April 16, 2017

A Sesquicentennial Challenge

2017 marks Canada's 150th birthday. And since everybody loves big round numbers, we'd wager that right now, a whole bunch of Canadians are trying to come up with bucket lists involving the number 150.

And Banff is getting in on the action.  Yesterday marked the first of the Banff Community Bird Walks, held every year from mid-April to mid-June.  The goal with this year's walks is to tally up 150 bird species.

It's our sesquicentennial challenge! (That's the fancypants way to say 150, by the way)

photo courtesy of Amar Athwal

The walks take place on Saturdays and Mondays at 8:15 a.m. and run until June 12. The meeting place is on Sundance Road near its intersection with Cave Avenue in Banff.  The area has wetlands, forest, a horse stable, and grasslands, so the birding is really good.  Some people come for half an hour and keeners sometimes stay until the early afternoon.

We've been to some of the walks ourselves (on one of them, we saw the “grand slam” of Banff's swallow species – all six of them – sitting on a single telephone line near Warner's Stables), and they are a lot of fun.  There's great volunteers who make walk participants feel welcome, spot species, help with bird identification, and share their books & equipment.

photo courtesy of the Banff Community Bird Walk

So join in a walk, and see if you can't contribute to the 150!

ps: one of the participants on most walks is Amar Athwal, who takes great photos of the birds.  His weekly "Moments" emails are superb, and we recommend you sign up by sending an email to warmlight@gmail.com.  Or, check out Amar’s website.

April 12, 2017

What is Your Home... River?

What is home?  Many an ecologist would argue that what really counts is your watershed - your "home river". It's a logical boundary to use for land management, and the water in your watershed is crucial to life and livelihoods.

Our home river is the Bow, and we live a mere 30 minutes from its headwaters. Last fall we had the opportunity to learn about its deepest nature.

We attended a talk by Dr. Richard Hauer on gravel-bed rivers in the mountain west. In a recently published paper, he and colleagues have documented and explained how important these kinds of rivers are to wildlife and ecosystems here.

We've been using this story on our snowshoe trips, as we travel beside and on the Bow River.
Nadine & Jun along the beautiful Bow River
It's the first time scientists have put this big picture story together, and it really is big news, big enough to have been covered by the New York Times.  The article summarizes nicely:

"Melting snow and groundwater flow down the channel; this is what we think of as a “river.” But underground, far more water is moving slowly through a labyrinthine network of cobbles, gravel and sand that make up the entire valley bottom. [our emphasis]

This deeply buried habitat is far more important and far more productive than thought. The matrix of gravel and sand cleans the water, filtering organic material and freeing up nitrogen and phosphorous embedded in the gravel.

These natural fertilizers spread across the valley bottom, a shot of adrenaline that nourishes plants in the flood plain such as willows and aspen, which in turn draw birds and beavers, elk and caribou. The plant-eaters attract predators like wolves and grizzly bears."

We've always known that rivers were movement corridors and hotbeds of biodiversity, but now we can see the bigger picture: the smallest sediments and the largest carnivores are tightly connected.

These days, we look at our "home river" with different eyes.

March 21, 2017

25 Years of Mountaintop Eagles

Yesterday, 323 Golden Eagles flew north over Mount Lorette, in Kananaskis Country, southeast of Banff.

If that strikes you as a very specific number, it is. And that's because for exactly twenty five years, dozens of keen volunteer bird watchers have been counting the Golden Eagles that migrate along the backbone of the Canadian Rockies every spring and fall.

On March 20, 1992, Des Allen and Peter Sherrington were doing a general bird survey in the Kananaskis Valley when they first noticed Golden Eagles flying high along the ridgetops. They saw over a hundred that day, but when they looked for other records of large numbers of eagles, they could find nothing even close.

They started watching, and they got others to watch too.  We remember that spring, because we heeded the call to volunteer. It was our very first summer in Lake Louise, and we spent a day in lawn chairs beside Banff's Lake Minnewanka, peering through binoculars to look for the mysterious eagles. And that's when we learned why nobody had noticed what Des and Peter had found that spring: you couldn't see these gigantic birds with your naked eyes! It seems impossible -- they can have 7-foot wingspans -- but they were flying so high that you needed to pick them out with scopes or binoculars.

The golden eagle migration down the spine of the Rockies.
Courtesy of the Rocky Mountain Eagle Research Foundation.
Since 1992, observers have spent over 4500 days in the field, and they've counted more than 180,000 Golden Eagles in total.  The birds are believed to nest in the Yukon and Alaska, and their wintering grounds stretch from Montana to Mexico.

On this, the first full day of spring, let's celebrate nature's splendour, and tip a hat to Peter and Des for their epic discovery.

If this blog post has made you curious about birds, we offer private birdwatching trips in June and early July every year. Come join us!

March 9, 2017

What's with all the Snow Mushrooms on the Fenceposts?

If you've driven between Banff and Lake Louise this winter, you've probably noticed the big globes of snow on top of the wildlife fencing posts. Or, if you've been snowshoeing with us, you've seen even bigger piles of snow on stumps or broken tree tops



How do these "snow mushrooms" form? Especially when the surface they're sitting on can be as small as a dessert plate.

To answer, we need to welcome you to the wonderful world of snow science, and specifically the process of equi-temperature or destructive metamorphism. We hope you're ready for a bit of physics!

When new snow falls in the Canadian Rockies through the winter, the cold temperatures almost always guarantee that it will fall as light, low density "champagne powder." But it doesn't stay that way.  If snow lands on something above the ground, like a log suspended in the air, or a stump, it will start to change. The newest snow will always be light and fluffy, but snow that's been on the log or the stump for a few weeks or months will feel like really high density styrofoam. You are hard pressed to push a ski pole into it more than a few inches, and the snow crystals stick to each other tenaciously, even though new snow in the Rockies can't even be formed into a snowball.

Here's what's going on: since the temperature around the suspended snow is the same at any given time (hence "equi-temperature"), the snowflakes start to break down in a surprising way: water in the spiky ends of the flakes sublimates (meaning it evaporates directly from ice into water vapour). The water vapour that is produced through this sublimation moves from the higher vapour pressure at the edges of the snowflakes toward the lower vapour pressure around the interiors of the snow crystals.

Still with us? This small scale water migration means that airy, fluffy snowflakes become denser over time, and closer together. This promotes the stickiness of the snow, meaning it can occupy a bit more space than the surface area of the stump or fencepost. With each subsequent snowfall the surface area for collecting new snow increases, until a giant blob of snow can sit on the tiniest of surfaces.  Big snow mushrooms can measure more than 3 metres across.

photo by Vaughan Cornish, public domain
We are not the first to notice these snow mushrooms.  In 1900, English geographer Vaughan Cornish took a winter trip on the CPR through western Canada.  He photographed giant snow mushrooms in Glacier National Park. Here's one of his archival photos, plus a few more from us.


February 7, 2017

Bison are Back in Banff!

In late January, at the Ice Magic competition in Lake Louise, one team of carvers had the prescience to sculpt a life-size bison in clear ice. I looked at that frozen figure, and thought to myself, "in just a few weeks, you are going to come to life!"


On February 1, 16 bison from Elk Island National Park were airlifted into the Panther Valley, in the wilderness heart of Banff, and released into their paddock. Bison are back!

Bison being released in Banff National Park last week.  Photo courtesy of Parks Canada
Many Rocky Mountain visitors remember the days of the bison paddock near the town of Banff, but this time things are different. This herd will be released into the wild once they've acclimatized to the landscape. Most of the bison are females, and they will have calves this spring, adding new blood to the fledgling herd. After another crop of bison calves in May of 2018, the population will have doubled, and the bison will be released from the paddock to roam in the centre of the park. They'll be the first free-roaming bison in the park in 140 years.

It's exciting stuff, and feels very appropriate for 2017: Canada is celebrating its 150th birthday this year, and this is Banff's birthday present to the ecology of the country.

Here's a few highlights from CTV's coverage of last week's bison relocation.

January 23, 2017

Ice Magic, 2017 Edition

Ice Magic, the international ice carving competition, returned to lake Louise this past weekend, and the sculptures were, as always, beautiful and captivating.  Here's a few of our favourites, captured yesterday as dusk turned to night.




The carvings usually stay in pretty good shape for about a week or ten days, so if you are planning a trip to Lake Louise, make sure you leave enough time fora walk through the "gallery."