Jamestown colonists brought donkeys, not just horses, to North America, old bones reveal

University of Florida

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An illustration of a donkey in colonilal Jamestown.

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Credit: Paula Calle Lopez, Courtesy of Jamestown Rediscovery (Preservation Virginia)

A new study published in Science Advances about centuries-old horse and donkey bones, unearthed in Jamestown, Virginia, is rewriting the story of how these animals first arrived in North America.

While written records from the earliest English explorers show that horses were among the animals brought to Virginia, the new zooarchaeological analysis of animal remains found at Jamestown is the first to show that colonists also brought donkeys to the New World.

The study also reveals a dark ending to these equids in the colony: The horses and donkeys were likely butchered and eaten during Jamestown’s infamous winter of starvation.

“There are no written records of donkeys on ship manifests and reports, yet evidence suggests they were valued as dependable work animals,” said John Krigbaum, Ph.D., professor and chair anthropology at the University of Florida. Krigbaum served as the senior author on this study alongside lead author William Taylor, Ph.D., at the University of Colorado Boulder.

The team’s work is a testament to the vast amount of information researchers can glean from just a small collection of centuries-old animal bones. With their preliminary tests, archaeologists linked the earliest parts of the settlement to the "Starving Time" winter of 1609-1610, a connection later confirmed by radiocarbon dating. The study provides an early glimpse into how and why horses and donkeys were transported and managed and how they were able to spread and establish wild populations across the continent.

Assisting Krigbaum with both the research and writing were George Kamenov, Ph.D., a senior associate in the Department of Geological Sciences, UF doctoral student Diana Quintero-Bisono and Nicolas Delsol, a former postdoctoral student at the Florida Museum of Natural History who currently works at Université Laval in Quebec.

With the species and timeframe confirmed, further tests unveiled new insights into how these animals once lived. Wear and tear on the bones showed evidence of bridling, suggesting their use as work animals. Ancient DNA and bone chemistry analysis of the isotopes in tooth enamel suggested that the donkey did not originate in Great Britain but was picked up by settlers along the route of their transatlantic journey.

“Ancient DNA points to Iberia or West Africa, which is consistent with its isotope signature, but the isotopic evidence is also consistent with Trinidad and Tobago, which is not far off the route sailed,” said Krigbaum. 

Examining the wear and tear on the samples also revealed a tragic end for many of these animals. Faced with hunger during the Starving Time and having soured their relationships with nearby indigenous people, settlers were forced to eat their animals and, in the direst situations, their dead. While we have records that horses were consumed during this time, this can also be observed with other samples, including donkey remains. “They show that adult horses were eaten, butchered and cooked or boiled, with most elements split open to extract even the minutest nutritional resources including dental pulp,” the team wrote in their study.

For Krigbaum and his colleagues, the Jamestown assemblage is just the beginning. Their next project will examine horse remains from the 16th century Spanish settlement of Puerto Real, in the Caribbean, to uncover further evidence of how horses and donkeys helped shape the earliest chapters of American history.

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Journal

Science Advances

DOI

10.1126/sciadv.adw2595 

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

Early transatlantic movement of horses and donkeys at Jamestown

 

Panama Canal may face frequent extreme water lows in coming decades

A new study found historic droughts could become common for Gatún Lake, the main source of water for the Panama Canal locks

American Geophysical Union

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WASHINGTON — In 2023, Panama experienced one of the worst droughts in its recorded history, and it severely depleted water available to the Panama Canal, so much that it decreased shipping by 30%. A new study projected that those historic water lows could become the new norm if greenhouse gas emissions continue to rise.

“If we mitigate emissions and we choose one of the lower emissions pathways, then it really keeps this system pretty stable,” said Samuel Muñoz, lead author of the a new study and a researcher studying  hydrologic and climatic variability at Northeastern University. “But if we don't, then these low water levels that are really disruptive now become the norm by the end of the century.”

The canal works by pulling water from freshwater sources such as Gatún Lake, a large man-made lake that also provides drinking water to thousands of residents in nearby Panama City and Colón.

The water is pulled into the canal to raise and lower water levels in locks which allows heavy boats to pass through Panama to move between the Atlantic and Pacific oceans. More than 26 million gallons of water is needed to fill the locks for ships to pass through.

In January 2024, the Woodwell Climate Research Center reported water levels in Gatún Lake, the main lake that feeds the Panama Canal locks, were lower than ever previously recorded. The lake was nearly 2 meters (6 feet) lower than it was just one year prior. This meant Panama Canal Authorities reduced how many ships could move through the canal from 38 to as low as 22 per day and the ship’s cargo needed to be lower in weight. 

Muñoz built a model to predict how water levels could change in the next 75 years in different greenhouse gas emissions pathways.

The study was published in Geophysical Research Letters, AGU’s journal for high-impact, short-format reports with immediate implications spanning all Earth and space sciences. 

The different scenarios looked at how increased greenhouse gases would change variables like temperature, evaporation, rainfall and other factors that shift with climate change. The scenarios ranged from strong mitigation of greenhouse gas emissions to the current trending levels to extreme and worsening scenarios of emissions.

Drying of the canal

The model used projected evaporation and precipitation in different greenhouse gas emission scenarios to make its predictions and was compared to historical data to confirm its accuracy. It considered changes in water levels from rain and evaporation over the Gatun Lake watershed.

The study found that the occurrence of historic droughts, like those experienced in the last few years, will double by the end of the century under high emissions pathways.

The biggest contributor to projected droughts were decreases in rain during Panama’s wet season, particularly as drought compounded over months and years. Higher emissions were associated with increased evaporation and a decrease in rain across all months; however May through August saw the highest decrease of 50 mm (2 in) rain per month.

In scenarios where emissions undergo more aggressive mitigation, water levels in the Gatún Lake looked as they have for the last century, with only slight decreases. If greenhouse gases continue to rise, however, droughts like the one in 2023 will become commonplace.

Right now, Muñoz said we are at a crossroads where the world can mitigate emissions that would stabilize Gatún Lake water levels. But if we head down a pathway of less mitigation, the Panama Canal will continue to face operational challenges in the coming decades. Canal authorities are already improving water use efficiency and beginning the development of a new reservoir to adapt to a potentially drier future.

Muñoz hopes to expand his study to include different operational decisions and scenarios, and to reduce uncertainties in climate model predictions for Panama. He expressed an interest in collaborating with Panamanian authorities and scientists in this work as they plan canal operations and adaptation strategies for the coming decades.

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Notes for journalists:  

This study is published in Geophysical Research Letters, an open-access AGU journal. View and download a pdf of the study here. Neither this press release nor the study is under embargo.  

Paper title: 

“Drying of the Panama Canal in a Warming Climate”

 

Authors:  

• Samuel E. Muñoz, Department of Marine & Environmental Sciences, Department of Civil & Environmental Engineering, Northeastern University, Boston, Massachusetts, USA
• Lindsay Lawrence, Department of Marine & Environmental Sciences, Northeastern University, Nahant, Massachusetts, USA
• Shuochen Wang, Department of Civil & Environmental Engineering, Northeastern University, Boston, Massachusetts, USA

# 

AGU (www.agu.org) is a global community supporting more than half a million professionals and advocates in Earth and space sciences. Through broad and inclusive partnerships, AGU aims to advance discovery and solution science that accelerate knowledge and create solutions that are ethical, unbiased and respectful of communities and their values. Our programs include serving as a scholarly publisher, convening virtual and in-person events and providing career support. We live our values in everything we do, such as our net zero energy renovated building in Washington, D.C. and our Ethics and Equity Center, which fosters a diverse and inclusive geoscience community to ensure responsible conduct. 

Journal

Geophysical Research Letters

DOI

10.1029/2025GL117038 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

Drying of the Panama Canal in a Warming Climate

 

Questionable lead reporting for drinking water virtually vanished after Flint water crisis, study reveals

UMass Amherst economists employ new statistical tools to detect suspicious reporting

University of Massachusetts Amherst

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Public water systems in the U.S. were far less likely to report suspiciously rounded lead levels after the Flint, Michigan water crisis drew national outrage and federal scrutiny, according to new research led by the University of Massachusetts Amherst. 

The study, published as the first article in the latest issue of American Economic Review: Insights, introduces new statistical methods to distinguish between natural rounding and potential “threshold manipulation” in reported figures.

“Existing methods can mistake rounding for manipulation,” explains Tihitina Andarge, assistant professor of resource economics at UMass Amherst. “Our approach allows us to separate the two.”

Andarge, David A. Keiser, professor of resource economics at UMass Amherst, Dalia Ghanem of the University of California, Davis, and Gabriel E. Lade of The Ohio State University analyzed how water systems reported lead concentrations from 2011 to 2020 under the Lead and Copper Rule, a key provision of the Safe Drinking Water Act. The rule requires systems to determine whether the 90th percentile of the lead concentrations in their water samples exceeds federal thresholds that can trigger additional monitoring, remediation and public notification.

The Environmental Protection Agency (EPA) relies on self-reported figures from about 50,000 water systems nationwide. Systems with reported lead levels above 0.005 milligrams per liter must continue frequent testing, while those above 0.015 must take costly corrective steps and notify the public. This creates an incentive for systems to report values just under the cutoffs.

The study found that before the Flint crisis prompted a state of emergency in 2016, about 3% of medium-sized systems and about 0.5% of small systems reported lead concentrations rounded exactly to the federal threshold—a pattern the researchers say is statistically unlikely to occur by chance. After Flint, those suspicious clusters all but vanished, and reported data aligned more closely with expected distributions.

Andarge notes that among small water systems, this pattern was concentrated in Alabama, while among medium-sized systems, it appeared throughout the country, though at a smaller scale.

The Flint crisis, which exposed thousands to dangerous lead levels, heightened public and regulatory attention to water safety nationwide. The EPA issued new guidance discouraging questionable testing practices, such as sampling lower-risk homes or manipulating collection procedures.

“We want to make sure that our drinking water systems are following through on the correct ways to measure for lead concentrations, so that people can take corrective actions if they need to,” Keiser says.

While the study does not allege deliberate fraud, it points to vulnerabilities in how the U.S. monitors drinking water quality. The authors warn that without continued oversight, some systems may again face incentives to downplay lead risks.

The EPA revised the Lead and Copper Rule, which covers more than 90% of the U.S. population, in 2021 and 2024. Lead exposure, even at low levels, has been linked to developmental delays in children and cardiovascular problems in adults.

Keiser adds that the new statistical methods could be applied to other areas where threshold manipulation is a concern, including air quality monitoring and academic testing.

The research was supported by the National Institutes of Health.

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Journal

American Economic Review Insights

DOI

10.1257/aeri.20240258 

Method of Research

Data/statistical analysis

Protecting public health: Rice’s Stadler honored by The Water Research Foundation

Rice University

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Lauren Stadler, associate professor of civil and environmental engineering at Rice University. 

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Credit: Rice University.

The Water Research Foundation (WRF) recently presented Lauren Stadler, associate professor of civil and environmental engineering at Rice University, with the 2025 Paul L. Busch Award at the Water Environment Federation’s Technical Exhibition and Conference in Chicago. With this $100,000 research prize, Stadler plans to advance wastewater monitoring through the investigation of real-time biosensors that utilize synthetic biology.

In addition to her roles at Rice, Stadler also serves as co-lead of the Houston Wastewater Epidemiology System and as an associate editor for the journal Environmental Science: Water Research and Technology. She has received many awards throughout her career for her research and teaching achievements.

Most existing wastewater surveillance systems depend on collecting and transporting samples to centralized laboratories for analysis. This approach is slow, costly and limits real-time responsiveness. To address this, there is a need for technologies that enable decentralized, continuous detection of disease targets and health-relevant biomarkers directly within wastewater infrastructure. Stadler will focus on developing a new class of real-time biosensors that harness engineered microorganisms. She aims to develop new monitoring technologies that allow for near-instantaneous detection of pathogens, health biomarkers and chemicals without requiring sample processing or lab-based instrumentation. With this prize, her group will study the performance of biosensors in wastewater systems and model their strategic deployment for early detection of disease outbreaks.

“I’m honored to receive the Paul L. Busch Award,” Stadler said. “Our vision is to harness microbes as precise sensors and build a decentralized, real-time monitoring network for detecting pathogenic threats in wastewater. This work builds on my group’s efforts to make wastewater-based epidemiology a cornerstone of public health surveillance, while integrating cutting-edge advances from synthetic biology. I’m proud of my team’s accomplishments and excited about the path ahead as we develop novel biosensing platforms that can transform how we monitor wastewater to protect public health.”

The Paul L. Busch Award is made possible by the Endowment for Innovation in Applied Water Quality Research and has provided $2.4 million in funding to up-and-coming researchers making major breakthroughs in the water quality industry.