Sunday, November 15, 2026

BAN DEEP SEA MINING

FIU scientists uncover hidden extinction risks in the deep sea

Florida International University

New genetic evidence suggests marine life in the deep Gulf may be more vulnerable than previously believed.

A biodiversity crisis is unfolding across the planet, but the deep sea was thought immune and even a refuge for marine life. New research led by Florida International University scientists suggests that assumption may be alarmingly wrong.

By examining more than a decade of genetic data, the research team uncovered troubling signs of extinction risk among five species living hundreds of meters beneath the surface of the Gulf, raising the possibility that a biodiversity crisis is also unfolding in one of the planet's largest and least understood habitats. Led by FIU marine scientist Pedro A. Peres from the Bracken-Grissom Lab, the study examined three species of lanternfish and two species of deep-sea shrimp collected between 2011 and 2023.

Researchers analyzed genetic information from 486 specimens to understand how populations have changed over time and how vulnerable they may be to future environmental pressures. This is one of only a few studies to examine how the DNA of deep sea animals has changed over time, according to Peres.

All five species exhibited genetic warning signs associated with elevated extinction risk, Peres said. One lanternfish species, Diaphus dumerilii, lost approximately 8% of its genetic diversity over 12 years — a decline comparable to or greater than losses documented in some threatened and endangered animals over much longer periods. The researchers also found that each species had a relatively small effective population size. This doesn't mean there are necessarily few animals. It means relatively few individuals are contributing genetically to future generations.

This challenges the idea that deep-sea species are naturally more resilient because they occupy such vast environments,” Peres said. “It shows how much we can miss when we look only at population abundance without considering their genetic diversity and long-term viability.”

Genetic diversity is essential to a species' survival, according to Heather Bracken-Grissom, assistant director of the Institute of Environment’s Coastlines and Oceans Division. A co-author of this study, she has spearheaded the research investigating the genetic diversity and resilience of deep-sea species.

“Genetic diversity provides the variation populations need to adapt to changing conditions, resist disease and recover from environmental disturbances,” she said. “When that diversity disappears, a species can also lose the ability to withstand future threats.”

The researchers used climate models to predict how suitable the Gulf's deep-sea habitats may become by 2050 and 2100. Four of the five species could experience significant shrinking of suitable habitat in the Gulf — as much as 70%. The findings are particularly concerning, Peres said, because deep-sea species have traditionally been assumed to maintain large, resilient populations due to their extensive habitats and broad distributions.

The research also raises questions about the lasting effects of the 2010 Deepwater Horizon oil spill. Previous studies documented substantial declines in deep-sea animal populations following the disaster.

Although the researchers do not directly attribute the genetic changes to the spill, the findings suggest environmental disturbances may have consequences that persist long after the immediate damage.

“Our results suggest some deep-sea populations may have already been genetically vulnerable before the Deepwater Horizon oil spill,” Peres said. “This has important implications for understanding the consequences of environmental disturbances. Events such as oil spills may affect populations that already have limited genetic resilience.”

The study also includes co-authors Keith Sellers from FIU and Tracey T. Sutton from Nova Southeastern University. The findings demonstrate how genetic monitoring can reveal conservation threats that traditional population surveys might miss.

“This study serves as a wake-up call for the scientific community,” Peres said, “highlighting the urgent need to integrate genetic monitoring into biodiversity assessments and emphasizing the importance of long-term monitoring to better understand and detect changes in marine populations over time.”

Journal

Nature Communications

DOI

10.1038/s41467-026-79098-0

Method of Research

Data/statistical analysis

Subject of Research

Animals

Article Title

Extinction risks in deep-sea populations revealed by genomic data and ecological niche modeling

Article Publication Date

12-Nov-2026

Robotic technology helps unlock the hidden microbial world of the deep sea

University of Manchester

Key Findings

New robotic technology recreates and maintains deep-sea conditions, allowing difficult-to-grow microorganisms to be studied in the laboratory.
Researchers successfully recovered 34 microbial isolates from samples collected 1,300 metres beneath the Sea.
The technology grew a microbe that depends on high pressure and cannot be cultivated under normal atmospheric conditions.
The platform kept a complex community of deep-sea microorganisms growing for 180 days by maintaining the conditions they needed.

Scientists have developed a robotic system that can recreate the extreme conditions of the deep ocean in the laboratory, opening up access to some microorganisms for the first time.

The deep sea is the largest microbial habitat on Earth and is home to a huge diversity of microorganisms. Many have evolved to survive extreme conditions, including intense pressure and near-freezing temperatures, developing unusual enzymes and other molecules that could have useful properties, with potential applications ranging from pharmaceuticals and new materials to food and energy.

But researchers estimate that less than 1% of its microorganisms can currently be cultivated using conventional methods.

Due to the extreme conditions they are used to, when samples are brought to the surface, rapid changes in pressure and temperature can kill the microbes before scientists have the opportunity to study them.

Recreating the deep sea in the laboratory

Now, researchers have developed a system called DISCUSS, which recreates and maintains the conditions experienced by microbes in their natural environment throughout the whole journey from collecting samples on the ocean floor to growing and isolating individual microorganisms in the laboratory.

The platform is explained in the journal Nature Sensors.

Zhengguang Liu, Researcher at The University of Manchester, said: “Scientists have long struggled to grow many microorganisms found in nature under laboratory conditions, limiting our understanding of how they live and function. DISCUSS helps address this challenge by recreating and preserving the environments these microbes depend on. By bringing together environmental sensing, digital modelling and robotics, we can study microbial life that has previously been difficult to access, while opening up new possibilities for exploring other extreme environments. We hope this work demonstrates how intelligent engineering systems can help overcome longstanding scientific challenges and enable new discoveries.

“Deep-sea microbes are particularly fascinating because they have evolved to survive extreme pressure, cold and unusual chemical conditions. Their adaptations may offer valuable insights and potential applications in areas such as energy, advanced materials and biotechnology. From an engineering perspective, what excites me most is how intelligent sensing, modelling and automation can help us explore biological systems that were previously difficult to study. I believe this kind of interdisciplinary approach could open up new opportunities, both for understanding life in extreme environments and for addressing broader scientific and technological challenges.”

Growing microbes that depend on extreme conditions

Researchers tested the system using samples collected from a cold seep 1,300 metres beneath the Sea.

The technology combines real-time environmental sensors, advanced robotics and ‘digital twin’ - or a virtual representation of the deep-sea environment - to continually monitor conditions such as pressure, temperature and chemical composition and make adjustments when necessary.

Once the microbes began to grow, cameras and deep-learning technology were used to recognise individual microbial colonies, while robotic tools could select and collect them for further study without removing them from the high-pressure environment.

In total, the researchers recovered 34 microbial isolates, including several that appear to be significantly different from previously identified strains.

Among those were two bacteria adapted to high-pressure environments. One of these, called HP_SR10, depends on high pressure to grow and cannot be cultivated under normal atmospheric conditions.

The system was also able to keep a complex community of microorganisms growing together for 180 days by maintaining the conditions they needed over an extended period.

Unlocking the mysteries of the deep ocean

Beyond discovering and studying new microorganisms, the technology could also help scientists answer fundamental questions about the role microbes play in the deep ocean.

Deep-sea microorganisms are important in global processes such as the carbon cycle. Carbon produced near the ocean surface can eventually sink into the deep ocean, but scientists still do not fully understand how microorganisms living at these depths transform it.

Being able to collect, grow and study a wider range of microbes under conditions closer to their natural environment could help researchers answer these questions investigate these natural processes that happen in the deep sea.

The researchers say the same approach could eventually be adapted to study microorganisms in even deeper parts of the ocean and other extreme environments such as high-temperature hydrothermal vents.

Journal: Nature Sensors

Full title: Closed-loop in situ isolation of deep-sea extremophiles through sensor-driven microenvironment preservation

DOI: 10.1038/s44460-026-00128-x

URL: https://www.nature.com/articles/s44460-026-00128-x

Journal

Nature Sensors

DOI

10.1038/s44460-026-00128-x

Peer reviewed research: Fiji Petrel eludes 10-day search as communities aim to protect bird’s habitat

Scientists document all known sightings of little-understood bird from Fiji, found nowhere else on Earth; secure only-known recording of its call

National Geographic Pristine Seas

Washington, D.C. and Sawaieke, Fiji (November 12, 2026) — A new peer-reviewed study released today details scientists’ search for one of the planet’s rarest birds in the waters off Fiji’s Gau Island. Spanning ten days, the expedition yielded no verified sightings of the critically endangered Fiji Petrel, one of the world’s most elusive birds. Fewer than 50 individuals are believed to remain on Earth. The researchers’ investigation helped secure the only known audio recording of the Fiji Petrel’s call.

Community members on Gau Island vowed to protect the forests on mountain slopes, known as montane forests, where the birds are thought to nest.

The expedition, which was carried out by National Geographic Pristine Seas in May 2025 in partnership with BirdLife International and NatureFiji-MareqetiViti, is detailed in a scientific paper — Fiji Petrel Pseudobulweria macgillivrayi a review

of historical sightings and the outcomes of a 2025 at-sea survey and tagging attempt — published today in the journal Bird Conservation International. In addition to documenting the team’s at-sea search, the paper compiles, for the first time, every confirmed sighting of the Fiji Petrel, locally known as Kacau-ni-Gau from 1855 to present day.

The species was spotted on land on Gau until the 2000s, but no confirmed land sightings have occurred since 2012. The last confirmed sighting at sea was during a scientific search in 2023. This is one of the few species of seabirds in which no nests have ever been found.

“We’re in a race against time to save the Fiji Petrel,” said Lindsay Young, Vice President of research for Pristine Seas who led the expedition. “We searched for the bird night and day through the most tried-and-true techniques available, but the Fiji Petrel eluded us. While we left Gau still chasing shadows, communities’ commitment to habitat protection and invasive species control gives any remaining Fiji Petrels a fighting chance.”

During their ten-day search, mostly at sea, the local and international scientists spent over 12 hours per day scouring the skies for the Fiji Petrel. While the sun shone, the team used a technique called chumming — dispersing bait and fish oil on the sea surface — to try to attract the birds. At night, they attempted to attract the petrels through spotlighting and acoustic attraction: two bright handheld spotlights were aimed vertically to create a strong beam visible from a distance, while an audio recording of calls meant to attract the Fiji Petrel was played on a loop. Sightings were only considered confirmed if they were supported by photographic evidence.

“We have records of humans seeing the Fiji Petrel only 16 times on land and 22 times at sea,” remarked Melania Bulimaitoga, biologist for BirdLife International. “That’s why this bird and everything about it remains a mystery: the bird’s breeding habits, population size, and foraging behavior are virtually unknown. We had hoped to tag a bird to finally understand where their nests are and how to protect them. After 10 days and nights of little sleep and lots of focus, we came up empty.”

As part of their information gathering, the team spoke to residents of Gau Island, who have deep traditional knowledge about the bird, and uncovered the only known audio recording of the Fiji Petrel call.

The Fiji Petrel — endemic to the country — holds deep significance in Gau Island and beyond. The bird adorns Fiji’s twenty-dollar banknote and is the subject of lullabies passed down through generations on Gau Island, Fiji’s fifth-largest island.

The study describes how oral histories shared by Gau village chiefs indicate that the Fiji Petrel and similar species used to be much more abundant. Chiefs recounted stories from their great-grandmothers, who described collecting seabird eggs from the lower montane slopes behind the village, especially during pregnancy, when eating the eggs was considered desirable.

The Fiji Petrel’s primary threats include invasive predators — feral cats, rats and pigs — and habitat degradation on Gau, the only island where the bird has ever been recorded. The lack of confirmed sightings during the most recent expedition underlines the peril of the bird’s status. But scientists acknowledge that external factors, including a cyclone that passed south of the expedition during the survey period, as well as a recent strong El Niño could have contributed to the Fiji Petrel’s absence.

“We were disappointed not to have any confirmed sightings, but a single survey is just a snapshot,” remarked Lindsay Young. “It doesn’t tell the whole story. Even so, we have to acknowledge the real risk that the Fiji Petrel may be slipping away as we watch — which is precisely why new protections being pursued by communities in Gau are so critical.”

###

About National Geographic Pristine Seas

National Geographic Pristine Seas works with Indigenous and local communities, governments, and other partners to protect vital places in the ocean through research, policy, and filmmaking. Since 2008, Pristine Seas has helped establish 31 marine protected areas, spanning more than 6.9 million square kilometers of ocean. Pristine Seas is part of the global non-profit, the National Geographic Society. Our mission is driven by science and filmmaking. We are fully independent from National Geographic publishing and its media arm.

Journal

Bird Conservation International

DOI

10.1017/S0959270926100768

Method of Research

Survey

Subject of Research

Animals

Article Title

Searching for the Fiji Petrel: Insights from a satellite tracking attempt and historical observations

Article Publication Date

12-Nov-2026

Turning coal gasification waste and corn stalks into high-strength briquettes for cleaner reuse

Higher Education Press

IMAGE: — image:
Preparation of CS binder and briquetting methods.
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Credit: HIGHER EDUCATION PRESS

Coal gasification is a key technology for the clean and efficient utilization of coal, but it produces large volumes of coal gasification fine slag (CGFS) characterized by high water content and low residual carbon reactivity. Stockpiling or landfilling this waste occupies space, risks secondary environmental pollution, and wastes coal resources. Direct reuse is difficult because the ultrafine particle size prevents it from being re-fed into gasifiers.

In a study published in ENG. Chem. Eng., researchers at the East China University of Science and Technology investigated using a carbon-rich residue (CR, with a fixed carbon content of 81.21%) separated from CGFS. They combined this CR with a corn stalk (CS) powder modified by an NaOH-urea solution to act as a binder, producing briquetted carbon-rich residue (BCR) via hot-pressing.

The team systematically optimized the briquetting conditions. When the CS binder content was lower than 15%, the mixed materials exhibited severe delamination. Optimal mechanical strength was achieved at a 25% binder content. Two-factor orthogonal experiments revealed that the optimal hot-pressing temperature was 175 °C and the optimal pressure was 7.5 MPa. Under these conditions, all BCR samples exhibited drop strengths exceeding 99.7%.

The height-to-diameter (H/D) ratio significantly affected the briquettes' properties. The BCR-0.8 sample exhibited the best mechanical strength, with a compressive strength of 620.8 N. However, increasing the H/D ratio compressed the internal pores and weakened gasification reactivity. Therefore, the BCR-0.4 sample, with a compressive strength of 333.0 N, was identified as having the optimal comprehensive performance, balancing mechanical strength and gasification reactivity.

The briquetting process also improved gasification performance. At 1000 °C, the raw CR required 13.9 minutes to reach a 90% carbon conversion rate, whereas the BCR-0.2 sample required only 8.9 minutes, a reduction of 5.0 minutes.

Mechanistic analysis showed that during binder preparation, NaOH disrupts the intermolecular hydrogen bond network of the corn stalk, releasing lignin, while urea undergoes an amidation reaction to generate viscous amide-N active substances. During hot-pressing at 175 °C, the softened lignin coats the CR particles, and the amide components bind tightly to them, forming a dense structure through chemical bonding, physical filling, and hot-pressing synergy.

The authors note that the proposed hot-pressing route is compatible with existing coal chemical solid waste treatment lines. Laboratory-scale equipment can be scaled up to industrial continuous roller-molding units without modifying the main gasifier, significantly reducing equipment renovation costs. This strategy also reduces both solid waste landfill costs and raw material procurement costs.

Journal

ENGINEERING Chemical Engineering

DOI

10.1007/s11705-026-2707-x

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Hot-press briquetting of carbon-rich coal gasification residues using a corn-based biomass binder: mechanical strength, gasification reactivity, and binding mechanism

Pumpkin seed protein puts a twist on nondairy coffee creamer

Taste testers share that the pumpkin seed creamer smooths out instant coffee much like a commercial nondairy creamer.

American Chemical Society

Pumpkin seed protein puts a twist on nondairy coffee creamer — image:
Adding pumpkin seed-based creamer to coffee lightened and smoothed out the drink like commercial nondairy creamer does.
view more
Credit: Adapted from Journal of Agricultural and Food Chemistry 2026, DOI: 10.1021/acs.jafc.6c12935

Pumpkin season is about more than cute décor. The squash contains lots of seeds with a high protein content, but they’re usually discarded. Researchers reporting in ACS’ Journal of Agricultural and Food Chemistry found another way to use the seeds, extracting that protein to create a plant-based coffee creamer. In initial taste tests, participants preferred the new creamer to a commercial nondairy option because it preserved the flavor and aroma of coffee better.

“A plant-based coffee creamer can improve mouthfeel without sacrificing the coffee’s own flavor.” — Jicheng Chen

Some pumpkin seeds are eaten, but most are either thrown out or processed for their oil, which leaves behind a food product that’s mostly protein. But this protein clumps in water, which limits its upcycling and incorporation in plant-based beverages. Previous food science research has shown that a group of chemical compounds called phosphates can help proteins form stable mixtures of oil and water, also called emulsions. So, Jicheng Chen, Jianyu Huang, and colleagues wanted to treat pumpkin seed protein with food-grade phosphates and test the product’s potential as a satisfying, nondairy coffee creamer.

The researchers first added different proportions of two phosphate salts to pumpkin seed protein extracts and measured the resulting powder’s ability to create smooth, stable emulsions. A blend of two widely used food texture modifiers and thickeners, sodium tripolyphosphate and sodium trimetaphosphate, in a 4:1 ratio performed best. The researchers mixed the powder into water and whipped the mixture with camellia oil, also known as tea seed oil, creating a prototype nondairy coffee creamer.

Next, the team poured the emulsion into instant black coffee prepared with room-temperature water.

A 10% creamer addition was chosen for taste tests because it slightly lightened the coffee’s color without substantially impacting the aroma, an effect that consumers expect from coffee creamers. In a taste test conducted by 12 people, participants preferred coffee with the pumpkin seed protein creamer over coffee containing a commercial nondairy creamer. They said that the commercial creamer improved the drink’s texture but was less effective at reducing the bitterness of the coffee and could add some off-flavors. In contrast, while the pumpkin seed creamer also improved the drink’s appearance, body, and smoothness, it retained the expected flavor and aroma of coffee.

Jicheng Chen says these findings show that “a plant-based coffee creamer can improve mouthfeel without sacrificing the coffee’s own flavor.”

And with further development, the pumpkin seed-based creamer has the potential to be a product found on store shelves. The team plans to explore the new nondairy creamer’s stability in coffee (as well as other beverages such as beer), evaluate its flavor and consumer acceptance, and develop it into liquid concentrates or powders for easy storage and transport, says Jicheng Chen.

The authors acknowledge funding from the Fujian Science and Technology Mission Serves Key Industrial Chain projects, and the Major Scientific and Technological Projects in Fuzhou. They also thank Fujian Agriculture and Forestry University for its encouragement and support of the researchers.

###

The American Chemical Society (ACS) is one of the world's largest scientific organizations and a global leader in advancing scientific knowledge. Founded in 1876, ACS' mission is to advance scientific knowledge, empower a global community, and champion scientific integrity. Guided by its vision of a world built on science, ACS brings together people, ideas, and resources to drive discovery and innovation, support the professional growth of scientists and students, and advance scientific discussion. Through its trusted publications, scientific meetings, community networks, education and career resources, and scientific information solutions, ACS helps scientists, educators, and students make a lasting impact on their communities and the world at large. Together, these efforts support ACS' commitment to improve all lives through the transforming power of chemistry.

Registered journalists can subscribe to the ACS journalist news portal on EurekAlert! to access embargoed and public science press releases. For media inquiries, contact newsroom@acs.org.

Note: ACS does not conduct research but publishes and publicizes peer-reviewed scientific studies.

Journal

Journal of Agricultural and Food Chemistry

DOI

10.1021/acs.jafc.6c12935

A pumpkin seed protein emulsion (top left) looks similar to a commercial creamer (top right) when they are added to instant coffee (bottom images).

Credit

Jicheng Chen

Article Title

Dual-Phosphorylated Pumpkin Seed Protein Pickering Emulsions: Structural Evolution, Interfacial Regulation, and Coffee Creamer Application Quality

Drought threatens to leave Amazonian communities isolated: a report identifies where and when

Universitat Autonoma de Barcelona

Falling river levels in the Brazilian Amazon during periods of severe and extreme drought can alter the way of life of the communities that depend on them, from food and income generation to mobility and access to essential services. Given this major concern, a new international report produced by the Institute of Environmental Science and Technology at the Universitat Autònoma de Barcelona (ICTA-UAB), Spain, in collaboration with IOM (the UN Migration Agency), the National Centre for Monitoring and Early Warning of Natural Disasters (Cemaden), Humboldt-Universität zu Berlin (IRI THESys, HU-Berlin), and the Universidade Federal de Minas Gerais, with support from the Brazilian Research Network on Global Climate Change (Rede Clima), makes it possible to identify the localities where falling river levels during El Niño months can increase the risk of immobility.

The "Drought and Immobility Risk in the Amazon Basin" report inaugurates a series of monthly editions that will be published throughout the coming Amazonian dry season. Each edition aims to track how hydrological conditions evolve and their possible impacts on the mobility of Amazonian communities, as well as provide information to support planning and decision-making by public managers and professionals working directly with vulnerable populations.

Amazonas State concentrates localities prone to immobility

The concept of involuntary immobility, used in preparing the report, refers to situations in which people or communities cannot leave their place of origin or residence in the face of extreme weather events or other types of disaster. Of the municipalities analyzed, São Gabriel da Cachoeira, in the state of Amazonas, Brazil, concentrates the highest number of localities prone to becoming isolated: 343, of which 318 are indigenous. It is followed by Lábrea, with 72 localities; Manicoré, with 68; Fonte Boa, with 66; and Atalaia do Norte, with 64. The analysis also identifies areas of concern in the states of Acre, Rondônia, and Pará.

The report goes beyond analyzing the intensity of droughts and identifies the places where a prolonged drop in river levels would generate mobility problems for populations. To this end, localities are considered prone to immobility when they are less than five kilometers from rivers and floodable areas, more than five kilometers from roads, and in areas where river levels are forecast to remain below historical patterns for prolonged periods. The analysis is based on data from 90 fluviometric stations.

As researchers Letícia Santos de Lima and Wilson Fernandes explain, "the method developed, which is still being refined, makes it possible to identify the localities most dependent on river and wetland navigation due to their geographic isolation, as well as those where water levels are expected to remain below normal for an extended period of time during the month analysed. Over the coming months we will work to refine these results, and we hope they can support decisions on assistance to communities."

Drought can affect mobility, agriculture, and access to services

The study also crosses data on the location of communities prone to isolation with drought alerts for family farming issued by Cemaden. The combination makes it possible to identify areas where the effects of drought can simultaneously hit agricultural production and mobility, suggesting a greater risk to food security.

"The Alerta-Secas platform estimates the potential impacts of drought on family farming, integrating drought intensity, local vulnerability, and the forecast of worsening conditions. The tool allows identifying municipalities at risk of losses in short-season rainfed crops, supporting early action to reduce productive, social, and economic impacts," explains Ana Paula Cunha, institutional relations coordinator and drought researcher at Cemaden.

The scenario gains relevance in light of the weather conditions forecast for the coming months. According to the El Niño Panel 2026-2027, there is a 95% probability of a very strong El Niño event occurring in the October-November-December quarter. The phenomenon could rank among the most intense recorded since 1950.

The latest data from Cemaden also point to the fact that special attention should be paid to Brazil’s North Region. On October 7, levels of main rivers were at conditions near or below the climatological average in the region, with a growing number of stations showing levels far below average in the northern part of that area. For November, the forecast indicates a predominance of flows below or far below average across much of the North Region. Cemaden's monitoring shows that drought affects indigenous areas. In September, 170 of the 275 units monitored experienced drought, equivalent to 61.8%.

"When rivers fall, the impacts for many Amazonian communities can extend to various dimensions of life, including access to essential services. By identifying in advance where there is a risk of conditions worsening, we want to contribute to the planning and implementation of solutions tailored to the needs of the affected people," explains Débora Castiglione, National Officer for Environment, Climate Change, and Disaster Risk Reduction at IOM.

"The launch of the Drought and Immobility Risk in the Amazon Basin bulletin seeks to expand monitoring capacity and support institutional responses to the climate crisis in the region. The initiative gives visibility to vulnerable populations in the Amazon, especially indigenous communities affected by isolation and involuntary immobility caused by extreme droughts. By bringing together expertise in disaster anticipation and impacts on family farming, the bulletin strengthens climate governance and provides input for preventive and humanitarian protection policies, reaffirming the commitment of science and human rights to the future of the Amazon," notes Érica Menero, from Rede Clima.

Access the full bulletin here: link

Article Title

Seca e Risco de Imobilidade na Amazônia.

Parrots' vibrant feathers are susceptible to bacterial attack

New study overturns previous research and shows that the most vibrantly colored parrot feathers are highly susceptible to being broken down by bacteria

Princeton University

Macaws in flight — image:

Two Red-and-green Macaws (*Ara chgloropterus*) in flight. Princeton biologists tested whether the psittacofulvin pigments in parrot feathers protected the feathers against damage caused by bacteria.
view more
Credit: Octavio Campos Salles

Flashy birds, from peacocks to parrots, have inspired a long tradition of using animal colors to study evolution. Colorful plumage often functions as a signal—for example, to attract a mate. Alternatively, drab colors can be used for camouflage. However, color can have functions beyond signaling and camouflage. This is because pigments, the molecules embedded in feather tissues to produce a broad range of colors, can also influence other aspects of feathers, ranging from mechanical strength to thermoregulatory properties. For example, melanin, a pigment that creates dark colors in many animals, has been shown to make feathers physically stronger. Melanin has also been shown to reduce the damage caused by bacteria that feed on keratin proteins, the building blocks of feathers. Beyond melanin, could the pigments responsible for vivid colors also have such non-signaling functions? New work led by Princeton University biologists sheds light on this question.

Parrots are hailed for their colorful plumage, yet psittacofulvins, the pigments primarily responsible for their brilliant colors, have remained somewhat of a mystery. Most birds use carotenoid pigments to produce bright red, yellow, orange and pink plumage. But not parrots. They evolved psittacofulvins, a group of pigments found in no other animals on the planet, to produce the same hues typically made by carotenoids in other birds. Why did parrots evolve a unique coloration system? A pioneering study in 2010 offered an answer, proposing that psittacofulvins might protect feathers from keratin-eating bacteria. Because feathers have so many functions, ranging from flight and thermoregulation to signaling and camouflage, susceptibility to bacteria-induced damage could have major effects on fitness. If psittacofulvins protected feathers from bacterial degradation, it might explain why these pigments—and their resulting colors—evolved in parrots. Using a relatively small sample of parrot feathers and the bacteria Bacillus licheniformis, which is ubiquitous in wild birds, the 2010 study found that red feathers, which have high concentrations of psittacofulvins, were resistant to bacterial attack, similar to black feathers.

In a new study published in the Journal of Experimental Biology, Ali et al. (2026) revisit the hypothesis that psittacofulvins protect parrots from microbial damage, but with a broader range of feathers from more species. The research team sampled thousands of parrot feathers, placing them in a solution inoculated with B. licheniformis. When these bacteria feed on feathers, small proteins are released into the surrounding liquid medium—making it possible to quantify the amount of feather breakdown that has occurred. By using the feathers of closely related parrot species, the researchers could control for variation in feather properties that would otherwise affect their findings. The least degraded feathers were black feathers, which was expected given their high melanin content. However, red, orange, yellow, and green feathers, all of which contain psittacofulvins, broke down the most, while feathers lacking psittacofulvins—blue, white, black and grey—fared substantially better. Given the results of the 2010 study, these results were unexpected.

“We thought psittacofulvins would combine with melanin to protect feathers,” explained lead author and former Princeton graduate student, Jarome R. Ali, “so our findings were entirely unanticipated”. Ali, now a postdoctoral researcher at New York University, continued, “The red feathers should have been intact, but they had totally fallen apart, while other colors, like blue, seemed mostly unbothered. We think our results may differ from those previously reported because we relied on a broader array of parrot feathers, which we sampled quite extensively. Parrots often seem to break the rules. In retrospect, we shouldn’t be surprised that they surprised us.”

Why do psittacofulvins provide such meek protection? The researchers suggest that incorporating psittacofulvins into the feather keratin could slightly destabilize its structure, making it susceptible to the enzymes bacteria use to break it down. Such a trade-off would have interesting evolutionary implications. “Our results suggest that the pressures favoring the evolution of the vibrant colors in parrots outweigh the potential negative effects of bacterial degradation,” said the senior author Mary Caswell Stoddard, professor of ecology and evolutionary biology at Princeton. “In other words, beauty over bacteria: parrots are often red, orange, yellow and green even though these colors are quite susceptible to bacterial attack.”

Alternatively, psittacofulvins might have some as-yet undiscovered role, in addition to producing beautiful colors. For example, their chemical structure is similar to some known antimicrobial and antifungal compounds and could protect feathers from microorganisms other than the B. licheniformis tested in this study. “Our findings really highlight the array of factors influencing feather coloration. It's not just about being bright," said Alexander Downie, postdoctoral researcher at the Max Planck Institute for Evolutionary Anthropology and former Princeton University graduate student. The authors say that whether bacteria actually pose a serious threat to feathers in the wild is an important area for future research. Ali ended, “This beauty and the bacteria story motivates us to ask new and exciting questions. Parrots have much to teach us about evolution and the natural world. I can’t wait to learn more from them.”

Two Red-and-green Macaws (Ara chloropterus). Princeton biologists tested whether the psittacofulvin pigments in parrot feathers protected the feathers against damage caused by bacteria

Credit

Octavio Campos Salles

Journal

Journal of Experimental Biology

DOI

10.1242/jeb.252685

Method of Research

Experimental study

Subject of Research

Animal tissue samples

Article Title

Colourful psittacofulvin-containing parrot feathers do not resist bacterial degradation

Article Publication Date

12-Nov-2026