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Coping With Climate Change | Earth Wise

October 11, 2022 By EarthWise Leave a Comment

Extreme weather events including prolonged drought and heavy rainfall are becoming more common and more severe as global temperatures rise. As the climate continues to change in the coming decades, how will animals respond?

Researchers from the University of Southern Denmark have examined how different mammals react to climate change. They analyzed data on population fluctuations from 157 mammal species around the world. They compared these fluctuations with weather and climate data from the same time period. The research team had 10 or more years of data for each species studied.

The researchers found that mammals that live for a long time and/or produce less offspring – like llamas, elephants, bears, and bison – are more climate resilient than small mammals with short lives — like mice, possums, lemmings, and rare marsupials.

For example, large, long-lived mammals can invest their energy into one offspring, or simply wait for better times if conditions become challenging. On the other hand, small, short-lived mammals like rodents have more extreme population changes in the short term. In the event of a prolonged drought, large portions of their food base may rapidly disappear, and they are left to starve because they have limited fat reserves.

However, the research team notes that the ability of a species to withstand climate change must not be the only factor when assessing a species’ vulnerability. In fact, in many cases, habitat destruction, poaching, pollution, and invasive species pose a larger threat to animal species than climate change.

While the study only examined 157 species, the findings enable researchers to also predict how animals they know less about will react to climate change.

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Which animals can best withstand climate change?

Photo, posted July 8, 2018, courtesy of Ray via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Could Lyme Disease Be Eradicated? | Earth Wise

November 22, 2021 By EarthWise Leave a Comment

Tiny ticks are a big problem. Measuring only three to five millimeters in size, ticks are widely distributed around the world. They are external parasites, feasting on the blood of birds, reptiles, amphibians, and mammals – including humans.

According to estimates from the Centers for Disease Control and Prevention, ticks infect an estimated 476,000 people with Lyme disease in the United States every year. Lyme disease is caused by a bacterium called Borrelia burgdorferi that lurks in wild mice. Ticks that feed on the mice become infected and can then in turn infect people and animals.

The disease is not only a problem in the United States, but in other parts of North America, Europe and Asia as well. It often causes a characteristic “bullseye” rash and flu-like symptoms. If left untreated, it can lead to serious long-term health problems.

Currently, lyme disease is treated using antibiotics. But antibiotics kill a wide range of bacteria – including healthy gut bacteria – which can lead to additional health issues and more antibiotic resistance.

A recent discovery by researchers from Northeastern University in Boston could allow Lyme disease to be eradicated in the wild. The researchers found that a compound called hygromycin A is deadly to the bacterium that causes Lyme disease but harmless to animals and has little effect on most other bacteria.

The little-known antibiotic cleared Lyme disease infection in mice, both when administered via injection and when ingested using bait. As a result, dropping feeding baits could eradicate Lyme disease from whole areas or even entire countries. The first field trial will be next summer.

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Drug treatment for Lyme disease could lead to its eradication

Photo, posted June 21, 2017, courtesy of NIAID via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Controlling Malaria Without Chemicals

August 28, 2019 By EarthWise Leave a Comment

Nearly half of the world’s population lives in areas vulnerable to malaria. The disease kills roughly 450,000 people each year, most of them children and pregnant women. Malaria is spread by Anopheles mosquitoes and, over time, the mosquitoes have been developing resistance to the chemical insecticides that are used to control them. In addition, there is great concern about the toxic side effects of the chemicals used on the mosquitoes.

About 30 years ago, scientists identified a type of bacteria that kills Anopheles, but the mechanism was not understood. As a result, the bacteria could not be replicated or used as an alternative to chemical insecticides.

But now, an international research team, headed by researchers at UC Riverside, has identified the neurotoxin produced by the bacteria and has determined how it kills Anopheles. The work is described in a paper published in Nature Communications.

It took the team 10 years to achieve a breakthrough in understanding the bacteria. Modern gene sequencing techniques were the key.

While many neurotoxins target vertebrates and are highly toxic to humans, the neurotoxin that kills Anopheles mosquitoes does not affect humans, vertebrates, fish, or even other insects. Known as PMP1, the substance is not even toxic to mice when given by direct injection.

The team has applied for a patent on this discovery and hopes to find partners to help them develop the bacteria-based insecticide.

There is a high likelihood that PMP1 actually evolved to kill the Anopheles mosquito. This finding opens the door to new avenues of research into other environmentally friendly insecticides that would be targeted at other disease-spreading pests.

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Controlling deadly malaria without chemicals

Photo, posted June 9, 2018, courtesy of Mario Yardanov via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Llamas And The Flu

December 21, 2018 By EarthWise Leave a Comment

Last year’s flu season was the worst in 40 years. More than 80,000 people died in the U.S. last year from the flu and its complications. Flu vaccines are the best preventative we have, but there are still high mortality rates around the world. Some individuals respond poorly to vaccination, and variations in viruses makes targeting with the optimal antigen very difficult. The World Health Organization estimates that between 290,000 and 650,000 people die from seasonal flu worldwide each year.

[Read more…] about Llamas And The Flu

Pollinators With Backbones

May 25, 2018 By EarthWise Leave a Comment

There is a great deal of concern about the status of pollinators like bees and butterflies. They play a crucial role for many important food crops. But it turns out that lizards, mice, bats and other vertebrates are important pollinators too.

The Tick Project

September 12, 2016 By WAMC WEB

Tiny ticks are a big problem. Anyone taking a walk in the woods is advised to do a tick check. Ticks infect more than 325,000 people with Lyme disease each year, and this number continues to rise.

[Read more…] about The Tick Project

Feast Before The Famine

December 7, 2015 By WAMC WEB

New York’s Hudson Valley is experiencing a “mast year.” Mast refers to the seeds of woody plants that are eaten by wildlife. “Soft mast” has seeds surrounded by fleshy pulp, and includes berries and fruits. “Hard mast” has seeds protected by an outer coat, such as acorns and hickory nuts.

Acorns And Lyme Disease

November 20, 2015 By WAMC WEB

In New York’s Hudson Valley, it’s hard to go outside without stepping on an acorn. Oaks have ‘boom and bust’ acorn production cycles. In lean years, trees produce a handful of nuts. In boom years, acorns seem to rain down from the sky. We are currently experiencing an acorn bumper-crop, or what ecologists call a ‘mast’ year.

In some forests, there can be more than 100 acorns per square meter. This is welcome news to animals like mice, chipmunks, and squirrels. They can gorge on the bounty and stock their larders. Acorn caches help wildlife avoid predators and survive the lean months of winter. They even give well-fed rodents a jump-start on the breeding season.

For this reason, acorn “mast” years are also harbingers of future Lyme disease risk. In the summer following acorn booms, white-footed mouse numbers explode. In New York’s Hudson Valley, these mice play a major role in infecting blacklegged ticks with the agents that cause Lyme disease, Babesiosis, and Anaplasmosis.

Cary Institute disease ecologist Rick Ostfeld explains.

“The ticks that are emerging as larvae in August – just as the mice and chipmunks are reaching their population peaks – they have tons of excellent hosts to feed from. They survive well and they get infected with tick-borne pathogens. And that means that two years following a good acorn crop we see high abundance of infected ticks, which represents a risk of human exposure to tick borne disease.”

Predictions are based on 20 years of field studies that have confirmed the relationship among acorn mast years, mouse outbreaks, and the prevalence of infected ticks. Mark your calendars – 2017 will likely be a bad year for Lyme disease.

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Web Extra

Full interview with Rick Ostfeld, a disease ecologist at the Cary Institute of Ecosystem Studies

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Biodiversity Is Good For Us

August 26, 2015 By EarthWise

There are many reasons to protect Earth’s biodiversity. One of the more underrated is that disease incidence is lower when ecosystems support a variety of plants and animals.