New study reveals preventing an hour of intense pain in chickens costs less than a hundredth of a cent

Welfare Footprint Institute

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A new study published today in Nature Food evaluates the impacts of the European Chicken Commitment (ECC), an initiative calling on food companies to adopt slower-growing breeds and higher welfare standards. While concerns over increased costs and emissions have been barriers to adoption, the study puts those concerns in perspective. For example, using EU carbon externality costs (the cost for companies to emit one tonne of CO₂ under the EU Emissions Trading System), the study showed that it costs less than one-hundredth of a cent to prevent each hour of intense pain —equivalent to the emissions from driving a standard car for about 15 meters.

The study also shows that switching from fast-growing to slower-growing chicken breeds, in line with the ECC, prevents at least 15 to 100 hours of intense pain per bird—at a cost of just US$1 more per kilogram of meat. The findings challenge assumptions that higher-welfare systems are too costly or inefficient, and offer a robust framework for weighing welfare, economic, and environmental considerations. They also call into question the idea that the intensification of animal agriculture, with a focus on faster growth, can be defended on environmental grounds, given the disproportionate and severe welfare harms intensive production entails and the minimal differences in environmental metrics.

The research applies the Welfare Footprint Framework, a scientific method that now makes it possible to put numbers on animal welfare. When applied to meat chickens—the most populous land vertebrates on Earth (over 70  billion birds are each year) — it reveals the toll of current industrial practices; rapid growth rates lead to widespread lameness, cardiovascular problems, heat stress, and chronic hunger, leading to disabling and excruciating pain.

“These are not abstract values. They allow us to put animal welfare on the same footing as other policy priorities,” said Dr. Kate Hartcher, Senior Researcher at the Welfare Footprint Institute and one of the authors of the study. “When you compare the cost of avoiding intense pain to the cost of other externalities, the numbers speak for themselves.”

The welfare impact estimates also include the hidden conditions of the parent birds used to produce meat chickens. Because they share the same genetics for fast growth and weight gain but need to survive for much longer, these birds must be severely feed-restricted, resulting in lifelong hunger and thousands of hours in intense distress. “Few people are aware that the pain and distress behind chicken meat production begins even before a chick is born — with the life of their mother”, said Dr. Cynthia Schuck-Paim, Scientific Director of the Welfare Footprint Institute and the study’s lead author. “To meaningfully improve welfare in meat chicken production, we need genetic changes. Without them, mother hens must continue to endure extreme hunger to avoid the health problems caused by rapid growth.”

Until now, animal welfare has lacked a standardized metric that can be integrated alongside financial and environmental indicators. The Welfare Footprint Framework fills that gap, enabling animal welfare impacts to be understood and  compared in common and easy-to-understand units. This study marks a turning point in how animal welfare is considered in food systems. By providing a clear, science-based way to measure animals' experiences, the Welfare Footprint Framework makes it possible to drive meaningful reforms and ensure animals are no longer left out of the conversation. 

The study was carried out through a collaboration between the Welfare Footprint Institute, the Stockholm Environment Institute, and the University of Colorado Boulder.

Publication: The Welfare Footprint Framework can help balance animal welfare with other food system priorities. Nature Food. DOI: 10.1038/s43016-025-01213-z

For more information: media@welfarefootprint.org.

The Welfare Footprint Framework is freely available for research and policy use at welfarefootprint.org

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Journal

Nature Food

DOI

10.1038/s43016-025-01213-z 

Method of Research

Commentary/editorial

Subject of Research

Animals

Article Title

The Welfare Footprint Framework can help balance animal welfare with other food system priorities

Article Publication Date

18-Aug-2025

 

Seabirds only poop while flying

Cell Press

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Using backward-facing cameras mounted on streaked shearwaters, researchers recorded seabirds’ pooping habits in the open ocean.

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Credit: Leo Uesaka

On Japan’s desert islands, researchers uncovered a peculiar bathroom ritual among seabirds. Reporting in the Cell Press journal Current Biology on August 18, the team found that streaked shearwaters (Calonectris leucomelas) poop while flying—not while floating on water—and they do so every 4 to 10 minutes. This habit may help the birds stay clean and fertilize the ocean below. 

But the team didn’t set out to document the seabirds’ bathroom habits. “I was studying how seabirds run on sea surface to take off,” says Leo Uesaka, the lead author from the University of Tokyo. “While watching the video, I was surprised that they dropped feces very frequently. I thought it was funny at first, but it turned out to be more interesting and important for marine ecology.” 

Seabird droppings enrich the soil and fertilize nearby coastal waters thanks to their high nitrogen and phosphorus contents. Researchers have studied how these nutrients shape ecosystems on land, but much less is known about how they impact what happens far from shore, in the open ocean, where seabirds spend most of their lives. With an estimated 424 million shearwaters and their kins, their droppings could fertilize the water below, providing nutrients to plankton and other marine life. 

Using eraser-sized, backward-facing cameras strapped to the bellies of 15 streaked shearwaters, Uesaka recorded and analyzed nearly 200 defecation events. He found that the birds almost always relieved themselves while flying and that defecation often followed shortly after takeoff. Occasionally, the birds took off solely for bathroom breaks and returned to the water within a minute. These findings suggest that they intentionally avoid pooping while floating, notes Uesaka. 

“Streaked shearwaters have very long and narrow wings, good for gliding, not flapping,” says Uesaka. “They have to flap their wings vigorously to take off, which exhausts them. This means the risk of excreting on the sea surface outweighs the effort to take off. There must be a strong reason behind that.” 

The researchers suspect this habit may spare the birds from fouling their feathers with feces, help them avoid attracting predators, or simply help the birds poop more easily compared to a floating position. 

While in flight, the birds pooped about every 4 to 10 minutes. The team estimated that the birds excrete 30 grams of poop every hour, which is about 5% of their body mass. 

“We don’t know why they keep this excretion rhythm, but there must be a reason,” says Uesaka. 

To find out, he plans to use cameras or temperature sensors with longer battery life, combined with GPS, to map where seabirds release their droppings at sea. He hopes that these future studies will offer further insights into the role of seabird feces in marine ecology. 

“Feces are important,” Uesaka says. “But people don’t really think about it.” 

Researchers found that streaked shearwaters have strict bathroom schedules, pooping every four to 10 minutes and almost always while flying, not while floating.

Credit

Yusuke Goto

This research was supported by funding from Grants-in-Aid for Scientific Research from JSPS, Japan Science and Technology Agency SPRING, and the Cooperative Program of Atmosphere and Ocean Research Institute of the University of Tokyo. 

Current Biology, Uesaka & Sato, “Periodic excretion patterns of seabirds in flight” https://www.cell.com/current-biology/fulltext/S0960-9822(25)00818

Current Biology (@CurrentBiology), published by Cell Press, is a bimonthly journal that features papers across all areas of biology. Current Biology strives to foster communication across fields of biology, both by publishing important findings of general interest and through highly accessible front matter for non-specialists. Visit: http://www.cell.com/current-biology. To receive Cell Press media alerts, contact press@cell.com. 

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Journal

Current Biology

DOI

10.1016/j.cub.2025.06.058 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Periodic excretion patterns of seabirds in flight

Article Publication Date

18-Aug-2025

 

Exploration and dispersal are key traits involved in a rapid range expansion

Researchers find that behavioral flexibility is related to exploration, and that great-tailed grackles disperse farther at their range edge

Max Planck Institute for Evolutionary Anthropology

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Picante, a male great-tailed grackle, flying by an unbanded female at the Arizona State University campus.

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Credit: © Melissa Folsom

To the point

• Exploratory behavior: Grackles who were trained to be more flexible were more exploratory after the training than untrained grackles. This indicates that the more an individual investigates a novel object, the more it can learn and adapt its behavior accordingly.
• Range expansion: Grackles in an edge population disperse farther than those in a more central population. This suggests that the rapid geographic range expansion of great-tailed grackles is associated with individuals differentially expressing dispersal behaviors.
• Key traits: Flexibility, exploration, and dispersal are key traits involved in this species’ rapid expansion into new areas.

Behavioral flexibility, the ability to adapt one’s behavior to changing circumstances based on previous experience, is thought to play an important role in a species' ability to successfully adapt to new environments and expand its geographic range. New findings from researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, the University of California Santa Barbara, and Auburn University, advance our understanding of the responses to novel circumstances by revealing flexibility in behavior on an individual level. These new results provide critical information for predicting which traits facilitate a species' ability to adapt its behavior to new areas, which is crucial in today's changing world.

Flexibility-trained grackles were more exploratory

The researchers investigated great-tailed grackles because they are an urban bird species that has rapidly expanded its range across North America over the past 140 years. Grackles who were trained to be more flexible were more exploratory after the training than untrained grackles.

“This shows that flexibility and exploration are linked - the more an individual investigates a novel object, the more it can learn and adapt its behavior accordingly,” says Corina Logan, a researcher at the Max Planck Institute for Evolutionary Anthropology and Gates Cambridge Scholar. These findings suggest that flexibility and exploration are key traits involved in this species’ rapid expansion into novel environments.

Just because it can be measured doesn’t mean it’s reliable

Large gaps exist in our knowledge of how behaviors relate to each other and the environment because researchers often rely on unvalidated behaviors or proxies to draw conclusions about how these systems work. To address this issue, the researchers in the current study measured four behaviors: exploration of new environments and novel objects, boldness towards known and novel threats, persistence, and motor diversity. However, only two of these behaviors, exploration of a new environment and persistence, were consistent across individuals. Consistency indicates that it is a stable trait that can be compared with other stable traits.

“Animals cannot tell us what they are thinking, so it's really important to ensure that our methods of quantifying behavior and cognition actually tell us what we want to know,” says lead researcher Kelsey McCune at the University of California Santa Barbara (currently at Auburn University). This highlights the importance of measuring multiple behaviors and validating their consistency before including them in analyses.

Grackles on the edge are less related, thus disperse farther

In a follow-up study, the researchers found that flexibility in behavior is linked not only to the exploration of novel environments on a small scale (e.g., a small tent), but also to novel spaces on a much larger scale. They found that grackles living closer to the edge of the expansion front in California exhibit greater dispersal behavior, with both male and female individuals moving farther away from their parents and siblings. In contrast, females in particular remained close to where they hatched in a population in the middle of the northern expansion front in Arizona.

“For a population to establish itself in a new area, many individuals of both sexes must move there,” says lead researcher Dieter Lukas at the Max Planck Institute for Evolutionary Anthropology. “The great-tailed grackles appear to have the flexibility to stay when they can, but to move when necessary.”

These results show that the rapid geographic range expansion of great-tailed grackles is associated with individuals expressing dispersal behaviors differentially.

Three female great-tailed grackles investigating a food opportunity in a parking lot in Sacramento, California.

A flock of great-tailed grackles flying in the mist in Sacramento, California.

Credit

© Corina Logan

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Journal

Peer Community Journal

DOI

10.24072/pcjournal.593 

Subject of Research

Not applicable

Article Title

Behavioral flexibility is related to exploration, but not boldness, persistence or motor diversity

Article Publication Date

18-Aug-2025

 

What geese teach us about leadership and followers

Courage and curiosity shape the flock's collective behavior

University of Vienna

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Influencer goose is leading a group of followers.

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Credit: Josef Hemetsberger, KLF

A new study led by the Konrad Lorenz Research Center for Behavior and Cognition at the University of Vienna sheds light on a long-standing mystery in animal behavior: why do certain individuals gain more influence than others within a group? The research shows that bold geese – but not aggressive ones – are more likely to be accepted as leaders, while exploratory individuals tend to follow them – revealing a nuanced interplay of personality and social roles in collective movement decisions. The results of the study have just been published in the journal iScience.

While simple interaction rules can explain how animal groups move together, we still know little about the long-term consistency of social roles in the wild – and why certain animals succeed in exerting more influence over collective decisions than others. To better understand these dynamics, the new study investigated whether individual greylag geese (Anser anser) show stable tendencies to lead or follow, and whether these behavioral patterns can be predicted by traits such as boldness, aggressiveness, and exploration. The researchers observed a marked flock at the Konrad Lorenz Research Station in Grünau im Almtal, Austria – a population originally introduced by Nobel laureate Konrad Lorenz in the 1970s. Over a period of four years, they documented hundreds of collective departures, noting who initiated flight, who responded, and how large the departing parties were. In parallel, they assessed personality through standardized tests: flight initiation distance for boldness, mirror response for aggressiveness, and novel-object interaction for curiosity. The goal was to understand how individual variation shapes movement decisions and the flow of information through the flock.

Bold leaders and curious followers

The study offers two key insights: individual geese exhibit stable personality traits – boldness, aggressiveness, and exploration – that persist over years, and they move daily in collective subgroups to forage and roost across various valley locations. Results show that bolder individuals are more likely to be followed when they give a departure call and take flight. Those who follow tend to be exploratory, preferring bold over aggressive or dominant leaders.

Each day, the flock faces a tradeoff when moving to new foraging grounds or sleeping sites: balancing the safety of familiar, secure locations with the potential benefits of exploring unknown areas. Geese with bold personalities help manage this tradeoff by offering protection during risky movements, while curious individuals promote discovery and spread innovation.

Contrary to expectations, aggressiveness did not predict leadership during group departures, even though more aggressive geese often occupy higher social ranks. The most influential initiators were bold but not aggressive – a pattern that suggests a protective rather than dominant leadership style. These bold individuals offer safety in uncertain situations, while exploratory followers contribute by identifying new opportunities and transmitting information through social learning.

Rethinking influence and Leadership

"This research helps to explain why individuals with specific traits consistently wield more influence," says lead author Sonia Kleindorfer. "More importantly, it draws attention to followers – often overlooked in our human fascination with securing resources. What if followers actively choose whom to follow based on the benefits they receive? This shifts focus to the cognitive abilities of followers and challenges traditional ideas about which traits matter most in leaders."

By shifting attention away from aggressive, dominant individuals – who may maintain control through fear – toward the social and cognitive strategies of followers, this study opens new pathways for understanding collective decision-making, social learning, and cultural evolution – not only in geese but across many species, including humans.

See more information about the geese on Youtube.

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Journal

iScience

DOI

10.1016/j.isci.2025.113170 

Article Title

Personality predicts collective behavior in greylag geese: influencers are bold and followers are exploratory.

Article Publication Date

15-Aug-2025

 

In the blink of an eye: How river noise shapes the dipper’s silent signals

By uncovering the blinking communication of river birds, scientists have shed new light on the mechanisms and evolution of animal interactions

Max-Planck-Gesellschaft

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At noisy rivers, dippers start blinking their white eyelids instead of singing louder. This is an impressive example of how animals use multiple senses to communicate, switching between them depending on the situation.  

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Credit: Kevin Duclos

As anyone who has tried to hold a conversation in a noisy room knows, it is sometimes easier to rely on hand gestures than to shout over the din. White-throated dippers face a similar challenge along the fast-flowing streams they inhabit, where the roar of fast-flowing waters can sometimes drown out their melodic songs. Rather than trying to out-sing the river to defend territory or attract mates, these plump, endearing birds sometimes switch strategy entirely – turning to sight instead of sound, by flashing their bright white eyelids in a striking visual display.

A new study led by researchers from the Max Planck Institute for Biological Intelligence and Lancaster University is among the first to document this kind of sensory shift in a wild bird. The findings shed light on how dippers adapt their communication depending on social and environmental cues – and how such flexibility may have evolved in response to noise.

Being seen to be heard

In the upland areas where white-throated dippers live, their varied, high-pitch metallic song is one of the earliest signs of spring. Sometimes seen perched on river rocks or skimming low over the water, these birds make their homes beside fast-flowing streams – ideal for feeding, but often difficult for communication, especially after heavy rains.

In a recent study of wild dippers in Britain’s Yorkshire Dales National Park researchers found that when river noise increases and other dippers are nearby, the birds don’t necessarily raise their voices. Instead, they may blink more conspicuously, fluttering their white-feathered eyelids, which stand out against their dark-brown plumage. These visual cues, the authors suggest, may help attract mates or signal presence to rivals that might otherwise miss them – and reveal how the birds can fine-tune their use of sound and sight in real time to navigate their noisy world.

“Dippers don’t just add visual signals on top of their songs – they seem to switch between them depending on the situation,” says Léna de Framond, first author of the study. “When the river gets louder and other birds are nearby, they blink more often. We even found that birds that blink most often don’t sing as loud– suggesting a shift to visual communication. But when they are alone, we saw they actually tend to sing louder to rise above the noise. That contrast tells us the behavior is social, not just a response to sound, and is a rare example of a noise-induced multimodal shift in a wild animal.”

Evolution shaped by river noise

Using more than one sense to communicate can be a big advantage in noisy environments. However, while many animals are known to adapt within a single sense – for example, by singing louder, changing pitch, or repeating themselves – clear evidence of animals switching between senses to send messages, like moving from sound to sight, or touch to smell, is still surprisingly rare.

The white-throated dipper made an ideal test case: it lives year-round beside fast-flowing rivers, where background noise is often high, and it has bright white eyelids that can act as a visual signal. If any species had learned to shift between senses to get its message across, the researchers reasoned, the dipper would be a great candidate.

The team spent more than 300 hours observing wild dippers, some marked with colored rings for identification. Through detailed observations, calibrated audio recordings, and statistical analysis, they uncovered one of the clearest examples yet of animals switching between senses to communicate.

“The study sheds light not just on how dippers communicate, but on how environmental challenges – like noisy rivers – can shape the evolution of signaling,” says Henrik Brumm, whose group at the Max Planck Institute for Biological Intelligence led the research. “What’s particularly interesting is the complexity of the dipper’s behavior and its ability to adapt to changing conditions.

“It also raises new questions about how species balance clarity and complexity. More signals can help get attention, but also increase the risk of being misunderstood – and signals need to match the senses of the animals they’re meant for. Now that we’ve seen this ability in dippers, it suggests that switching between senses may be more common in nature than we realize. In that sense, we may be seeing just the tip of the iceberg – and it’s exciting to think about where this research could go next.”

Journal

Current Biology

DOI

10.1016/j.cub.2025.07.049 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Stream noise induces song plasticity and a shift to visual signals in a riverine songbird

Article Publication Date

15-Aug-2025