bird

Climate change and an iconic Florida bird

December 31, 2024 By EarthWise Leave a Comment

The Florida scrub-jay is a medium-sized bird native to Florida, known for its striking blue plumage and distinctive call. It is the only bird species that is entirely endemic to Florida, found mainly in the scrubby, sandy habitats of the central and southern part of the Sunshine State.

But extensive development, habitat fragmentation, and habitat degradation have caused the scrub-jay population to decline significantly over the past century.

Another threat facing the Florida scrub-jay is climate change. According to a new study by researchers from the Archbold Biological Station and the Cornell Lab of Ornithology, warmer winters driven by climate change are causing Florida scrub-jays to nest one week earlier than they did in 1981. This seemingly innocuous change has reduced the number of offspring raised annually by 25% since 1981.

The research team examined 37 years of data to assess the impacts of warming on reproductive efforts. From 1981 to 2018, the average winter temperature at Archbold Biological Station in Florida increased by 2.5 degrees Fahrenheit. Despite increases in the number of nests built and eggs laid over the longer breeding season, Florida scrub-jays are not producing more young.

The researchers hypothesize that warmer temperatures make the nests susceptible to predation by snakes for a longer period of the Florida spring than in the past. The findings, which were recently published in the journal Ornithology, suggest that climate change could dampen the success of conservation efforts for this threatened species.

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Long-term study reveals warming climates threaten Florida scrub-jay

Florida Scrub-Jay

Photo, posted October 15, 2018, courtesy of Judy Gallagher via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Caterpillars And Light Pollution | Earth Wise

May 3, 2023 By EarthWise Leave a Comment

Most of us are familiar with air pollution, water pollution, soil pollution, and even noise pollution. But it turns out that light can be a pollutant as well, and it’s a consequence of industrial civilization. In fact, nighttime light pollution now covers approximately 23% of the globe and over 80% of inhabited regions.

Light pollution affects more than just our view of the stars. For example, light pollution can alter our circadian rhythm, disrupting our sleep cycle. In nature, light pollution can kill baby turtles by causing them to head inland instead of into the ocean, can cause birds to migrate during the wrong season, and can deter nighttime pollinators like bats. And those are just a few of the examples.

According to new research from scientists at Cornell University, moderate levels of artificial light at night – like a porch light – attract caterpillar predators and reduce the chance that caterpillars grow up to become moths.

In the study, which was recently published in the journal Proceedings of the Royal Society B: Biological Sciences, the researchers placed 552 lifelike caterpillar replicas made of soft clay in a forest to measure predation rates compared to a control group. They found that predation rates on clay caterpillars and the abundance of arthropod predators were significantly higher on the artificial light at night treatment plots. In fact, of the 552 clay caterpillars deployed and glued to leaves to look authentic, 521 models were recovered and 249 of them- or 47.8% – showed predatory marks from arthropods during the summer-long nighttime study.

In addition to light pollution, caterpillars also face major threats from habitat loss, pollution, invasive species, and climate change.

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Artificial light at night aids caterpillar predators

Photo, posted July 23, 2020, courtesy of Judy Gallagher via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An Accelerating Rate Of Mountain Forest Loss | Earth Wise

April 27, 2023 By EarthWise Leave a Comment

Mountains contribute disproportionately to the Earth’s diversity of life. While mountains account for about 25% of the land area on Earth, they are home to more than 85% of the mammal, bird, and amphibian species. But alarmingly, forested mountain habitats in which these species live are disappearing, and they appear to be disappearing at an accelerating rate.

According to a new study recently published in the journal One Earth, more than 300,000 square miles of mountain forest has been lost globally since 2000, which is an area larger than the state of Texas.

A research team led by scientists from Leeds University in the United Kingdom and the Southern University of Science and Technology in China tracked changes in mountain forests on an annual basis from 2001 to 2018. The researchers found logging to be the biggest driver of mountain forest loss, responsible for 42% of the overall decline. This is followed by wildfires at 29%, so-called “slash-and-burn” cultivation at 15%, and permanent or semi-permanent agriculture at 10%. Significant losses occurred in Asia, Africa, Europe, Australia, and South America, but not in Oceania or North America.

The research team also found that the rate of mountain forest loss seems to be accelerating: in fact, the annual rate of loss increased 50% from 2010-2018 when compared with 2001-2009.

While developing additional forest protection strategies and interventions is critical, the researchers emphasize the importance of also considering food production, livelihoods, and human wellbeing in any new measures.

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Mountain forests are being lost at an accelerating rate, putting biodiversity at risk

Photo, posted December 6, 2018, courtesy of Lance Cheung / USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Spring Is Coming Earlier In Britain | Earth Wise

March 1, 2022 By EarthWise Leave a Comment

The United Kingdom has some of the most detailed records of seasonal changes anywhere in the world. Since the 18th century, observations of seasonal changes have been recorded by scientists, naturalists, amateur and professional gardeners, and organizations such as the Royal Meteorological Society. Researchers at two British institutions have collected and collated these records into a database they call Nature’s Calendar, which currently has about 3.5 million records going back to 1736.

By analyzing more than 400,000 observations of 406 plant species in Nature’s Calendar, they found that the average first flowering date from 1987 to 2019 is a full month earlier than the average from 1753 to 1986. The change correlates very well with rising global temperatures.

The ecological risks associated with earlier flowering times are high. When plants flower too early, a late frost can kill them – a phenomenon most gardeners have experienced at some point or another. Beyond that, plants, insects, birds, and other wildlife have co-evolved to be synchronized with plants in their development stages. A certain plant flowers and attracts a certain kind of insect, which then attracts a particular kind of bird, and so on. If plants get out of sync with the animals in the ecosystem and the animals can’t change their behavior quickly enough, it can lead to species collapse.

If global temperatures continue to increase at their current rate, spring in the UK could eventually start in February, creating serious problems for many of the species that inhabit forests, gardens, and farms. The dangers of climate change are not just about extreme weather.

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UK plants flowering a month earlier due to climate change

Photo, posted February 1, 2012, courtesy of Mandy via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bald Eagles And Lead Poisoning | Earth Wise

February 21, 2022 By EarthWise Leave a Comment

The bald eagle is the national bird of the United States. It was once a common sight over much of the continent but was severely affected in the mid-20th century by a variety of factors, particularly the use of the pesticide DDT, which caused thinning of its eggshells and sterility. In the 18th century, the bald eagle population was 300,000 – 500,000. By the 1950s, there were only 412 nesting pairs in the 48 contiguous states.

The bald eagle was declared an endangered species in the US in 1967 and additional regulations strengthened protections for the bird. The banning of DDT in 1972 was a major factor in the recovery of the species.

Bald eagle populations have been rebounding for decades but another issue is weakening that rebound – lead poisoning from gunshot ammunition. According to a new study published in the Journal of Wildlife Management, poisoning from eating dead carcasses or parts contaminated by lead shot has reduced population growth by 4% to 6% annually in the Northeast.

Bald eagle numbers in the lower 48 states quadrupled between 2009 and 2021 to more than 316,000, according to a report by the U.S. Fish and Wildlife Service. But even though the population has seemingly recovered, some combination of factors such as habitat loss, climate change, infectious disease, and lead poisoning could reverse the trends and lead to population declines.

The hope is that the study could help educate and inform policy on ammunition choices for hunters. There are alternatives such as copper-based ammunition. Human health can also be affected when bullets fragment inside game species and are then consumed.

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Bald eagle rebound stunted by poisoning from lead ammunition

Photo, posted March 28, 2013, courtesy of Ben Johnson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Synthetic Palm Oil | Earth Wise

February 18, 2022 By EarthWise Leave a Comment

Palm oil is the world’s cheapest and most widely used vegetable oil. Producing it is a primary driver of deforestation and biodiversity loss in the tropics. In Borneo, for example, oil palm cultivation has accounted for more than half of all deforestation over the past two decades. More than one million square miles of biodiversity hotspots could be threatened by oil palm cultivation, which could potentially affect more than 40% of all threatened bird, mammal, and amphibian species.

Today, the world consumes over 70 million tons of palm oil each year, used in products ranging from toothpaste and oat milk to biodiesel and laundry detergent.

Given this situation, there are now multiple companies developing microbial oils that might offer an alternative to palm oil while avoiding its most destructive impacts.

A company called C16 Biosciences is working on the problem in Manhattan, backed by $20 million from a Bill Gates’ climate solutions investment fund. A California-based startup called Kiverdi is working to manufacture yeast oil using carbon captured from the atmosphere.

Xylome, a Wisconsin-based startup is working to produce a palm oil alternative that they call “Yoil”, produced by a proprietary strain of yeast. The oil from the yeast strain is remarkably similar to palm oil.

The challenge is to be able to produce microbial oils at large scale and at a competitive price. Unless valuable co-products could be manufactured along with the oil, it may be difficult to compete with palm oil. Without regulatory pressures and willingness of consumers to pay more, it may be difficult to replace palm oil in many of its applications.

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Can Synthetic Palm Oil Help Save the World’s Tropical Forests?

Photo, posted December 9, 2008, courtesy of Fitri Agung via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Non-Native Plants And Insect Decline | Earth Wise

January 15, 2021 By EarthWise Leave a Comment

Global insect populations have been in decline since the beginning of the 20th century. The decline accelerated during the 1950s and 1960s, and it has reached alarming levels during the past 20 years.

The causes of plummeting insect populations include habitat destruction, deforestation, climate change, light pollution, and the rise of industrial agriculture. This so-called insect apocalypse is being mirrored by a bird Armageddon because so many bird species depend on insects for their diets.

A still controversial, but increasingly likely factor in the decline of insect populations is the spread of non-native plants in agriculture, agroforestry, and horticulture. A recent study published in the journal Ecological Entomology presents recent data supporting the proposition that the widespread displacement of native plants is a key cause of insect declines.

Many insects depend on a limited number of plants for survival. In many cases, insects’ diets are restricted to a single plant family. When native host plants dwindle or disappear from an area, the population of insects that depend on those plants shrinks.

There are examples of insects that adopt introduced plants as food sources, such as silver-spotted skipper butterfly larvae feeding on invasive kudzu in the eastern U.S. But generally, the widespread incursion of non-native plants is harmful to native insect populations.

Non-native plants are especially popular for horticulture. Millions of acres of potential insect habitat have been transformed into food deserts for native insects. The authors of the recent study recommend that Americans should extensively include native plants in their yards to help preserve insect diversity.

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How Non-Native Plants Are Contributing to a Global Insect Decline

Photo, posted May 2, 2004, courtesy of Bernard Spragg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bird Migration And Climate Change | Earth Wise

January 22, 2020 By EarthWise Leave a Comment

A new study of bird migration shows the migration patterns are shifting as a result of climate change. Researchers at Colorado State University, the University of Massachusetts, and the Cornell Lab of Ornithology, looked at the impacts of climate change on a continental scale.

The team looked at the nocturnal migratory behaviors of hundreds of species representing billions of birds using radar and other data. They found that spring migrants are likely to pass certain stops earlier now than they would have 20 years ago. Temperature and migration timing are closely aligned and the greatest changes in migration timing are occurring in regions warming most rapidly. During the fall, shifts in migration were less apparent.

Migratory birds play an important role in ecosystems. They consume insects, disperse seeds, and perform various other significant functions. Birds serve as critical metrics of the health of ecosystems.

Bird migration is a global phenomenon that can provide unique visibility into changes in the climate. The ability to look at it on a global scale has only recently become practical as a result of big data technology and cloud computing. The team was able to crunch the numbers for the study in 48 hours, a task that previously would have taken over a year of continuous computing.

The findings have implications for understanding future patterns of bird migration because birds depend on food and other resources as they travel. As the climate changes, the timing of blooming vegetation or the emergence of insects may end up out of sync with the passage of migratory birds. This could have negative consequences for the health of migratory birds.

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