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.

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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.

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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.

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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.

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

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

 

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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Phabulous Pheasants

In my previous post, about Burnaby Mountain, (click here) I showcased one of our spectacular resident birds, the Sooty Grouse. And not to be outdone by that strutting beauty, we have another resident chicken-relative in our parks, that many would consider even more spectacular, the Ring-necked Pheasant. He’s a very showy guy, as you can see.

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Ring-necked Pheasants are named for the white collar circling their necks.
Click to enlarge.

And I say “guy”, because like all members of this family of birds, it’s the males that are the showy ones. The females incubate the eggs, and being ground nesters, they need to stay hidden and well camouflaged. In fact, they are so well hidden at this time of year that I haven’t been able to even see one, let alone get a photograph.

Just take a close-up look at this guy. He’s probably got a greater variety of colours than any other bird in our area. What’s your count? And look at the length of that tail, not only to appreciate its striking length, but because on this tail hangs a tale – keep reading.

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Multicoloured describes it, but really doesn’t capture the detail and intricacy of the
Ring-necked Pheasant’s spectacular plumage. Click to enlarge.

If you take a walk along the upper trail, immediately below the Oaklands development at the west end of Deer Lake Park, you’re almost certain to hear the loud, hoarse, crowing of a cock pheasant. Variously described as koork-kok, or kok kok, just like a farmyard rooster, he’s proclaiming his territory.  On Thursday I counted three males here claiming their turf, often replying to each other in turn. If you’re close enough to one crowing, you’ll also hear a wing-drum, or wing-whirr immediately following the the loud vocal call. This second sound is produced by rapidly flapped wings as the bird rears up to its full height.

The one photographed here can be approached with some care. But if you do see him, don’t walk straight at him. You may be able to get a little closer by taking a very slow, angular path to bring you closer to the bird. Watch his behaviour closely and if he crouches down and starts to retreat, you’ve come too close. Whatever you do, admire him from a respectful distance. Better yet, take your binoculars to bring him into close view.

Of course, all this show, the crowing and the wing flapping is all about reproduction – you know, the Birds and the Bees stuff. Also at this time of year, the facial wattles are crimson and enlarged, as can be seen above. A sign of a vigorous, in-condition male.

In each cock’s territory will be a harem of females that he guards from the intrusion of other males. In technical lingo this is called female- or harem-defense polygyny. No judgements here please; it’s just the way things are in pheasant land. Females under the protection of the male get to focus on egg-laying and incubation and don’t have to expend energy and suffer disturbance from unwanted attempts at copulation by non-territorial, usually young males. Display and crowing will decline as the females finish laying their clutches of typically around ten eggs, but sometimes up to fifteen or more. Pheasant harems tend to be modest in size, frequently around two females per male, but have been recorded with up to fifteen females per male. Whew!

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Erect feather “horns”, and bright wattles are all marks of the territorial cock pheasant.
Click to enlarge.

A native of Asia, Ring-necked Pheasants have been introduced around the world, mainly for hunting. The birds at Deer Lake probably descend from birds originally introduced for hunting when Burnaby was much more rural. However, I suspect there may have also been “supplemental” releases over the years by nostalgic hunters who still like to see the birds around.

The ones in our parks are of course protected from being shot . However, you’d think that such a brightly coloured bird, that spends nearly all its time on the ground, would be easy prey for a number of predators. Indeed the pheasant’s life can be a risky one. With all the coyotes, racoons, skunks, and hawks in the park, both adults and in particular the chicks, are very susceptible to predation, as are the eggs that the females are now incubating. The fact that these birds persist in the park is always quite remarkable to me, given the number of things that could make a meal of them. Of course, they provide another very good reason for keeping dogs leashed at all times.

So here’s the tale of the tail. When I photographed this male a couple of weeks back, he was beautifully long-tailed, a plumage characteristic common to all pheasants.

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Pheasant with a phull tail

But when I photographed him yesterday something was missing. The same bird is now tailless.

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Now tailless, the long plumes gone, the cock pheasant continues to crow and display.

Territorial males rarely fight among themselves, and such a battle would be unlikely to cause this kind of damage. So it seems our friend here had a near fatal encounter and a successful escape. Perhaps a long tail is helpful for more than show. A predator may grab it as the bird tries to escape, and end up with a mouthful of feathers instead of meat. Coyote, or off-leash dog? We’ll never know, but I suspect an encounter with one of the two.

Even though he’s not at quite his former glory, and is just a bit tattered, he hasn’t been displaced from his territory; he persists in guarding his females, and lives to crow another day. Phabulous!