Sunday, November 7, 2010

Tallest Beaver Dam?

Beaver dams are amazing constructions of wood, rocks, and mud that dwarf their makers. Apart from termite mounds they may be the tallest structures made by animals other than humans. Unfortunately there aren't many measured records of dam-building champs to rely on. I've heard reports of and found dams that were about 12 feet (about 3.7 meters) tall but I've never seen a study describing dam dimensions and the folks at the Guiness Book of World Records don't seem to be too interested in beaver dams.

The photo with this post shows a tall beaver dam from Algonquin Park in Ontario. Using Norma as a guide (she's 64" tall) and considering she's not standing at the lowest base of the dam I estimate this dam is pretty close to 10 feet tall.

Feeding the Beavers 2010

This fall marked the 4th year of my annual fall beaver feeding program. I do this to reduce damage that the beavers do to trees that people don't necessarily want to lose, and to ensure that the beaver colony doesn't eat all their food supply. And the feeding program creates a great opportunity to see the beavers at their food gathering best. Despite the free food, the beavers cut quite a few trees of their own this fall. I'm going to count them and make that into the subject of a future post.

This year I gave the beavers 32 pickup loads of aspen and balsam poplar branches. The photos show one load. It might not seem like much, but the aspen saplings shown in the lake are about 5 m long. That's a lot of branches for me to haul. What's truly amazing though is the removal rate by the beavers. This particular load was dropped off in the late afternoon and it was entirely gone the next morning. Working through the night, the beavers cut up and hauled off the entire load, floating the loot about 300 m from the depot to the food cache they built beside the lodge. Of course all that work takes lots of energy, so the beavers are eating a lot of food as well. What amazes me though is how they take 32 loads like this and make them into one pile at the lodge. The underwater architecture of that pile must be amazing to cram so much into such a small space.

Sunday, September 19, 2010

Plastering the Lodge

Beaver winter preparations include additions to the lodge. There are usually some more logs and branches, but the main ingredient is a fresh coating of mud. When frozen the mixture of mud and wood becomes pretty much impenetrable armour for any predator that might try to break into the winter safehold. It's a little comical to watch the plastering process. The beaver dives to the bottom and scoops up a huge wad of wet mud. When swimming with this load the beaver is front-heavy and tends to sink, so more often the beaver surfaces right where it intends to exit the water. Standing upright on it's hind legs and using the tail for support, the beaver more or less waddles up the lodge to just the right spot.

I've yet to get really good photos of the lodge plastering. These two show a beaver just out of the water with the mud just visible, and a beaver high on the lodge about to dump it's load.

Thistle Clipping 2010

Last year volunteers clipped 2 heaping pickup loads of Canada thistle along the beaver dam while the plants were flowering. The idea was to remove the plant while all of it's energy was devoted to flowering but not to stimulate the roots to end up new shoots. Pulling the plants would have that effect - clipping is more time consuming but doesn't stimulate the roots. Over time, other plants should be able to out-compete the weakened thistles, and they should either die out or become much reduced.

The plan seems to be working. I finished clipping just one pickup load of thistles last week. So in a single year thistles have been reduced by half. And also where the thistles were still growing they didn't dominate the plant community like they did last year. Other plants are getting a foothold. I hope this positive trend continues next year!

Saturday, September 18, 2010

Fall Migration is Underway

Migrating birds wind up in unusual places. Every fall a few birds not usually found in this area stop at the Beaver Boardwalk for a brief rest or visit before moving on to their winter range. In the past several weeks I've seen long-billed dowitcher, pied-billed grebe, horned grebe, and sharp-shinned hawk. Yesterday evening an immature common grackle flew in to roost in the tall shrubs near the beaver feeding area. That was a surprise and I think the first record of common grackle at the Beaver Boardwalk. The horned grebe was a new record also. The list of birds observed at the Beaver Boardwalk continues to grow and now includes more than 150 species. The Whisky-jack Club maintains the official list and publishes a brochure updating the records as they come in.

Red-necked Grebe Rescue

September 14 was a pretty miserable day - cold and raining hard. Numerous puddles and the wet ground fooled a red-necked grebe into thinking the log yard at Hinton Wood Products sawmill was a water body. Not so, and once on the ground the grebe wasn't able to get airborne again. Grebes and loons must have water deep enough to get a run at if for liftoff. They patter across the water surface building speed using both their wings and their feet. For this purpose, the shallow puddles in the log yard wouldn't do.

Fortunately for the grebe, Dave Wallace, Neil Holder, and Morris Archibald came to the rescue. They caught the bird in a fishing net and deposited it in a cardboard box. Of course the bird didn't know they had good intentions and was quite indignant about the whole affair. A bit of a rodeo, according to the guys. After a short drive Morris opened the box at the Beaver Boardwalk and the grebe got a new start on Maxwell Lake. It was gone a few days later, probably carrying on with fall migration.

Dave Wallace took the photos with this post. The first shows the bird on the ground, and the second shows Morris releasing the grebe at Maxwell Lake.

Sunday, August 22, 2010

Beavers Grooming

Beavers spend a lot of time grooming their luxuriant fur to keep it clean and waterproof. The waterproofing comes from an oil they secrete from their anal glands and comb through their fur using a split claw on their hind leg. Recently it's been easy to see beavers grooming over at the feeding station by the Maxwell Lake picnic tables. After the free feast they gather as singles or small groups and set about the serious business of grooming. Sometimes they groom each other. Sometimes a youngster wants to play, and the older beaver decides to move and groom somewhere else. In this photo 3 yearlings have finished eating and have started to groom, while the animal on the left is still having dinner.

Tuesday, July 27, 2010

Beaver Photographers

The Beaver Boardwalk is starting to attract the attention of some pretty serious photographers. Last fall renowned Vancouver wildlife photographer Norman Rich (check out his amazing photos here) came for a visit, and I hear he plans to return sometime this summer. This evening 3 photographers from Jasper with some impressive camera equipment were here taking beaver photos. Our beavers are so used to a human audience they go about their business at close range and often in broad daylight. And the boardwalk gives great access to their living space. There probably aren't too many better places to get great photos of wild beavers in their natural habitat than right here at the Beaver Boardwalk.

Beaver Balancing

That amazing beaver tail serves many purposes. When a beaver wants to eat while floating it has to raise it's head a little higher than normal so it doesn't get a mouthful of water with it's food. That tends to sink the middle of the body. To remain floating neutral and balanced, the beaver arches it's back and raises it's tail. An adult like the animal in this photo only needs to raise the tail to the water surface. Smaller beavers will actually raise their tail right out of the water. It's a somewhat comical sight. I'm sure the beavers don't care - floating with no effort while dining is what they are after, and that amazing tail makes it easy to do.

Summer feeding

Just for fun I hauled a couple of loads of fresh aspen branches to Maxwell Lake in July. The beavers didn't take long to find them, and even though it's still a month from food cache building time, they took advantage of the free feast. The photo shows 3 beavers happily munching. The animal in the lower left is an adult, and the other two are yearlings (born in 2009). I haven't seen any young born in 2010 yet but I'm sure they've been out for at least short periods around the lodge already. I still see beavers taking green branches into the lodge so I'm assuming that meals are still being served in the dark and cozy kit nursery.

Friday, July 16, 2010

Dam Maintenance

The beavers have started repairing their dams with a fresh coat of mud, perhaps in response to the recent rains and higher water levels. This evening about a dozen people watched at very close range as an adult repeatedly dove for arm fulls of mud to place on the dam. A boil of bubbles marked the location of the underwater beaver's excavation, and then a line of bubbles marked underwater progress toward the dam. The beaver surfaced just before the dam, with it's head pretty low in the water. That top-heavy load of mud must be pretty hard to swim with!

I noticed that the beaver often closed it's eyes while carrying and placing the mud - perhaps to protect against debris. The technique was pretty simple - the beaver simply pushed up on the dam, using it's chest to bulldoze the mud, and then it's front paws to distribute the load to it's satisfaction.

The first photo shows the load of mud, and the second shows the load being pushed up by the beaver's chest.

Sunday, July 4, 2010

Construction Completion

On July 1, 2010 I put up the last 3 Welcome signs and the last 5 You Are Here signs. That brings to completion all of the construction work for the Beaver Boardwalk. I don't have anything left to do that I wanted to do. Guess it's fitting to finish it on Canada Day, 4 1/2 years since the start. I sure didn't think it would go on that long when I got the original idea, nor did I think it would get to be such a big project. The reward was just as much in the work as it was in the achievement. It gave me something to focus on, and I met a lot of great people who volunteered their time to help.

The best reward though is seeing people using the Beaver Boardwalk and enjoying themselves. While I was putting up the last sign at the east end of Maxwell Lake I met a couple visiting from somewhere non-local (I forgot to ask where). It was mid-morning so they hadn't seen any beavers and were a little disappointed. As I was installing the sign they walked the lower path to the lake tower. I could hear an upset sora over there. When they came back they asked if I knew what that small bird with the bright yellow bill was - a sora had walked out right in front of them at very close range. They were thrilled. For those who don't know the sora, it's a small very secretive bird of freshwater wetlands. Although it's the most widely-distributed member of the rail family in North America, it's much more often heard then seen. There's always special moments on the Beaver Boardwalk!

Monday, June 28, 2010

A Beaver to Touch

I'm always amazed by some of the beaver behaviours I see. Beavers like to eat their supper in peace and quiet, and shallow water they can put their back feet down in is always a good choice. That lets the beaver use it's front paws to manipulate the food item. But what to do when supper is in a small shallow pond with people walking by? Simple - take your willow branch under the boardwalk. This young beaver figured out of sight was out of danger. It wasn't just hiding under the boardwalk - it was quite happily munching. And it didn't stop even when I stood on the boards it was hiding under. I'm sure it knew I was there. After several minutes of being amazed at this, I couldn't resist putting my finger down between the boards to touch the beaver on the back, just to see what would happen. Nothing - beaver simply kept on with the meal. Now how often can one claim to have touched a wild beaver? That's a first for me!

When the beaver was finished it came out from under the boardwalk, saw me, and promptly dove. Not for long though. It swam alongside the boardwalk for about 15 m and then came up again underneath. This must have been a routine, because there was another willow branch already there, and the dinner continued. Two other people came by and we all marvelled at the beaver beneath our feet. The first photo shows the original willow branch just disappearing under the boardwalk, and the second shows the beaver's rich chocolate fur between the boards. Click the photo to see a closer view.

Ring-necked Duck Drama

This evening a ring-necked duck hen accompanied by 10 active youngsters was minding her own business at the west end of Maxwell Lake. Then she was ambushed by 2 aggressive males. They chased her and wouldn't leave her alone. At one point one of the males climbed on her back, perhaps in an attempt to mate. Her brood was scattered, although they didn't seem to mind and continued to catch insects along the shoreline and over the lily pads. The photo shows the males, the female, and one duckling in a calmer moment. Eventually the female retreated to the sedges and the males flew over to the beaver pond. I checked again about 15 minutes later and 6 ducklings were still foraging. The others and the female were probably out of sight in the sedges.

Saturday, June 26, 2010

A Slap-happy Beaver

Beavers slap their tails on the water when they are upset about anything they view as a threat. The loud noise may startle an animal and it also warns other beavers about the danger. The Maxwell beaver family is pretty tame and normally it's members don't slap their tails a lot at people to indicate their alarm. The beaver colonies further up Happy Creek are another story. Those beavers don't particularly care for people at close range, and a large adult let me know it last week, swimming back and forth and slapping repeatedly while I sat on the bank nearby and tried to capture the action in photos.

How can you tell when a beaver is going to slap? First off, they swim with their head much higher in the water than usual, as shown in the first photo. After the first slap swimming back and forth is a sure sign of continued agitation. It's really hard to time the actual action because it happens so fast. I got a decent photo of the early part of the slap - the beaver initiates a dive which raises it's tail above the water and produces speed. As the beaver continues the dive the flat tail whacks the water hard.

Unfortunately I wasn't able to get a good picture of the height of the splash. This somewhat blurry frame was the best I could do. The splash is pretty impressive, and the noise carries a long way. Often the beaver surfaces again right away and continues to swim back and forth slapping until the intruder leaves. Other times the beaver simply disappears - either swimming underwater to a burrow or lodge or simply holding it's breath while wedged under some underwater anchor like a log. I once watched a beaver who had slapped and then stayed under a log for over 10 minutes. I could clearly see the beaver remaining still under the submerged log. I left because I really didn't want to see how long a beaver could hold it's breath and I'm sure that beaver agreed with me.

Bufflehead Broods

It looks like no ducks nested in the Maxwell Lake nest boxes I put up this spring, but I had much higher hopes for the 4 boxes up Happy Creek. All were well attended by bufflehead and I'm pretty sure they were occupied. I won't know for sure until this winter when I open the boxes to clean them. That's when I'll see if there are any eggshells inside.

Last week my watching was rewarded with two bufflehead broods near two of the nest boxes. The first hen had 10 tiny ducklings and the second had 8. There are still bufflehead hens near the other two boxes, so they might produce little fluffballs yet.

I haven't had much luck getting a good photo of the broods. This photo shows the bufflhead hen with 8 ducklings. Also on the Happy Creek ponds are two mallard hens, one with 2 ducklings and the other with 9.

Saturday, June 19, 2010

Goats and Groundhogs

Eight days ago I was lucky enough to get into good position to watch a mountain goat nanny with a new kid feeding in the trees below me on a steep slope. Although I was only about 30 m from the goats they had no idea I was there. Unfortunately the dense vegetation didn't make for great photography opportunities, but I did get this "window in a wall of green" shot of the kid.

While I was waiting I heard a sound to my left. The noisemaker turned out to be a marmot (also known as groundhog or woodchuck). Marmots are pretty uncommon sights in our area, especially in forest habitats. This marmot cautiously moved to the entrance to it's den, where I took the second photo that shows both the marmot and the goats in the same frame. You never know what you will see when you stand quietly in the forest.

Tuesday, June 15, 2010

Mallard Family

This hen mallard with 9 ducklings appeared on Maxwell Lake over a week ago, which is pretty early for ducklings around here. Many have seen her since as she's quite tame and let's people approach fairly closely. On Saturday evening I got a chance to take some photos of her with brood as the light was fading. The ducklings are growing rapidly and are more than twice as big as they were when they first appeared.

I'm still seeing ring-necked ducks on the lake so I'm hopeful that we'll soon see a few broods from them as well. And bufflehead broods from the new nest boxes up Happy Creek are a virtual certainty. I'm pretty sure all 4 boxes are occupied.

Wednesday, June 9, 2010

June Hail

Yesterday around dinner time the Hinton Hill District was treated to a really strong storm cell. Pea-sized hail followed by heavy rain. A real frog-drowner, as a friend once said. By the time I got home from work there was about 5 cm of hail on my front lawn. The hail severely damaged the newly sprouted leaves on deciduous trees and neatly plucked the small new candles of spruce needles from a tree beside the house. All the bedding plants my wife put out over the weekend were thrashed.

At 10:00 PM I went over to the Boardwalk to see if there were any changes. Happy Creek was raging at bank full depth, and the beaver dam was overflowing at many places. Two beavers were swimming back and forth watching for big leaks, but otherwise they weren't attempting to repair the flows. The dam is designed to take floods in stride - the excess water washes over but doesn't breach the dam.

At Maxwell Lake 3 more beavers were either feasting on water lily pads or up on the bank bending over willows to eat the new leaves. I watched two up on the bank about 10 m away for 15 minutes as the light faded and the mist after the rain wafted over the lake. Then a barred owl called 3 times from across the lake. A fitting end to an unusual day.

Sunday, May 30, 2010

Beavers on Cue

Friday evening was cool, cloudy, and wet - not the best weather to tour tourism folks squired by Ashley Kalk from the Town. We met about 6:15 PM and walked the main beaver pond and the upstream loop. At the start I mentioned that beaver sightings were pretty much guaranteed in the late evening, but we might be a little early for today. As we only had 20 minutes for the tour I hoped at least one would be out and about.

Sure enough, a yearling was swimming in the main pond between the lodge and the dam. One woman said that was the first beaver she had ever seen in her life. She was thrilled. We watched for a few minutes and then quickly walked the upstream loop, where we encountered an adult. This beaver swam right alongside us, came out of the water to browse willow leaves, and clipped a willow to continue it's supper in shallow water beside the dam. All of this was less than 10 meters from 8 excited people.

Our last stop was at the observation tower, where 4 beavers were active in the waters below. One climbed up on the lodge with a load of mud. Needless to say, the duration of the tour got extended a bit by all the beaver watching.

Wednesday, May 26, 2010

Coltsfoot is flowering

Queen Victoria's birthday was kind in 2010. We didn't get snow on the long weekend, at least in Hinton town. But the hills and mountains had a fresh white coat and it was pretty cool. Pretty typical. That doesn't take away from the hardy early spring flowers, which are used to the occasional snowfall. The flower stalks of the palmate-leaved coltsfoot Petasites palmatus are blooming along the Beaver Boardwalk right now. With this species it's hard to connect the characteristic palmate leaves with the flowers, because the flowers appear before the leaves. The young flower stalks and the leaves are edible. If you'd like to try them please don't pick near the Boardwalk, and only take a portion of the plants in any area so they will continue to grow there.

Interestingly, the palmate-leaved coltsfoot leaves are far more common than the flower stalks. It's a very common forest floor sight, but most of these plants don't have enough sunlight to flower. The genus name Petasites means "wide-brimmed hat", which refers to the large leaves.

Wednesday, May 19, 2010

Waterfowl Sign

The last of the 3 new signs put up last Saturday was the waterfowl sign. Still to come is the large mammals sign, but first we need to replace the plywood backing, which was damaged over the winter.

Wildflowers Sign

Here's the new wildflowers sign. I apologize for the resolution of the image on these. I haven't figured out yet how to get a high quality .jpg from the .pdf original. When I do I'll replace these low quality versions.

Owls Sign

The last of the 12 interpretive signs recently arrived from the production company, and I put up three of them last Saturday. I'll do a series of short posts to publish them on the blog. The first one shows some of the owls that frequent the boardwalk. A walk in late evening or a calm moon lit night is a good chance to hear one or more of the local species. I'm also planning to put up a few owl nesting structures this coming winter.  The locations of those will be secret because owls like their privacy when they are nesting.

Tuesday, May 18, 2010

Loons on Maxwell Lake

Another loon has joined the bird that's been on Maxwell Lake for over a week now. Perhaps this is the pair that nested last year on nearby Thompson Lake about 1 km east. Or maybe it's another pair that is not going to breed this year or just resting on the way to somewhere else. Regardless, it's nice to see loons visit even if they will probably decide not to stay. I'm sure they are both feasting on the plentiful sticklebacks in the lake.

Two days ago I walked around Wildhorse Lake and enjoyed the loud calling between 2 pairs of loons, along with the creaky caterwauling of several pairs of red-necked grebes. One loon pair escorted me by swimming alongside as I walked the shoreline trail. They did a lot of calling at one point and I wondered if I might be near a nest, but I couldn't see any likely spots. Loons nest very near water because their legs are located too far back for good mobility on land.

I saw a website poll a few days ago that is collecting suggestions for a Canadian National Bird. The red-tailed hawk was leading the poll, followed at a distant second tie between the Canada goose and the common loon. In my opinion it's no contest - the loon is the quintessential Canadian bird. After all, it's on our money and we nickname no less than two of our coins after the loon.

Saturday, May 15, 2010

A Log in the Forest

A morning or evening walk in mixedwood or deciduous forest in late April or early May often yields a spring icon - the drumming of a male ruffed grouse. Have you ever attempted to sneak in close enough to see the drumming male? It can be surprisingly difficult. The grouse is out to impress the females, but he isn't too keen to end up on some predator's menu while he beats his ardor to the world.  Fortunately, the grouse is a creature of habit. He has a favourite log to drum on, and he will return to that log over and over again, even between years. If one flushes him from his log and sits and then waits patiently nearby (but not too close) he may return fairly quickly. Even better is to locate the log, and then get there ahead of him to await his next session.

If you don't see the grouse leave his log, keep walking and look for an accumulation of droppings and a worn look, as shown in the photo with this post. Older logs with some rot are favoured, and so are logs located in cover (the better to discourage predators).

Back in high school a friend and I headed to our favourite lake for a fishing trip. We got there after dark, pitched our tent in the forest, and turned in. The wake-up call came at about 4:30 AM. In the dark we had inadvertently tied our tent rope to a ruffed grouse's drumming log. That particular grouse wasn't going to let a minor thing like a tent deter his schedule. At close range the drumming is really loud. We wanted to sleep, so we shooed him away. He was back within 15 minutes. After 2 or 3 repeats of this exercise we gave up and got up. And we moved our tent so he could have his log to himself the next morning.

How to Find a Goose Nest

Canada geese often nest in very conspicuous locations. But not always. Years ago I spent an enjoyable 7 springs searching for goose nests along the Columbia River in B.C. and learned a lot of their preferences. Usually a single goose in the spring is a good indicator that there's a nest not too far away. A secretive single goose is a smoking hot sure thing. Usually that single goose is the gander and he's not too far from the nest - in fact he can usually see it from his watch position.

Next comes a mental picture of the kinds of sites the goose chooses for her nest. She likes privacy but also wants a good view of her surroundings. A small island or isolated penninsula is ideal. Her brown plumage blends in with the dry grasses and other muted colours, and she hides that spectacular black head with the white markings by putting her head down and remaining very still when an intruder is near.

So putting all this together, recently I surprised a gander at close range on an old beaver pond. He had his head down when I first saw him which means he saw me first but didn't have time to do a better job of hiding. The photo shows him after he knew I had seen him and he's just about to leave. He left silently instead of the usual loud honking exit, which is another tip-off a nest was near.

It didn't take me long to find the goose on her nest. She was on top of an old beaver lodge only about 40 m from the gander. You might have to zoom in to the second photo to see her right in the middle of the frame.

She's pretty hard to see, isn't she? But not hard to find at all if you know what to look for. The goose will hold very close to her nest as long as she thinks you haven't seen her. I've seen people walk right by a nesting goose in plain view within a few meters and never see the goose. Look at her though and she's gone, and she leaves loudly. If you aren't expecting it, you could get a pretty good startle! When she leaves the gander will immediately fly to her and both will remain very upset and vocal until the intruder leaves the area.

Wednesday, April 21, 2010

Aspen leaf flush

Nature sometimes acts pretty fast. This morning I drove to Edson for a meeting. By the time I returned in mid-afternoon leaf flush on aspen trees was obvious. No sign of green in the morning, and I was looking for it. Of course the fact that today was an extraordinarily warm day probably had something to do with the accelerated appearance of leaves. The thermometer at my house said +27 at 5:00 PM.

Leaf flush isn't even. Only some trees are turning green, and often they are in clumps. The clumps are actually clones - all genetically identical with a common root system. Each clone has it's own clock. Some turn green a week or more before their neighbours. It's the same pattern in the fall - some clones turn golden earlier than others.

On my drive I noted a common loon on a roadside lake and a rough-legged hawk soaring over the highway. Those are both first observations of the year for me.

Tuesday, April 20, 2010

Wood frogs quacking

The unseasonably warm weather of the past few days has the spring wood frog chorus going in full quack. That's what they sound like - more like a duck than a frog. I counted about 150 mostly males serenading themselves and a few females along the south shore of Maxwell Lake in the largest group. Other males were calling individually or in small groups all along the shore and in the beaver pond right beneath the observation tower. Only a few males were clutching females, and there were no egg masses. This means that the main breeding period is still to come. As the water continues to warm the evening chorus will continue to swell.

An adult bald eagle flew over the lake while I was there, and 3 Wilson's snipe swirled down to roost in the dry sedges at dusk. Robin song filled the air, along with a few dark-eyed juncos and a solitary red-winged blackbird. There aren't many birds back yet, but those that are were busy establishing their territorial claims. I wasn't alone appreciating the fine evening - I counted 74 people in the hour and a half I was there.

Thursday, April 15, 2010

Gray jay nest

Yesterday while on a run I heard gray jays making a big commotion in the forest ahead. I slowed down and then stopped to watch 2 adult birds harassing a raven perched in a nearby tree. A few minutes later the raven, obviously having had enough of the frantic jays, flew off. The jays settled down immediately. Within another minute they both flew to their nest, giving away the location high in a spruce tree. I couldn't see the nest very well because of obscuring branches, but I did see the adults carrying food to the nest and carrying away fecal sacs, so I know there are young in the nest.

Gray jays are among the earliest nesting of our local birds. Often the dark fledged young of the year accompany their parents about the same time as migrants arrive and start building nests. The photo with this article was taken by Dan Strickland and it illustrates one of the risks of nesting early. Gray jays are very tough birds. I was thrilled to see this first ever, for me, gray jay nest.

Vandal hits nestbox

I thought about it. I knew better. I did it anyway. I put a nestbox on a living black poplar because I didn't want to prune limbs from a nearby spruce tree. I thought, it's pretty unlikely the beavers will come all the way down to this end of the lake just to cut down one little tree. Ha! A lot I know. As you've guessed by now, the beavers cut down that poplar. They chopped up the tree and ate every last bit of the twigs and bark. Donna LeLacheur called today and said she and Jodi Archibald had fished the waterlogged box, still attached to the remains of the beaver's feast, out of the lake and would I like to come and pick it up. Thanks for helping out and yes I would. The box is now at home drying out before I put it up again. And this time it won't be on a deciduous tree!

The waterfowl have returned to Maxwell Lake. This evening there were a pair each of American widgeon, bufflehead, and common goldeneye on the lake. The goldeneye and bufflehead are the target species for the nest boxes. It's ironic that the ducks arrived on the same day the vandals struck. Oh well, these vandals were just after a square meal. Or maybe they don't like ducks for neighbours.

Tuesday, April 13, 2010

Lots of beavers

Maxwell Lake is almost completely ice-free and the beavers are enjoying their freedom after a long winter cooped up in the lodge. Both adults and a long yearling (almost 2 years old) were in the main lake this evening, and 4 short yearlings (approaching their first birthday) were near the lodge. Three  young girls followed one of the adults down the channel toward the lake and they were thrilled when it swam under the bridge at their feet. The picture with this post is that animal after it climbed out for a look just above the bridge. It's just diving back into the water.

At the lodge the youngsters were clipping and noisily munching on green shoots from the sedge clumps at the edge of the pond. Three of them were engaged in this activity right below the pond tower. The light was too poor for good photos. I got lots of blurry shots that could be called abstract or artistic if one was in a charitable mood. I deleted them. The light was good enough for video though and I got a couple of short videos that were pretty good.

This evening also marks the arrival of the first singing male red-winged blackbird of the season, and I heard 2 wood frogs calling from 2 separate locations. With a few more warm evenings the frog chorus should start to build quickly.

Sunday, April 11, 2010

An early spring flower

Catkins of poplars and willows have been in bloom for several weeks now. I found new blossoms of the prairie crocus in Jasper on March 28, but those spring pioneers don't grow at the Beaver Boardwalk. The flower in the picture is from the Canada buffaloberry, a low deciduous shrub of dry habitats that's common in the Boardwalk area. The showy but very small yellow flowers aren't open at the Boardwalk yet but the flower buds are swelling and should open soon. This picture was taken today on a warm open slope about 20 km west in Jasper National Park.

Sheperdia canadensis has many common names, including buffaloberry, soopalalie, soapberry, and foamberry. Male and female flowers appear on separate plants. While it's easy to miss the tiny flowers, the clusters of shiny red berries that appear in summer are hard to miss. I'll cover them in a future post.

Friday, April 9, 2010

Return of the geese

OK, the photo doesn't show geese, but read on... Last night the mercury dropped to -9 and today was raw, windy, and cold. Much of the beaver pond and about half of Maxwell Lake had been open water but now a thin clear sheen of new ice covers all but the middle of the lake. Spring is still pushing ahead. At dusk a single honk heralded the arrival of a Canada goose pair, who glided in and landed on the ice near the lake tower. I 'm sure they will check out the waterfowl platform. There's been a crow checking it out plenty lately - the black bandit shown in the photo. I think it's been having a feast on the grass seed I spread a few weeks ago. Or at least that's what it seemed to be eating. I hope it doesn't get all of the future greenery.

At the west end of the lake two beavers were having supper along the shoreline. They have been back in the lake and actively cutting fresh willow shoots for almost a week now. Pussywillows seem to be a favourite.

Sunday, April 4, 2010

Beaver close up

Open water is still in scarce supply at the Beaver Boardwalk, but every day a little more appears. This evening a large adult beaver surfaced from under the ice right beside the boardwalk and posed for this portrait. Then it climbed out of the water and ambled up the dam to cut a willow shoot, which it dragged the rest of the way up the dam. After towing the branch to the lodge the beaver submerged with it's supper, which was no doubt shared with others inside.

Six people were fortunate to see this display of calm nonchalance within a few meters, talking and taking photos all the while. I got a couple of great video clips as well as some good stills. I'm going to set up a YouTlube account and post some of the better videos soon.

Woodpecker stripes

Many people know that denuded tree trunks and piles of bark scales on the ground at the end of winter are the work of woodpeckers, but have you ever noticed the striped scaling pattern on living pine trees created by the king of the scalers, the three-toed woodpecker? This photo, taken yesterday, shows fresh horizontal stripes created by methodical exploration for the larvae of bark beetles. I know they're fresh because the bark scales were  on top of last fall's needlefall. Close examination of the pattern shows a shallow irregular furrow created by the bird's bill striking sideways blows. I've often watched three toed woodpeckers working industiously across and up and down tree trunks. In this case bark beetle galleries and chambers were hard to find, indicating that the woodpecker did a lot of work for little reward.

Once one knows what to look for, pine stripes are actually fairly common in our local forests. For some reason stripes are usually only on one side of the tree, and that side often faces an opening.

This second photo shows what happens when a woodpecker locates bark beetle larvae under the bark. The stripes merge to form large patches, and if you look closely you can usually find larval galleries and chambers with missing larvae - clear evidence that the woodpecker got a meal. Three toed woodpeckers spend the winter finding and feasting on bark beetles that have attacked dead or dying trees. Evidence of their work is everywhere at this time of the year.

And soon, the sound of drumming will announce the start of the woodpecker breeding season. More on that in a future post.

Thursday, April 1, 2010

Pileated woodpecker sighting

This afternoon I went back to check out the pileated woodpecker excavation I found on March 28. I don't think the birds have done much since, but I'll keep watching. I also checked a tree used for nesting a decade ago for new sign, because pileateds often reuse old nest trees. Sure enough, there were a few handfulls of fresh chips on the ground. Another one to watch.

Yesterday Diane Renaud saw a pileated woodpecker chiselling holes in the roots of a dead black spruce beside the boardwalk on the upstream loop. The bird was after carpenter ants, which is both the favourite food and diet mainstay of our largest woodpecker. Fresh excavation sign is all over the boardwalk area, which is another sign that the local pair of pileated woodpeckers will nest somewhere in the vicinity this year. During the nesting period pairs pick a nest site and then don't go too far away until the young leave the nest. Lots of sign in an area during the nesting period is a sure indication a nest isn't too far away.

A Raven's Nest

My running route this afternoon went to the top of the Just Giver trail west of Happy Creek, which is where I spied a bundle of sticks in the forked top of an aspen tree that wasn't there last year. Whacking the trunk with a stick rewarded me with the silent exit of an adult raven. Likely the pair is incubating eggs right now. It will be interesting to watch the progression of the raven family over the nesting season.

Ravens, red-tailed hawks, northern goshawks, ospreys, and bald eagles are the main builders of large stick nests in our area. Raven nests are often near openings, sometimes in isolated trees. Goshawks and red-tails are more secretive, locating their nests below the top of the canopy in denser forest. Ospreys and eagles make massive nests, often in the open near water, that they add to year after year.

Other big birds, especially our 2 largest owls, use old stick nests for their own nests - great gray owls and great horned owls are the likely opportunists. You never know what might be on top of that platform. Several years ago a researcher studying American marten sometimes found his radiotagged animals loafing on stick nests on warm days. A nice private breezy place. What more could a snoozy marten want?

Tuesday, March 30, 2010

Beavers and robins

There's open water around the beaver lodge so I went over after sundown this evening to look for beavers. I saw 3. Two were floating near the lodge and both of these slapped their tails and went under when they saw me. The 3rd beaver was just below the dam and this one submerged silently and swam under the ice. I waited 5 minutes but it didn't come up. Beavers can hold their breath for 15 minutes or more and I'm sure this one just decided to wait me out, as it really didn't have anywhere to go other than back over the dam into the main pond.

While I was waiting for the beaver to reappear a robin started chirping by the observation tower. That is the first robin of the year for me. I got a blurry photo of my bird, a male, sitting on top of a spruce tree. There was another one calling further away toward Maxwell Lake.

Sunday, March 28, 2010

Pileated woodpecker nest testing

Pileated woodpeckers in this area often nest in a living aspen infected with a fungus called Phellinus tremulae. The fungus attacks living trees and rots the heartwood inside an outer shell of sound living sapwood. The fungus forms hoof-shaped fruiting bodies on the outside of the tree called conks. Hence the common name for this fungus - the horse-hoof conk. Although they are strong enough to chip away at very hard wood, even pileated woodpeckers don't like to excavate their nest cavities entirely in hard wood. Large aspens with heartrot are their favourite.

Each spring mated pairs explore for possible nest trees. They are well into the process for this spring, and yesterday I found a test excavation behind Maxwell Lake. There were actually 3 test holes on one tree. Perhaps the tree didn't have enough rot, because I couldn't see any fungal conks on the trunk and the chips on the ground were sound. There is dark hardwood at the back of the excavation however, which might mean rot is present. I'll keep watching the tree to see if the woodpeckers agree with me or not.

Sometimes a woodpecker pair will return years later to an old abandoned start and complete it for use as a nest cavity. There's some evidence to suggest that the original test hole might have actually introduced the fungus to the tree, in which case the woodpeckers are helping their own cause. Clearly the original tree met their requirements, but it didn't have enough rot. No problem, just inoculate the tree and come back later. A neat process to ensure a long-term supply of suitable nest trees.

Spruce buds and squirrels

Every year about this time tiny spruce branch tips appear on the ground. What's going on? Red squirrels are clipping the tips to eat the buds, which are starting to swell as spring advances. Squirrels don't have much to eat right now. Their winter cone middens are getting low, and not much new growth has started. The spruce buds are probably both nutritious and tasty, at least until something better comes along.

I've watched squirrels clipping the tips. They're pretty quick, clipping the twig, turning it to bite off the bud, and dropping it almost in one motion. The first time I watched this activity I had a hard time picking up the bud removal part even with binoculars. To complicate things, sometimes the squirrel clips the twig and just drops it. I don't know if that's deliberate, but I suspect it is. Maybe the squirrels can discern whether or not the bud is a good one, or maybe the protective nest of needles on some buds is too much trouble.

I have another theory about the significance of this. Spruce cone crops are variable, with several years of low crops followed by a bumper crop. Red squirrels actually have bigger litters in the bumper year. This makes sense - the young squirrels will have better survival if there's lots of food for them in that difficult first winter. But what signal causes the squirrels to have bigger litters, which are born before the cones ripen in the late summer? Perhaps this twig clipping is a way to measure how many of those buds are normal vegetative buds, and how many are reproductive buds which will form male and female cones. Whatever the mechanism is, the squirrels somehow know when it's time to have lots of kids. Amazing.