Thursday, December 31, 2009

New Year's Eve at the Boardwalk

This afternoon my daughter Susan and I walked around the Boardwalk and for a change we had it all to ourselves. Maybe that's because the temperature was -20 and there was a stiff breeze. Regardless, tracks in the snow showed that others had braved the path before us. And there were other stories written in the snow. We saw numerous tracks of snowshoe hares, especially where the brush was thick.

Snowshoe hare populations follow a cycle that peaks about every 10 years before crashing. We must be near the peak this winter because there are lots of hare tracks.

The hares get their name from their enormous hind feet which serve as snowshoes to keep their owner from sinking into the soft snow. I think it's pretty likely that people copied the hares when the first human snowshoes were invented. In typical rabbit family fashion, hares hop with both hind feet, and the hind feet actually land ahead of the front feet in the somewhat heart-shaped track.

Snowshoe hares use the same trails over and over again to move between feeding and resting areas. Some of these cross the Boardwalk, either under or over depending on how far above the snow the structure is. I looked underneath at one crossing location and found where a hare had rested. Hares spend their resting time in sheltered locations called forms and it seems at least one hare thought the Boardwalk made an excellent shelter.

All the best to everyone for a prosperous New Year!

Wednesday, December 16, 2009

Trees of the Boardwalk - Lodgepole Pine 1

Although the lodgepole pine is the most abundant tree species in the Alberta Foothills, it isn't very common around the Beaver Boardwalk. Partly that's because the local soils are very calcareous and pine prefers more acidic soils. Another likely explanation is the history of fires in the area and how pine reproduces. Some people call the lodgepole pine the phoenix tree. Why? Because lodgepole pine requires fire to assit the reproduction process. Like the mythical phoenix a new pine generation rises from the ashes of parent trees scorched by forest fires.

Pine cones contain the secret. Cones take two growing seasons to mature after tiny yellow pollen grains produced by tan-coloured male flowers fertilize the reddish female flowers. Each summer pine and spruce trees produce huge quantities of pollen blown by the wind to female flowers. The excess pollen coats surfaces and forms a yellow film on puddles, and makes some alergy sufferers miserable.

Mature pine cones remain fixed to the parent tree. Cone scales protecting the precious seeds remain tightly locked by a bond of resin, waiting for a fire. It takes a temperature of 45-60°C to melt the resin and release the seeds. Normally that much heat is only produced by a forest fire, which kills the trees but doesn't completely burn the cones. The seeds fall to a cooling and fertile ash bed on the forest floor, where they germinate in incredible numbers.

Pine seeds aren't easily dispersed by the wind or other agents. In nature, fires must usually kill cone-bearing trees to establish a new generation. If there are no pine trees to kill or fires occur infrequently, other tree species replace pine as dominant species in an area.

Sunday, December 6, 2009

Bear Tracks

It's a pretty fair bet that most local bears have entered their winter dens, but it's still possible to see bear tracks in the forest if one looks carefully. Several aspen trees along the Beaver Boardwalk have old scars in their bark made by black bear claws. Let me qualify that - the marks were probably made by black bears. Young grizzly bears can climb trees, but they don't do it a lot. I wouldn't either if I were a grizzly cub with such a powerful Mom to defend me.

Black bears climb trees for lots of reasons. Getting food and escaping danger are probably the most common activities. The method is pretty straightforward. A bear grabs the side of the tree with it's front paws and their longer claws, jams the shorter claws on the hind feet into the bark, and hitches up the tree front to back. Black bears can go both up and down pretty fast - as fast as or faster than human climbers you see in lumberjack competittions.

Bruin claws easily penetrate the relatively soft and smooth aspen bark. Damaged bark darkens as the tree heals from the injury, leaving a permanent record of the claw marks. So why climb aspens? The smooth bark is fairly slippery when compared to other local tree species, as anyone who trys to shin an aspen could tell you. Of course, people don't have nice sharp claws to assist the process.

Every spring hungry black bears climb a lot of aspen trees. They are after the nutritious reproductive catkins that appear very early in spring greenup when there's not much else for a bear to eat. I once flew over a patch of aspens on an early spring evening and saw 5 black bears up in the treetops feasting on catkins. That aspen patch was the only one in the area. It drew bears like a magnet, but only for a very short period of time that I was fortunate to witness.

Thursday, December 3, 2009

Trees of the Boardwalk - Tamarack

Alert folks have noticed that the interpretive sign describing tree species found in the Beaver Boardwalk area was missing a prominent local species. That's because there was no tamarack close to the trail in the first two years. However the 2009 construction passes by lots of tamarack. The resolution of the original sign was also below standard, so we're redoing the sign and the new version will include Larix laricina.

The tamarack is an oddball tree in one respect. It's a conifer, which means it bears its reproductive structures in cones. But unlike most local conifer species that have evergreen needles, the tamarack needle clusters turn a deep gold in the autumn and join the parade of falling leaves from aspens and poplars.

In our area tamarack usually grows in fens, which are wetlands on organic soils that have water flowing through them. This makes them more nutrient rich than bogs, which usually have stagnant water. The relationship is so strong that tamarack trees are diagnostic - if you see a tamarack you are likely looking at a fen.

The word tamarack comes from an Algonquin word that translates loosely as "wood used for snowshoes". The tough springy wood of this small to medium sized tree is also used for posts and poles because its high resin content provides good decay resistance. The James Bay Cree use tamarack twigs to make goose decoys which are true works of Canadian artisan craft.

Monday, November 16, 2009

A Big Tree

Sometimes beavers get pretty ambitious and try felling a really big tree. This isn't always successful, and it's fair to say that most of the larger trees tackled by beavers survive the experience, at least for a period of years. Ultimately the beaver may benefit, especially if wind finishes the job the beaver started.

Most of the bigger trees around Hinton are well within the capabilities of an ambitious beaver lumberjack. This picture shows a big black cottonwood on the floodplain of the Nechako River at Prince George, B.C. The beavers chewed away about 2/3 of the circumference of the tree, which I estimated at about 120 cm in diameter at the point of beaver attack. Eventually the beaver gave up, and the tree survived. The bark has since grown over part of the wound, so this tree has certainly survived a number of high wind events. There was an active beaver lodge less than 20 m from this tree. This beaver colony is still waiting for their windfall.

Our Green and Brown Fall

A normal Hinton fall sees the local aspen and balsam poplar trees in golden glory during the last 2 weeks of September and the first strong wind in early October usually strips the trees bare. 2009 was a very unusual year. First we had a late spring and leaf flush was at least 2 weeks later than usual. Then the summer and early fall was exceptionally warm and dry. By the end of September our deciduous trees were still green and the leaves were still strongly attached. Through October the leaves remained on the trees. Some turned golden but most either turned brown or a lighter shade of green. Eventually they fell, though mostly a month or more past their usual trip to the ground.

So what caused this? Were the trees trying to make up for lost time? Were they stressed by drought? Why did the trees fail to withdraw their chlorophyll from their leaves? Nobody knows for sure, but we certainly missed out on a normal fall. Next year I hope we return to normal. I love the rain of golden leaves and the "yellow brick road" on all the local trails.

Sunday, October 25, 2009

Anatomy of a Food Cache

In Finishing the Food Cache I talked about how beavers arrange their food cache to maximize the space available. Yesterday I got this close up picture of a small food cache made up almost entirely of willow branches. Click on the photo to see the fine branch tips radiating out from the underwater core of the cache.

The beavers anchored the branches butt-first into the mud and the branches are interwoven with each other. A skilled floral arranger couldn't have done a better job!

The second picture shows the small lodge near the food cache. Based on the grass on the lodge and the minimum amount of mud I think this was an older lodge that has been renovated. This colony is probably a pair of young 2 year old beavers that met and bonded this summer and are now getting ready to spend their first winter together. If all goes well this winter they may start raising a family next year.

Happy Creek Forest Fire!

I just got back from a run on the Happy Creek Trail. A little before 5:00 PM MST I came across a forest fire east of the trail on the east side of the creek. The location is about 1.5 km south of Maxwell Lake. The fire was about 20 m x 20 m and blazing almost to the treetops. Another 10 minutes of running brought me to the Beaver Boardwalk where I borrowed a cell phone and called 911 to report the fire.

Now I'm home and writing this post! The government folks are on their way out to the fire. I don't expect it will do much. It's pretty cool and not much wind. I'll get a picture of the aftermath and post it here in the next several days.

November 16, 2009 update

It turned out the fire I saw was an old cabin that was fully ablaze. The SRD folks went up the next day. They hauled in some fire hoses to soak the site and they cut down some scorched trees. Here's a photo of the aftermath.

The fire started in or around the cabin, which was completely destroyed. Fortunately the weather was cool and the forest was moist, so the fire didn't spread.

Beaver Trails

Most of the year beavers don't stray too far from the safety of water. All that changes in the fall when they strart putting up their winter food supply. Then it's necessary to travel overland to the groceries. Travelling the same routes each time and dragging back branches forms recognizable trails. Sometimes these are hard to capture in a picture. Yesterday I lucked out and found this trail network highlighted by a light covering of snow - in fact it was snowing when I hit the shutter button.

The second picture shows the overall layout of this beaver colony. The view is looking downstream from a road. I added arrows showing a dam, a bank lodge, and the location of the food cache. Click on the picture for a larger view. The open water in the upstream pond is being kept open by beaver activity, not water flow. Soon the cold will win and this colony will be iced in to just the lower pond, which is maintained by another lower dam not visible in the picture.

Friday, October 23, 2009

The Outdoor Classroom

Hexagon in shape, the outdoor classroom commands the best corner on the original phase of the Beaver Boardwalk. The idea here was to provide a larger area for small groups to use. Maybe it's a little small for a full school class, but that doesn't seem to matter. And who might have imagined what innovative uses might occur? I've personally seen yoga, a game of chess, and a watercoulor artist at her easel. Hinton Town Council has held meetings there, and someone told me that it was used once for wedding pictures. And yes, it's used by school groups. That's all great - just the kind of things I had in mind.

There's a story behind the hexagon shape. I thought that shape would be interesting and more efficient for talking to a group. The construction of a hexagon was another matter altogether. Fortunately for me, Mark Schoenberger and some of his kids volunteered just when I was trying to figure out the framing. Mark has a lot of carpentry experience and with his knowledge between the two of us we got the framing done in record time. Not bad considering there was about 6" of water on top of mud and ice at the time, which made for treacherous footing and more than one pratfall by both of us. We finished muddy and triumphant. Another great day building the boardwalk!

The Waterdeck

When we designed the 3rd phase of the Beaver Boardwalk I wanted to extend a short section into Maxwell Lake and build in seating so people could relax and enjoy nature. Originally I thought it would have to be a floating structure because I thought the lake bottom would be too soft to support posts. But that assumption was wrong, so the waterdeck is supported by pressure-treated posts just like most of the boardwalk is.

So for those who didn't notice, a little secret. I didn't want the waterdeck to be a great height above the water (remember my "close to nature" desire above). Turns out that I should have been a little more careful with my estimation. When spring came and the lake level began to rise it was pretty obvious the new waterdeck was soon going to be the underwaterdeck. There was nothing to do but admit error and raise the deck, which ended up being an enjoyable Saturday's work. I unscrewed everything and raised the whole structure by the width of a 2 x 8, which turned out to be just about right.

The extra benefit to that beautiful day was the chance to talk with a couple from Austria and a family from England who were enjoying the boardwalk and wanted to know what I was doing. They were very interested in natural history and I enjoyed chatting with them.

By the way, it's called the waterdeck because of a great suggestion by Beth MacCallum. She didn't think we should call it a wharf or a dock because we didn't want to encourage watercraft use of Maxwell Lake. Voila - the waterdeck!

Tuesday, October 20, 2009

Finishing the Food Cache

Warmer weather in the past week has opened up most of Maxwell Lake again, and the beaver colony is really working hard to get their lodge and food cache in top shape for the winter. I've given them a full pickup load of aspen each of the last 3 evenings. Normally it takes them 2-3 days to float that much aspen down to the lodge but lately they've been topping thier own accomplishments. Their rate of food removal has increased to a pickup load a day. All of the 11 beavers help build the food cache but the kits can't take larger branches - only the adults can handle those.

So besides the incredible work capacity of these amazing animals there's another marvel. How do they manage to cram 24 pickup loads of aspen branches into a compact pile that seems to take up no more room on the surface than a single pickup load of loose branches? Of course 11 beavers working so hard must need a lot of food, so it's not all in the winter food pile. But a lot of it is. Someday I want to go snorkeling around one of these food caches in the late fall. I'll bet there's an interesting sight to see.

By the way, I've been giving the beavers some pretty large logs just to see what they can handle. I don't know if they might cut some of these into smaller pieces or take them as they are, but logs of 8" diameter and about 8' long have disappeared. That's a pretty fair weight for me to lift, and I'm over 200 lbs. Even considering the log is floating in the water, for a 45 lb beaver to wrestle it with no problem demonstrates awesome strength.

Lake Tower

The 2nd observation tower was built in spring 2009 at the east end of Maxwell Lake as part of the 3rd and final constuction phase of the Beaver Boardwalk. This lake tower has two stories, with a separate section of boardwalk accessing the ground floor and an elevated ramp to the upper floor. The ramp ended up being considerably longer than planned to keep it on Town of Hinton property and still support wheelchair access. An unintended benefit turned out to be the birding in the willow canopy along the ramp. There were great views of many small birds such as this family of yellow warblers (photograph by Paul Higgins) that are often very difficult to see in the dense shrubbery.

So why two levels? Like the pond tower, the upper floor on the lake tower is for nature observation. The ground floor (actually it's the water level floor) is also for use by skaters in the winter. Skaters will have a place to sit and put on their skates or get out of the wind, and somewhere to stash their gear.

A few people have asked me why you can't get from the upper floor to the lower floor without going the long way around. I did think about putting in stairs (and I had a dream about a fireman's pole, which would have been fun!) but I abandoned those ideas pretty quickly. I couldn't see any way to connect the two floors without creating a safety issue. Wood stairs in the winter covered in snow aren't my idea of a safe undertaking. Take the time to visit each level - you won't be disappointed.

Saturday, October 17, 2009

Lumberjack Beavers

There's one drawback to providing so many pickup loads of aspen branches to the beavers each fall. Because they don't cut their own trees, nobody gets to see the results of their normal behaviour. Fortunately all one has to do is hike the Happy Creek Trail to see one of the active colonies upstream in action. This photo taken this afternoon shows a large aspen that the beavers have been working on. We counted more than a dozen large trees that were either felled or showing evidence of serious gnawing.

The second photo shows a large lodgepole pine cut about half through. Beavers don't normally cut conifer trees because they prefer deciduous species like aspen, balsam poplar, paper birch, and willows. In fact, cutting conifers might indicate not enough preferred food. Most of the aspen close to the upper Happy Creek ponds has long since been cut. Beavers will travel further from water, but this increases the risk they will be killed by a predator. There may be another reason to cut conifers though. I've noticed over the years that sometimes conifers and other non-preferred species like alder are placed on top of the food cache. This weighs down the preferred species that are stuffed underneath. When the pond freezes the ice isolates the capping and keeps the good stuff available below.

Beaver Lodge Armour

In the last week or so the beavers have plastered a thick coat of fresh mud on their lodge. The frozen mud will provide an impenetrable barrier to protect the beaver family during the winter. It would be pretty hard for a wolf or a late-hibernating bear to break through. More importantly, the mud seals air leaks and provides extra insulation so the body heat of the beavers can keep their lodge warm. OK, warm is a relative term. The recorded temperature inside one lodge in the depth of winter was 0.8-1.0 °C, or just about the same temperature as the water beneath the ice. Compared to outside though, which might be -30 °C or colder, it's a tropical resort. The beavers always leave a small area at the top of the lodge as a breathing hole. On a cold winter day one can see the warm air rising up through the hole, indicating all is well with the beavers below.

Here's the process. A beaver dives to the pond bottom and scoops up a big dollop between it's front legs, chest, and chin. Then it walks up the lodge on it's hind legs using the tail as a brace and balance. At the chosen spot the beaver slaps the load down and smooths it out with it's front paws. Then it's back to the pond, this time on all fours, to get another load. In this photo the wet line on the right side of the lodge is the path recently followed by a wet beaver.

In their book Wild Alberta at the Crossroads Marian and Robin White have a great picture of a beaver carrying mud.

Hooded Merganser Visit

This evening a male hooded merganser visited the beaver pond. He decided to preen on the food cache located beside the beaver lodge. I couldn't get a sharp photo and this one is the best of a blurry lot. Hoodies are pretty uncommon in the Hinton area and we usually only see them during spring and fall migration. Our area is near the northern limit of their Alberta distribution.

This second-smallest member of the merganser tribe feeds on small fish. By now he's probably full of brook sticklebacks from the pond. Hooded mergansers nest in tree cavities located near small woodland ponds. There are about a dozen pileated woodpecker cavities in the area, which would make good nesting sites. We also will be putting up nest boxes this winter. Wouldn't it be great to someday see a brood of hooded mergansers on Maxwell Lake?

There's a postscript to this story. When we came by 2 hours later there were 3 beavers around the lodge, and one youngster was curious about the stranger fishing beside the food cache. It followed the somewhat distraught duck around until he decided to escape by climbing out onto the food cache.

Wednesday, October 14, 2009

Berry Cold Birds

The interesting story this week is the many birds that got caught by the unseasonably cold and snowy weather we're "experiencing". The last laggards of the bird species known as short-distance migrants were still here when the Arctic blast arrived. Short-distance migrants don't head for Florida or more southern climes. They just go as far as they need to, which is why the greater Vancouver area (for example) has a lot of robins in the winter.

Now the stragglers are surviving on mountain ash berries, crabapples, apples, and the berries of the May bush. Most of them will quickly move on if the weather warms up as it's supposed to do in the next several days.

Rocky Morin took this "frozen moment" photo of a male American robin about to swallow a mountain ash berry. Other species spied in the past few days at the mountain ash U-pick are varied thrush, hermit thrush, and Bohemian waxwing.

Monday, October 12, 2009

Witch's Butter

Halloween is coming soon, so this picture I took of the witch's butter fungus on a dead pine log near the Beaver Boardwalk seems like a fitting subject. Apparently this jelly fungus, probably Dacrymyces palmatus, got it's common name because if it appears on decaying wood at your house you are supposedly under a witch's spell.  Witch's butter is actually a parasite of other wood-decaying fungi and gets no help from supernatural sources, but it does appear very suddenly after fall rains, as if by magic.

Most of the jelly fungi are reported to be edible, but I've never tried this one and I wouldn't recommend it or any other fungus unless an expert is involved in identification and assurance. Mushrooms and other fungi don't have much nutrition value, so never take a risk unless you are sure. You won't starve without them, and you could get very ill or even dead with them.

Sunday, October 11, 2009

A Beaver Family Who's Who

A question I hear often is "How many beavers are there?' Before I answer that let's look at beaver social structure, which is built around a family, also called a colony. A colony consists of an adult male and female plus their offspring from the past 2 years. When young beavers reach their second birthday they leave the parent colony and wander far and wide seeking a mate and a place to set up their own colony.

Back at the home colony, the adult female produces a new litter of usually 3-4 beaver kits every year. The number of kits depends on the body condition and age of the adult female. If she is young or in poor condition fewer or no kits will be born. I know the Maxwell Lake beaver colony had at least 4 kits in both 2008 and 2009 because I saw 4 kits at one time in both years.

The next consideration is the fact that beavers are very territorial. All members of the colony defend their territory against any strange beaver, so all beavers seen in Maxwell Lake and upstream and downstream along Happy Creek for a few hundred meters are members of the Maxwell Lake colony. There are several other colonies further up Happy Creek above the powerline crossing .

Now we have all the pieces to answer the question. Assuming all the kits survived, there are at least 10 beavers in the Maxwell Lake colony. I've personally seen 7 at once in 2009. There could be more than 10, but that's my best estimate.

Update October 20, 2009 This evening I saw 5 kits at the same time, so I'm upping my estimate to 11 beavers for this year: 5 kits, 4 yearlings, and 2 adults.

The best time of year to count beavers is from June-August after the kits are born and are active around the lodge. That's when the size difference between the adults, yearlings, and kits is most pronounced and a minimum count of each category is most reliable. Dave Conlin took a great photograph of a Saskatchewan beaver family with 8 members. Check it out and make your own estimate for the Maxwell Lake beaver colony in 2010!

Thursday, October 8, 2009

Maxwell Lake on a Snowy October Day

The first photo was taken this afternoon just after I gave the beavers yet another load of aspen branches. I've lost count but I think that's number 16 for this year. I marvel at how they tow off all those branches and pack them into a compact food cache pile at their lodge. This evening there were 3 beavers there waiting, and even me tossing the branches into the lake didn't dissuade them.

One big beaver couldn't wait. A few seconds after the lake photo was taken, it dragged a good sized branch down to the lake (second photo) and towed it off. Free food is great, but a busy beaver doesn't wait if the load is a little late. The instinct to store food is very strong. The colony members will keep storing food until the lake freezes over and they are locked into their winter routine by a shell of impenetrable ice.

Do Beavers Eat Wood?

Trick question - it depends on what your definition of wood is. Let's take an aspen branch for example. The beavers absolutely love the leaves, small twigs, and bark. But as soon as the twigs get to the diameter of a baby pinky finger the beaver starts to peel the bark off, leaving the white twig behind, as shown in the 2nd photo. So the answer is more or less no, they don't eat wood. This makes sense when one looks at what food value wood has to a beaver. The wood is mostly indigestible cellulose bound together with lignin. Great fare if you're a termite, but not so much if you're a beaver who has trouble digesting cellulose.

Are the leaves, twigs, and bark much better? Well yes they are. They contain most of the nutrients in the aspen branch and there is much less cellulose. Probably they taste better too, at least to a beaver. A beaver's stomach has lots of bacteria that help to digest their food but even so it's a tough job to digest coarse plant material. The first time through the digestive system produces a soft pellet which the beaver eats. A second digestion pass extracts more nutrients before the final pellet is produced.

Sunday, October 4, 2009

Happy Creek Trail

The Beaver Boardwalk is located where Happy Creek and Maxwell Lake come together. The Happy Creek Trail was built by West Fraser about 15 years ago. It starts on either side of Happy Creek off the gravel Town of Hinton Trail near the Pond Tower, loops upstream over 3 km along a series of beaver ponds, crosses the creek on a footbridge, and returns downstream. The Happy Creek Trail is well used by walkers, runners, and mountain bikers.

Working with West Fraser, the Hinton Mountain Bike Association helps to maintain the trail and signs. For single-track bike enthusiasts it's a challenging trail. I'm told only a few local expert bikers are able to ride the entire trail without getting off their bike. Personally I love to run it. There are lots of ups and downs, roots to trip over (which keeps me on my toes - most of the time), and a micro-wilderness experience on the outskirts of Hinton. Combine that with at least 3 active beaver colonies and the dams and ponds they maintain and you can't beat it.

Mallard reflection

Every visit to the Beaver Boardwalk is a chance to see a special moment in nature. Last week I spent an enjoyable 15 minutes watching this mallard hen preening on a log. Although I was only 10 m away she clearly thought keeping her plumage in good shape was more important than worrying about me.

I snapped a series of photographs and took a couple of short videos. Although it's not as sharp as I'd like, this photo showing her reflection in the cold pond water was most pleasing to my eye.

Grand Opening Summary

On a warm September 15, 2009 we celebrated completion of the Beaver Boardwalk after 3 years of dedicated effort by a lot of folks. The kick-off was at the Reimer Drive trailhead where the partners congratulated all who contributed funds, time, and support to make the project a reality. We also announced the winners of the children's colouring contest (more about that in another post) and Beth MacCallum and I led a walking tour of the new sections.

After the tour I gave a talk on beavers at the Hinton Library attended by about 50 people. Then the day was topped off by several dozen people watching the beavers munching on fresh aspen at Maxwell Lake. At one point I counted 42 people there, and all the while up to 6 beavers were tucking into supper. The photo shows the watchers - the beavers are over the bank in the centre right.

Saturday, September 19, 2009

Beaver Feeding Time

The fourth annual beaver feeding program got underway on August 23 and will run until about the middle of October. As I write this post 8 pickup loads of aspen branches have been cut along roadsides where they aren't wanted, trucked to Maxwell Lake, and dumped into the lake at the picnic tables by the east end of the Maxwell Lake Apartments. The beavers take over from there, feasting and hauling away the branches to build their winter food cache beside their lodge west of the lake.

Why do this? Well, it's fun! The beavers are used to humans and feed on the leaves, twigs, and bark while people are standing a few meters away. But more importantly, supplementing their food supply reduces damage to deciduous trees around the lake and ensures the Maxwell beaver colony will continue to live in the area. Beavers aren't great conservationists - they often exhaust accessible winter food supplies over a period of several years and then have to move on. Either that or they have to travel further from water and increase risk of predation by a hungry wolf or bear.

I give the beavers another pickup load every 2-3 days. Come out at dusk for the best chance of viewing. Hope to see you there!

Thinning the Thistles

The Canada thistle is an attractive plant - lush green foliage and purple flowers. But it's invasive and very hard to control once it's established. Unfortunately thistle got a foothold several years ago along the beaver dam and the perennial plants were increasing. New shoots come up from the underground roots each spring.

Pulling the plants just makes the roots put up more shoots, so Rocky Morin, Beth MacCallum, and I spent several hours clipping the plants just as they started to flower. The idea is to let the plants put energy into growth and then remove the above-ground parts before they can seed or send energy back to the roots. In theory over several years that will do them in, and at the very least it gives other plants a chance. We took away two pickup loads this year. I sincerely hope it will be less next summer! Thanks Rocky and Beth for your help.

Monday, August 3, 2009

Pond Tower

I'm going to include pictures of some of the Beaver Boardwalk features in a series of blog posts. The first feature is the observation tower overlooking the main beaver pond, built in spring 2008. It was an instant hit with visitors. Lucky or patient folks were often rewarded with a bird's eye view of the beavers below them. Here's two examples from my personal observations:

Last June an adult beaver cut a willow branch and proceeded to eat the leaves, bark, and tender twigs right below the tower. In typical beaver fashion, it left a small uneaten portion for the next family member. Sure enough, within 10 minutes after the first beaver left another came to finish the meal. Then it went off to find a main course of its own.

Last September, two beavers spent more than an hour diving to the bottom and gathering armloads of mud to repair and armour their lodge for the winter. The beavers waddle up the lodge on their hind feet to plaster their load of mud. Always a breathing hole is left un-mudded near the top of the lodge. I'm sure the beavers must be able to sense the location of the hole, perhaps by smelling or feeling the warm air coming up from below.
The pond tower is a great place to spend some quality time. Take a pair of binoculars and some patience and you will soon be rewarded with amazing glimpses into the lives of the wildlife of the Beaver Boardwalk.

Maxwell Lake Ducklings

Good news! Last winter's break in the beaver dam that lowered Maxwell Lake about 50 cm and the very cool spring including a significant snowfall in early May didn't affect waterfowl reproduction in 2009. Right on cue in early July two ring-necked duck hens appeared with broods of ducklings. One hen had 6 little ones and the other had 3. A few weeks later two mallard hens also showed up with ducklings in tow. One mallard hen had 5 ducklings and the other had 4. The mallard ducklings were already fairly large when first seen, so they could have come down Happy Creek from the beaver ponds upstream.

Four broods of young ducks is about normal for Maxwell Lake, and ring-necked ducks and mallards are the species that usually nest there. Buffleheads are fairly common spring visitors, so in an effort to encourage these cavity-nesters to stay and raise a family I'm going to put up several nest boxes this fall. Other cavity nesting ducks such as goldeneyes might also use the boxes, and many other species will find them useful. More about those in a future post.

Wednesday, July 8, 2009

Grand opening September 15

Book your calendars for Tuesday September 15 and join us to celebrate the completion of the Beaver Boardwalk! Plans are still being developed, but here's what we have so far. The first 3 activities will be at the Reimer Drive boardwalk access at the east end of Maxwell Lake, starting in late afternoon.

Colouring contest winners
Official ribbon cutting
Beavers - slideshow at the Hinton Library
Dusk viewing of beaver feeding at Maxwell Lake

This is a community event that is open to all. Watch for further details coming over the next few months.

4 new signs coming soon

Work has begun on 4 new interpretive signs for the Beaver Boardwalk. Two of the signs will incorporate art from the children's art contest that recently concluded. The 1st will feature flowers of the boardwalk and the 2nd will look at larger mammals - the coyote and the white-tailed deer.

The other 2 signs will highlight waterfowl and owls of the area.

Speaking of owls, recent sightings of barred owl and great gray owl have excited birders. Other owl species recorded in the area are saw-whet owl, boreal owl, and northern pygmyowl. These last 3 species are very small and nest in old woodpecker cavities. We don't yet have a confirmed record for great horned owl, but it's likely this large owl frequents the area as well.

Thursday, May 28, 2009

Construction completed

Tuesday May 26 was a great day. Rocky Morin finished the last remaining section of boardwalk construction south of Maxwell Lake. There are still some new signs and metal brackets on the lake tower to come, but the boardwalk itself is complete. Thanks to Rocky and all the other volunteers this year we built the most ambitious of the 3 phases on budget and ahead of schedule.

Overall we now have 3 km of continuous boardwalk to enjoy, with main access from either the Sutherland Avenue or Reimer Drive trailheads. This completes the Beaver Boardwalk project. There are no plans to expand in the future.

If you haven't already checked out the new sections please give the boardwalk a visit. I'm sure you will be pleased.

Raising the Waterdeck

OK bad pun, but there was no way to call if a roof. The beaver dam at the west end of Maxwell Lake broke last winter, draining the pond. And because the dam contols the level of Maxwell Lake, the lake dropped by more than 2 feet. When we installed the new wharf we had to estimate how much the water would come up when the beavers repaired their dam. I underestimated by about 4 inches.

Last Saturday the lake was back up to within a few inches of the wharf boards and waves were already slopping onto the deck. So I spent a day removing the deck, adding another layer of 2 x 8 joists, and then replacing the deck. Now we have several inches of freeboard.

I've had people ask what would happen if the beavers build their dam higher. They aren't likely to do that because they would flood their own home inside the lodge, which is only a few inches above the water. If the beavers decide to renovate there is a safety valve at the east end of Maxwell Lake. When the beaver dam is full the excess water flows both over the dam and out the east end of the lake toward the Hardisty Creek watershed. So even if the beavers raised the dam the water level wouldn't go higher. They wouldn't dam the east end of the lake because the water isn't flowing noisily. Beavers build dams in response to the sound of running water. No noise, no dam.

Friday, May 22, 2009

Fly-catching warblers

On Wednesday May 20 I walked the Maxwell Lake portion of the boardwalk just after lunch. The 25 cm of snow we received on Monday was still melting, and a lot of birds were taking advantage of the bare areas around the lake. The highlight was dozens of yellow-rumped warblers (maybe as many as 150 in all) along the lakeshore all around the lake. The warblers were fly-catching and gleaning for adult chironomids.

I watched warblers fly under the decking on the boardwalk to pick off chironomids clinging to the stringers. The birds were very tame and allowed me to approach within a few meters. Later that day I found a dead male yellow-rumped warbler that didn't survive the storm. Perhaps that's why the birds were so tame - they were likely desperate to find food and the chironomid hatch must have seemed like a feast to them after days of snow and cold.

Construction is almost done

It's been awhile since my first post. A lot has happened and we have been very busy indeed. Most of the 3rd and final phase of the beaver boardwalk has been completed. About 100 m of decking on the connector south of Maxwell Lake remains to be fastened down. Add curbing and the bulk of the construction will be done, hopefully by the end of this weekend. Special thanks to
Rocky Morin who once again took care of the lion's share of the construction.

Celebration! But the work isn't all done yet. I underestimated how much the water level dropped in Maxwell Lake last winter when the beaver dam broke. Now the new goose nesting platform is underwater. Good thing the geese decided to nest elsewhere this year. Do you think they may have known something? Raising that will have to wait for the winter.

And we're down to about 3" of freeboard on the new wharf. So this weekend we're going to unscrew the decking and add another layer of stringers to raise the wharf about 7". That should keep the wharf higher than the lake will likely rise.