnessing energy from waves, tides and rivers,” Polagye said.

, a 91̽��principal research scientist of aquatic and fishery sciences participated in a panel discussion, where he shared his work on habitat in , which borders downtown Seattle. Toft’s lab studies how shoreline development impacts habitat value for young salmon.

“Although the shorelines of Elliott Bay have been heavily modified, restoration efforts have had positive results,” he said. “The panel gave us a chance to discuss the importance of maintaining a healthy shoreline along a major urban working waterfront.”

Despite the density of human activity along the shores of Elliott Bay, these waters are home to key species, including kelp, orcas and salmon. Maintaining functionality without losing habitat is a challenge, requiring input from various stakeholders, and creativity.

, a coastal hazards specialist at , provided an update on observed and projected sea level rise during a Friday workshop bringing together coastal managers and tribes around the Puget Sound region.

“The opportunity to meet in person with that many people who all came for the workshop was invaluable,” he said.

To connect with a 91̽��expert in ocean or environmental science, contact Gillian Dohrn in 91̽��News at gdohrn@uw.edu.

According to the fossil record, cetaceans — whales, dolphins and their relatives — evolved from four-legged land mammals that returned to the oceans beginning some 50 million years ago. Today, their descendants are threatened by a different land-based mammal that has also returned to the sea: humans.

Thousands of whales are injured or killed each year after being struck by ships, particularly the large container vessels that ferry 80% of the world’s traded goods across the oceans. Collisions are the leading cause of death worldwide for large whale species. Yet global data on ship strikes of whales are hard to come by — impeding efforts to protect vulnerable whale species. A new study led by the 91̽�� has for the first time quantified the risk for whale-ship collisions worldwide for four geographically widespread ocean giants that are threatened by shipping: blue, fin, humpback and sperm whales.

In a published online Nov. 21 in Science, researchers report that global shipping traffic overlaps with about 92% of these whale species’ ranges.

“This translates to ships traveling thousands of times the distance to the moon and back within these species’ ranges each and every year, and this problem is only projected to increase as global trade grows in the coming decades,” said senior author , a 91̽��assistant professor of biology and researcher with the .

“Whale-ship collisions have typically only been studied at a local or regional level — like off the east and west coasts of the continental U.S., and patterns of risk remain unknown for large areas,” said lead author Anna Nisi, a 91̽��postdoctoral researcher in the Center for Ecosystem Sentinels. “Our study is an attempt to fill those knowledge gaps and understand the risk of ship strikes on a global level. It’s important to understand where these collisions are likely to occur because there are some really simple interventions that can substantially reduce collision risk.”

The team found that only about 7% of areas at highest risk for whale-ship collisions have any measures in place to protect whales from this threat. These measures include speed reductions, both mandatory and voluntary, for ships crossing waters that overlap with whale migration or feeding areas.

“As much as we found cause for concern, we also found some big silver linings,” said Abrahms. “For example, implementing management measures across only an additional 2.6% of the ocean’s surface would protect all of the highest-risk collision hotspots we identified.”

“Trade-offs between industrial and conservation outcomes are not usually this optimal,” said co-author , a research scientist with the National Oceanic and Atmospheric Administration and the University of California, Santa Cruz. “Oftentimes industrial activities must be greatly limited to achieve conservation goals, or vice versa. In this case, there is a potentially large conservation benefit to whales for not much cost to the shipping industry.”

Those highest-risk areas for the four whale species included in the study lie largely along coastal areas in the Mediterranean, portions of the Americas, southern Africa and parts of Asia.

The international team behind the study, which includes researchers across five continents, looked at the waters where these four whale species live, feed and migrate by pooling data from disparate sources — including government surveys, sightings by members of the public, tagging studies and even whaling records. The team collected some 435,000 unique whale sightings. They then combined this novel database with information on the courses of 176,000 cargo vessels from 2017 to 2022 — tracked by each ship’s automatic identification system and processed using an algorithm from Global Fishing Watch — to identify where whales and ships are most likely to meet.

The study uncovered regions already known to be high-risk areas for ship strikes: North America’s Pacific coast, Panama, the Arabian Sea, Sri Lanka, the Canary Islands and the Mediterranean Sea. But it also identified understudied regions at high risk for whale-ship collisions, including southern Africa; South America along the coasts of Brazil, Chile, Peru and Ecuador; the Azores; and East Asia off the coasts of China, Japan and South Korea.

The team found that mandatory measures to reduce whale-ship collisions were very rare, overlapping just 0.54% of blue whale hotspots and 0.27% of humpback hotspots, and not overlapping any fin or sperm whale hotspots. Though many collision hotspots fell within marine protected areas, these preserves often lack speed limits for vessels, as they were largely established to curb fishing and industrial pollution.

For all four species the vast majority of hotspots for whale-ship strikes — more than 95% — hugged coastlines, falling within a nation’s exclusive economic zone. That means that each country could implement its own protection measures in coordination with the U.N.’s International Maritime Organization.

“From the standpoint of conservation, the fact that most high-risk areas lie within exclusive economic zones is actually encouraging,” said Nisi. “It means individual countries have the ability to protect the riskiest areas.”

Of the limited measures now in place, most are along the Pacific coast of North America and in the Mediterranean Sea. In addition to speed reduction, other options to reduce whale-ship strikes include changing vessel routings away from where whales are located, or creating alert systems to notify authorities and mariners when whales are nearby.

“Lowering vessel speed in hotspots also carries additional benefits, such as reducing underwater noise pollution, reducing greenhouse gas emissions, and cutting air pollution, which helps people living in coastal areas,” said Nisi.

The authors hope their global study could spur local or regional research to map out the hotspot zones in finer detail, inform advocacy efforts and consider the impact of climate change, which will change both whale and ship distributions as sea ice melts and ecosystems shift.

“Protecting whales from the impact of ship strikes is a huge global challenge. We’ve seen the benefits of slowing ships down at local scales through programs like ‘’ in California. Scaling up such programs will require a concerted effort by conservation organizations, governments and shipping companies,” said co-author Jono Wilson, director of ocean science at the California Chapter of , which helped identify the need for this study and secured its funding. “Whales play a critical role in marine ecosystems. Through this study we have measurable insights into ship-collision hotspots and risk and where we need to focus to make the most impact.”

Co-authors on the study are , a research scientist with the Commonwealth Scientific and Industrial Research Organisation in Australia; research scientists Callie Leiphardt and Rachel Rhodes, and professor , all at the University of California, Santa Barbara; , research ecologist with NOAA’s Southwest Fisheries Science Center; , associate vice president, Anderson Cabot Center for Ocean Life, New England Aquarium; the UW’s , professor of aquatic and fishery sciences, and , a research scientist with the Center for Ecosystem Sentinels; , professor at the Universidade do Vale do Itajaí in Brazil; senior research biologist with the Cascadia Research Collective; data scientist , chief scientist and senior manager with Global Fishing Watch; research scientists Lauren Dares and Chloe Robinson with Ocean Wise; with Oceanswell in Sri Lanka and the University of Western Australia; with Carleton University; biologist with the British Antarctic Survey; , emeritus research scientist with the University of Rhode Island; Russell Leaper with the International Fund for Animal Welfare; Ekaterina Ovsyanikova at the University of Queensland; and Simone Panigada with the in Italy.

The research was funded by The Nature Conservancy, NOAA, the Benioff Ocean Science Laboratory, the National Marine Fisheries Service, Oceankind, Bloomberg Philanthropy, Heritage Expeditions, Ocean Park Hong Kong, National Geographic, NEID Global and the Schmidt Foundation.

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

, 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.

In the Pacific Northwest and British Columbia, scientists have been sounding the alarm about the plight of southern resident orcas. Annual counts show that population numbers, already precarious, have fallen back to mid-1970s levels. Most pregnancies end in miscarriage or death of the newborn. They may not be catching enough food. And many elderly orcas — particularly post-reproductive matriarchs, who are a source of knowledge and help younger generations — have died.

With just 73 individuals left, conservationists and members of the public alike are concerned that southern resident orcas may not survive.

Yet over the same period, the region’s northern resident orcas, who have a similar diet and an overlapping territory, grew steadily in population. Today, there are more than 300 northern resident orcas, leaving scientists wondering why these two similar but distinct populations have had such dissimilar fates over the past half century.

A new study led by scientists at the 91̽�� and reveals that the two populations differ in how they hunt for salmon, their primary and preferred food source. The research, done by an international team of government, academic and nonprofit researchers, March 4 in Behavioral Ecology.

“For northern resident orcas, females were hunting and capturing more prey than males. For southern resident orcas, we found the opposite: The males were doing more hunting and capturing than females,” said lead author , a senior research scientist at the 91̽��’s . “We also found that if their mother was alive, northern resident adult males hunted less, which is consistent with previous work, but we were surprised to see that southern resident adult males hunted more. Adult females in both populations hunted less if they had a calf, but the effect was strongest for southern residents.”

The study’s five years of observational data show that southern resident males catch 152% more salmon per hour than females. In other words, for every two fish a southern female caught, a southern male would catch five. For the growing northern resident population, the trend is flipped: females caught 55% more salmon per hour than males.

This is the first study to track the underwater pursuit, hunting and prey-sharing behaviors of both northern and southern resident orcas. Their findings reveal that, though the two populations overlap significantly in territory and have similar social structures and reproductive behavior, they should not be treated identically for conservation purposes.

“In the past, we’ve made assumptions about these populations and filled in the gaps when designing interventions, particularly to help the southern resident orcas,” said Tennessen, who conducted this study while she was a research scientist with NOAA’s . “But what we found here are strikingly different patterns of behavior with something as critical to survival as foraging. And as we develop management strategies, we really need to consider these populations differently.”

NOAA scientists and an international team of collaborators temporarily tracked the movement, sounds, depth and feeding behaviors of 34 northern and 23 southern resident adult orcas non-invasively from 2009 to 2014 using “Dtags,” cellphone-sized digital devices. Dtags attach via suction to the back of an orca and, for this study, were programmed to fall off hours later and float back to the surface so the researchers could collect them and download their data.

As the name would suggest, northern resident orcas have a more northerly distribution, preferring waters around Vancouver Island and the Queen Charlotte Strait. In contrast, core areas for southern resident orcas hug the southern reaches of Vancouver Island, inland waters surrounding the San Juan Islands, Puget Sound and the Washington coast. Both populations were devastated by the capture of orcas for theme parks, a practice that ended in the 1970s. Since then, northern resident orcas have increased steadily, seeing at least 50% growth since 2001.

Both populations hunt for salmon using echolocation. Adult orcas can dive at least 350 meters — or 1,150 feet — to pursue fish on their own, though they often bring kills to the surface to share with others. Pods travel between the outflows of major rivers and streams in British Columbia and Washington, and have been heavily impacted by dams that have reduced salmon runs. Increased vessel traffic and noise in the Salish Sea — from tourism, recreation and shipping — have also negatively affected these populations, particularly the southern resident orcas, according to Tennessen.

This new study showed that southern residents had fewer successful hunts overall, indicating that they were presumably catching less food. This impact is particularly evident with young mothers.

“In both populations, a mother with a young calf foraged less than other females, possibly due to the risk of leaving the calf temporarily with ‘a babysitter’ — another adult — while she hunts, or because of the time demands of nursing a calf,” said Tennessen. “But for southern resident females, which are more prone to disturbance and stress from vessel traffic, there was an outsized effect: Our study found no instance of a southern resident female with a young calf who successfully carried out a hunt.”

The study also has much to say about the impact of elderly female orcas on their adult sons. Both northern and southern resident orcas are grouped into matriarchal clans, often led by post-reproductive females. They also help feed their adult sons even, as a led by the nonprofit Center for Whale Research showed, at the expense of their own reproductive capacity.

The new study adds complexity to the role of elderly females. Among northern resident orcas, adult males with a living mother hunted less than adult males without a living mother, perhaps because the mother still provides food. But among southern resident orcas, the opposite is true: Adult males with a living mother hunted more.

“These unexpected differences left us scratching our heads. It is possible that southern resident adult males could be sharing with other members of their group, including their mothers, to help out, especially since an adult male’s survival is strongly linked to his mother’s survival,” said Tennessen. “Relatedly, southern resident matriarchs may be leading the group to areas where their adult sons may be able to capture more prey, since healthier sons might be more successful at mating and passing along some of their mothers’ genes. We need more studies to determine what role the presence — or absence, for southern resident orcas — of matriarchs has on male foraging behavior.”

Future studies on the behaviors of northern and southern resident orcas could bring these differences to the surface, as could studies of Alaska resident orca populations, which forage for salmon farther north, where salmon stocks are generally healthier. Such comparative studies can help isolate cause and effect, said Tennessen.

“Understanding how healthy populations behave can provide direction and goals for management of unhealthy populations,” said Tennessen. “Future comparisons to healthy fish-eating orca populations could help us understand whether the divergent behavior we’re seeing in the southern residents is indicative of a population trying to survive.”

Co-authors on the paper are Maria Holt, Bradley Hanson and Candice Emmons with the NOAA Northwest Fisheries Science Center; Brianna Wright and Sheila Thornton with Fisheries and Oceans Canada; Deborah Giles with the 91̽��Friday Harbor Labs; Jeffrey Hogan with the Cascadia Research Collective; and Volker Deecke with the University of Cumbria in the U.K. The research was funded by NOAA, Fisheries and Oceans Canada, the University of Cumbria and the University of British Columbia.

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

Research on the impacts of climate change often considers its effects on people separately from impacts on ecosystems. But a new study is showing just how intertwined we are with our environment by linking our warming world to a global rise in conflicts between humans and wildlife.

The research, led by scientists at the 91̽��’s and Feb. 27 in Nature Climate Change, reveals that a warming world is increasing human-wildlife conflicts.

“We found evidence of conflicts between people and wildlife exacerbated by climate change on six continents, in five different oceans, in terrestrial systems, in marine systems, in freshwater systems – involving mammals, reptiles, birds, fish and even invertebrates,” said lead author , a 91̽��assistant professor of biology. “Although each individual case has its own array of different causes and effects, these climate-driven conflicts are really ubiquitous.”

To identify trends, the team pored over published, peer-reviewed incidents of human-wildlife conflicts and identified cases that were linked specifically to the effects of climate change. These include both short-term climate events — such as a drought — as well as longer-term changes. Warming in the Arctic, for example, is leading to loss of sea ice which has left polar bears short of food. They increasingly travel on land, sometimes entering human settlements and attacking people, as a in Alaska illustrates.

The new study shows that climate shifts can drive conflicts by altering animal habitats — like sea ice for polar bears — as well as the timing of events, wildlife behaviors and resource availability. It also showed that people are changing their behaviors and locations in response to climate change in ways that increase conflicts. Other examples of the effects of short- and long-term climate events include:

• Torrential floods in Tanzania led to more lion attacks after their usual prey migrated away from floodplains.
• Higher air temperatures in Australia triggered more aggressive behavior in eastern brown snakes, leading to more incidents of snake bites.
• Wildfires in Sumatra, Indonesia — triggered by El Nino — drove Asian elephants and tigers out of reserves and into human-inhabited areas, leading to at least one death.
• Disruption of terrestrial food webs during La Nina events in the Americas drove black bears in New Mexico and foxes in Chile into human settlements in search of food.
• Warmer air and ocean temperatures in a severe El Nino led to an increase in shark attacks in South Africa.

Most cases of human-wildlife conflict linked to climate involve a shift in resources — not just for wildlife, but also for people.

A majority of cases on land also involved a change in precipitation, which will continue to be affected by climate change. Many resulted in human deaths or injuries, as well as property damage.

In 2009, for example, a severe drought struck the western part of Tanzania’s Kilimanjaro Region. This reduced food supplies for African elephants, which in turn entered local fields to graze on crops — at times destroying 2 to 3 acres daily. Local farmers, whose livelihoods were directly threatened by the drought, at times resorted to retaliatory killings of elephants to try to mitigate these raids.

“Identifying and understanding this link between human-wildlife conflicts is not only a conservation issue,” said Abrahms. “It is also a social justice and human safety issue.”

These types of conflicts are likely to rise as climate change intensifies, particularly as mass migrations of people and wildlife increase and resources shift.

But, it doesn’t have to be all bad news.

“One major motivation in studying the link between climate change and human-wildlife conflict is finding solutions,” said Abrahms. “As we learn about specific incidents, we can identify patterns and trends — and come up with interventions to try to address or lessen these conflicts.”

Some interventions may be as simple as public-awareness campaigns, such as advising residents of the American Southwest during La Nina years to carry bear spray on a hike. Governments can also plan for times when extreme climate events will bring people and wildlife into closer contact. Botswana, for example, has funds in place to compensate herders and ranchers for drought-induced attacks by wildlife on livestock, often in exchange for pledges not to engage in retaliatory killings of wildlife.

“We have effective drought forecasts now. So, governments can engage in fiscal planning for mitigating conflicts ahead of time,” said Abrahms. “Instead of a ‘rainy day’ fund, have a ‘dry day’ fund.”

To Abrahms, one success story of note lies in the waters of the eastern Pacific. In 2014 and 2015, a record number of humpback and blue whales became ensnared in fishing lines off the California coast. Research later showed that an extreme marine heat wave had pushed whales closer to shore, following their primary food sources. California regulators now adjust the start and end of each fishing season based on climate and ocean conditions in the Pacific — delaying the season if whales and fishing gear are likely to come into close contact.

“These examples show us that once you know the root causes of a conflict, you can design interventions to help both people and wildlife,” said Abrahms. “We can change.”

Co-authors on the paper are 91̽��postdoctoral researchers T.J. Clark-Wolf, Anna Nisi and Kasim Rafiq; 91̽��doctoral students Erik Johansson and Leigh West; Neil Carter, an associate professor at the University of Michigan; Kaitlyn Gaynor, an assistant professor at the University of British Columbia; and Alex McInturff, 91̽��assistant professor of environmental and forest sciences.

For more information, contact Abrahms at abrahms@uw.edu. See a related feature story about Abrahms’ research.

Climate change will reshape ecosystems worldwide through two types of climate events: short-term, extreme events — like a heat wave — and long-term changes, like a shift in ocean currents. Ecologists call the short-term events “pulses,” and the long-term changes “presses.”

Presses and pulses will likely have different effects on animal species. But how? And how will animals respond? Answering these questions is no easy feat because individual events can have dramatically divergent impacts on an animal species. Yet understanding the effects of presses and pulses is essential as conservationists and policymakers try to preserve ecosystems and safeguard biodiversity.

Researchers at the 91̽�� have discovered how different presses and pulses impacted Magellanic penguins — a migratory marine predator — over nearly four decades at their historically largest breeding site in Punta Tombo, Argentina. In a paper published the week of Jan. 9 in the Proceedings of the National Academy of Sciences, the team from the UW’s reports that, though individual presses and pulses impacted penguins in a variety of ways, both were equally important for the future survival of the penguin population. They also found that these types of climate changes, taken together, are leading to an overall population decline at this particular site.

“We found that penguin survival doesn’t rest solely — or even largely — on one or a few climate effects,” said lead author T.J. Clark-Wolf, a 91̽��postdoctoral researcher in biology and center scientist. “Instead, many different presses and pulses impact penguin reproduction and survival over time.”

The study analyzed data collected at Punta Tombo from 1982 to 2019 by co-author , founder of the Center for Ecosystem Sentinels and a 91̽��professor of biology, and collaborators. The data include:

• survival and reproductive success for nearly 54,000 penguins at the site, which historically is where hundreds of thousands of Magellanic penguins have come to breed each summer
• climate conditions during each breeding season
• ocean conditions off the coast of Punta Tombo, where adults feed during the breeding season and bring food back to the nest to feed their chicks
• offshore ocean conditions along the coast of South America, where adults and juveniles feed when migrating outside of the breeding season

Clark-Wolf and senior author , a 91̽��assistant professor of biology, folded these data into an integrated population model that parsed out the effects of separate presses and pulses on penguin survival over time. They found that different climate effects had distinct impacts on the Punta Tombo population. For example, heat waves — a climate pulse — have a detrimental effect on the population by killing both adults and chicks, as illustrated by a 2019 single-day heat wave at Punta Tombo that killed more than 350 penguins. A climate press, increased rainfall at the site, also negatively impacted the population, because storms during the breeding season kill chicks due to exposure.

The gradual weakening of the plume of silt expelled into the ocean by the Río de la Plata, the second largest river basin in South America, is one press that positively affected penguin survival. This press impacts the penguins’ winter feeding waters off the coast of northern Argentina, Uruguay and Brazil. Past research by , a co-author on the new study and a 91̽��research scientist, has indicated that a weaker plume may make it easier for penguins, particularly females, to catch enough food each winter and return to the breeding site in prime condition.

But the positive effects of a weakening plume could not overcome the negative effects of other climate events at Punta Tombo, which over nearly four decades has become warmer and wetter. The number of breeding pairs at the site has declined from a high of approximately 400,000 in the early 1980s to about 150,000 in 2019.

“This colony will be 100 years old in 2024, but we finished another on-the-ground survey in late October at Punta Tombo and its numbers continue to decline,” said Boersma. “The penguins are instead moving north to be closer to their food.”

Surveys have reported that Magellanic penguins are establishing other breeding sites farther north on the South American coast in search of better foraging opportunities.

Understanding how these presses and pulses shape this population is crucial for informing conservation efforts, the researchers said.

“For conservation to be most effective, we need to know where, when and how to apply our limited resources,” said Abrahms. “Information generated by this study tells us which climate effects we need to worry about and which ones we don’t — and therefore can help us focus on measures that we know will have a positive impact.”

The decades of data faithfully collected at Punta Tombo made it possible for the team to consider the effects of long-term climate changes and extreme events in combination, and as a result, to better predict how climate will impact this population in the future. It is this same approach, they believe, that can help conservationists and scientists understand how climate shifts will shape other long-lived animal species across our warming globe.

Fieldwork over the years at Punta Tombo has been funded by the Wildlife Conservation Society; the ExxonMobil Foundation; the Pew Fellows Program in Marine Conservation; the Disney Worldwide Conservation Fund; the Chase, Cunningham, CGMK, Offield, Peach, Thorne, Tortuga and Kellogg Foundations; the Wadsworth Endowed Chair in Conservation Science at the UW; the Friends of the Penguins fund; and private to the Center for Ecosystem Sentinels.

For more information, contact Clark-Wolf at tc130053@uw.edu and Abrahms at abrahms@uw.edu.

As climate change alters environments across the globe, scientists have discovered that in response, many species are shifting the timing of major life events, such as reproduction. With an earlier spring thaw, for example, some flowers bloom sooner. But scientists don’t know whether making these significant changes in life history will ultimately help a species survive or lead to bigger problems.

A study published the week of June 27 in the shows for the first time that a species of large carnivore has made a major change to its life history in response to a changing climate — and may be worse off for it.

A team led by researchers at the 91̽��, in collaboration with Botswana Predator Conservation, a local NGO, analyzed field observations and demographic data from 1989 to 2020 for populations of the — Lycaon pictus. They discovered that, over a 30-year period, the animals shifted their average birthing dates later by 22 days, an adaptation that allowed them to match the birth of new litters with the coolest temperatures in early winter. But as a result of this significant shift, fewer pups survived their most vulnerable period because temperatures during their critical post-birth “denning period” increased over the same time period, threatening the population of this already endangered species.

This study shows that African wild dogs, which are distantly related to wolves and raise young cooperatively in packs, may be caught in a “phenological trap,” according to lead author , a 91̽��assistant professor of biology and researcher with the . In a phenological trap, a species changes the timing of a major life event in response to an environmental cue — but, that shift proves maladaptive due to unprecedented environmental conditions like climate change.

“It is an unfortunate ‘out of the frying pan, into the fire’ situation,” said Abrahms. “African wild dogs shifted birthing dates later in order to keep pace with optimal cool temperatures, but this led to hotter temperatures during the denning period once those pups were born, which ultimately lowered survival.”

The study demonstrates that species on high “trophic levels” in ecosystems — like large predators — can be just as sensitive to climate change as other species, something that scientists were uncertain about. Other research has shown that long-term warming can trigger phenological shifts, or shifts in the timing of major life events, in “primary producer” species like plants and “primary consumers” that feed on plants, including many birds and insects. But, until now, scientists had never documented a climate-driven phenological shift in a large mammalian carnivore. Abrahms and her colleagues show that large predators can indeed exhibit strong responses to long-term climate change, even though predators are “farther removed” up the food chain.

For this study, the team analyzed more than three decades of data that they and collaborators collected on 60 packs of African wild dogs that live across a more than 1,000 square-mile region of northern Botswana. This species breeds annually each winter. After birth, pups spend about 3 months with their mother at the den before beginning to travel and hunt with the pack.

Abrahms and her colleagues analyzed the dates that African wild dog mothers gave birth to their litters each year, which is how they determined that adults gradually delayed breeding by about one week per decade over the 30-year study period.

“Although most animal species are advancing their life history events earlier in the year with climate change, this finding represents a rare instance of a species delaying its life history, and at a rate twice as high as the average rate of change observed across animal species”, said Jeremy Cohen, a researcher at Yale University and the Center for Biodiversity and Global Change, who was not involved in the study.

Such a large shift is likely due to the rapid pace of warming in the region, and because African wild dogs have evolved to breed within a narrow “thermal window,” according to Abrahms.

The team used long-term demographic data to calculate how many pups survived the denning period each year. They discovered a correlation between temperatures during the denning period and survival: Warmer denning periods led to fewer pups recruiting to packs at the end of winter, which indicated that fewer pups survived the denning period.

Average daily maximum temperatures in the study period rose by about 1.6 degrees Celsius, or 2.9 degrees Fahrenheit, over 30 years. Over the same time frame, annual maximum temperatures spiked by 3.8 degrees Celsius — just over 6 degrees Fahrenheit.

The team could not have come to its unexpected conclusions without those decades of detailed field observations led by Botswana Predator Conservation, Abrahms said.

“We could only conduct this study because of the existence of this unique, long-term dataset for a large predator, which is really rare,” said Abrahms. “It shows the value for this kind of data in studying how climate change will impact ecosystems.”

The study area in northern Botswana is part of the largest continuous habitat for African wild dogs, which are threatened by habitat fragmentation and loss, disease and conflicts with people. The International Union for Conservation of Nature that there are only about 1,400 mature adults left in the wild.

“Large predators play extraordinarily important roles in ecosystems, but we still have a lot to learn about the implications of climate change for these animals,” said Abrahms. “Big climate-driven shifts like the one we found may be more widespread in top predators than originally thought, so we hope our findings will spur new climate-change research on other predator populations around the planet.”

Co-authors on the study are Kasim Rafiq, a 91̽��postdoctoral researcher in biology; Neil Jordan with the University of New South Wales; and J.W. McNutt with Botswana Predator Conservation. The research was funded by numerous public and private donors over the thirty-year study period.

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