lethal

The American butterfly census

April 15, 2025 By EarthWise Leave a Comment

There has been a great deal of interest in the plight of monarch butterflies in this country. Monarchs’ population and migratory habits are closely watched, and many people have been planting milkweed in their gardens to help their caterpillars. But other butterfly species have received much less attention despite the fact that many butterfly populations are in decline.

A groundbreaking new study has provided comprehensive answers about the status of butterflies in America. Over the past 20 years, the contiguous US has lost 22 percent of its butterflies.

The study is based on over 12 million individual butteries counted in 77,000 surveys across 35 monitoring programs from 2000 to 2020. Three hundred forty-two butterfly species in total were analyzed. Thirty three percent showed statistically significant declines while less than 3% displayed statistically significant increases. Overall, 13 times as many species decreased as increased.

Why are butterfly populations crashing? Experts point to a combination of factors: habitat loss as land in converted for agriculture or development, climate change, and pesticide use. It is not clear which factor is most important and may well vary by location. Pesticide use – especially neonicotinoids – has been shown to play a particularly lethal role in studies.

Insects including butterflies play a huge role in supporting life on earth. They pollinate plants, feed birds and many other creatures in the food web. Nature collapses without them. And butterflies are clearly in trouble.

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See How Butterflies Are Surviving, or Not, Near You

Photo, posted August 9, 2016, courtesy of Rachel Larue/Arlington National Cemetery via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The most endangered marine mammal

July 9, 2024 By EarthWise Leave a Comment

For the better part of a decade, conservationists have been trying to eliminate the use of gill nets by fishermen in the Gulf of California. Species such as the corvina fish have been decimated by the use of this fishing gear. The nets also trap other marine creatures, include the rare and elusive vaquita porpoise.

The vaquita is the world’s smallest porpoise, measuring no more than five feet in length. It is the most endangered marine mammal. They live only in the Gulf of California, which is the site of intense fishing activity. Some of that activity is directed towards a fish called the totoaba, which is an endangered species itself. The totoaba’s swim bladder is highly prized for Chinese traditional medicine, so there is a booming illegal market for it. The gill nets used to catch totoaba are especially lethal to vaquitas.

Every year, for a few weeks, an international team of scientists searches the Gulf for vaquitas. Recent surveys estimated that there are around 10 individuals in the area where they are most likely to be living. This year’s survey estimated that six to eight vaquitas are in the area. The ones spotted appeared to be in good health and one yearling was seen.

Officially, fishing with gill nets is banned throughout much of the upper Gulf of California. In practice, enforcement has been difficult to do. However, the Mexican government has been making an effort to improve the situation. The Mexican Navy dropped 193 concrete blocks with giant hooks designed to entangle gill nets to deter fishers and they plan to drop more.

The survival of the vaquita depends on whether the use of gill nets stops.

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The Most Endangered Marine Mammal Still Exists. Here’s the Latest Count.

Photo, posted July 12, 2011, courtesy of Semarnat via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wild pigs in the U.S.

November 17, 2023 By EarthWise Leave a Comment

In the U.S., there are as many as nine million feral swine living in 38 states. A conservative estimate indicates that they cause about $1.5 billion in property and agricultural damage each year in this country.

Pigs were introduced to the United States centuries ago as a food source, but they quickly established wild populations. Feral domestic pigs bred with purebred Eurasian boar that were introduced for hunting, and these hybridized wild pigs spread across the landscape thanks to their prolific reproductive rates and willingness to eat just about anything.

When wild pigs forage, they upturn roots and soil with their snouts, damaging natural habitats and other animals. A 2021 study found that wild pigs are releasing over five million tons of carbon dioxide annually by uprooting carbon trapped in soil.

As a result, many programs were implemented nationwide to try to reduce populations, usually through lethal methods.

According to new research from the University of Georgia’s Savannah River Ecology Laboratory and Warnell School of Forestry and Natural Resources, recent conservation efforts have proven effective at controlling wild pig populations in the Southeastern U.S. Within 24 months of the start of control efforts in the study area in South Carolina, the research team found a reduction of about 70% in relative abundance of pigs, and a corresponding decline in environmental rooting damage of about 99%.

Wild pigs are basically a human-caused problem, and controlling their populations will require continued cooperation and collaboration.

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Wild pig populations in U.S. can be managed

Wild Pigs And The Environment

Photo, posted January 28, 2013, courtesy of Don and Janet Beasley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Shipping And The Endangered Whale Shark | Earth Wise

June 9, 2022 By EarthWise Leave a Comment

Whale sharks are the largest fish in the world. While they measure up to 60 feet long and weigh up to 15 tons – larger and heavier than a school bus – whale sharks are actually harmless. They are a graceful, slow-moving, filter-feeding carpet shark. They are found in marine environments around the world and play an important role in the marine food web and healthy ocean ecosystems.

Whale sharks are an endangered species. According to the International Union for Conservation of Nature, growing human pressures are putting whale sharks at an increased risk of extinction. The numbers of these gentle giants have declined by more than 50% over the last 75 years despite many international protections. Fishing bycatch, poaching, and collisions with ships are the main drivers of the population decline.

According to new research from marine biologists from the Marine Biological Association and the University of Southampton in the U.K., lethal collisions between whale sharks and large ships are vastly underestimated, and could be the reason why populations are continuing to fall. Whale sharks spend a large amount of time in surface waters in coastal regions, and the research team theorized that collisions with ships could be causing significant whale shark deaths.

In the study, researchers tracked the global movements of both ships and whale sharks, and then mapped so-called hotspots where their movements overlapped. The research team found that more than 90% of whale shark movements fell under the footprint of shipping activity.

While many conservation measures have been taken to protect whale sharks, no international regulations currently exist to protect them from ship collisions. The researchers say it’s time for that to change.

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Shipping poses significant threat to the endangered whale shark

Whale sharks (Rhincodon typus)

Global collision-risk hotspots of marine traffic and the world’s largest fish

Photo, posted July 8, 2010, courtesy of Marcel Ekker via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Livestock Expansion And Global Pandemics | Earth Wise

August 18, 2020 By EarthWise 1 Comment

The domestication of cows, pigs, chickens, and other animals as livestock for their meat, milk, and eggs was historically revolutionary. It boosted food security by giving people a readily-available means of feeding themselves as opposed to more traditional methods such as hunting and fishing.

But animal agriculture has plenty of drawbacks. The industrialization of animal agriculture has led to horrendous conditions. Animals are kept in huge quantities and packed together with little regard for their health and welfare. This approach to agriculture is simply designed to maximize production while minimizing costs.

With its chemical inputs and toxic outputs, intensive animal agriculture is also a major threat to the environment. In fact, it’s a major driver of habitat degradation and biodiversity loss all around the globe.

But it’s not just animals and the planet that pay a price. Humans have inherited several lethal pathogens from livestock over the years, including the influenza virus that likely jumped to humans from poultry.

According to a study recently published in Biological Conservation, there is a connection between the global increase in the emergence of infectious diseases and epidemics, the accelerated loss of biodiversity, and the expansion of livestock. In the study, the research team from the Institute of Evolution Sciences of Montpellier cross referenced databases on human and animal health, livestock expansion, and biodiversity loss between 1960-2019. The team found that the number of epidemics identified in humans increased in correlation with both biodiversity loss and livestock expansion.

In the era of COVID-19, it’s important to understand how global livestock expansion directly threatens both human health and the health of the planet.

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Livestock expansion is a factor in global pandemics

Photo, posted July 22, 2018, courtesy of Artem Beliakin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving African Cattle With Perfume

November 27, 2017 By EarthWise Leave a Comment

Tsetse flies are widespread in Africa. They feed on blood and are the source of the dreaded sleeping sickness, an infection that can be lethal, damages the nervous system and, in its final stage, causes a dozy state, which gave the disease its name. Sleeping sickness is a real danger for people in tropical Africa, but tsetse flies can also transfer the disease to cattle. This leads to huge losses in milk, meat and manpower. The damage caused by the flies in Africa is estimated to be nearly $5 billion a year.