Wildlife
Plus: skydiving salamanders, Canada’s returning monarch, orca blubber insights, and the woodpecker-wasp conservation dream team.
Think of it as a swoop in the right direction for the endangered burrowing owl. Last summer, the Calgary Zoo collected 20 burrowing owlets from the wild, removing the youngest and least likely to survive owlets and caring for them over the past year (last-hatched owlets typically have just a three per cent chance of surviving their first year).
The process, known as head-starting, is an innovative conservation technique to help bolster the wild burrowing owl population. The owlets were raised to adulthood and returned to the wild in southeastern Alberta this past spring.
The idea is that the strong and healthy owls will go forth and prosper (and hopefully mate, too). Though once common on the Prairies, the population of burrowing owls, which are smaller than pigeons, has shrunk over the past 40 years with estimates setting the number of breeding pairs at fewer than 500 in Canada today. Severe habitat loss and climate change are the main contributors to the population loss.
The owls have been brought back to near where they were originally hatched and installed in secure burrows to ensure they can safely mate and lay eggs.
“Burrowing owls have existed on the prairie for millennia. And they’ve only been declining for the last several decades, and that’s because of changes to the landscape that are happening because of things that people are doing,” Graham Dixon-MacCallum, a conservation research population ecologist with the Wilder Institute/Calgary Zoo, told CBC News in Calgary. “And if people are part of the cause of a decline, it means we can also be part of the cause of a solution.
The Queen isn’t the only monarch worth celebrating this year!
In Mexico, where butterflies usually go to spend the winter in warmth, experts say that 35 per cent more monarch butterflies have arrived this year for their winter migration than the previous season. Good news after their steep decline of monarchs in previous years!
Setting off from Mexico, monarch butterflies normally return to Canada and the U.S. in March, but have begun leaving in February instead in order to avoid the drought and heat that hits the area just a little later. This certainly shows the butterflies’ ability to adapt to more extreme and rapidly changing climate conditions, allowing them to avoid the life-threatening heat and drought, along with other threats like loss of habitat and deforestation in butterflies’ wintering grounds in Mexico.
However, there are other factors at play affecting the butterflies’ migration, especially the presence (or absence) of milkweed — the only plant that both adult monarchs and their caterpillars feed on, and where they lay their eggs. Gloria Tavera, the regional director of Mexico’s commission for national protected areas, has been urging Mexicans to stop planting milkweed as it encourages the butterflies to stay longer, disrupting their migration timing. Meanwhile, activists and students in Canada and the U.S. have been encouraged to plant more milkweed to make up for its absence due to land clearing and herbicide usage.
The wandering salamander may well be due a name upgrade after scientists find they use their limbs to ‘skydive’ from one redwood tree top to another.
Braving heights of up to 90 metres, the courageous critters, native to California but also found in B.C., have an interesting habitat preference — the giant redwoods of North America’s west coast. While it would seem that getting around the tree tops wouldn’t be easy for the 10 centimetre-long amphibians, a researcher from the University of South Florida in Tampa has found that by leaping into the air and guiding their fall like a skydiver, the salamanders are able to navigate the world’s tallest trees in style.
To prove this, researchers created an artificial vertical wind tunnel — similar in concept to those used for indoor skydiving — and observed the salamanders in freefall action using high-speed video cameras. The little amphibians first prepare their leap by bending their bodies to generate power, similar to the way a fish swims. They then launch themselves forward with all limbs splayed outwards, and then — now hovering in place due to the wind tunnel — use their feet, toes and tail to adjust the body and guide their descent.
Taking the ‘gravity elevator’ (as the researchers have termed it) allows the vulnerable salamanders to both avoid predators and conserve energy. Smart!
When the emerald ash borer arrived in North America some time in the 90’s, devastation for the continent’s ash trees soon followed. More than 20 years later, despite numerous attempts to quarantine infected wood and limit the spread, the destruction continues.
Two conservation hopes have come to the fore, however. Woodpeckers are emerging as prolific emerald ash borer predators, and have been found to kill around 40 per cent of ash borers in their given area. Not enough to save the trees, but enough to massively slow down the spread of the invasive insect when given a chance. Woodpeckers and other bird species are now being touted as having a big role to play in bringing equilibrium to ash borer populations and giving ash trees a fighting chance.
The other unlikely potential hero are parasitoid wasps, four species of which exclusively target the species in their native habitats in China and Russia. After vigorous testing to ensure these wasps wouldn’t prey on native North American insects, the U.S. Department of Agriculture began releasing the wasps in heavily emerald ash borer-inflicted areas. Time has shown that they also have a great impact on emerald ash borer numbers, reducing them by as much as 57 per cent.
Although woodpeckers do eat some of the wasps, the two are now being used to fight the battle against the emerald ash borer in tandem. An unlikely team, they are proving to be a mighty force. “We’ve found in both Michigan and the Northeast that with the woodpecker and wasp combination we have young trees without one late-stage emerald ash borer larva,” says one scientist involved in the project. “This gives us hope.”
Orca populations are making their way north, invading the Arctic and causing significant disruptions to an ecosystem already deeply affected by climate change.
Now a team of McGill researchers is looking to better understand how orcas impact their environment — by figuring out what, exactly, they’re noshing on. The method? Reconstructing their diets using lipids in their blubber.
Researchers used a model known as Quantitative Fatty Acid Signature Analysis. They took samples from captive killer whales and measured them against the fatty acid composition of the wild Greenland killer whales, as well as the species they thought the whales might be feeding on.
When they modelled the results, researchers discovered that orca in the Arctic are mainly feeding on harp and hooded seals, species that researchers also found in some of the whales’ stomachs.
This new tool has the potential to improve our understanding of the diets of orca around the world, and how they might impact Arctic food webs in the future.
It’s a pretty handy tool given that it’s not as easy to keep tabs on what an orca is having for lunch as it is to follow a land-based apex predator like a lion or tiger.
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Wildlife
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Wildlife
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