food sources

Deer vs. caribou

June 13, 2024 By EarthWise Leave a Comment

The combination of a warming climate and human disruption of traditional habitats has been causing changes in the ranges of many animal species. Over the past century, white-tailed deer have greatly expanded their range in North America. Researchers from a group of Canadian institutions have been investigating the expansion of the deer in the boreal forest of Western Canada. A five-year study used 300 wildlife cameras throughout the region to track the activities of large mammals.

Climate change has created milder winters and habitat alteration from forestry and energy exploration have created new food sources for deer.

The expansion of deer in the forest has not been a good thing for the woodland caribou. The species was designated as threatened in 2002. As of 2011, only 34,000 remained in the region. Deer are ecosystem disruptors, in this case disrupting existing predator-prey dynamics. Areas with more deer typically have more wolves and wolves are predators of caribou. Deer can handle high predation rates, but the already threatened caribou cannot.

Understanding the relative roles of climate and human land use is essential in efforts to recover caribou populations. It is complicated because further north, the climate becomes harsher and human land use decreases. The debate over the relative effect of climate or habitat change is one of the most pressing issues facing ecologists globally as they pursue efforts for ecosystem restoration.

In any case, winter severity is expected to decline as climate change progresses. Therefore, deer are expected to keep expanding northward and increasing in abundance, which means increasing risk to caribou.

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Deer are expanding north, and that’s not good for caribou

Photo, posted January 12, 2016, courtesy of Gerry via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Megafires and ecosystems

November 15, 2023 By EarthWise Leave a Comment

Wildfires are a natural phenomenon. They have occurred long before there were people around. Ecosystems adapt to fires and some species can benefit from them or even depend upon them. But in recent times, fires have been intensifying and increasing in frequency and they are beginning to outstrip nature’s ability to bounce back from them.

So-called megafires – ones that dwarf typical wildfires in size – have an immediate ecological toll. They kill individual plants and animals that might have survived smaller fires.

Over millennia, many species of plants and animals have evolved to adapt to periodic fires. They are especially sensitive to smoke and take protective action in a timely fashion. Others take advantage of food sources that arise when trees burn.

But even species that capitalize on burned-out areas of forests require oases of healthy woodland for at least part of their activities. When fires are too widespread, such oases are too few and far between.

Animals that survive fires must find food, water, and shelter in the aftermath. And all air-breathing animals are going to be impacted by smoke exposure because the chemicals in smoke are toxic to them as well as to people.

In places like Canada’s Northwest Territories, repeated fires have transformed some forests, eliminating dominant tree species and replacing them with others whose light seeds were carried on the wind.

Scientists have estimated that increased global fire activity could push more than 1,000 threatened plant and animal species closer to extinction. Changing fire patterns are transforming landscapes and utterly remaking ecosystems.

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How Megafires Are Remaking the World

Photo, posted December 19, 2022, courtesy of Brian Pippin/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Insects On The Menu | Earth Wise

March 6, 2023 By EarthWise Leave a Comment

According to the World Food Programme, a record 349 million people across 79 countries are facing acute food insecurity. This constitutes a staggering rise of 200 million people compared to pre-pandemic levels. Nearly one million people globally are fighting to survive in famine-like conditions, which is ten times more people than just five years ago.

As a result, many experts contend that alternative or so-called novel food sources – such as lab-grown meats, seaweed aquaculture, and insects – will be necessary to help fight global hunger and global food insecurity.

Insects already form a significant part of diets in many cultures around the world. Insects are great sources of nutrients, including protein, vitamins, and minerals. But insects have yet to be embraced in any substantial way in western cultures… but that may be changing.

In fact, the European Union has now certified four types of bugs as food fit for human consumption. The larvae of lesser mealworms and house crickets recently became the third and fourth insects approved for sale as food in the EU, joining yellow mealworms and grasshoppers. Eight more applications are awaiting approval.

Insects are already a delicacy in many high-end restaurants around the world, and a normal and healthy part of diets in countries like Mexico and Thailand. Embracing insects as a food of the future will not only help in the fight against global hunger, but will also help to reduce greenhouse gas emissions and to slow species extinction.

In Western food markets, the so-called “yuck factor” remains the biggest hurdle to cross. But as the world population grows, the need for sustainable solutions in the food industry grows with it.

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Insects on the menu as EU approves two for human consumption

World Hunger Surged in 2020, U.N. Says

A global food crisis

Photo, posted April, 2014, courtesy of Shankar S. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tropical Species Moving North | Earth Wise

April 19, 2021 By EarthWise Leave a Comment

Climate change is leading to warmer winter weather throughout the southern U.S., providing opportunities for many tropical plants and animals to move north. A new study by scientists at UC Berkeley looked at the changing distribution of tropical species driven by the warming climate.

Some species are appreciated in their new locations, such as sea turtles and the Florida manatee, which are gradually moving northward along the Atlantic Coast. Others, like the invasive Burmese python are not so welcome. That goes double for many insects, such as the mosquitoes that carry diseases like the West Nile virus, Zika, dengue, and yellow fever, as well as beetles that destroy native trees.

The transition zone, northward of which experiences freezes every winter, has always been a barrier to species native to more temperate places. For most organisms in such places, if they freeze, they die. Cold snaps like the recent one in Texas usually don’t happen for decades and are now likely to be less and less frequent. In the meantime, tropical species can get more and more of a foothold and maybe even develop populations that can tolerate more cold extremes in the future.

The warming climate is leading many plant species to expand their ranges, in some cases pushing out native species. The general story is that the species that do really well are the more generalist species whose host plants or food sources are quite varied or widely distributed and can tolerate a wide range of conditions. By definition, they tend to be the pest species.

We need to prepare for widespread shifts in the distribution of biodiversity as climate, including winter climate, changes.

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Tropical species are moving northward as winters warm

Photo, posted May 7, 2010, courtesy of Jim Reid / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.