wild birds

Bad news for birds

April 1, 2025 By EarthWise Leave a Comment

The 2025 U.S. State of the Birds report was released recently. The report is produced by a coalition of leading science and conservation organizations. The bottom line is that there have been continued widespread declines in American bird populations across all mainland and marine habitats.

More than one-third of U.S. bird species are of high or moderate conservation concern. Among these, 112 are tipping point species that have lost more than 50% of their populations over the last 50 years.

Protecting bird species is not just about biodiversity and stewardship of nature. Wild birds have surprisingly large economic impact. Nearly 100 million Americans are engaged in birding activities which contribute substantially to local and state economies. The 2022 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation estimated that the total economic output related to bird watching activities was an amazing $279 billion and birding-related activities support 1.4 million jobs. Bird watching and other encounters with nature are beneficial for human well-being, including reducing stress, anxiety, and depressive symptoms.

The rapid declines in birds are related to habitat loss, environmental degradation, and extreme weather events. Moreover, if conditions are not healthy for birds, they are unlikely to be healthy for people as well. Fortunately, many actions that are good for birds are good for us, so conservation efforts going forward are important.

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State of America’s birds: Population declines continue

Photo, posted October 30, 2018, courtesy of Shenandoah National Park via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Microplastics and birds

March 19, 2025 By EarthWise Leave a Comment

Microplastics are tiny plastic particles, less than 5 millimeters in size, that come from the breakdown of larger plastics, synthetic fibers, microbeads, and tire wear. Microplastics are found in oceans, rivers, soil, and even the air we breathe. These particles can take hundreds of years to degrade, spreading across ecosystems and accumulating in unexpected places, such as deep-sea sediments and Arctic sea ice.

According to a new study by researchers from the University of Texas at Arlington, microscopic plastic pollutants drifting through the air are lodging in the lungs of birds. These findings raise significant concerns about the impact on their respiratory health, but also raise alarms about potential risks to human health.

Birds were chosen for the study because they are found in almost every corner of the world and often share environments with humans.

In the study, the research team examined 56 different wild birds from 51 distinct species, all sampled from the Tianfu airport in western China. The researchers found high concentrations of microplastics in bird lungs, with an average of 221 particles per species. The most common types identified were chlorinated polyethylene, which is used for insulating pipes and wires, and butadiene rubber, which is a synthetic material in tires.

Although there is no established “safe” level of plastic particles in lung tissue, high levels of microplastics have been linked to serious health risks, including heart disease, cancer, respiratory issues, and fertility problems.

The study highlights an urgent need to tackle plastic pollution in the environment because of its far-reaching impact on ecosystems and human health.

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Birds breathe in dangerous plastics—and so do we

Photo, posted January 28, 2017, courtesy of Pete Richman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Heatwaves And Bird Populations | Earth Wise

July 28, 2022 By EarthWise Leave a Comment

The increased occurrence and intensity of heatwaves around the world is affecting most living things. Heatwaves can be lethal for warm-blooded animals – including people – but the behavioral and physiological effects of sub-lethal heat have not been extensively studied. Heat that doesn’t kill animals can still impact their ability to adapt and thrive as the climate changes.

Researchers at the University of Tennessee in Knoxville recently published a new study that examined how heat impacts the behavior and physiology of Zebra finches. They exposed the birds to a four-hour heat challenge, similar to what wild birds might experience during a hot summer afternoon. They used Zebra finches because these songbirds experience extreme temperature fluctuations in their native Australia.

The team measured heat effects on thermoregulatory behavior, how heat alters gene activity in tissues critical to reproduction, and how heat affects the area of the brain that controls singing. The evidence showed that even sub-lethal heat can change a bird’s ability to reproduce both from the functioning of its reproductive system and its motivational circuits for mating behavior.

The researchers found that some individual birds were better able to minimize the physiological effect of heat, for example by adjusting their behavior to dissipate heat. Some individuals and even some species are likely to be able to adapt to increasingly extreme temperatures.

Global bird populations have been dramatically declining over the past few decades. Previous studies have shown that birds sing less during heatwaves. Based on the new study, it appears that increasing heatwaves may be a potential underlying mechanism for the decline in bird populations.

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New Research Suggests Heat Waves Could Lead to Avian Population Decline

Photo, posted August 22, 2017, courtesy of Dennis Jarvis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Birdseed And Weeds | Earth Wise

April 16, 2020 By EarthWise Leave a Comment

More than 55 million adult Americans feed wild birds and along the way spend more than three billion dollars a year on bird food as well as nearly a billion on bird feeders, bird baths, bird houses and other bird feeding accessories. Feeding birds is a very popular hobby in both the United States and the United Kingdom.

Researchers at the University of Missouri in Columbia Missouri investigated the content of 98 commercially available bird feed mixes. They uncovered several significant things.

The various mixes contained seeds from 29 weed species and almost all of the mixes contained seeds for pigweed, which can be a significant threat to agriculture. One in ten of the mixes contained Palmer amaranth or waterhemp seeds that demonstrated a resistance to glyphosphate. Other common weed species found in many of the mixes were kochia, common ragweed, foxtail species, and wild buckweed.

The overall collection of seed mixes contained an average of 363 amaranthus seeds in each kilogram of bird feed. Based on this, it is possible that 105 million amaranthus seeds are transported in bird feed mixes each year.

According to the researchers, it is difficult to estimate the exact role that commercial bird seed plays in spreading troublesome weed species into new regions, but it is clear that the widespread use of these seed mixes is a contributing factor to the spread of weeds.

The researchers recommend careful weed management in crop fields designated for bird feed, as well as sieving during packaging to reduce weed seed contamination. They also noted that regulatory measures adopted in Europe to limit weed seed content in bird seed have proven to be effective.

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Examination of commercially available bird feed for weed seed contaminants

Photo, posted August 18, 2013, courtesy of Emma Craig via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mealworms And Plastic | Earth Wise

January 21, 2020 By EarthWise Leave a Comment

Mealworms are widely cultivated beetle larvae that people feed to pets and to wild birds. But it turns out, they may have an even more valuable purpose: they can eat plastic and even plastic containing dangerous chemical additives.

Four years ago, researchers at Stanford discovered that mealworms can actually subsist on a diet of various types of plastic. They found that microorganisms in the worms’ guts actually biodegrade the plastic. It might be possible to cultivate the worms using unrecyclable plastic, rather than feeding them grains and fruits. However, there is the issue of whether it would be safe to feed the plastic-eating worms to other animals, given the possibility that harmful chemicals in plastic additives might accumulate in the worms over time.

Recently, the Stanford researchers studied what happens when the worms ingested Styrofoam or polystyrene. The plastic commonly used for packaging and insulation typically contains a flame retardant called hexabromocyclododecane, or HBCD. Studies have shown that HBCD can have significant health and environmental impacts, ranging from endocrine disruption to neurotoxicity.

According to the study, mealworms in the experiment excreted about half of the polystyrene they consumed as tiny, partially degraded fragments and the other half as carbon dioxide. With it, they excreted the HBCD. Mealworms fed a steady diet of HBCD-laden polystyrene were as healthy as those eating a normal diet. And shrimp fed a steady diet of the HBCD-ingesting mealworms also had no ill effects.

It is true that the HBCD excreted by the worms still poses a hazard and must be dealt with in some manner, but mealworms may have a role to play in dealing with unrecyclable plastics like Styrofoam.

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Stanford researchers show that mealworms can safely consume toxic additive-containing plastic

Photo, posted May 11, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.