Mountain lions coexist with outdoor recreationists by taking the night shift

How mountain lions in Los Angeles are adjusting to avoid human interactions

University of California - Davis

 

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P65 walks with her kittens. In a UC Davis study, female mountain lions were generally more active during the day and closer to sunrise, perhaps because they are constrained by avoiding male mountain lions and not able to respond as strongly to recreation.

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Credit: National Park Service

Mountain lions in greater Los Angeles are proactively shifting their activity to avoid interacting with cyclists, hikers, joggers and other recreationists, finds a study from the University of California, Davis, Cal Poly Pomona and the National Park Service. 

The study, published Nov. 15 in the journal Biological Conservation, found that mountain lions living in areas with higher levels of human recreation were more nocturnal than lions in more remote regions who were more active at dawn and dusk. The authors said their findings offer a hopeful example of human-wildlife coexistence amid a large, dense human population.

“People are increasingly enjoying recreating in nature, which is fantastic,” said lead author Ellie Bolas, a Ph.D. candidate in the UC Davis Department of Wildlife, Fish and Conservation Biology. “This flexibility we see in mountain lion activity is what allows us to share these natural areas together. Mountain lions are doing the work so that coexistence can happen.” 

Mountain lions prefer to avoid people, but in a metro area of more than 18 million people, natural areas inhabited by mountain lions and other wildlife are also heavily used by recreationists. To learn whether and how lions were adjusting their activity in response to recreationists, the study authors monitored the movements of 22 mountain lions living in the Santa Monica Mountains and the surrounding region between 2011 and 2018.

The lions were captured and fitted with global positioning system (GPS) and accelerometer collars as part of a long-term study conducted by biologists at Santa Monica Mountains National Recreation Area, a unit of the National Park Service. The authors analyzed the collar data and quantified human recreation in the area using a global database of GPS-tracked activities that users opted to make public.

“These results are really important in that they show how humans may be affecting wildlife in less obvious ways than killing them with vehicles,” said Seth Riley, branch chief for wildlife at the park. “The study also continues to drive home the amazing fact that a population of a large felid predator persists in one of the largest urban areas in the world. That would not be possible if mountain lions weren’t able to adjust to human activity in ways like this.”

How mountain lions respond to more humans

The study showed that Griffith Park hosted the highest levels of recreational activity, while the Santa Susana Mountains and Los Padres National Forest were least active. How did mountain lions respond? 

The least nocturnal mountain lion was female P13 in the central and western Santa Monica Mountains. Females, in general, were found to be more active closer to sunrise and during daylight hours as compared to males. The authors say this may be so they can avoid overlapping with male lions, who pose a threat to them and their kittens.

 The most nocturnal were two male mountain lions living in small, isolated natural areas with many trails, high levels of recreation, and surrounded by intense development and freeways. Both individuals occupied two of the smallest home ranges ever recorded for adult males. P41, the study’s most nocturnal lion, lived in the Verdugo Mountains, a small mountain range spanning several cities.

The famous “Hollywood Cat,” P22, preferred to stay out of the limelight. P22, who managed to cross two busy freeways as a young lion to earn fame, hearts and a home in active Griffith Park, was the second most nocturnal lion studied. He died in 2022 when he was roughly 12 years old — one of the oldest cats in the study.

The authors said the urban experiences of P41, P22 and others in the study illustrate how, when faced with increased human activity, mountain lions actively seek to avoid people rather than becoming habituated to them. 

How people can help

Still, the authors note, this doesn’t mean mountain lions should do all the work. People can help protect themselves and mountain lions by being aware that dawn or dusk is prime time for mountain lion activity. They can also be extra cautious when driving at night, when mountain lions in populated areas are more likely to be active. 

Mountain lions in the Los Angeles area deal with many challenges — busy roadways where they’re often killed, wildfires, rodenticide exposure, low genetic diversity and fragmented habitat. 

“Even something as innocuous as recreation can add to these other stressors we’re bringing into their lives, potentially by altering the amount of energy they have to expend for hunting and other needs,” Bolas said. “But we can feel a sense of optimism that they are flexible in the timing of their activity. Coexistence is happening, and it’s in large part because of what mountain lions are doing.” 

The study’s additional co-authors include Adam Pingatore and Daniel Blumstein of UCLA, Maya Mathur of Harvard Westlake High School, Jeff Sikich of the National Park Service, Justine Smith of UC Davis, John Benson of University of Nebraska and Rachel Blakey of California State Polytechnic University, Pomona, and UCLA.

The study was supported through funding from the National Science Foundation, National Park Service, La Kretz Center for California Conservation at UCLA, and the UC Davis Graduate Group in Ecology Fellowship.

  

Ellie Bolas, a PhD Candidate at UC Davis, uses radio telemetry to locate research animals in Santa Monica Mountains National Recreation Area.

One of P13's kittens enjoys a sunrise meal in the Santa Monica Mountains near Los Angeles, California in 2014. P13 was among the least nocturnal lions studied.

P41, the most nocturnal mountain lion in the study, lived in the Verdugo Mountains near Los Angeles, an area with high levels of human recreation.

P22, the well-known "Hollywood Cat," was among the mountain lions of Los Angeles who shifted his activities to be more nocturnal in response to humans.

Journal

Biological Conservation

DOI

10.1016/j.biocon.2024.110812 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Human recreation influences activity of a large carnivore in an urban landscape

Article Publication Date

15-Nov-2024

 

Smart robots could withstand waves to cut green energy costs

University of Edinburgh

Underwater robots that can predict waves in real-time could reduce the cost of producing offshore renewable energy, a study suggests.

New technology that enables robots to work stably in turbulent seas could make it cheaper, faster and safer to maintain offshore wind farms and tidal turbines, researchers say.

Until now, the unpredictable nature of waves – which make it difficult for machines to remain stable and perform precise movements – has limited the use of robots in the upkeep of offshore platforms.

Stationing autonomous robots offshore to perform routine maintenance would reduce the cost of generating renewable energy, which is typically much higher than using fossil fuels, the team says.

It could also simplify operations – which currently can involve ships and helicopters or hoisting equipment out of the water – and remove the need for people to work in dangerous settings.  

Engineers at the University of Edinburgh developed new computational and experimental tools to enable autonomous robots to maintain a steady position amid irregular, buffeting waves.

The researchers trialled their system at the University’s FloWave testing tank, using wave data captured by a buoy in the North Sea to mimic the types of conditions robots might work in.

Wave-detecting devices are tethered to the seafloor and measure the direction and height of incoming waves, relaying the information in real-time to a robot working nearby. This enables the unmanned machine to pre-empt complex future disturbances in the water, precisely counteracting these to maintain a stable position.

Findings indicate the system is compatible with robots operating near the surface and those working at greater depths, where disturbances can still be felt strongly.

The new technology improves on conventional control systems, the team says, which operate in a corrective fashion. These are prone to responding slowly to the fast-changing disturbances of the ocean, making them much less reliable in such hazardous environments.

Dr Kyle Walker, who developed the work as part of his PhD at the University of Edinburgh, said: “A major limitation at present is robots’ ability to perceive and counteract environmental disturbances effectively, which fundamentally restricts the current use of small subsea vehicles. By forming a prediction of future wave disturbances and integrating this within the control system, we're able to expand this range with little to no change to the robot hardware.

“In terms of translating this technology into the field, this is a huge benefit and makes our system applicable to most vehicles currently available on the market.”

Future research aims to improve autonomous machines’ ability to perform precise tasks – such as using robotic arms to detect rust or fix electric equipment – while holding a steady position in water.

The study, published in the International Journal of Robotics Research, received funding from the Engineering and Physical Sciences Research Council. An open access version of the paper is available here: https://www.research.ed.ac.uk/en/publications/nonlinear-model-predictive-dynamic-positioning-of-a-remotely-oper.

The work was a continuation of the now-finished ORCA Hub project, an initiative to support the green energy transition led by Heriot-Watt University and the University of Edinburgh.

Dr Francesco Giorgio-Serchi, of the University of Edinburgh’s School of Engineering, who led the study, said: “Increasing the use of autonomous robots to help maintain offshore renewable installations could have a transformative effect on cutting the cost of producing clean energy. Advancing this technology further could help bring about a step change in the adoption of unmanned robots at sea and drastically increase the degree of automation in the offshore sector.”

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Journal

The International Journal of Robotics Research

DOI

10.1177/02783649241286909 

 

Land-use policy rethink vital to hit net zero

Changing how land-use subsidies are implemented would give UK taxpayers better value for money and improve chances of meeting environmental targets such as Net Zero

University of Exeter

A fundamental shift in how land-use subsidies are implemented would give taxpayers better value for money and improve the UK’s chances of meeting its environmental targets. 

The government’s commitment to the biggest expansion in woodland for half a century to reach Net Zero by 2050 requires them to pay landowners to convert agricultural land into woodland.

These payments are allocated using flat-rate subsidies, which provide a consistent per-hectare payment to landowners regardless of the suitability of the land for tree-planting.  

Researchers from the University of Exeter Business School have demonstrated that these flat-rate subsidies are not only ineffective but could actually increase net greenhouse gas emissions. 

This is because paying a flat rate for land incentivises subsidy uptake from lower agricultural productivity farms, frequently located on carbon rich soils where tree growth is poor and where planting acts to dry out peaty soils, resulting in greenhouse gas emissions rather than sequestration.

The solution, they argue, is to stop offering subsidies everywhere and instead target subsidies based on their expected effects. This ‘Natural Capital’ approach prioritises areas with the greatest environmental, climate change, biodiversity and recreational value.

In a study published in PNAS, the researchers tested three approaches to subsidy allocation: the current flat rate, the Natural Capital approach, and the ‘Land Use Scenarios’ approach, as set out by the UK National Ecosystem Assessment which promotes tree planting in most areas.

The researchers compare these three approaches using the NEV (Natural Environment Valuation) decision support system, which integrates natural, physical and economic science models to quantify environmental, agricultural and economic outcomes.

Maps of new afforestation show the spatial distribution of the different approaches, with flat-rate subsidies leading to forest planting clustered into areas where financial returns to farming are lowest, making planting subsidies more attractive.

Although this approach delivers a number of benefits it provided poor value for money against the policy’s main objective of carbon storage. Uptake of subsidies on carbon rich soils led to the overall release of greenhouse gases to the atmosphere.

The Land Use Scenarios, while spreading woodland across the largest area of Great Britain and storing high volumes of greenhouse gases, almost doubled the cost of subsidies with planting on some of the most agriculturally productive areas the country.

The Natural Capital approach was found to deliver the best results environmentally, socially and in terms of value for taxpayer money.

Based on the Natural Capital Framework – the basis of the UK Government’s 25 Year Environment Plan – the approach resulted in a greater concentration of planting in and around major urban areas, which generated improved recreational access to high quality environments for large urban populations and delivered an overall net benefit that is 50% higher than the current flat-rate approach. The approach also improved biodiversity an, perhaps most importantly, resulted in a much better outcome for the climate, meeting the net zero requirement of removing 13MtCO2 annually by 2050.

Professor Ian Bateman, Director of the Land, Environment, Economics and Policy Institute at the University of Exeter Business School, said: “The flat-rate payment approach to the implementation of policy objectives is so globally commonplace that its relative inefficiency goes unnoticed. This study lays these failings bare and shows that the decision-making approach adopted to implement policy can have a very highly substantial impact on the effectiveness of that policy.

“By targeting public money to those places it has its greatest benefits we can address climate change, biodiversity loss and food security, and hugely improve value for money to the taxpayer. 

“This is no minor technical issue; if different approaches yield different results, then how we make decisions changes the decisions we make.”

“How to make land use policy decisions: Integrating science and economics to deliver connected climate, biodiversity and food objectives” is published in the journal PNAS (Proceedings of the National Academy of Science).

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Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2407961121 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

How to make land use policy decisions: Integrating science and economics to deliver connected climate, biodiversity and food objectives

Article Publication Date

13-Nov-2024

 

Genetic legacy of Jomon hunter-gatherers linked to increased BMI in modern Japanese

Trinity College Dublin

New research exploring the roots of modern Japanese populations has linked the genetic signature of Jomon hunter-gatherers to a higher body mass index (BMI) among individuals, underlining that ancient human ancestors can leave a genetic legacy with impacts on health in modern day populations.

The research – just published in leading international journal Nature Communications – also found broad support for the “tripartite ancestry model”. This effectively means variations in modern day Japanese genetic patterns can be explained by the historical influence of ancient Jomon hunter-gatherers and two continental groups from Northeast and East Asia that collectively left their genetic imprint on the people of today.

The research analysed genetic data from Biobank Japan (including over 170,000 individuals), along with ancient Japanese and Eurasian genomes, as well as those from East Asian individuals from the UK Biobank. In total, the analyses used genetic data of ancient and modern genomes that involved over 250,000 participants.

BMI links

The researchers tested associations of Jomon ancestry with 80 different complex traits (from height to BMI) by making robust adjustments for genetic and geographic subpopulations.

They found that the Jomon genetic signature, which on average accounts for 12.5% of a person’s genetic make-up, was associated with an increased BMI. And that held true when they expanded their analyses to include East Asian individuals in the UK Biobank – underlining the robustness of this trait that echoes from a largely forgotten time. 

Shigeki Nakagome, Assistant Professor in Trinity College Dublin’s School of Medicine is a senior author of the research. He said: “Overall, these results suggest that the genetic legacy of the ancient hunter-gatherer Jomon significantly influences BMI across populations today, regardless of geographic differences, and it may consequently contribute to an increased risk of obesity. 

“It is a really important discovery that ancient hunter-gatherer ancestry is likely to play a key role in the health of modern day populations. The link to an increased BMI could also help to explain some of the disparities in obesity prevalence among Asian populations residing in Western countries. 

“By emphasising the importance of incorporating Jomon ancestry as a factor in BMI, this analysis essentially provides a proof-of-concept for research that bridges our human past with current health challenges.” 

The tripartite model

A long-standing model of Japanese origins is a dual-ancestral structure  comprising the Jomon, who were hunter-gatherer-fishers who inhabited the archipelago as far back as 16,500 years ago, and immigrant farmers from Northeast Asia. This was recently refined by the tripartite model, which also incorporates East Asian ancestry linked to the state formation phase, the Kofun period, which began around 1,700 years ago.

And the new research found strong support for that tripartite model.

Prof. Nakagome added: “Our analysis, which presents the first in-depth characterisation of the tripartite structure across the entire Japanese archipelago, widely and consistently fits better than the dual structure hypothesis. It also unveils substantial variation in the proportion of Jomon ancestry, mirroring the genetic ancestry continuum observed in present-day populations. 

“The field of ancient genomics is rapidly evolving, and future research that encompasses a diverse range of ancient humans across various time periods and geographic locations will provide a more comprehensive understanding of the extent to which the human past has shaped genomic and phenotypic variation in contemporary populations. I am sure there is much left to discover, both in Japanese populations, and in others across the globe.”

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Journal

Nature Communications

DOI

10.1038/s41467-024-54052-0 

 

Markets for forest products respond to technology

New Southern Forest Outlook report now available

USDA Forest Service ‑ Southern Research Station

Asheville, NC — Technology is changing every facet of the forest products market. That may mean fewer jobs in the future as the industry shifts to labor-saving technology, with the steepest declines in the pulp and paper sector, according to a new report released by the USDA Forest Service’s Southern Research Station and Southern Region, as well as the Southern Group of State Foresters.

“From how trees are cut, to how they are processed at sawmills, and every step in between, technology is changing the industry,” said Forest Service scientist Jeff Prestemon who specializes in forest economics. “Researchers are partnering with the forest products industry to find ways to recycle and use materials that typically would be discarded as waste.”

Prestemon co-authored the report – Markets in the Southern Forest Outlook – with economist Jinggang Guo from Louisiana State University.

The new report analyzes six scenarios for the future and how each might impact the forest products markets in the South. The analysis considers how changes in income, population, climate, technology, and trade openness could affect markets.

The report also found:

• The South is projected to continue to be a net exporter of forest products.
• Prices of industrial roundwood are projected to rise, reversing recent downward trends.
• If mass timber were more widely used, the southern softwood market would strengthen.
• Additional trade barriers would enhance softwood exports and reduce hardwood exports.
• Most scenarios project a growth in wood pellet production in the South.

The report is part of a regional assessment, known as the Southern Forest Outlook. Its goal is to inform forest sector decision makers and the interested public about observed trends, anticipated futures, and critical issues based on authoritative synthesis and interpretation of existing science, data, and projections. This is the first of four reports that will be released in the coming months. A report on water is expected next month.

For decades, Forest Service scientists have conducted region-wide assessments of natural resources in the South. In fact, results from past assessments were used to develop research priorities for the Southern Research Station, including fire, water, markets, and restoration. The Southern Research Station and the Forest Service’s Southern Region work closely with the Southern Group of State Foresters, and the results of the markets report are organized by state.

The Southern Forest Outlook relies on the same core scenarios as the 2020 Resources Planning Act Assessment, which in turn relies on climate projections developed by the 2014 Intergovernmental Panel on Climate Change. The four main scenarios vary along two axes: high, moderate, or low amounts of economic growth and warming. The research team modified two scenarios to explore how markets would be affected if mass timber became more widely used in construction and if existing forest product trade restrictions were tightened.

“Wood is actually a new trend in sustainable building,” said Prestemon. “Mass timber, as it’s called, is produced to be strong enough to replace concrete or steel. If mass timber continues to catch on, then the South’s softwood market would grow.”

In all scenarios, the number of jobs across forest product sector is projected to decline. The steepest declines are projected for the paper manufacturing sector, due to labor-saving technologies and reduced demand for newsprint and printing and writing paper. The pulp and paper sector also includes packaging and sanitary papers, which is closely related to economic growth and are generally not projected to decline, and wood pellets. Wood pellet production is projected to rise across all southern states except in the scenario that combines high warming and low economic growth. The chapter also includes a section on the market effects of the COVID-19 pandemic.

The new report builds on the Southern Forest Futures Project, which was completed in 2012. Since then, the southern forest products sector has experienced significant changes including rising timber inventory, declining softwood timber prices, increased barriers to international trade, and continued contraction of the forest sector workforce despite growth in production.

Read the report. 

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About Us 

The Southern Research Station, headquartered in Asheville, N.C., is comprised of more than 100 scientists who conduct natural resources research in 20 locations across 13 Southern states, from Virginia to Texas. The station’s mission is to create the science and technology needed to sustain and enhance southern forest ecosystems and the benefits they provide. Learn more about the Station.

The Forest Service’s Southern Region oversees 14 national forests and two special units in 13 states and Puerto Rico, working with states and private landowners to sustain the health, diversity and productivity of forests and grasslands to meet the needs of present and future generations. Learn more about the Southern Region.

The Southern Group of State Foresters represents state forestry agencies within the 13 Southeastern U.S., and the U.S. territories of Puerto Rico and the Virgin Islands. Its members collectively provide leadership, coordination, expertise and resources to sustain the economic, environmental, health and societal benefits of Southern forests. Learn more about the Southern Group of State Foresters.

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DOI

10.2737/SRS-GTR-275 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

Markets: An Analysis to Support the Southern Forest Outlook

Article Publication Date

14-Nov-2024

 

Decline in West African coastal fish stocks threatens food security and livelihoods

A new ICTA-UAB study integrates different knowledge systems for the assessment of fish stock conditions and historical performance

Universitat Autonoma de Barcelona

 

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Fishing in Cabo Verde

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Credit: Thais Peixoto Macedo /ICTA-UAB

Fish stocks along the West African coast have declined significantly over the past five decades, threatening food security and the livelihoods of the fishing communities that depend on them, according to a study by the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) in collaboration with Fundação Maio Biodiversidade (FMB).

Small-scale fisheries play a vital role in providing food and livelihoods for millions of people around the world, particularly in low-income countries in Africa. However, there is limited statistical data on the composition, abundance, and distribution of the fisheries’ resources, which is crucial for effective management.

New research, recently published in the journal Marine Policy, documents changes in the catches of small-scale fisheries, highlighting a significant decline not only in volume of catches, but also in the size of fish for key local species.

Scientists compiled official catch landing data and combined it with local ecological knowledge from local fishermen and fishmongers on Maio island, in Cabo Verde, designated a UNESCO Biosphere Reserve since 2020.

“Monitoring of fish landings in West African countries is limited and under-represents catches at the local level, especially from artisanal fisheries, creating data gaps that hinder effective management,” says Thais Peixoto Macedo, ICTA-UAB researcher and lead author of the study, who explains that traditional fishers' accounts revealed trends that are poorly captured in official records. “The findings in this area show us trends that are likely to occur on other islands of the archipelago or other West African coastal areas and should be taken into account in marine resource management plans.” 

Local communities believe that certain fishing practices, such as spearfishing with scuba gear and semi-industrial fishing with purse seines and night lights, are major contributors to the decline of fish stocks. In the case of semi-industrial fishing, they report that vessels fish within the three-nautical-mile zone and in marine protected areas reserved for artisanal fishing.

The most reported depleted species include groupers (dusky grouper, island grouper and the African hind) and small pelagic fish such as mackerel and bigeye scad. “According to local fishermen, the decline of small pelagic fish due to semi-industrial coastal fishing is negatively affecting artisanal catches of large pelagic species, such as yellowfin tuna and albacore, an important commercial species for local and international markets”, says Benalsy Varela, FMB staff who contributed to the study. Spiny and slipper lobsters, particularly targeted to supply more tourist-intensive islands, were also considered depleted.

The research highlights a phenomenon known as “Shifting Baseline Syndrome”, where people gradually adjust their perception of what is healthy or natural to a new reality, forgetting past conditions and accepting it as the 'new normal'. Younger fishermen reported smaller catches and fish sizes than older generations, but a larger proportion of the younger group believe that fish stocks are not in decline.

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Journal

Marine Policy

DOI

10.1016/j.marpol.2024.106447 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Local knowledge and official landing data point to decades of fishery stock decline in West Africa

Article Publication Date

13-Nov-2024

 

Backyard birds learn from their new neighbors when moving house

Puzzle box experiment shows that after immigration, birds rapidly learn useful tricks from local experts

Max Planck Institute of Animal Behavior

 

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Image of great tit solving puzzle box to gain a food reward.

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Credit: Hervé Glabeck - Docland Yard

Scientists have found a trigger for social learning in wild animals. An experiment on great tits has pinpointed a single factor—immigration—that can cause birds to pay close attention to others, leading them to rapidly adopt useful behaviors. The study is the first to provide experimental support of a long-held assumption that immigrants should strategically use social learning. The study, conducted by scientists from the Max Planck Institute of Animal Behavior (MPI-AB) and the Cluster of Excellence Collective Behaviour at the University of Konstanz in Germany, is published November 14 in PLOS Biology.

Many animals that live in groups learn from one another, but few wild animals have opened a window into understanding animal social learning like a single bird species: the great tits. Great tits flew to fame in the 1920s after birds started opening the foil lids of milk bottles to feed on the cream within. Residents of a small town in England were the first to report the behavior, but soon people across Europe were opening their doors to find that their milk bottles had been raided by birds. The behavior spread so far so quickly that scientists considered it unlikely that individual birds across a continent were inventing this trick on their own. Could the birds be learning from each other?

The answer remained hidden until 2015 when a team led by Lucy Aplin, then at the University of Oxford, conducted an experiment on a population of great tits in an English forest. Her experiment showed that birds were able to learn how to liberate food from a puzzle box by copying the solution from others—confirming that the original milk-raiding birds had also been passing on their thieving ways to their flock.

“Social learning is a great shortcut when it comes to safely testing new waters,” says Chimento, a postdoctoral researcher who worked in Aplin’s team at the MPI-AB. “Paying attention to what others are doing gives you the chance to see whether a new behavior is beneficial, or potentially dangerous. Copying it means that you too can reap the reward.”

By copying the behaviors of others, animals can potentially unlock resources. So Chimento and Aplin wanted to know if there was an ingredient that would catalyze social learning, allowing animals to more efficiently realize its rewards. According to theory, there was a possibility: “Theoretical models have suggested that animals should change their social learning strategy when faced with new environments,” says Chimento who is now at the Cluster of Excellence Collective Behaviour at the University of Konstanz. In other words, when animals move into a new place, they might learn more from others. “But nobody has experimentally shown this in non-human animals,” he says.

Using an automated puzzle box system they developed, the team designed an experiment to test this immigration hypothesis. They created experimental social groups of wild-caught great tits. Each group was provided a tutor which was trained to access food from a puzzle box by either pushing the door left or right. One tutor was then released into each group, so that their flock mates learned to prefer using one solution over another.

Next came the immigration event. Right-pushing birds were transferred into aviaries where resident birds were using the left-hand solution, and vice versa. Not only did immigrants see that residents were opening the puzzle box in a new way, but in some groups, the newcomers also discovered that residents scored a superior reward by doing so.

“What’s important is that the immigrants were blind to the fact that the food reward had changed,” said Chimento, the study’s lead author. “Immigrants could only know something changed by either watching the residents use the puzzle, or by trying the other side themselves.”

And watch, the immigrants did. After being released into the new aviary, the vast majority of immigrants—80 percent—switched their method immediately. Instead of attempting the method they had been trained on, the immigrants used the resident solution on their first try. Chimento says that this stark result makes a compelling case that social learning was at play: “Of course we can’t ask the birds exactly where they were getting their information from, but these behavioral patterns are striking enough to suggest that the birds were watching residents very closely from the moment they entered their new social group.”

But there was an extra twist. These immigrants were not just moved to a place where residents were getting better food; their visual world was also drastically transformed. The scientists manipulated the environment of immigrants by changing the foliage in the experimental aviaries as well.

And it was the altered visual environment that proved to be the linchpin for learning. In trials where the foliage was not changed, only 25 percent of the newcomers tried the resident solution on the first attempt, even when locals were earning better food. “They didn’t necessarily ignore the residents, but they took much longer to all switch over to the more rewarding solution. Our analyses suggested this was because they weren’t as influenced by the residents” Chimento says.

This is the first experimental evidence to show the powerful impact that immigration has on how animals learn from each other. And in the real world, this can be profound.

Says Aplin, the study’s senior author: “In nature, animals are often moving from one environment to another, so it’s helpful to have a strategy to weed out what are good and bad behaviors to use in the new place.” That’s why the theory predicted that different learning strategies should evolve to act as a filter when animals enter new environments. “Our study provided the experimental evidence to show that this is also what happens in real life,” she says.

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Journal

PLOS Biology

DOI

10.1371/journal.pbio.3002699 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Immigrant birds learn from socially observed differences in payoffs when their environment changes

Article Publication Date

14-Nov-2024

 

Emerging alternatives to reduce animal testing show promise

Summary author: Walter Beckwith

American Association for the Advancement of Science (AAAS)

In a Policy Forum, Chad Nelson and colleagues highlight the efforts of the U.S. Food and Drug Administration (FDA) in advancing alternative methods to reduce animal testing for regulatory use. Animal studies have been crucial for advancing disease understanding, developing therapies, and assessing the safety and effectiveness of consumer products. However, reducing animal use and developing effective alternatives is an ongoing priority. Although advances in biology, engineering, and artificial intelligence offer new opportunities to improve product safety assessments, these technologies require extensive development to meet regulatory standards. According to Nelson et al., the FDA is working to advance alternative methods – new approach methodologies (NAMs) – that improve the safety, risk, and efficacy understanding of regulated products while reducing animal use. Here, the authors highlight these efforts. Over the years, the FDA has advanced NAMs, such as in vitro ocular irritation tests, which have replaced traditional rabbit testing. The FDA has also advanced the use of computational models to assess drug safety. Additionally, the agency has developed qualification programs to evaluate and validate these alternative methods for regulatory use, ensuring their effectiveness in making regulatory decisions. The FDA encourages innovation through programs like ISTAND, which supports new tools like organ-on-a-chip technologies. Nelson et al. argue that by collaborating with stakeholders, hosting workshops, and conducting its own research, the FDA continues to lead efforts in validating and adopting alternative methods that reduce reliance on animal testing.

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Journal

Science

DOI

10.1126/science.adg6228 

Article Title

Advancing alternative methods to reduce animal testing

Article Publication Date

15-Nov-2024