Hundreds of years ago, tens of millions of bison roamed North America. They were an essential resource and cultural foundation for many Native American tribes. And by 1890, European colonists had hunted them nearly to extinction. 

When President Theodore Roosevelt moved to conserve the remaining bison in 1908, he established the National Bison Range, an 18,800-acre reserve that the government took directly from the tribes of the Flathead Reservation—the Salish, Kootenai, and Pend d’Oreille. The tribes were not invited to help manage the recovery of a bison herd that they had helped save. At times, they were even excluded from the land entirely. For the past several decades, the tribes have been lobbying for the land—and management of its several hundred bison—to be returned.

Then, in December 2020, Congress included in its COVID-19 relief package an unrelated bill with bipartisan approval: returning that land to the tribes. 

Ira talks to Montana journalist Amy Martin, who has been covering the National Bison Range for Threshold, a podcast about environmental change, about why the return of the land is meaningful in the context of U.S. colonization, and the relationship between the environment and justice. Listen to the full report on the National Bison Range on Threshold. 

As global honey bee decline continues through yet another decade, researchers have learned a lot about how complicated the problem actually is. Rather than one smoking gun, parasites like the varroa mite, combined with viruses, pesticides, and other factors are collectively undermining bee health to an alarming degree.

One part of the mystery is the increasing rate of ‘queen failure,’ when a reproducing queen is no longer able to produce enough fertilized eggs to maintain the hive. When this happens, beekeepers must replace the queen years before they ordinarily might.  

Producer Christie Taylor talks to North Carolina State University researcher Alison McAfee about one possible reason this may occur—a failure to maintain the viability of the sperm they store in their bodies after a single mating event early in life. The condition may be caused by temperature stress, immune stress, or a combination of factors. McAfee explains this problem, plus the bigger mystery of how queens manage to keep sperm alive as long as they do.

With more time at home over the last year, many people have experimented with baking sourdough bread. In new work published in the journal ELife, researchers are taking sourdough science to a new level. The team collected and genetically-sequenced 500 sourdough starters sent in by bakers on four different continents to try to draw a map of their microbial diversity.

A sourdough starter culture contains a microbial community made up of both yeasts and bacteria. As the starter is fed and grows, those microbes ferment the carbohydrates in flour, producing the carbon dioxide gas that makes the bread dough rise. Over the years, a mythology has grown up around sourdough—that certain places have special types of wild yeasts that are particularly suited for breadmaking. However, the researchers found that on a global level, it was hard to tell the microbes in Parisian bread apart from those found in San Francisco or elsewhere. The differences in the starter culture seemed largely to be based on specific conditions within each bakery kitchen, and how the starter is grown and maintained.  

Erin McKenney, one of the authors on the report and an assistant professor of applied ecology at North Carolina State University, joins SciFri director Charles Bergquist to slice into the bread study, and explain the team’s findings.

There are certain skylines that come to mind when you think of big, urban cities. Maybe it’s New York City, dotted with skyscrapers and lit up by Times Square. Or it could be the central plaza of Mexico City, and its surrounding galleries and museums. But in Four Lost Cities: A Secret History of the Urban Age, author Annalee Newitz considers long-lost urbanity like Cahokia or Angkor. 

These were huge, sprawling ancient metropolitan areas, constructed thousands of years ago. They had complicated infrastructure, and equally complex political systems that governed the tens of thousands of residents that lived there. But these cities were also eventually abandoned. 

Newitz explains who built these places, and how their residents lived, providing a new perspective on how the ecosystem of a city works.