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Wildlife crossings

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Every year, there are one to two million collisions between motor vehicles and large animals in the U.S.  About 200 people are killed annually.  Counting smaller vertebrates, around a million animals are killed by vehicles each day.  Research has shown that global warming is triggering widespread species redistribution.  As a result, more and more animals are on the move, changing their habitats to escape warming temperatures and climate extremes.

This situation has created renewed interest in creating wildlife crossings.  These are various kinds of structures that allow animals to traverse human-made barriers like highways.  They include such things as a grassy overpass that allows pronghorn to run across a highway in Wyoming and a long underpass that allows tigers to scamper beneath a highway in India.

In the U.S., there are more than 1,000 wildlife crossings and there are more being built all the time.  Data shows that they are highly effective.  A study of wildlife crossings on Highway 9 through the Blue River Valley in Colorado found that they reduced wildlife-vehicle collisions by nearly 90%. 

Wildlife crossing structures can be expensive to build, costing between $500,000 and $6 million, but research has shown that the money saved by avoiding crashes can recoup these costs in just a few years along with the fact that they potentially save lives.  Federal funding is largely distributed based on areas with the highest number of wildlife-vehicle collisions, which is crucial for addressing public safety issues.  However, a recent study suggests that future proposals need to incorporate climate-driven changes in animal behavior and habitat.

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As Climate Changes Fuels Animal Movement, Will These Structures Still Help Species Cross the Road?

Photo, posted April 5, 2017, courtesy of Jeffrey Beall via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Moving Endangered Species | Earth Wise

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People have intentionally or accidentally introduced numerous invasive species to habitats around the world.  At the same time, the planet’s wildlife is in a steep decline.  A recent study estimated that the populations of over 5,000 vertebrate species have declined by an average of nearly 70% since 1970.  A United Nations report warns that human activity has threatened as many as a million species with extinction.

With all of this as a background, there is climate change that is altering the habitats of the world’s species – warming lakes and oceans, turning forests into grasslands, tundra into woodland, and melting glaciers.  In response to these changes, living things are rearranging themselves, migrating to more hospitable locations.  But many species are just not capable of finding more suitable habitats on their own.

Conservationists are now increasingly considering the use of assisted migration. In some cases, when a species’ critical habitat has been irreversibly altered or destroyed, agencies are establishing experimental populations outside of the species’ historical range.  Such actions are often deemed extreme but may be increasingly necessary.

However, clear-cut cases are relatively rare.  More likely, it is a more difficult judgement call as to whether assisted migration is a good idea or is possibly a threat to the ecosystem of the species’ new location.  The relative dearth of assisted migration experiments is less likely a result of legal barriers than it is a lack of scientific and societal consensus on the practice. Scientists are now trying to develop risk-analysis frameworks that various agencies can use in considering potential assisted migration experiments. 

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Last Resort: Moving Endangered Species in Order to Save Them

Photo, posted March 18, 2010, courtesy of Jean via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Living Planet Index | Earth Wise

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The World Wildlife Fund and the Zoological Society of London recently published the latest Living Planet Index, which is designed to measure how animal populations are changing through time.  The purpose is to provide an assessment of the health of ecosystems and the state of biodiversity.

The LPI only looks at the population of vertebrates:  birds, mammals, reptiles, amphibians, and fish.  The latest survey looked at how populations have changed between 1970 and 2018.  The results are that populations of these animal groups have declined by an average of 69% over that 48-year period.

This result highlights a very real and very severe crisis of biodiversity loss.  However, it does not mean that there are 2/3 fewer animals today than 48 years ago.  The way the index is calculated is to look at the changes in individual populations of over 5,000 different species.  Then these individual relative declines are averaged to get the result.  

There are shortcomings in the LPI.  For example, individual species that have seen massive population declines will bring the average down.  But even removing the outliers both of a negative and a positive impact does not dramatically change the result.

There is no perfect indicator for biodiversity and ecosystem health.  The Living Planet Index is nonetheless a useful metric and indicates that many species around the world are in decline.  Policymakers and environmental advocates need to make decisions about conservation and protection measures and this index is one tool they can use.

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There’s a frightening new report about wildlife declines. But many are getting the story wrong.

Photo, posted October 12, 2019, courtesy of Visit Rwanda via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Controlling Malaria Without Chemicals

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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.

Making Room For Wildlife

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Protecting biodiversity is a critical challenge facing humanity.  Global vertebrate populations – from elephants to amphibians – declined by 58% from 1970 to 2012 and losses are expected to reach 67% in the next two years.  Think about it:  at least two-thirds of all vertebrate animals on earth have vanished over the lifetime of anyone fifty years old or over.

[Read more…] about Making Room For Wildlife

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