Purple Martins – First Confirmed Nesting in Burnaby

Back in September 2012 I wrote a blog post here on the pre-migration gathering of Purple Martins at Deer Lake Park.

In Martins Departin’? the birds involved in the “… noisy, energetic, and exuberant convocation in the tree tops along the boardwalk”  were almost certainly from the colonies at Maplewood Flats, North Vancouver, and at Rock Point, Port Moody. There were no breeding locations in Burnaby at that time.

Adult female and immature Purple Martins, August, 2012.

But now, almost five years later, I’m delighted to report that Purple Martins are actually breeding here in Burnaby, down at Burnaby Lake on the pilings at the west end of the rowing course. Not only is this a first modern-day record for the City (they likely did breed here historically), but there’s a special bonus involved here too.

The spectacular, province-wide recovery of Purple Martins, described in the earlier post, has been almost entirely due to the use of nestboxes erected by many dedicated volunteers here on the Mainland, and on Vancouver Island. Nearly all these locations have been over salt water, usually on wooden docks and pilings.

For some years now there has been great anticipation that, with the expanding population, martins will nest again over freshwater locations, which they historically did. Bingo! Burnaby Lake is freshwater, and the nesting here is one of only four very recent locations where nesting around freshwater has been confirmed – the others being in the mid-Fraser Valley.

How do we know they are nesting at Burnaby Lake? Well, head down to the Rowing Pavilion and take a look for yourself. With a little patience, every 10 to 15 minutes you’ll see the martins entering the upper-right nestbox on the fourth piling from the left. If all the numbers on the box were were readable, it would be 06 – 24. See the picture below.

Adult male Purple Martin exiting the occupied nestbox

A brief aside: this post is notable for its poor pictures. Unfortunately, the birds are distant, fast moving, and adding an additional murky quality today, was the smoke-filled air. Earlier pictures like the above are a little brighter. Today’s are, well, foggier.

Take your binoculars, and you’ll notice the returning adults are carrying food (mainly dragonflies and other large flying insects) into the nest. Try clicking once on the picture below for a larger view. Look carefully at the bird’s bill to see it’s stuffed with insects.

Male Purple Martin about to enter nestbox with food

Carrying food into the nest is one thing, but are there actually young birds inside? We can’t see them after all. However, a higher level of certainty is provided by the picture below. Here you can see the female departing the nest which a large white blob in her bill which she will very quickly drop into the lake. Like many birds, young Purple Martins’ poop is contained in a white mucous membrane “bag” which enables parents to keep the nest clean.

Female Purple Martin carrying fecal sac from nestbox confirming “someone” pooped inside.

Parents carrying out the fecal sacs suggests the youngsters are older than 8 days. After about 13 to 14 days, the young will defecate at the entrance to the nestbox from where parents carry off the fecal sac. I saw no evidence of fecal sacs at the nestbox entrance during my two visits. I estimate from these observations that the young are between about 10 and 14 days old.

Natural Hazards

After about 28 days the young should be ready to fledge i.e. take their first flight – always a risky time for all young birds as they learn the skills of flying and maneuvering, catching prey and avoiding predators.

An added hazard for these young martins is that there is at least one, and probably a pair of Merlins in the area, probably nesting too. I have seen one on both my visits. The parent martins are very vigilant however. Along with the Barn Swallows, which are quite numerous here, they instantly go into attack mode, calling loudly, and vigorously diving and swooping at the Merlin to drive it out of the area. The male seems to be more aggressive than the female in these interactions.

Distant shot of Merlin. The bird was aggressively chased from this perch by the adult male Purple Martin soon after this photo was taken.

However, Merlins, small falcons, are for their size, powerful bird predators. Often making their captures in mid-air after a high speed chase, they could be a significant threat to an inexperienced young martin taking one of its first flights.

A Long History Finally Rewarded

Joe Sadowski, a founding member of the Burnaby Lake Park Association, trail builder, and nestbox constructor extraordinaire, has been waiting 20 years, he tells me, for the Purple Martins to nest in the nestboxes he was instrumental in putting up at the lake. Along with the Park Association, Roy Teo, and Kiyoshi Takahashi have been monitoring these nest boxes and other Purple Martin nesting colonies for many years.

It’s a credit to all their hard work that we finally have these largest North American Swallows nesting in our midst. Rewarded indeed.

 

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Kestrels Breeding in Burnaby

This past Sunday (July 16), following my own advice to “… get out there and take a look”, I was cycling east along North Fraser Way in Burnaby’s Big Bend area when an interesting bird silhouette caught my eye.

Kestrel silhouetted on a dead snag in the Big Bend area

Grabbing my bins from the bike pannier to get a better look, I was soon able to resolve the dark shape into that of a Kestrel. A “good” bird anywhere in the Lower Mainland, and a real and unexpected treat to see in Burnaby.

Grabbing my camera, I started a slow walk along Abbotsford Street toward the perched bird hoping for some good pictures, or at least a record shot of this Burnaby rarity, when I noticed a second Kestrel, this one sitting low down but half hidden in a thicket next to the tree in which the the first bird was perched. Two Kestrels! Wow!

Juvenile American Kestrel

Juvenile Kestrels are difficult to visually tell apart from their adult parents; however, this guy (yes, it’s a male), was making the occasional begging call, and when the adult male swooped down into the grassy road edge to catch some prey, and then flew up with it, junior was in hot pursuit for a meal.

So this was a recently fledged bird, which virtually guarantees it was hatched right here in the Big Bend area. In the 1 to 2 weeks immediately post-fledging, the young birds solicit food from their parents. After this period they cease begging as they become adept at capturing prey independently. So this young guy left the nest and took his first flights within the previous 2 weeks, and as a young, relatively weak flyer would not have travelled into the area from outside. It was Burnaby born and raised. Yay!

The Kestrel diet is primarily insects, especially grasshoppers, beetles, and dragonflies, and small rodents, especially voles and mice. All of the these prey items would be available in the area. The farming here is predominantly mixed vegetables, with some large areas of cranberry bogs to the north. The field edges are nicely unkempt, scruffy, and weedy providing lots of just the kinds of foods Kestrels need. Farming and wildlife can happily co-exist if the farming isn’t too industrialized and intensive.

Fields of vegetables with good Kestrel foraging habitat along its weedy edges in Burnaby’s Big Bend.

 

Fallow field of rough grass meadow full of insects, and small rodents – Kestrel food

I don’t know how much pesticide use there is on these farms, but the insect life was abundant when I visited. Perhaps this is a sign it is minimal, which is not only good for our health, but also that of the insect-eating Kestrels and other birds. Along the Byrne Road side of the area, the organic farm that was Urban Digs is now getting going again under new stewardship and name – Seed of Life Farm. No pesticide use there for sure. Another positive for the Kestrels.

So where would the nest itself likely have been? Kestrels are cavity nesters, using woodpecker-excavated and natural cavities in larger trees which are surrounded by large open areas for hunting food. We’ve got the open patches in Big Bend, but not so much the larger trees in the immediate area where I saw the birds.  However, there are many large black cottonwoods surrounding the fields, and Kestrels are known to use buildings too for nesting. A number of the old farm buildings in the area looked quite suitable to me.

Vegetable fields surrounded by the old farm buildings which may have provided a suitable Kestrel nest site

Both male and female Kestrels feed the young except for a short period after first hatching when the male provisions the female and the chicks on the nest. After 7-10 days both parents feed the young and this continues through the post-hatching period.

Breaking News (July18)

Went down to Big Bend again this morning to check up on the progress of the Kestrels. Despite the fact that somehow I had put a mostly un-charged battery in my camera and as a result missed all sorts of photo opportunities, it was a wonderful morning. The news is getting better.

There were at least 4 kestrels there this morning. Two adults, a male and female, and two juveniles, a male and female. Likely this represents the whole family, but given the birds were very active hunting and begging, I could have missed more family members. The young are still being fed by the parents, but are taking up perches and stances showing they are making the transition to feeding on their own. No more perching low down and tucked in like the juvenile I first observed Sunday.

The accepted common name for this species is American Kestrel. These ones, of course, are “Canadian” born and raised. In fact, I think we can safely claim this family group as “Burnaby” Kestrels.

Adult male “Burnaby” American Kestrel

If you head down to N Fraser Way and Abbotsford St. to see the happenings for yourself, please respect the farmland and private property, and stay on the roads. This area is not a public park.

 

 

2015 Christmas Bird Count – a record count again.

There’s always some excited anticipation ahead of a day’s birding, and for the Vancouver Christmas Bird Count (CBC) in Area G in Burnaby, it comes in two types: what birds will we find, and what will the weather be like? The latter, I guess, is more trepidation than anticipation. We’ve had some brutal days of rain and snow over the years on this count. It can make counting birds an endurance test rather than a pleasant day birding.

The weather forecast in the week preceding the count was consistently bad: Sunday, December 20, would see a front sweep in from the Pacific and give us a good soaking all day long. Yuck! A regular day’s birding can be postponed, but not a CBC. It’s the designated day and out we go, storm or sun.

And out we went, and wouldn’t you know it, the sun shone! The Jet Stream had slipped direction overnight, the storm roared though while we slept, and the morning dawned to scattered clouds, blue sky, and sun. Augury for a good day, perhaps.

SunriseMouthEagleCrk

Sunrise mouth of Eagle Creek, Burnaby Lake

Note: you may view larger images of all pictures with single click on each.

Not only do the forests and fields look better and brighter in the sun, the birds are much more active, show themselves more readily, and are more vocal. Identifying birds by their calls is particularly important on a Christmas Bird Count. Because there’s not time to get a visual on each one, calls count: One towhee, another Song Sparrow, a Pacific Wren… and on we go, listening and tallying as we walk.

SPTOsun

Spotted Towhee in the sunshine

With teams at Burnaby Lake and Deer Lake, we were set for a good count. Good weather and skilled counters make a difference. Not only was the weather change a surprise, but the Burnaby Lake group was in for another just as we started counting. Stepping up to the bank of Eagle Creek to begin tallying the ducks, a bobcat burst out from under the creekside salmonberry canes, almost right under our feet, and bound across the base of the spit giving everyone a close, but fairly fleeting look in the daybreak gloom – too fast for any of us to capture a picture. Was it sleeping there, or waiting for duck breakfast? Possibly both.

Burnaby Lake team at Phillips Point, Burnaby Lake

Burnaby Lake team at Phillips Point, Burnaby Lake

I know; it’s a Christmas Bird Count. So what’s with the mammals? Well, a day’s birding is always enlivened by other wildlife seen, and the bobcat wasn’t our only bonus wildlife sighting. As we birded Phillips Point on the north side of the lake, we watched a family of river otters fishing just a short distance off-shore.

River Otter photographed while birding at Iona Island, Richmond

River Otter photographed while birding at Iona Island, Richmond

Burnaby Lake and Deer Lake parks are in area ‘G’ of the Vancouver CBC. Although area ‘G’ covers a lot of territory, we focus most of our counting efforts on the two parks, but also spend time along other sections of the Still Creek corridor. At the end of the day, we count the crow roost along Still Creek. This year we tallied 7000 Northwestern Crows, but it was a difficult count this year because the crows entered from multiple directions. Our count involved a lot of estimation, and therefore was conservative.

So how did we do? As the headline suggests, we set a new species record for the count. Seventy-two species, beating last year’s total of 69. We also had high counts of a large number of species for the count. We recorded three new species since I started keeping detailed records for the count in 2001: Redhead, Lincoln’s Sparrow, and Pine Grosbeak.

DeerLWestend

West end of Deer Lake where the Redhead was first found

Redhead, a species of diving duck, is a rare bird for Deer Lake at any time of year. Seeing one on the CBC makes it an added bonus. If you’d like to see it for yourself, the bird seems to have taken up residence on the lake. I went down today to get a few photos and it was easily observed from the boardwalk along the north shore of the lake toward the west end.

Redhead, Deer Lake

Redhead with Ring-necked Duck behind, Gadwall female in front

Lincoln’s Sparrow is a dapper little sparrow that overwinters in the Lower Mainland in small numbers. This bird is not new to the count. We’ve recorded them in the 1990’s, but it makes the highlight list because it’s not been recorded since 2001.

Based on my detailed records and memory, Pine Grosbeaks have not been recorded previously in area ‘G’ , but have been seen for the past two years on Burnaby Mountain. In fact, there are around 20 birds up there now near Horizon’s Restaurant, and easily observed. We saw five of them near Sperling and Glencarin feeding on Pacific crabapples, a favourite food for many wintering birds such as finches.

PIGRmale1

Pine Grosbeak photographed on Burnaby Mountain last year

Among the many high counts we recorded, I would highlight American Coots (207), which may have finally re-established their large wintering flock on Burnaby Lake following the completion of the lake dredging in 2011 that seemed to disturb their traditional wintering location.

American Coot flock, Burnaby Lake

Part of the large American Coot flock at Burnaby Lake

American Coot flock, Burnaby Lake #2

Closer view of American Coots with two Gadwall at Burnaby Lake.

Perhaps benefiting from the deeper water produced by the dredging, there now seems to be a good sized winter flock of Common Mergansers (66) on the lake.

COMEfishing

Common Mergansers actively fishing on Burnaby Lake

A bird that continues a long-term upward trend is the Cackling Goose (261), a smaller relative of the Canada Goose that at one time was considered just smaller type of Canada Goose, but is now recognised as a species in its own right.

TwoCacklers

Cackling Geese photographed at Deer Lake in November

The high counts of gulls, Glaucous-winged (181) and Ring-billed (76), I think are related to the transfer station on Still Creek Avenue where our curbside collected food waste is handled. Most of these birds were counted on the beach at the east end of Deer Lake. Watch the gulls over the course of the day, and you will see a continual stream heading to and from the lake where they fly in to rest up, bathe and preen. They then head out again to the north west, in the direction of the transfer station where there is always a substantial gull flock. The gulls don’t feed on the lake; they feed at the transfer station.

RBGU

Winter plumaged adult Ring-billed Gull

Another high count was Green-winged Teal (340), which find the muddy mouths of Still and Eagle creeks where they flow into Burnaby Lake, particularly good habitat.

Green-winged

Green-winged Teal preening

Here’s a link to see the full count from the day. Green indicates new to the count this year, high counts are in red.

So why did we break the record two years in succession? A combination of factors led to this fantastic result. We had good weather both years; we had a group of skilled counters in the field, and there were birds somewhat out of their usual ranges – further south or north, or up in the mountains. Good food supplies locally and poorer ones further north and in the mountains (heavy snowfalls), contributed to birds moving here, and staying.

Examples of somewhat out of range birds are Cedar Waxwings, usually found further south but finding a good Pacific crab apple crop locally. Common Redpolls from the north may not have the normal cone crops on which they depend, and Pine Grosbeaks may have been driven down from higher elevations for the easier pickings at lower elevations.

Birds like the Redhead are just serendipitous outliers from the Interior where they are quite common in winter. Such is the fun of Christmas Bird Counts.

Redhead, Deer Lake

Adult male Redhead, Deer Lake

 

 

 

 

 

 

 

 

 

 

 

 

Sad End for First Breeding Record of Sandhill Cranes in Burnaby

As I was about to publish the post below, I heard that the good news story that had been unfolding all last week at Piper Spit on Burnaby Lake had come to a sad end. The Sandhill Crane chick (colt) pictured below is no longer with its parents, and has likely died from some unknown cause.

To document the cranes’ story I have decided to let the original post stand, with some slight modifications, because it’s such a good story, and worth telling. While many will consider the outcome a local tragedy, it does illustrate how precarious life can be in the wild, especially for young animals. Survival rates are often low.

Let’s hope the cranes nest again next year. There’s a good chance they will, and we can all hope for a better outcome.

Original post written July 5/6, 2015

The risk with a post like this is that the story gets buried in the overabundance of cute at its centre.

SACRChickAdult27th

Sandhill Crane chick and adult (June 27)

Now I’m not denying (how could I?) the cute factor here , but the story is the historical first that this new arrival represents, and the cute needs no elaboration from me. Just look at the pictures.

And while the chick may be the epitome of cute, let’s not overlook that we’ve got one of the Lower Mainland’s most majestic and uncommon birds breeding right here at Burnaby Lake for the first time since we’ve been keeping records. And they’re putting on a show for everyone.

How do I know these birds have set a breeding record here? A quick search of the literature shows that this new arrival is the first record ever record of breeding Sandhill Cranes at Burnaby Lake, and anywhere else in Burnaby for that matter.

SACRChick&Parents

Sandhill Crane chick and parents (June 26)

The chick pictured above, the first day I saw it, is just a few days old, and was being fed and guarded by both parents. Watching it, I was surprised to see it was picking at and eating some food items independently, which is notable for such a young bird. Usually the parents supply all its food requirements at this early age. After their natal down has dried, and within 24 hours of hatching, Sandhill Crane chicks leave the nest permanently. Such behaviour defines these hatchlings as nidifugous (Sorry, couldn’t resist such an unlikely word), and then they’re off on the risky journey to adulthood.

Sandhill Cranes are rare breeders in only a few locations in the Lower Mainland/Fraser Valley. The wetlands south of Pitt Lake in Maple Ridge were their breeding centre for many years, with just a few pairs actually nesting there. A few more bred in Langley. We do see large flocks of Sandhill Cranes in the Lower Mainland, but only in migration – spring heading north and fall flying south. For the most part these birds continue on their migrations and we are fortunate to see them when they pass over.

However, over the past decade or so, a small breeding population has established itself at the Reifel Migratory Bird Sanctuary in Delta. Birds, likely from that population, have been turning up in Richmond, where they started to breed about five years ago (first time since 1946), and they’ve also been showing up on our local golf courses, where they haven’t nested, perhaps from dodging flying golf balls!

Sandhill Cranes at Reifel Migratory Bird Sanctuary, Delta

Sandhill Cranes at Reifel Migratory Bird Sanctuary, Delta

In British Columbia, Sandhill Cranes breed mostly in the Central Interior (Northern Okanagan and the Cariboo/Chilcotin, with some breeding in the north east (Fort Nelson area), and others on the central coast islands and Haida Gwai. Breeding in the Lower Mainland is much less common.

Sandhill Crane chicks grow rapidly, and “our” Burnaby bird seems to be doing just that. Compare the picture taken June 26 with the one here below taken July 5th. Junior is gaining height and bulk, and both parents are supplying it with food.

Chick and parents, July 5

Chick and parents (July 5)

Unlike many birds that spend their first weeks in the nest, nidifugous birds are incredibly mobile for such young animals.

It can wade, even on its junior-sized legs.

 

SACRSwim

It can swim.

SACR BbyLRun

It can run.

SACR BbyLChick

It can preen.

Or, it can simply look disarmingly cute.

IMG_6735

Sandhill Cranes have been showing up irregularly at Burnaby Lake for the past few years. This year they clearly stayed to breed.

Between one and three eggs is the usual clutch size, with two being typical. One or two young are usual. Both parents incubate the eggs, although the female does the overnight shift which means she does about 70% of the incubation duties. Once the chicks leave the nest, both parents protect and feed the young.

SACR BbyLFed#5

Sandhill Cranes are monogamous and tend to maintain pair bonds over many seasons, especially if they successfully breed together. So barring accidents, this pair may be together for the long haul.

As to which is the male and which the female, the birds know of course, but the sexes are similar and not separable by appearance. During their courtship displays though, the males and females can be identified by their specific bugling calls and head motions.

Postscript

I headed down to the lake this afternoon (July 6) to confirm the reports of the chick’s disappearance. Sure enough the two parents were there, occasionally bugling quietly, but no chick was in sight. Given the birds’ extreme attentiveness to their young, the conclusion has to be that the youngster is dead.

It was apparently showing some respiratory distress yesterday which got progressively worse during the day. The chick was nowhere to be seen this morning. A sad ending, but there is hope for next year.

Pair

Pine Grosbeaks – Burnaby Mountain Park

It’s not every winter that Pine Grosbeaks show up at lower elevations of the Lower Mainland. But what a treat it is when they do.

PIGRmale1

Pine Grosbeak, male

The beautiful male shown above is one of a flock of at least fourteen birds that are providing a show for visitors to Burnaby Mountain where they can be found feasting on the buds of the flowering cherry trees that line the path south of Horizon’s Restaurant.

In the West, this large member of the finch family is usually found in the coniferous forests of the mountains where it breeds. More commonly seen in lower elevations in the Interior, it only rarely puts in an appearance in coastal areas of southern BC. These irregular movements to lower elevations are called irruptions, and are perhaps related to changes in food supply, but like many aspects of this species’ life, the phenomenon is poorly understood.

Found across the continent, mostly in Boreal Forest regions, the Pine Grosbeak’s range also extends to Eurasia where it is found from Eastern Asia to Scandinavia. Despite the wide geographical range of this species, it’s likely that the different populations do not wander very widely from their home territories. Our visitors to Burnaby Mountain have likely not travelled great distances to get here.

PIGRfem2

Pine Grosbeak, female

Males and females are very different in appearance. The females’ colouring is more subdued, a subtle mixture of grays and greenish gold. This cryptic colouration is no doubt important during nesting, when the female is the only one of the pair to brood the eggs and chicks. Both parents, however, share in feeding the young.

While the males and females in the flock are easy to pick out, there are also a couple of differently plumaged individuals in the flock. The one below shows a lot of red on the head and neck in an otherwise female plumage. This individual may be a first year male, not yet fully red, or a female that is more colourful than is typical.

PIGRimm?

Female or first year male Pine Grosbeak

Given these birds live mostly in inaccessible mountain forests, it’s perhaps not surprising that they tolerate close approach by people. It appears they do not see humans as potential danger. If you pay a visit to the cherry trees on the mountain, make sure you take a camera or binoculars. Move slowly, without sudden movements, and you’ll be rewarded with close views of the birds unconcerned with your presence. You will get the opportunity to see some of their more subtle features in close-up, for example the striking back pattern on this bird.

PIGRback

So enjoy them while they’re here; it may be many years before we see them again.

PIGRmaleClose

 

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.

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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.

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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.

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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.

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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.

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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.

 

Northern Harriers – Update

Perhaps quite predictable, but good news nonetheless for the prospects for raising another generation of Northern Harriers at Deer Lake was the arrival on the breeding territory of a female harrier just a couple of days after the male was scouting out the lay of of the land.

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Female Northern Harrier newly arrived on her breeding territory.
Photo: Jason Hung

And of course we can anticipate the outcome of a male and a female on the breeding territory. The male was soon in courtship mode, and pursued the female whenever she landed on the meadow.

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Male harrier takes off in pursuit of female
Photo: Jason Hung

Copulation was not captured photographically, but here the male is approaching the female very closely.

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Harrier pair. Photo: Jason Hung

In the meantime I’ll keep you posted as events unfold. Even better, get down to the meadows and check out the action for yourself. However, please keep out of the meadows and observe from the trails. The birds’ breeding success depends on us, and our dogs not disturbing them.

I’ve also updated the photographs with higher resolution images on the previous post about the harriers at Deer Lake. Click here to view that post and the upgraded images.

Northern Harriers – A Sign of Spring

Not only is the calendar telling us that today (March 20th) is Spring Equinox, but nature too is showing us the seasons are changing. The first Tree Swallows of the year showed up at Burnaby Lake just over three weeks ago, and there are all sorts of signs of spring in our parks. From the blooming of the indian plum in the forests, to the peeping of tree frogs down at Burnaby Lake, all confirm what the birds are telling us – spring is here.

For me, one of the most exciting signs of spring is the return of the Northern Harriers to their nesting area in the meadows at the west end of Deer Lake. And just this past Friday (March 14) I saw the male harrier checking out his regular nesting area.

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Male Northern Harrier checking out its nesting territory prior to breeding

Not a great picture, but the bird was far out in the meadow. Below is a much better picture of the male harrier in flight. Jason Hung, who kindly let me use some of his photographs for this post (thank you, Jason), has much superior pictures of the birds than I can capture with my more basic camera gear. A lot of patience waiting for the birds to fly close-by is needed, and Jason’s patience and skill with a camera has certainly paid off. He’s managed to get some great shots over the past couple of years.

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Male Northern Harrier photographed at Deer Lake by Jason Hung

The fact that we’ve got harriers nesting at Deer Lake, is a real feather in the cap for Burnaby Parks – pun intended! We’re tremendously fortunate to have them nesting pretty much in the centre of the City because harriers need undisturbed wetlands or grasslands in which to nest and raise their young. Unlike many raptors, harriers nest on the ground, and as a result are very susceptible to disturbance from people and dogs. The Deer Lake birds arrived here about 10 years ago, and set up nesting territory in the park. As the park has got busier over the years with the increasing population around Metrotown, the pressure on the birds’ habitat has increased. At least once in the past few years, a dog killed a young harrier on the ground, but in most years the pair has successfully raised one or two young.

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This city sign is important protection for our ground-nesting Northern Harriers. Let’s watch and enjoy them from the nearby trails.

Now known as Northern Harriers, these birds were previously named Marsh Hawks and many readers may know them by the previous moniker. “Hawk” is a generic name applied to many raptors, but in the case of harriers it’s not a particularly apt descriptor.Compared to other North American raptors, harriers have a number of unique characteristics. Firstly, the males and females have strikingly different plumage; they are sexually dimorphic. As can be seen from the photos above, the males are grey backed, and mostly white underneath with black wingtips. The females, in contrast to the males, are mostly shades of brown above with buffy, streaked undersides.

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Female Northern Harrier. Photo: Jason Hung
Click to enlarge

Looking at the picture above, it’s possible to see that harriers have another interesting feature not found in other day-hunting raptors. They have facial disks like owls, which perform the same function for harriers as they do for the raptorial nightshift. They focus the sounds of prey to enable the capture of mice and voles, even when they may be out of sight in thick grasses over which the harrier is gliding.

Even more interesting, perhaps, is that the males are polygynous i.e. they mate with more than one female, sometimes up to five. However, mostly they are monogamous or bigamous, and in all cases the males provide most of the food for both females and the young. Our male at Deer Lake has typically had two females to provide food for. The second nest is in a virtually inaccessible part of the park, and while the patch of habitat is smaller, it may be more protected from intrusion because of its isolation.

The provisioning of food for female and young by the male gives us the opportunity to see a very exciting and dramatic event. When the male returns to the incubating female sitting on the nest, he gives a whistling call, which is the signal for the female to get airborne. Once she’s up and flying she also calls insistently. The male, flying higher, drops the prey for the female below to pursue and to catch in mid-air. It’s a wonderful aerobatic display.

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Male above, female below with prey just released by the male.
Photo Jason Hung

When the young are flying, the adults will drop in prey for the young to catch in mid-air. Below, Jason once again captured the action. This time it’s the female making the aerial exchange with one of her young.

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Female to young prey exchange. The in-transit food is probably a Townsend’s vole.
Photo: Jason Hung

The next couple of months will provide many opportunities to observe the comings and goings of the Northern Harriers at Deer Lake. Keep your distance, and enjoy the show. Nesting starts in earnest in the next couple of weeks. Spring is definitely here.

Our Dandiest Duck?

So let’s see: iridescent greens, blues, cobalt, purple, violet, bronze, ultramarine, crimson, burgundy spotted with white, black, and vermiculated gold; we could just as well be reading a list of exotic colours on an artist’s palette as descriptions of Wood Duck plumage – a dandy’s colours for sure. See for yourself; click on the image below.

WODU3pairWood Ducks frequently perch on logs, and tree limbs near the water

The females above are noticeably subdued in their plumage compared to the drakes, but being the sole incubator of the eggs, and the guardian of the young when they first emerge from the nest, it makes sense to be less eye-catching to predators. It’s all about remaining inconspicuous, and not drawing unwanted attention. This is a common evolutionary adaptation among many bird species, and among North American ducks nearly all species show this strong sexual dimorphism. Wood Ducks happen to be one of the species that push these male/female differences to the extreme. While it is the drakes that catch the eye on a first look, both females and males are worthy of close scrutiny that reveals the real complexity and subtlety of the colours of both sexes. Let’s start with a closer look at the females.

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Female Wood Duck – showing the diagnostic white eye-patch that tapers to the rear.

Most species of female ducks are relatively drab in colour, often a mixture of browns, buffs, and tans, but our Wood Duck above shows some iridescence both on the top of the head, and in the shoulder feathers (scapulars) spreading out below the neck. Taking an even closer look at the scapulars we see the subtle, but beautiful colours that we might otherwise miss when seeing a female perched alongside her fancier mate.

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Subtle but striking – the shoulder and some wing feathers of the female Wood Duck

Wood Ducks are unique among North American duck species. They are the sole representative on the continent of their genus, Aix (Greek for waterbird). In fact, the Aix genus contains only two species worldwide. The other is the Australasian Mandarin Duck – another contestant in the “dandy duck” stakes. Both are part of a larger group called the perching ducks. Wood Ducks certainly live up to that classification. They are often seen perching along the water’s edge on logs and in sometimes in trees.

Confirming their scientific classification as perching ducks, Wood Ducks line a tree limb over Eagle Creek

Confirming their scientific classification as perching ducks, Wood Ducks line a tree limb over Eagle Creek, loafing, preening and snoozing.

There’s a certain irony, however, to the dramatic sexual dimorphism we see in Wood Ducks. It’s the drabber females’ choice of mates that drives the evolution of the spectacular male plumage. Pairs are seasonally monogamous, i.e. they pair-up anew each year,  but because the males play no part in rearing the young (more “dandy” behaviour?) their breeding success is more strongly determined by their ability to attract a mate. Therefore, the bolder the plumage, which indicates to the female readiness and suitability of the male for breeding, the more chance the male has of being selected and passing on his genes to the next generation. Other species of birds in which the males do assist with rearing the young are frequently less sexually dimorphic. Here’s the drake Wood Duck.

Wood Duck male – Dandy indeed!

Wood Duck male – Dandy indeed!

The colours above need no more description, but it is worth noticing the rakish crest that flows down the back of the head. The female has one too, and among the dabbling ducks in North America (Mallards, wigeons, and teals etc), the crest sported by the Wood Duck is unique.

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This drake is perched next to a female, and is lifting his head to display to her the “full effect”.

The gradations of colours here on the head are quite striking in close-up. No doubt they’re just what an interested female is looking for.

Paired Wood Ducks

Paired Wood Ducks

And while all this fantastic plumage is in pursuit of one thing – passing on the male’s genes to the next generation, Wood Ducks also need suitable habitat to breed successfully – marshy lakes and ponds with lots of surrounding vegetation. Oh yes, and one more thing; they need nest cavities. Before the forests of North America were extensively cleared, and the old trees that contained natural cavities from broken branches and abandoned woodpecker holes were cut down, Wood Ducks were numerous. However, by the late nineteenth century there were real fears that the Wood Duck would go extinct from the combination of habitat loss and over-hunting. After the Migratory Bird Act of 1918 ended the legal hunting of Wood Ducks, the species recovered rapidly. Concerned conservationists also helped them along by providing nest boxes to replace the natural cavities that had been lost in forest clearing.

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Wood Duck nestbox – Piper Spit, Burnaby Lake

The best place locally to see lots of Wood Ducks is Burnaby Lake at Piper Spit, and it’s no coincidence that at this location you’ll also see many nest boxes put up specifically for Wood Ducks. Although there are many nestboxes at Burnaby Lake, there may not be enough for all the ducks needing one. There are frequent incidents of egg-dumping here when more than one female lays her eggs in a single nest box – up to thirty eggs in a one box. Now not all the eggs will hatch in these conditions, but for a female that can’t find a nest cavity of her own, it seems a good strategy to ensure that at least some eggs produced by the female will hatch.

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