Wildlife

Wildlife Wednesday: loons are suffering as water clarity diminishes

Plus: the elephant seal that keeps coming back, the fox that solved an infection mystery, and the hypersexual zombie cicadas about to emerge from the ground

Declining water clarity is impacting loon's ability to hunt. (Photo: Gary J. Wege/USFWS [Public Domain])
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The common loon, that icon of northern wilderness, is under threat from climate change due to declining water clarity. Published earlier this month in the journal Ecology, a study conducted by biologists from Chapman University and Rensselaer Polytechnic Institute in the U.S. has demonstrated the first clear evidence of an effect of climate change on this species whose distinct call is so tied to the soundscape of Canada’s lakes and wetlands.

Through the course of their research, the scientists found that July rainfall results in reduced July water clarify in loon territories in Northern Wisconsin. In turn, this makes it difficult for adult loons to find and capture their prey — mainly small fish — underwater, meaning they are unable to meet their chicks’ metabolic needs. Undernourished, the chicks face higher mortality rates. The consistent foraging techniques used by loons across their range means this impact is likely echoed wherever they are found — from Alaska to Canada to Iceland.

The researchers used Landsat imagery to find that there has been a 25-year consistent decline in water clarity, and during this period, body weights of adult loon and chicks alike have also declined. With July being the month of most rapid growth in young loons, the study also pinpointed water clarity in July as being the greatest predictor of loon body weight. 

One explanation for why heavier rainfall leads to reduced water clarity is the rain might carry dissolved organic matter into lakes from adjacent streams and shoreline areas. Lawn fertilizers, pet waste and septic system leaks may also be to blame.

The researchers, led by Chapman University professor Walter Piper, hope to use these insights to further conservation efforts for this bird Piper describes as both “so beloved and so poorly understood.”

Return of the king

 

 

He's back. (Photo: Courtesy DFO-MPO)
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Emerson the two-year-old adolescent elephant seal is back in Oak Bay on Vancouver Island once again, just five days after he was relocated 150 kilometers from the area. He travelled more than 30 kilometers a day to get home.

The Department of Fisheries and Oceans has dubbed this an “incredible feat” of navigation in an interview with CBC News.

“I was pretty floored,” Van Kirk, who helped relocate Emerson last week, told CBC’s All Points West. “I got the email on the weekend and said to myself, ‘there’s absolutely no way it could be him already.’”

Emerson’s most recent displacement comes after four previous attempts to relocate him since May. These relocation efforts have been in the interest of Emerson’s own safety after he tried to climb stairs, cross roads and was found meandering through garden beds. He’s also been harassed by humans, which can lead to bad outcomes for both seals and people.

The Marine Mammal Rescue Unit is continuing to keep tabs on Emerson and will relocate him again if his interactions with humans continue.

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Cold case closed

Scientists have finally solved the long-standing mystery of why people and animals in Northern ecosystems have been exposed to parasites at disproportionately high rates. (Photo: Ray Hennessy on Unsplash)
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For a long time, scientists have been unable to explain why people in Northern communities were being exposed to a dangerous parasite usually associated with kitty litter at disproportionately high rates. However, researchers at the University of Saskatoon may have cracked this cold case thanks to a surprising source —  foxes.

Toxoplasma gondii, or T. gondii for short, is a parasite associated with kitty litter and can cause flu-like symptoms. It is especially dangerous for fetuses and people who are immunocompromised. The fact that it’s found at such high rates above the treeline, in remote Arctic communities, made little sense to those studying it.

Scientists started making progress on this case when they realized that foxes in Nunavik, Q.C., were being exposed to this parasite through a similar route to humans. Since foxes scavenge a lot of meat, researchers deduced that they could be used as an indicator species that can help understand human parasite exposure.

By comparing the diets of foxes infected with the parasite with those who aren’t, they discovered that it is specifically foxes that eat fish and waterfowl that are being exposed to T. gondii. This is consistent with recent reports that marine prey and migratory birds are linked to human exposure to T. gondii in Nunavik. 

Knowing this can help reduce human exposure to these parasites in people in Northern communities and other species in the region.

Saltshakers of death

Mating season turns into a game of Russian roulette when one in twenty cicadas has a deadly and contagious fungus instead of genitals. (Photo: Patrick Coin/Flickr [CC BY-NC-SA 2.0])
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The southeast United States is set to become cicada central this summer, with two broods of cicadas totalling trillions of individual insects expected to emerge out of the ground. And there’s another twist: approximately one in twenty cicadas have been infected with a sexually transmitted fungus that controls them like ‘zombies’ and alters their sexual behaviour.

One brood surfaces every 13 years in Georgia and southeastern U.S.A., while the other emerges every 17 years around Illinois. However, their life cycles are converging this year, an event that only happens every 221 years.

Coinciding with this remarkable event is an outbreak of infection by the fungus Massospora cicadina. Essentially, some cicadas have genitals, while others have a giant contagious fungus where their genitals would normally be. Turning the cicadas into what scientists are calling “saltshakers of death,” the fungus possesses the cicada, facilitating its transmission before killing the host.

But despite having a fungus growing out of its abdomen, these infected cicadas will continue on with mating season as usual. Actually, they will be even more promiscuous than regular cicadas.

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