Exploring Burnaby’s Parks and Natural Areas

Saturday November 22, 2014 saw the inaugural walk in the series I’ll be leading over the next few months called Exploring Burnaby’s Parks and Natural Areas.

A keen group of eleven participants, we found ourselves outdoors on a beautiful fall morning – blue sky, fluffy cumulus clouds, and sun. Yes, sun. Luckily, it seemed the weather gods were looking upon our enterprise favourably. We managed to find the one fine day between soaking Pacific fronts that had been storming across the region on the belly of the jet stream for a week; and then continued the downpours afterwards.

CentVGrnwGrp

Searching for a Fox Sparrow skulking in a blackberry thicket

Starting at the rugby fields at the foot of Sprott St., we wanted to see as much as we could during a relaxed 3 hour walk by following the Still Creek corridor upstream from its outlet at Burnaby Lake.

However, before we got to creekside, the large flock of Canada Geese on the rugby fields (not playing of course) got our attention. Taking a closer look at the more than 150 birds happily grazing the grass fields we noticed that in fact there wasn’t a single Canada Goose among them. They were the Canada’s smaller cousin, the Cackling Goose. Originally thought to be just small Canada Geese, scientific studies, including genetics, have recently shown these birds to be a separate but similar species,

CACG

Cackling Goose. Note the darker colour, small, rounded head, short neck, and small bill which separate the Cackling from the Canada.

Looking around from the parking area, we had excellent views of a flock of American Goldfinches actively feeding in the treetops. After walking across the fields to the banks of Still Creek, we were soon appreciating the many waterbirds at the mouth of Still Creek including Double-crested Cormorants, Buffleheads, and Common Mergansers. Shortly after, we walked north-west along the creek where we saw our Bird of the Day, a beautiful adult Northern Shrike, an uncommon bird in Burnaby. Perched at the top of a large black cottonwood, it was out of camera range unfortunately, but the spotting scope provided great views for everyone.

As we continued, a shrubby area off the main trail featured our most active group of birds for the morning feasting on the berry-sized fruit of Pacific crab apple trees, and red-berried hawthorns. Cedar Waxwings, Purple Finches, American Robins, Spotted Towhees, and Fox Sparrows made up the mixed feeding flock.

In all during the walk, we saw about 30 species of birds, but I won’t retell the details of each sighting, but encourage you to join us next time to see them for yourself. The schedule of walks and details will be published by the City of Burnaby. The dates are:

Saturday Jan 10 – Burnaby Lake Winter Water Birds
Friday Apr 17 – Welcoming Spring at Deer Lake Park
Tuesday Apr 28 – BBY Mnt Conservation Area Spring Songbirds
Saturday May 9 – Dawn Chorus at Deer Lake

A full list of our sightings on November 22 is shown below.

Cackling Goose  150
Canada Goose  6
Wood Duck  2
Mallard  10
Bufflehead  8
Hooded Merganser  1
Common Merganser  3
Double-crested Cormorant  25
Cooper’s Hawk  1
American Coot  7
Glaucous-winged Gull  5
Rock Pigeon (Feral Pigeon)  25
Downy Woodpecker  2
Northern Flicker  3
Northern Shrike  1
Steller’s Jay  1
Northwestern Crow  60
Black-capped Chickadee  8
Brown Creeper  1
Pacific Wren  2
Golden-crowned Kinglet  1
Ruby-crowned Kinglet  2
American Robin  40
European Starling  20
Cedar Waxwing  12
Spotted Towhee  10
Fox Sparrow  5
Song Sparrow  8
Purple Finch  5
American Goldfinch  25

 

Advertisements

Exploring Burnaby’s Parks and Natural Areas

Announcement

I’ll  be leading a walk for the City of Burnaby on Saturday, November 22 – rain or shine. The walk is billed as: Exploring the Still Creek Corridor & Central Valley Greenway.

We’ll spend about three hours walking the trails bordering Still Creek from where it flows into Burnaby Lake. Registration is required, and is limited to 15 participants. I’ll focus on the birds, of course, but we’ll keep our eyes out for all aspects of the natural world.

NOFL–display

The Northern Flicker is the most likely woodpecker species to be encountered on the walk. Here are two displaying adults from earlier this fall.

To register, go to the City’s website WebReg page and enter event number 350173 into the search box. The walk is not in the Parks and Leisure Guide as it was organized after press time for that publication.

There will be lots to see, and with the wet weather lately we may be lucky enough to find some interesting fungus like this bird’s nest fungus (how appropriate!) I photographed a couple of days back in Deer Lake Park.

Bird's Nest Fungus 2

Bird’s Nest Fungus growing on decaying wood.

The close-up below shows the still developing cups covered in a white membrane that will split away to reveal the egg-like peridioles held within.

Bird's Nest Fungus

Bird’s Nest Fungus growing through moss on a decaying log

Because I’m a birder and not a mycologist, I’m not able to tell you the actual species of bird’s nest fungus pictured here; there are many. Perhaps a reader can help.

July – Moult Month for Waterfowl

July is mid-summer for us humans, and the time of year when we head out to our parks and beaches. However, despite the attractions of the season, it’s just not as pleasant and pretty down at the Deer Lake beach as it usually is. In fact, things are looking downright scruffy and untidy.

All that feather shedding and goose pooping are making quite the mess. What’s going on?

For sure it’s the birds making the mess, and over one hundred Canada Geese can make a good one, but before getting ticked off, spare them a sympathetic thought. July is a pretty tough month to be a goose or a duck. They’re going through a big part of their annual moult. It’s biology and they have no choice.

CANGBeach

Not a pretty sight – moulting geese crowd Deer Lake beach

Walking around the beach, feathers are strewn everywhere and most of them are from the park’s ducks and geese.

FeathersBeach

For all species of waterfowl (ducks, swans and geese), moulting is a pretty dramatic and stressful affair. Not only do they shed some of their body feathers, but also their wing feathers. And not just one by one; waterfowl lose their flight feathers all at once. Now if your flight feathers are gone, you’re flightless, and that can be serious – especially if you need to escape from a predator.

So our ducks and geese gather in areas where they have easy access to an escape route – in this case to the lake itself. The beaches at Deer Lake and Piper Spit at Burnaby Lake offer great locations for moulting birds.

CANG2

Canada Goose with all its flight feathers missing from moulting

Take a look at the goose above. The long, dark wing feathers that extend to the rear and partly cover the tail are completely missing and expose the black back and white rump that we see like this only at this time of year.

Here’s another bird, and here you can see the newly growing pin feathers, or blood feathers as they are also called. Over a period of a couple of weeks they will become fully developed and fully functioning wing feathers, or primaries. Right now they’re just tiny stubs.

CANG1

Note the emerging wing feathers encased in a blue, waxy coating on each side of the bird

The base of the pin feathers shown above are engorged with blood to aid their rapid growth. You can just see the new feather material emerging from the tip of the waxy coating. Damage to these pin feathers at this stage can be dangerous for the birds – it can lead to significant blood loss.

A little further along in the moulting process, here’s a bird with partially-grown new flight feathers that have not yet reached their full length.

CANG3

The dark-coloured, newly growing flight feathers (primaries) are best seen on the bird’s left wing. Note the still-to-be-moulted, old, paler, worn-looking, unshed flight feather on the extreme lower left.

As the flight feathers continue to grow they will once again cover the white rump and much of the tail. The bird above is also growing replacement tail feathers – note the uneven length at the tips. Growing so many large feathers at one time uses a lot of the birds’ energy, and they tend to loaf around to conserve it.

CANGBathe

Loafing on the beach, and then bathing in the lake. Remind you of anything?

Loafing on the beach enables the moulting birds to bathe frequently and preen those new feathers into good condition. This is important work; they will have to last until this time next year before being replaced.

Ducks also moult their flight feathers after breeding, but their transformation is even more dramatic. As they moult their wing feathers, they enter what is known as eclipse plumage. The males loose all their fancy body feathering, and often look much the same as females of the species. However, given they are flightless, it’s no doubt best to be as inconspicuous as possible. Plus the fancy, female-attracting plumage is no longer required now that breeding has just finished.

MALLHead

This drake Mallard is losing his glossy green head feathers, rufous breast plumage and gray back and sides as he moves further into eclipse plumage

Here’s a picture taken earlier this year showing how much the drake Mallard transforms from eclipse to breeding plumage. Eclipse above, breeding below.

MALLAlt

Breeding plumage Mallard – the plumage we see most of the year

Ducks are very unusual in the bird world as the males have their two annual moults very close together in summer and fall. Most birds that take on different plumages for the breeding season have their second moult in the spring, ready for the breeding season.

Ducks in contrast, form pairs in the winter and males develop their pre-breeding finery during fall to be ready for winter pre-breeding pairing.

Lastly, here’s a very scruffy looking Gadwall at the lake.

GADWEclipse

A very “female looking” drake Gadwall in eclipse plumage

Along with moulting waterfowl, many other birds  also undergo a moult at this time of year. Just like our ducks and geese, even our crows come down to the beach to make use of the fresh water from Buckingham Creek to bathe and condition their new feathers.

NOCRBeach

Moulting crows gather around the mouth of Buckingham Creek

Unlike waterfowl, crows do not moult their flight feathers all at once, but lose and replace them serially over a period of several weeks. Such a moult strategy enables these birds to continue flying while undergoing this annual transformation. Looking up at crows flying overhead at this time of year you will notice the shape of the wings at the trailing edge is somewhat jagged, the result of new feathers growing in and others having been shed.

NOCRMoult

Crow showing its moult in progress

The picture above is really illustrates what’s going on. This Northwestern Crow photographed last week at Deer Lake shows both body and wing feathers being replaced. The old, sun-bleached, brownish feathers contrast quite strikingly with the glossy, black new feathers just growing in. This bird has also lost feathers at the base of the bill, likely as a result of continually stuffing food into the mouths of its hungry young. All will be restored to glossy glory in a few weeks.

It’s enough to make you want to take a bath.

NOCRBathe

Bathing Northwestern Crow, Buckingham Creek

While photographing the geese, ducks and crows shown above, I suddenly noticed feeding right along the edge of the Deer Lake beach were these two Long-billed Dowitchers – a rare treat at this location.

LBDO1

Long-billed Dowitchers newly arrived from Northern breeding grounds

These two birds are adults in worn, breeding plumage. You’ll have to take my word on the “worn” part. Now these sandpipers have a different moulting strategy from the birds we’ve looked at so far. After breeding, the dowitchers migrate from the breeding grounds and then moult into their drabber winter plumage on the wintering grounds.

And many Long-billed Dowitchers spend the winter at Burnaby Lake. Here’s a picture from last winter. Look at the transformation. Breeding above, winter below.

LBDO

Long-billed Dowitchers in winter plumage

You can just see in the flanks of the bird below the first few hints of the greyer feathers of the winter plumage.

LBDO3

Long-billed Dowitcher, Deer Lake beach

With all this shedding of feathers and growing of new ones it’s enough to make you want to scratch that itch. It’s that time of year.

LBDOItch

****

It’s been a busy spring of birding and travel that has kept me away from the blog. However, it’s back, at least for a while.

 

Halloween Nightmare – for a snail!

It’s All Hallow’s Eve. Gore-spattered ghosts, ghouls, and goblins roam our streets in packs.  Vacant eye-sockets glare at us from dark doorways, and dripping bushes. Blood curdling wails of pain and screams of fear echo through the neighbourhoods.

Putting the frighteners on ourselves is all part of the fun, and the scary stuff is not that nightmarish when we know that once all ‘tributes’ have been collected, a warm home awaits us with hot chocolate and a feast of goodies.

However, from our comfy seats at home, can we give a thought for the lowly snail? If snails could think like we do (they don’t) surely their Halloween Nightmare would be one that would terrify us too – trapped, unable to move, and being eaten alive, head first, Hannibal Lecter style.

And that’s what’s happening below; not in the movies, and not in our imaginations, but for real.

Calosoma and snail

Calosoma ground beetle eating a snail.
Click to enlarge.

With the beetle’s mandibles plunged into the opening of the snail’s shell, the hapless gastropod is being eaten alive, head first. I witnessed the dramatic scene above while gardening this week .

Ground beetles, like the one above, are quite common carnivorous denizens of our gardens. Often unseen because of their nocturnal habits, we frequently disturb them while digging around in our gardens. Far less frequently do we see them with their prey.

However, it’s a good reminder that many of the invertebrates in our gardens are actually doing us favour, although I’m sure the snail wouldn’t see it that way. In this case our friendly beetle is consuming a garden-plant-eating snail. Remember: Don’t squash the insects, and do avoid the pesticides!

The two hard “shields” covering the back of the beetle and protecting the wings underneath are called the elytra. They are nicely striated in the above specimen, and suggest that it’s in the Calosoma genus. As I’m a bird man, and less of a bug man, my identification of the beetle is provisional.

And while I’m on the topic of ground beetles, I thought I would take the opportunity to share a picture of another striking member of this large family of insects. I managed to photograph this beauty last year in my garden after a brief shower left it with a shiny coating of water over its smooth, red elytra. Again, my identification is provisional. I believe this one is a member of the Carabus genus.

Both beetles are in the 25 to 30 mm size range.

Carabus beetle

Carabus ground beetle after a rain shower.
Click to enlarge

Take a close look at the beetle above and you’ll notice it’s missing part of its left front leg, and part of its right antenna.  It’s an eat-and-be-eaten world all around us. So if snails could have Halloween nightmares, then I’m certain that ground beetles would have theirs too. Who can imagine what frightening beasts could attack and dismember ground beetles?

Happy? Halloween.

Cooper’s Hawks

Cooper’s Hawks are likely the commonest raptor found in Burnaby, but much of the time you wouldn’t know it. Like all members of the accipiter family (true hawks) they are specialized, bird hunting, ambush predators, that mostly remain hidden deep in cover from where they launch surprise attacks, and pursue their avian prey through the woods.

However, in July and early August when the young birds have just fledged (left the nest), they frequently perch out in the open for a few days, noisily begging for food. Recently, friends in North Burnaby phoned to tell me that they and their neighbours were being entertained by a family of four recently-fledged, and two adult Cooper’s Hawks in nearby Montrose Park.

COHAGroup

Three of four juvenile Cooper’s Hawks await their parents’ return with food – Montrose Park.

When I headed over there the next day, the birds seemed to have learned their first lesson as young raptors – stay hidden. No doubt the youngsters had been mobbed by smaller birds, and the neighbourhood crows, which will attempt to drive all raptors from their territory. But, while staying hidden, they were still calling loudly for food. After a bit of searching, and using their long, wheezing whistles to guide us, we finally managed to find a couple of the young birds perched, and begging for food in the deciduous trees along the Trans-Canada Trail through Montrose Park.

COHA#1

Juvenile Cooper’s Hawk concealed in big-leaf maple, begging for food

The adults were not  around when we were there, and were likely out hunting for the young birds’ next meals. Over the next two or three weeks the young will continue to be fed by their parents, but they will increasingly be left to their own devices until, and after four or five weeks, they will be abandoned to their make their own way in the world. If they haven’t honed their hunting skills sufficiently in the meantime, they’ll not survive. They may still hang around in the area of their birth up to six weeks after fledging. You should have a good chance of finding one if you head down to Montrose.

It’s a steep learning curve for the young Cooper’s Hawks to become independent hunters, but they’re born with all the equipment they need. Their incredibly sharp vision puts human  eyesight into the piker division. Cooper’s Hawks can not only resolve much greater detail at greater distances than humans, but they are also able the track the rapid movements of their prey through the forests, which for us would simply be a blur. Their binocular vision gives them the very precise judgement of distances which is essential for capturing fast-moving prey.

COHA#6

Forward facing eyes give Cooper’s Hawks a wide field of binocular vision, essential for hunting.

Cooper’s Hawks wings are relatively short and rounded, whereas their tails are relatively long. You can see in the picture above the long extension of the tail beyond the wing-tips. This combination makes them stunningly maneuverable in flight. Fast to accelerate, they are able to make incredibly sharp turns at very high speeds to pursue their prey through dense vegetation. And they often seem totally fearless when chasing down their quarry.  I recall watching one chase a starling from a bird feeder, and then crash full force into a dense shrub, into which the starling had plunged to make its escape, only to yank it out, clutched in one foot.

COHA#4

Long, sharp talons make for a deadly grip on the Cooper’s Hawk’s prey

Cooper’s Hawks are a success story in the urban bird world. Once in serious decline across North America due to hunting, pesticide contamination, and loss of forest habitats, they have now rebounded and adapted extremely well to urban environments, including our parks, where they find plenty of prey.

Andy Stewart in Victoria has had a long term program of banding and monitoring Cooper’s Hawks in the capital city, and he has discovered some of the highest densities ever recorded on the continent just across the Straight from us. I would not be surprised at all if we have comparable population densities of these beautiful predators right here in Burnaby.

Hawks banded in Victoria have been recorded a number of times on this side of the Strait of Georgia. Keep an eye out around your bird feeders this winter. Cooper’s Hawks often snatch their prey from our gardens.

To read more about Andy’s work, click here. A longer article, with a more continental perspective on Cooper’s Hawks can be found here.

Here Be Dragonflies

Written on ancient maps as warnings to mariners, Here be Dragons conjured up images of fire-breathing monsters lurking in unknown regions of the world ready to incinerate the unwary.

Here be Dragonflies is not a warning, but instead an invitation to head down to our local lakes and ponds to see these intricate and beautiful creatures that are just now taking to the air as the full heat of summer has arrived. Not scary, and not fire-breathing, dragonflies compete with butterflies as one of the top insect attractions in our parks and gardens.

8SpotSkim#2Male

The eight-spotted skimmer is common, easy to see, and easy to identify. Photographed at Burnaby Lake, this one’s a male.

Living Fossils

Whenever I watch dragonflies, I’m always awed by the thought that these insects are the modern descendants of a fantastically ancient lineage. Fossil dragonflies, very similar to those we see today, were flying around almost 300 million years ago. That’s a staggeringly long time ago. As a comparison, the last Ice Age ended about 10, 000 years ago. Dragonflies have been around about 30, 000 times longer. Few animals living today have remained essentially unchanged for such a long stretch of geological time. When dragonflies were darting around the giant forests of the Carboniferous Period, mammals had not yet even appeared on earth. A very successful evolutionary “design” indeed.

8SpotSkimFem#2

Eight-spotted skimmer female. Notice the different body colour, and lack of blue in the wings found in the male. Compare her black spots to the male’s, and you’ll notice they are the same size, shape and position on the wings.

Below is a second common Burnaby dragonfly – the blue dasher. What a great name! No doubt why it’s called blue, and it is pretty zippy in flight too. However, this dragonfly’s wings are not boldly marked like the eight-spotted. However, look at the rakish angle they are held in contrast to the more conventional stance of the eight-spottted.

BlueDashMaleCrop

Blue dasher – male. Photographed at Deer Lake

Climate Change Connection

The blue dasher is found only in the most southerly areas of Canada; however it is a species that is likely responding to global warming. It has extended its range northward in recent years, and continues to do so. Not one of the dramatic signals that things are changing rapidly on the planet, but nonetheless, a signal from nature that they are.

Acute Vision

Dragonflies mostly feed on flying insects, sometimes even other, smaller dragonflies. To see, pursue, and capture their fast-moving prey they need fantastically sharp vision. The two large compound eyes which take up a large proportion of their head have evolved to capture even the slightest movement. Made up of up to 30, 000 individual simple eyes, the compound eyes of dragonflies not only give very fine detection of movement, but because in some species they form an almost spherical array around the head, they give a field of view approaching 360 degrees. Click the image of the blue dasher above to get a close look at its stunning turquoise eyes.

BlueDFemCrop

Blue dasher – immature female.

Powerful Wings

No doubt part of the evolutionary success of dragonflies can be attributed to their wings. The intricate pattern of veins (venation) which carries blood to the wings also provides structural strength for powerful wing beats. Coupling this with the ability to flap and rotate all four wings independently, makes dragonflies incredibly manoeuvrable fliers. They can hover, rotate on a dime, make rapid vertical climbs and descents, and maintain forward flight at high speeds, and even fly backwards, all the time keeping the body horizontal.

4SpotSkim

Four-spotted skimmer – female. The striking venation on the leading edge of the wing on this beauty is worth a closer look. Click to enlarge.

Dragonfly Cousins

Much smaller than their larger and more aggressive cousins, damselflies are also emerging in numbers and flying around the water’s edge at our local lakes and ponds. Slower moving than dragonflies, they hunt mostly by gleaning insects (aphids) hiding in the waterside vegetation. Damselflies are distinguished from dragonflies by the way they generally hold their wings closed over their bodies. The males, and some females, are mostly eye-catchingly blue, like tiny electric-blue pencils floating in the air on almost invisible wings. To many people damselflies are known as bluets, which is an entirely appropriate name. Bluet is also frequently seen as part of the common name for a number of species of damselflies.

Much more difficult to identify than some dragonflies, many species of damselflies look superficially similar. The one I photographed below is, I think, a tule bluet – a common species hereabouts. However, birds are where I’m confident in my identifications; I’m far less certain when it comes to damselflies. Please correct me if I’ve made a misidentification.

BluetSp

A damselfly (tule bluet?) perched on lakeside vegetation at Deer Lake.

So whether it’s dragonflies or damselflies that catch your fancy, it’s time to take a look because Here (they) be….

And take your binoculars and camera. Close-ups are definitely in order when viewing these beauties.

If you’re interested to learn more about our local dragonflies, I suggest Dennis Paulson’s Dragonflies and Damselflies of the West. It’s also available in Burnaby libraries. I consulted the book extensively for this post.

Butterfly Bonanza

As we move into July and the weather really starts to warm up, the long grass meadows in our parks are the centre of a remarkable, once-a-year explosion of skipper butterflies.

Skipp&Blkberr

Skippers, crowding on to a blackberry flowerhead feeding on nectar from the flowers

What these small butterflies lack in size, they more than make up for in the sheer numbers that hatch, take to the air, and adorn almost every flowering plant in and around the fields at this time of year. It’s a spectacle, and one well worth a closer look. The Deer Lake meadows, at the western end of the lake, are a particularly good place to see the action, and enjoy what is by far our largest flight of butterflies in Burnaby.

Skipp&Vetch#1

Purple vetch flowers are a favourite for nectaring skippers

Taking a closer look at these small butterflies, it’s noticeable right away that they’re not quite conventional butterfly shape. To some people they suggest moths, rather than butterflies. Their wings are more “swept-back” instead of being held either flat and open, or upright and closed, like “regular” butterflies. The hind wings are held out flat, while the forewings are held above them at a 45-degree angle – very rakish! They do at times, however, close both wings over their backs like regular butterflies. As you can see from the pictures, the open-winged stance is very common. This distinctive shape and stance shows that these butterflies are members of the grass skipper family.

Skipp&Dand

Skippers feeding (nectaring) on a dandelion – click to enlarge

So let’s take a close-up look. When you click to enlarge the photo above, you’ll see a couple of good clues as to why these insects are butterflies, and not moths. First take a look at the antennae which emerge from the head, angling outwards. They’re thin and thread-like with noticeable, club-shaped ends. In contrast, many moth antennae are feathery, and if they are thin like a butterfly’s, they lack the club end. Most moths are, of course, nocturnal, whereas these “guys” are active in the daytime. Two ticks for butterfly.

Now take a look at the skipper on the far right on the dandelion. You’ll see a third, thread-like organ emerging from the centre of the head, which then makes an angular curve downward into the flower. This is the proboscis, the hollow tube through which the butterfly draws up the nectar on which it is feeding. Now that you’ve looked at one skipper, a quick glance reveals that they’re all at it. This single flower is feeding a whole bunch of skippers.

Skipper Profusion

So what species of skipper are these? Well, thereby hangs a tale. These are European skippers. That’s right, they’re an introduced species from Europe.  First accidentally introduced to Ontario in 1910 they’ve spread across the country, and there have been many subsequent introductions since, including Duncan on Vancouver Island about 15 years ago. Ours could have spread from there, or they could have been introduced here separately. A particular aspect of the European skipper’s reproduction makes spreading to new locations very easy. And as usual, it’s we humans that are big contributors to skipper profusion, and skipper spread.

Unlike all native species of North American skippers, which overwinter as pupae, European skippers overwinter as eggs. This makes it very easy to survive being mowed, and then moved when hay is transported from one place to another. And hay fields is where skippers thrive. They’re called grass skippers because the larvae, the caterpillars, feed on grasses. As we can see, the adults get their food from flowers.

Skipp&Clov

European skippers feeding on clover

Although an introduced species, the European skipper is yet another example of a benign addition to our fauna. In this case, a very beautiful one too. There is no evidence that this introduced skipper has negatively affected our native skippers. It seems to have found a place here without causing problems for other species.

As John Acorn says in Butterflies of British Columbia  … we now have more butterflies on the wing than we ever could have without this cute little addition to our fauna. Here, here!

Skipp&Vetch#2

European skippers – a welcome addition to our butterfly fauna

Deer Lake Heronry Flourishes

Within sight of Burnaby’s City Hall, the word is out that Great Blue Herons have constructed a huge and rapidly growing colony, and they’ve done it all without a building permit! It’s nesting season, and right now there’s so much going on in the colony at Deer Lake Park, it’s definitely time for us to get out there, take a look, and enjoy all the action.

BranchPluck

Great Blue Heron grabs a tree branch to add to its nest of sticks.
(Click to enlarge)

So head down to Deer Lake Avenue, opposite City Hall, to enjoy the sights and sounds. However, please watch only from the paths and the sidewalks. Entering the colony under the nests is definitely a No No. Peering in from the edges of the colony gives the best views of the birds, their nests, and all the goings on. Standing under the nests is unwise for many reasons, especially when looking up, mouth agape.

Search

Sticks are searched for diligently within the colony. or carried in from further afield.
(Click to enlarge)

Sticks are being gathered, nests built, nest sites squabbled over, and the occasional predator is vanquished. Egg-laying will start soon, if it hasn’t already, and after about 30 days incubation, the young will hatch. Following hatching, it takes another two months before the young fledge. And as the young grow, noise levels will rise, as will the colony’s strong, olfactory presence. Yes, it gets pretty stinky, and furthermore, later in the season the trees will be fully leafed-out, and activities harder to see. Now is a very good time to pay a visit.

Heronry

Almost 30 nests are visible here, most located in just two trees on the west side of the colony. (Click to enlarge)

For the past six years, much to the delight of park users, passers-by, interested scientists, and City and Ministry of Environment staff, the Deer Lake heronry has been growing in size at a fantastic rate. It has made a big jump in numbers this year. Don Jones, who, every season makes a very careful inventory of the nests, counted 104 in March. Last year (2012) the count was 66 nests – a whopping increase! As each nest represents a pair of herons, we now have over 200 birds using the colony. That’s a huge number of these big, spectacular birds.

So just how quickly has this colony grown? In 2008, I made the following notes about the heronry:

”There has been a small colony (2-3 pairs) of GBHE at the west end of the lake for the past 4 years. Last year (2007) the colony was predated by Bald Eagles, and no young were fledged. Up to three young were fledged, or were close to fledging in previous years.

This year the birds, presumably the same ones, relocated north and east of the previous location to a grove of black cottonwoods bounded on the south by Price St., on the north by Deer Lake Drive, and on the west by the trail that heads north-east diagonally from the foot of Price. In early May, three nests were visible with adults standing on and/or next to two of the nests.

On May 30, the leafing-out of the trees made observing the nests very difficult. Only the southern-most nest was fully visible, and an adult was sitting (presumably incubating) on it. The second nest was mostly concealed, and its top was not visible. The third nest was not visible at all.

Jul 02 visit. Two large juvenile birds (fully feathered) standing in and on the edge of the southernmost nest. The second nest seems to be unoccupied by either adults or young.”

So, from three nests in 2008 the colony has now grown to over one hundred nests. It seems that herons take note of which colonies are being successful, and will transfer to these new locations from others where conditions may not be as good.

CondoStyle2

Herons nest quite close together in the tall, 30 meter plus, black cottonwood trees. Separation of nests is governed by stabbing distance from those impressive bills. (Click to enlarge)

In fact, the transfer from another colony seems to be a likely cause of this year’s big jump in numbers. The Colony Farm heronry, visible along the Mary Hill Bypass in Coquitlam, has been abandoned this year, likely due to nearby bridge construction at the start of nesting season. The Deer Lake colony may well be attracting some of the birds from the Colony Farm heronry.

Bald Eagle incursions are also a problem for heron colonies. Bald Eagle attacks frequently cause colonies to be abandoned. Both the Deer Lake and the Colony Farm colonies have suffered from eagle attacks. However, Don Jones reported a very interesting observation at the Deer Lake colony this year. A Bald Eagle entered the colony, but was attacked strongly (pecked from above) by one of the herons. The other herons didn’t abandon, but just retreated a short distance. The eagle was finally driven away pursued by a heron. It makes me hopeful that perhaps the birds are learning strategies to defend their nests, even at this relatively early stage in the breeding season.

NB

Sticks are worked into place to build the nest.
(Click to enlarge)

LgeNest

Some nests are quite substantial structures.
(Click to enlarge)

Activities other than nest building are also taking place in the colony. Unfortunately, I didn’t manage to get a picture, but frequent copulations are happening. Despite that miss, I did, manage to capture some tender moments of mutual preening by a nesting pair.

Preen

Copulation, and mutual preening as shown here, both take place on or adjacent to the nest.
(Click to enlarge)

I was recently asked, if there are so many birds on the colony, how come we only see one or two in the park itself? Great Blue Herons will travel long distances (5 to 10 kms) to good feeding areas to forage. Watching the direction of birds flying to and from this colony suggests they are probably foraging along Burrard Inlet, and as far south as Boundary Bay. Both locations are within easy flying distance.

Some individuals do forage locally, and there are frequently one or two birds in Deer Lake Park itself. Some may not go as far as the Inlet or Boundary Bay. I managed to capture this not-very-good picture just a couple of days ago along Chub Creek, a tributary of Still Creek, of a heron just about to swallow its prey. I suspect it was fishing, but made this opportunistic capture instead.

WithVole

Great Blue Heron about to swallow a Townsend’s vole captured along the banks of Chub Creek.
(Click to enlarge)

It’s wonderful to have a such a success story on our doorstep, and we should celebrate our good fortune. However, we shouldn’t be complacent about the threats to the Great Blue Heron. We have a special, non-migratory subspecies here on the BC coast (Ardea herodias fannini), and it is designated a “Species of Special Concern” due to loss of wetland habitat in the Georgia Basin, and a declining population.

And not to be forgotten, too, is how this success story illustrates the importance of preserving the natural areas in our parks. In the 1980’s, the stand of black cottonwoods in which this colony has now established itself was designated for paving as a parking lot for the park. Thankfully, this City-inspired plan for the Park is long abandoned, and we now live in more enlightened times in Burnaby.

Thirty years ago this stand of trees was seen as dispensable. Today, completely unpredictably, it has become a significant colony for this threatened bird. A great example of why the precautionary principle is best applied consistently, especially to our natural areas.

HuntRCanGr

Great Blue Heron foraging at Deer Lake.
(Click to enlarge)

Let’s hope the success of our local colony will help us continue to enjoy these magnificent birds.

If you’ve been wondering why no posts lately, it’s because I’ve been travelling in South East Asia – birding of course. 

Posts should pick up to a regular pace from now on. Thanks for your patience.

George Clulow

Birds of a Feather….

…indeed do flock together. While many of our smaller birds in winter gather in mixed-species flocks to forage, and collectively keep their eyes out for predators, there are other species which, for the most part, stick with their own kind during the winter months. Perhaps the most obvious of these are our Northwestern Crows, which not only spend their days in extended family groups in their neighbourhood hang-outs, but return each evening to the huge communal roost along Still Creek. But there are others too, mostly smaller birds, that are notable for hanging out exclusively with their close feather-mates.

You’ve probably noticed the huge swirling flocks of Pine Siskins, small members of the finch family that are here in huge numbers this winter. Feeding on our native red alders, these flocks are almost entirely made up of the single species. Although occasionally, a few Common Redpolls or American Goldfinches may mix in.

Pine Siskin flock feeding in red alder.

Pine Siskin flock feeding in red alder

By far the largest flock I’ve seen this season, more than 800 birds, was swirling around the trees at the entrance to Deer Lake Park at Baffin Place earlier this week. I looked and listened, but as far as I could tell the entire flock was Pine Siskins – truly all birds of a feather. While mostly staying in the tree tops, sometimes these flocks move lower down to feed, and will even come right to ground level looking for food, or to pick up grit or small stones, which they swallow and store in their gizzards. If you don’t have teeth, a gizzard is evolution’s perfect solution for “chewing” food. The grit and stones are used in the muscular organ to grind up the bird’s food as part of the digestive process.

Pine Siskin on the ground looking for food or small stones or grit.

Pine Siskin on the ground foraging for food, or small stones or grit for its gizzard

Grit and small stones are not, however, the only reason for these birds to come to ground. Spending most to their time in tree tops, there comes a time for siskins to drink and bathe, and many in this huge flock were intent on both.

Here at Baffin Place, Third Beach Creek emerges from under Oakland St. and plunges deep into the forest as it makes its way into the lake below. A narrow, shallow stream, concealed in the forest is the perfect location for birds to drink and bathe.

Pine Siskins drinking along Third Beach Creek.

Pine Siskins crowding and drinking along Third Beach Creek.

And just like humans after a few drinks, the urge to jump in the hot tub is irresistible for some. In this case, the icy stream standing in for the warmer waters that we softies prefer.

Pine Siskins bathing along Third Beach Creek

Pine Siskins communally bathing along Third Beach Creek

Bathing itself is quite the explosive activity. In the centre of the “water bomb” below is a bathing, but invisible Pine Siskin. You’ll have to take my word for it.

Bathtime

Rapidly beating wings and shaking body produce an explosion of spray from this bathing siskin

After getting the feathers clean, it’s time to perch a little higher to carefully preen and get ready for flight, and to keep feathers waterproof.

After bathing the Pine Siskin preens the feathers into prime condition

A Pine Siskin preens its feathers into prime condition

Another of our familiar birds, the Bushtit, also flocks pretty much exclusively with its own kind during the winter months. This diminutive bird is related to chickadees, but not very closely, and is usually seen in flocks of from ten to thirty or so birds. Much easier to observe closely than Pine Siskins, Bushtits rarely feed in the tree tops, and are frequent visitors to suburban gardens where they will eagerly swarm the fat feeders put out for woodpeckers.

Is there room for me? Bushtits swarming a fat feeder

Is there room for me? Bushtits swarming a fat feeder

And not just one side.

Crowding both sides of the feeder, Bushtits eagerly eat the fat supplied for woodpeckers

Crowding both sides of the feeder, Bushtits eagerly eat the fat supplied for woodpeckers

Bushtit flocks are in almost constant motion, and will usually stay just a minute or two at the feeder before moving on. Sometimes one will stay still long enough to catch a solo picture.

Female Bushtits have yellow eyes, the males have dark eyes

Female Bushtits have yellow eyes; the males’ eyes are dark

Given their habit of flocking, it’s not surprising that Bushtits are very social birds, and this sociability extends beyond spending their winter days in together in feeding flocks. Come night-time and dropping temperatures, Bushtits will huddle in tight groups to maintain body heat overnight. In the breeding season, some populations of Bushtits have helpers at their nests in addition to the breeding pair – true birds of a feather.

Beavers, Birds, Byrne Creek, and Fraser Foreshore

Fraser Foreshore Park at the foot of Byrne Road, is a park I usually visit only a few times a year, most often in spring when migrant birds are moving through, and the trees and bushes are full of birdsong. But given my recent, interesting journey along the Still Creek corridor (See: Still Creek – Urban Wild, Birds and Poetry!) I thought I’d give another of Burnaby’s more “industrial” settings a look to see what I could see.

With no high expectations for what I might encounter, I headed down on Friday morning ready for a long walk along the river, both west and then east from the parking area. Much to my surprise, expectations were exceeded, and the long walk turned into a much shorter one, as I found much to see and enjoy just a short distance west of the parking area, and later walking north along Byrne Creek to the edge of the Riverway golf course, and back.

Cottonwoods

The magnificent black cottonwoods along the river, pictured above, are one of the outstanding features of this park. Their leafless forms make intricate patterns of light and shade in the soft, winter sun.

LogBoom

However, this is the North Arm of the Fraser, which is industrialized for much of its length as seen here by the huge log booms tight against the shore.

And while we humans are busy being industrious along the river, that epitome of Canadian busyness is being extremely industrious too in the large pond, south of Glenlyon, that is just a short walk up the west side of Byrne Creek off the main trail along the Fraser River.

Castor canadensis, the Canadian beaver (Canadian even in its scientific name!), is causing a certain level of mayhem in the area. Perhaps it’s good to see that there’s more than a little bit of wild going on here amid the factories and traffic. But what’s good for me, is perhaps a bit of a nightmare for the good folks who are planting trees and trying to naturalize our industrial landscapes.

Huge are trees felled. Here a willow.

Castor#6

Paper birches are cut down in their prime – stakes, wire fencing, and strapping seemingly offering no barrier to a hungry beaver.

Castor#3

And then the trunk is seriously gnawed, probably being cut into shorter lengths for dragging back toward the lodge.

Castor#2

The drag lines the beavers use to tug their twiggy bounty back to the pond go right over the top of their lodge where, to the right, freshly-cut red alder branches lie in the water ready to eat.

Castor#8

Beavers chew a lot of wood, but they don’t eat it, which explains the piles of wood chips they leave behind. They do cut through the wood to fall the trees, but they actually eat the bark and the nutritious cambium layer beneath it – their main foods for the winter months when other vegetable matter is in short supply.

Large areas of bark and cambium are stripped off the large willow branches shown below.  The beavers have been feasting on these large limbs. If the pieces are too big to drag back to the lodge, then it’s eaten it where it falls. The smaller stuff they neatly prune off to drag over to the lodge, and into the pond to eat.

Castor#7

Of course the beavers are not the only wildlife using this pond. A pair of Hooded Mergansers were actively fishing while I was there.

HOME#1Here’s the male, hauled up out of the water on…? Right – a red alder log, newly felled by the local beavers, and trimmed of its branches. Possibly those same branches lined up outside the lodge in the earlier picture.

For me, the “Hoodie” is one of the most beautiful ducks in North America – its spectacular crest gives it its name. In the picture above, it’s about half extended. When displaying to a female, or strutting its stuff in front of a competing male, the white crest extends in a beautiful arc right over the head. Remember to click on the picture to enlarge it.

Take a look at the bill of the merganser above, and compare it to the female mallard below, and you’ll notice the huge contrast in the shape and size of the bills of the two birds. Both are ducks, but the Mallard has a typical duck-shaped bill, whereas the merganser’s is long and thin. And if you could see it close up, you’d notice it has serrated edges.

MALLfem

Unlike the Mallard, a dabbling duck that eats mostly aquatic vegetation, the mergansers are divers that eat aquatic insects, fish, and crustaceans. The slender, serrated bill is used for grasping and manipulating their slippery, mobile prey.

Not all the action was in the pond. The surrounding shrubby areas were busy with birds too, some of which were obviously regularly fed by visitors. The Black-capped Chickadees were almost landing on me as I stood to watch them, but this offered the opportunity for some very close photographs.

BCCHFrsrFore

The Spotted Towhees were interested too, but stayed concealed for the most part.

SPTO

Another member of the mixed flock of birds here is the Ruby-crowned Kinglet, a hyper-active, wing-flicking midget of a bird (one of Canada’s smallest birds) that utters a buzzy ji-dit, ji-dit call as it scolds you from shrubbery. Listen to the call here.

Ruby-crowned Kinglets are difficult to photograph because they are rarely still, and outside of the breeding season their ruby crown is usually hidden. On Friday, I was lucky enough to not only get a reasonably good picture of the bird, but also a glimpse of its ruby crown too. Click to enlarge.

RCKI

And the last photograph I managed on my walk was of this Fox Sparrow in a Himalayan blackberry bush. As I’ve noted elsewhere on this blog, here’s one of my favourites in one of our most important shrubs for wintering birds.

FOSPByrneWhile I did get a number of pictures of birds on Friday, I hoped to get a beaver picture to round off this post. Mostly nocturnal, beavers often get active before nightfall, so I returned to the pond in the very late afternoon. Despite some patient waiting, I found no beavers out and about before nightfall, and had to be satisfied with a picture of the cottonwoods in the fading light reflected in the pond. Not a bad consolation at all.

CottonwoodsSunset