Wildlife Wednesday: do trees really use underground networks of fungi to talk?

Plus: Orca missing out on the fattiest fish, the happy decline of humpback whale song, the 3,000-year-old caribou calving grounds and B.C.’s crabby green-shelled army

Fungi are living organisms such as moulds, yeast and mushrooms that can connect roots of multiple plants underground. (Photo: Julia Volk/Pexels)
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From mushroom zombies in HBO series The Last of Us to psilocybin’s medical properties, fungi are all the rage. But are they aiding the trees populating the planet’s forests in communicating via a fungus-fueled “wood-wide web”? Probably not, according to researchers from the University of Alberta. The belief that trees can “speak” to each other has become the talk of the town, but these ideas may be more fantasy than fact. 

The theory that underground fungi — known as common mycorrhizal networks (CMN) — can facilitate communication among, share resources between and even provide protection to trees, has been around since Suzanne Simard’s famous research was published in the late ‘90s. However, these claims may not be fully supported by scientific proof, according to a study published in Nature Ecology & Evolution

To evaluate these popular claims, the researchers reviewed evidence from existing field studies on CMNs, each of which resulted with little to no scientific evidence to support the suggested abilities. One of the claims, that CMNs are widespread in forests, can not be scientifically supported since there has not been enough research on CMN structure and its function in forests. 

The researchers also found a second questionable claim, which says CMNS are beneficial because they help transfer nutrients and provide a boost of growth from adult trees to seedlings. After reviewing 26 studies, they found instead that CMNs don’t necessarily bring about that flow of nutrients and there was equal evidence that a connection to a CMN could actually hamper seedlings.

While theories relating to the “wood-wide web” may put the fun in fungi, the researchers say overblown or understudied information can disfigure the narrative about CMNs, which could negatively affect how forests are managed. 

Declining Fine Dining 

As of September 2022, there are only 73 Southern Right killer whales left in the world. (Photo: NOAA/Unsplash)
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Not all salmon are created equal — and not all salmon have the delectable nutrients killer whales depend on. The fattier the fish, the better, but researchers are finding variations in the amount of fat in Chinook salmon.

A study on Southern Resident killer whales, published in Scientific Reports, found that the lipid content, or fattiness, of Chinook salmon in the Fraser River can have implications for orca eating habits and energy accumulation in the Pacific Ocean. 

Due to a shifting climate, these whales are migrating later in spring, leading them to miss out on the early migrating Chinook salmon. Through measuring the lipid content of the remaining late migrating salmon, the researchers theorize these fish are usually less fatty with lower energy density, affecting their quality as food for orcas. 

These changes could give insight into killer whale population trends and their ability to meet their nutritional requirements amid a narrowing availability and quality of fish. 

As oceans warm and food webs shift in the Pacific, the researchers are concerned energy accumulation in Chinook salmon will decline, resulting in reduced prey and energy availability for the already endangered killer whales. 


Tuning Out  

As the quantity of humpback whales increased, their romantic pursuit tactics changed. (Photo: Vivek Kumar/Unsplash)
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Humpback whales are known for their somber songs, wailing to each other in the deep blue as they migrate the planet’s oceans. A new study shows, though, that humpback whales’ songs may very well be melancholic sounds of loneliness. 

Scientists who tracked humpback whales in Australia observed that fewer whales have been wailing to find mates as their population continues to grow.

We first began to hear the labored songs of humpback whales in the 1970s, when new underwater microphones were developed. Since only male whales sing, researchers have determined that their ballads act as a tactic to attract mates. 

Whaling heavily depleted the humpback’s numbers, highlighting how crucial their songs were in their continued breeding, according to the study published in the journal of Communications Biology. With the successful reduction of commercial whaling, and a significant increase in humpback whale populations, the researchers found that the males were wailing less and less. 

Not to fear — though there are less songs overall, there are still some wistful wails to be heard as humpbacks continue to woo their female counterparts.

Creatures of habit

Caribou have one of the longest migrations of any terrestrial mammal, moving from winter ranges to spring calving grounds annually. (Photo: Barnabas Davoti/Pexels)
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When it comes to calving, caribou really do stick to what they know. Researchers have found the first carbon dated evidence that caribou herds have been returning to the same Arctic grounds to calve for over 3,000 years. Female caribou shed their antlers after giving birth, leaving key pieces of skeletal remains for researchers to observe. 

After carbon dating discarded antlers found in the Coastal Plain region of the Arctic National Wildlife Refuge in Alaska and Ivvavik National Park in Yukon, researchers from the University of Cincinnati found that some antlers have remained undisturbed on the arctic tundra since the Bronze Age. This means that some of these antlers were growing while ancient Greek poet Homer composed his epic poems, the Iliad and the Odyssey

Although Traditional Knowledge of the Gwich’in people and historical records of early European explorers also cite caribou use of the grounds for at least hundreds of years, these ancient antlers provide radiocarbon dated evidence of calving activity from previous millenia.

Not easy being green

The invasive European green crab is destructive and always hungry, pushing out the locals, tearing up eelgrass beds and chowing down on clams and mussels. (Photo: David Reed/Flickr [CC BY-NC-SA 2.0])
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Local shore crabs along the coast of Vancouver Island have been retreating into their shells, feeling most definitely shell-shocked by an uninvited guest that’s trashing their home. The invasive European green crab is destructive and always hungry, pushing out the locals, tearing up eelgrass beds and chowing down on clams and mussels. A huge effort has been underway to get rid of them — trapping them, packing them into large tubs, flash-freezing them and dumping them in landfills.

But local Ahousaht, Tla-o-qui-aht and T’Sou-ke First Nations are proposing a better idea, according to a report by The Narwhal. Why not eat them or perhaps use them as fertilizer? They may be an environmental disaster, but they taste quite fine in a bisque or, believe it or not, in a green crab flavoured whiskey (this from New Hampshire, where a green crab cookbook has all manner of innovative recipes in a bid to nourish humans and keep the invader in check). 

In the short-term Fisheries and Oceans Canada is assessing how to evaluate the risks of these various options to make sure they don’t inadvertently lead to the further spread of the Euro crabs. The government is expected to test a draft approach to permitting the use of invasive species in B.C. in the coming year.


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