North America’s bee populations are in trouble, but don’t blame the honey bees. While some people argue that an overabundance of managed honey bees – those raised to help pollinate crops and produce honey – is causing native bees to disappear, the evidence doesn’t support the claim.

What is true is that populations of many species of bees, including honey bees, are struggling.

Half of all honey bee colonies die every winter in the United States, on average. Commercial beekeepers experienced their highest losses on record – more than 60% of their colonies – in the winter of 2024-25. Overall, one-fifth of pollinators in North America are considered to be at risk for extinction due in large part to habitat loss, rising temperatures, extreme weather, diseases and pesticides.

We study bees and other vital pollinators, and we can tell you that there are good reasons to love all the bees. In fact, they’re essential.

A bee on a flower
A honey bee collects pollen from a flower. Bob Peterson/FlickrCC BY

Why care about pollinators?

Bees help farmers grow the foods people love to eat, everything from apples to almonds.

Along with other pollinators – such as flies, butterflies and moths – bees help nearly 80% of flowering plants produce fruit and seeds, which in turn support birds and other wildlife.

About 75% of the world’s agricultural crops, including vegetables, fruits and tree nuts, benefit from pollinators. Additionally, pollinators contribute to production of feed for livestock and fiber crops, such as cotton.

In the United States, pollination by insects contributes $34 billion to the economy.

Among the pollinators, honey bees are the most important for agriculture crops. Managed honey bees, which beekeepers can move from field to field, are particularly essential in intensively farmed areas that lack the natural habitat to support wild bees.

So, why are people concerned about honey bees?

Honey bees were introduced to North America by European settlers in the early 1600s.

Since honey bees are not a native species, the most common concern you might hear is that they will outcompete wild bees for pollen and nectar. This is typically portrayed as a numbers game: If resources are limited, the more bees present on the landscape, the less food there is to go around.

Honey bees live in large social colonies and are adept at capitalizing on high-quality patches of flowers, leading to the concern that this species in particular may have a rapid, outsized effect on native bees that share the same food.

The queen bee is marked with nontoxic green paint to make her easy to find when examining the health of this Apis mellifera European honey bee hive in Maryland.
The queen bee is marked with nontoxic green paint to make her easy to find when examining the health of this Apis mellifera European honey bee hive in Maryland. David Illig via FlickrCC BY-NC-SA

Managed bees can also carry viruses and other pathogens that may infect native bee species. Because viruses are shared among colony members, viruses can persist in managed honey bee colonies and then be spread to other bees that forage on the same flowers.

Scientists and farmers also have a concern about economic sustainability if farms are too reliant on honey bees alone for crop pollination. Threats to honey bee health and high colony mortality in the United States could put crops at risk if other pollinators aren’t in the vicinity to do the job.

Why don’t studies find a honey bee impact on native bees?

Humans actually know little about bee interactions. The U.S. has more than 4,000 native bee species, but there is enough data to estimate population sizes and ranges for less than half of them. Meaningful data examining the effects of honey bees on other species are even more scarce.

In a recent analysis, we found that only 15% of 116 published studies on resource competition involving honey bees measure how competition from honey bees affects the survival, reproductive output and long-term population trends of native species.

A bee with its face in a flower.
Bee populations face several threats, including pesticides and losing habitat to urbanization and agriculture. Andony Melathopoulos

The majority of published studies on honey bee and wild bee competition address different versions of a narrow question: Do honey bees and native bees visit the same plants?

Because honey bees are “super generalists” that thrive worldwide well beyond their native range, most scientists would predict that the answer to this question is a resounding “yes.”

However, about half of the research suggests that honey bees don’t change the way native bees go about their day at all. From the perspective of a wild bee, the honey bees simply don’t exist in their world.

Different bee species can coexist with very little evidence of direct interaction. An analysis of bee communities measured across diverse agricultural, urban, grassland and forested environments found the abundance of honey bees and the abundance of native bees were positively associated about five times as often as they were negatively associated. In other words, rather than landscapes supporting one bee species at the expense of another, the same habitats support both.

A map shows bee species everywhere, but the most species in the Southwest and Midwest.
Bees species can be found just about everywhere in the U.S., as this map, modeled from 3,158 species found in museum collections, shows. But some regions, such as the Southwest deserts, are particularly rich in bee species, with the color scale representing the estimated number of species. Paige R. Chesshire, et al., 2023CC BY

Calls to restrict honey bees from certain locations also often miss a key reality: Native bee hot spots and urban and commercial beekeeping rarely overlap.

Beekeeping is anchored in agricultural lands. North America’s rarest bees thrive in environments like the Sonoran Desert – habitats that are poorly suited for managed colonies.

If competition occurs, it is typically the product of agriculture practices that strip the land of flowering plants that bees need.

Research that has artificially introduced hives into natural areas like the high Sierra – places beekeepers don’t typically go – has generated competition that left less pollen and nectar for the native bees. But frequently competition involves common native bees that are not under threat.

A chunky bee on a flower with pollen on its legs.
Bumble bees transport pollen on their legs as they move from flower to flower, bringing some of it home while pollinating plants in the process. Andony Melathopoulos

So, if honey bees aren’t to blame, what is?

The top drivers of pollinator declines are considered to be land use – the spread of cities and agriculture, as well as the way land is managed – along with rising temperatures, extreme weather and pesticide use.

Agriculture and urbanization reduce the amount and diversity of flowering plants, and droughts can reduce plant flowering and the resources bees rely on. Pesticides can reduce bees’ ability to lay eggs and care for their offspring, or they can kill bees outright.

The U.S. Geological Survey’s Native Bee Inventory and Monitoring Lab tracks bee populations in the U.S. mid-Atlantic region. Studies using its data have found that urbanization and weather changes have been the major drivers of changes in wild bee abundance and diversity in that region.

As temperatures rise, wild bee populations are expected to decline there. Warmer winters mean bees active in spring emerge earlier from their nests, and increased spring rain and temperature fluctuations can limit their ability to feed their offspring, meaning fewer bees.

The western bumble bee, Bombus occidentalis, was once widespread and abundant across western North America, but it has been in decline since the late 1990s. Long-term monitoring of its populations from 1998 to 2020 shows the primary reasons are land management changes, increasing temperature, drought and pesticide use.

What can you do to support pollinators?

The biggest threat to pollinators is the disappearing variety of flowering plants.

You can help reverse this by filling your garden with more flowering plants, trees and shrubs to give bees, butterflies and other pollinators a variety of food sources.

Three bees on a flower
Planting wildflower gardens in your yard can help many kinds of pollinators, including bees. Clare Rittschof

You can also advocate for bee-friendly behavior in your community, such as creating pollinator habitats in public and private spaces and reducing the use of harsh pesticides and herbicides. Planting more flowers in parks and along roadsides, and protecting wildlands where the rarest native bees live, can help keep these wonderful species thriving.

This article originally appeared on The Conversation. You can read it here.

  • How D.C.’s ‘humanure’ fertilizer creates lush gardens and big profits while improving the environment
    Photo credit: CanvaWhat you flush away could help your garden grow.

    The District of Columbia Water and Sewer Authority—now known as D.C. Water—has long provided water and sewer services to Washington, D.C. But for the past decade, the utility has also had an unexpected side hustle: turning human wastewater into fertilizer with flourishing results.

    At most wastewater treatment plants, flushed water is cleaned, while the remaining solid matter is hauled away for disposal. Over time, transporting and disposing of that waste can cost millions of dollars while increasing carbon emissions from the trucks carrying it. A decade ago, however, D.C. Water decided to invest in transforming the solid waste into “humanure” rather than throwing it away.

    Growin’ grass and makin’ gas

    At the end of the wastewater treatment process, the collected human waste solids are processed into biosolid fertilizer using technology developed by Norwegian company Cambi. The process doesn’t just produce high-quality fertilizer—it also generates biogas that can be put to good use.

    “So you get up to 40% more biogas,” Cambi CEO Eirik Fadnes said. “That biogas can be used to generate electricity to be used elsewhere in the wastewater-treatment plant or put on the grid and sold.”

    D.C. Water sells the biosolid fertilizer under the brand name Bloom, and it’s already proving to be a success. Bloom has been used throughout the Washington, D.C., area by customers including Catholic University, Mount Olivet Cemetery, and the Franciscan Monastery. It’s also used on numerous lawns, school grounds, community gardens, and golf courses.

    Success by the numbers

    The numbers underscore D.C. Water’s success. To date, nearly 400,000 tons of Bloom have been sold across Washington, D.C., Maryland, Pennsylvania, and Virginia, generating $13.6 million in revenue. D.C. Water originally estimated it would take 20 years for Bloom to pay off its investment. But thanks to strong demand from institutions, landscapers, and local garden centers, the utility is now on pace to recoup that investment in just 12 years.

    Bloom is also helping D.C. Water meet its environmental goals. By turning waste into a useful product instead of hauling it away for disposal, the utility has reduced its carbon footprint by roughly 50,000 metric tons of CO₂ emissions each year—the equivalent of taking more than 11,700 gas-powered cars off the road annually. The process also produces biogas, which can be converted into electricity to help offset the energy costs of wastewater treatment.

    Human waste works wonders

    None of this would matter if human biosolids weren’t effective at improving soil. “Humanure,” a term coined by Joseph Jenkins, refers to compost made from properly treated human waste. Because human feces can contain disease-causing pathogens, it must be handled carefully. After all, we call it “waste” for a reason.

    When human waste is composted correctly, naturally occurring microbes break down the organic material while generating enough heat to destroy harmful pathogens. Over time, the result is a nutrient-rich compost that can improve soil health. Some farmers even build specialized outdoor composting toilets to create humanure for use on their land.

    Should D.C. Water continue on this path of simultaneous profitability and environmental improvement, it’s likely other wastewater treatment plants will follow its lead.

  • A Spanish park has been free of wildfires for over a decade thanks to 18 donkeys
    Photo credit: CanvaDonkeys and other livestock could help prevent mass wildfires.

    According to NASA, wildfires have doubled worldwide due to climate change. Throughout the globe, governments and environmentalists have been trying to find ways to curb the fires. One particular national park in Spain has found a solution that has been keeping them fire-free for over a decade: donkeys.

    Since 2014, the Firefighting Donkey Battalion unit consisting of 18 donkeys has been preventing wildfires in Doñana National Park in Doñana, Spain. The mission these donkeys do is simple: eat the dry brush that usually sparks and fuels wildfires. The donkeys spend up to seven hours a day using their voracious appetites to graze and clear a 130 by 50 feet area of dried grass, scrub, and other vegetation.

    Why donkeys?

    While humans can do this type of clearing out of dry brush, using donkeys for this work is arguably more effective. While it is a slower process, it is consistent and thorough. Donkeys are able to quietly patrol in areas that are inaccessible to vehicles. In exchange for the feasting, the donkeys get about eight gallons of water and rest. No money or fuel needed.

    The donkeys’ bodies are also pretty much built for this kind of environmental work, too. Their stomachs are built to eat the same rough and dry grass repeatedly without issues. These daily grazings slowly but surely remove potential origin sources for fires. As a bonus, the donkeys are naturally disposing of the dried vegetation whereas humans would have to find a different way to dispose of it.

    Having donkeys or other livestock graze in such areas was once more common in agriculture prior to modern farming. Some argue that the machinization of farming and urbanization have reduced the number of grazing animals. This in turn allows more vegetation growth that become dry spots for more wildfires to occur.

    The method expands

    This method has been so successful that other areas of Spain have adopted it. In 2020, Tivissa launched the Burros Bomberos project with three donkeys to so much success they’ve expanded. They now have 40 donkeys grazing and clearing nearly 400 hectares of land.

    The Andrea Association in Allariz uses a team of donkeys to clear and maintain nearly 1,000 hectares of a biosphere reserve. Using GPS to monitor the donkeys’ activity, the group of grazers travel 19 kilometers per day to feed. Similar initiatives have since started in Basque Country, Catalonia, and Galicia, too.

    Other ways to combat wildfires

    In the United States, California has been using goats in a similar function. The group Fire Grazers Inc. has been contacted throughout California to bring hundreds of goats to eat dried vegetation. Much like donkeys, goats are built to eat rough and dry brush. This includes certain plants such as star thistle that are painful for human hands to grab.

    It’s important to note that donkeys or other animals that eat dry scrub are the primary solution to wildfires. The same folks behind these initiatives also advocate proper forest planning and land management. This includes reducing the amount of easily flammable species of plants and trees such as pine. It takes thought, care, work, and maybe a bunch of donkeys to make a difference.

  • Beyond birds and mice, free‑ranging cats eat a surprising number of insects
    Photo credit: SKashkin/iStock / Getty Images PlusDoes that look tasty?

    It’s pretty commonly known, and not very startling, that free-ranging cats eat birds and small rodents. But the degree to which they eat insects might surprise you.

    We are biologists who for many years have been trying to figure out what feral or outdoor-roaming pet cats eat outside.

    When domesticated cats – Felis catus – live freely in the wild or are allowed to hunt outside the homes where their owners live, they are an invasive species, which live in every ecosystem of the world except the continent of Antarctica. We wanted to know all of the species they eat – and to what degree free-ranging cats are eating endangered or threatened species.

    Examining reams of research

    Over the past two decades, we have evaluated hundreds of scientific findings, including searching through Google Scholar and Web of Science using the keywords “cat predation,” “feral cat,” “cat diet” and “Felis catus.” For each item we found, whether peer-reviewed or not, we evaluated whether it contained conclusive evidence of cat diet or predation. We also reviewed each one’s reference section for additional unique articles or databases pertaining to cat diet and predation, and included those in our search.

    Overall, we identified 533 unique publications – books, journal articles, theses and agency reports – that reported specific animal species consumed by cats. Cats’ plant-eating habits are occasionally, but haphazardly, noted in studies, so we did not include them in our analysis.

    Our initial work focused on an overall assessment of what free-ranging cats eat around the world. Published in 2023, this paper analyzed the 533 studies on cat diet or predation events published over more than a century and found that cats ate nearly 2,100 different species of animals, including invertebrates.

    Of those 2,100, the International Union for Conservation of Nature’s Red List of Threatened Species listed 347 as “near threatened,” “vulnerable,” “endangered,” “critically endangered” or “extinct” in 2023. Some of the species went extinct during the many decades covered by the data.

    Most of the species cats eat are not in danger

    Insects and the like

    Most of the species cats ate were vertebrates – mostly birds, followed by mammals and reptiles. But the data also indicated that at least 7% of the species cats eat are insects and other invertebrates, particularly beetles, and less frequently crustaceans, arachnids, centipedes, snails and slugs, and millipedes.

    Many of the cat studies we reviewed did not report on how many individuals of a given species cats ate, so it was unclear what the total amount of insects was or how many calories cats are deriving from insects.

    Invertebrates make up more than 70% of all terrestrial animal species and are important pollinators, predators and herbivores in virtually every nonmarine ecosystem. Many invertebrates are in decline globally due to urbanization, habitat destruction, increases in both light and pesticide pollution, and climate change. So we dug deeper into the data to understand what invertebrates cats are eating.

    While a little more than one-third of all the studies we analyzed included invertebrates as part of cats’ diet, most of those failed to identify specific species of invertebrates. But we were able to find identifications of 148 invertebrate species.

    Of those, two are considered endangered by the International Union for Conservation of Nature: the Aldabran grasshopper (Pternoscirtus aldabrae) in Seychelles and the Tasmanian giant freshwater crayfish (Astacopsis gouldi), which can grow up to 13 pounds (6 kilograms). Two others are considered vulnerable: wētāpunga (Deinacrida heteracantha), an insect native to New Zealand that can be about the size of a mouse, and the common yabby (Cherax destructor), a freshwater crayfish native to southeastern Australia. One other, the Canary Islands horned beetle (Arhopalus pinetorum), is listed as “near threatened.”

    A cat licks its lips while crouching over a dead mouse.
    Not surprising: Cat eats mouse. Julian Stratenschulte/picture alliance via Getty Images

    Effects on populations

    We have not found formal research evaluating how cats’ eating habits affect invertebrate populations. And for many species, they are likely not as significant a factor as wide-scale pesticide use.

    But it’s possible that cats could be significant contributors to the deaths of rare species or in specific locations.

    Cats require a large amount of protein, as much as one-third of their daily diet, and invertebrates are good sources of protein.

    In many places, invertebrates provide an easy source of food. Whether in an urban backyard or on a remote island, cats are unlikely to turn a blind eye to available prey. And some cats may find it entertaining to chase, catch and eat insects even if they don’t need their nutrition.

    A challenge of researching this question is that many invertebrates are relatively small, which makes direct observation in the field harder and can require more analytical approaches in the lab. And they have soft bodies, without distinguishing characteristics that could be easily recognized in scat or stomach contents.

    However, molecular technologies can identify species using trace amounts of DNA left in the environment by animals. Promising new studies are beginning to identify what cats eat by analyzing the DNA found in their stomachs and scat. That research may help explore in even more detail what cats are eating in the outdoors, and how it’s affecting various species and the environment as a whole.

    This article originally appeared on The Conversation. You can read it here.

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