Can I get a Whoop Whoop?

The Whooping Crane was, and is, one of the most endangered birds in North America. Though probably never abundant, the population reached a staggering low of about 15 birds in 1941 due to hunting and habitat loss/degradation. From these beleaguered survivors, strong protection and good management practices have increased the main wild population up to almost 300 today. A couple hundred more birds occur in re-introduced flocks in eastern North America and in captivity. Nevertheless, it is fair to say that this large, long-lived, slow reproducing species is still exceedingly rare (a sad trend for many crane species).

Whooping Crane (Grus americana). Photo: Wikimedia Commons

The one remaining wild flock breeds almost exclusively in Wood Buffalo National Park on the northeastern Alberta-southern Northwest Territories border. The breeding grounds are luckily remote and inaccessible, offering a safe breeding area. Pairs return in April and begin nesting soon after. Typically birds don’t begin nesting until they are around 4 years of age (they may live over 30 years in the wild), and only lay up to 2 eggs. Though 2 eggs are laid, typically only one survives to fledging. The incubation period lasts about a month, and chicks are able to fly well about 3 months later. With a 4-month nesting period, there typically isn’t time to lay another clutch if the first one fails. Atypical for most bird species, young migrate and remain with their parents for 10 to 11 months. And so, family by family, the whole population migrates south, staging for several weeks in Saskatchewan, before continuing on to the wintering area in Aransas National Wildlife Refuge, Texas.

It is there, in Texas, that most birders catch up with the great white Grus. Indeed a Whooping Crane anywhere is a sight to behold, but there is something extra special about catching a glimpse of this species in Canada. It certainly adds a dimension of challenge to the hunt. If one does the math, there is roughly 1 Whooping Crane per 300 square kilometres within the Saskatchewan fall staging area. Considering that family groups migrate together, and birds are often clustered, the amount of land you need to cover in order to actually see one can be considerably greater. On the flipside, Whooping Cranes often remain in the same area for several weeks. Within the past few years, the area of Muskiki Lake east of Saskatoon has been just such an area. Flocks numbering in the twenties have started to accumulate at Muskiki, sizes not seen since historical times.

I’ll be making my own migration to Muskiki Lake soon, in hopes of finding these cranes; the tallest birds in North America with one of the smallest populations.  Stay tuned!

Posted in birds | Tagged , , , , , , | 1 Comment

Are we there yet?

Sharp-tailed Sandpipers have always held an allure for me. For starters, they are rare here in British Columbia (and absent from the rest of Canada). Although present along the coast every autumn, usually from mid-September into October, they are always exciting to find. Part of this rests on the fact that they are an Asian bird. This alone, in my eyes, sets them apart from other equally-rare species occurring locally that are otherwise found in North America, such as Hudsonian Godwit.  In coastal BC they can be expected in places such as Reifel Bird Sanctuary and Iona, but they have the ability to show up anywhere, and even inland. Another intriguing fact is that virtually all the Sharp-tailed Sandpipers that turn up in North America are juveniles. In addition to their relative scarcity, another alluring factor is their appearance. They stand out from other shorebirds with their bright chestnut cap, buffy wash across the breast, and bright rufous edging to scaps, coverts and tertials.

Adult Sharp-tailed Sandpiper (photo: Wikimedia Commons). The juveniles are even more colourful and strikiing in my opinion.

In the February issue of The Condor, a paper by Lindstrom et al.1 helped explain why juvenile Sharp-tailed Sandpipers are as common as they are in North America, while adults so scarce. But before delving into specifics, let’s take a look at the broad view of shorebird migration. The general, well-known idea is for a bird to get from its breeding grounds to its wintering grounds, and vice versa. However, there are a number of different strategies a species/individual can employ. A bird can migrate using a time-minimizing strategy, or it could use an energy-minimizing strategy. The two are not necessarily exclusive. We can use the analogy of driving a car cross-country. In a time-minimizing strategy you would get in your car, fill the tank, and drive as fast, as long and as far as possible before filling up the tank again. In an energy minimizing strategy you would get in the car, fuel it up, drive at the most fuel-efficient speed, and probably put it in neutral downhill. For example, falcons may be good at time-minimizing while the soaring raptors are much better at energy-minimizing. Of course there is a third, equally important consideration, and that is predation. You can think of avoiding predators as a risk-minimizing strategy, but as the result of predation is death, it’s really a survival-maximizing strategy, and in that sense may actually be the greatest driver in the evolution of migration strategies.  At any rate, now when you fill up the car there is a hungry monster potentially hiding behind the pumps, and the longer you spend fuelling the greater your chance of getting eaten!  To add a greater complexity to the situation is that not all birds leave at the same time. In the world of arctic-breeding shorebirds, typically adult females migrate south first, followed by the adult males, and lastly the juveniles (though for Sharp-tailed Sandpiper adult males head south first).

In the case of Sharp-tailed Sandpipers, adults migrate from their breeding range in north-east Russia, through continental East Asia and then onwards to wintering areas in and near Australia. Many juveniles (possibly tens of thousands), on the other hand first make an ~2300 km detour eastwards to major shorebird stopover locations in western Alaska. On the surface, such behaviour seems neither time nor energy-minimizing. Lindstrom et al. found that Sharp-taileds generally arrived in their study site in early September and departed on average at the end of September (to be exact, departing on Sep. 27 and Sep. 29 for males and females respectively). Individual birds had a median minimum length of stay of 12 days, upwards to a maximum of 33 days. That is, most birds spent approximately the month of September in Alaska. An earlier paper covering more areas of Alaska found birds present from late August until early November.

Migration Routes of Adult (solid lines) and juvenile (dashed line) Sharp-tailed Sandpipers. Map from the USGS Alaska Science Center webpage accessed here: http://tinyurl.com/3smn4sf

When the birds first arrived in early September they were relatively lean, carrying just slightly higher fuel loads than their lean body mass, and their rate of fat deposition was low. By mid-September, however, the rate of fuel deposition increased markedly as birds began to fatten up for migration, often doubling their weight. With tanks full, it is estimated that these Sharp-tailed Sandpipers can then make a single flight in still air of nearly 10,000 km! It is postulated that these birds join the ranks of other trans-oceanic migrants, such as the Bar-tailed Godwit and Ruddy Turnstone, in making a single, non-stop flight from these staging grounds in Alaska to wintering grounds in Australia.

There are a couple of things to consider here. First is that the staging area is relatively free of predators. Such a high fueling rate would not be possible if under constant attack, especially as it’s been proven in other species that high fuel loads increase the risk of being captured.  The second is that this predicted long-distance flight would not be possible if not for such a rich stopover location. We can then start to see that if other stopover locations along the East Asian-Australasian Flyway are (a) more dangerous and/or (b) less profitable, that a safe (from predators, pathogens, etc.) but long-distance trans-oceanic flight might actually be advantageous, despite that initial detour.

So how does the evolution of migration in Sharp-tailed Sandpipers impact birders in British Columbia? Well, we can see that the chronology of sightings in the province fits with the period of when birds show up in and migrate from Alaska. In addition, it explains why all of our birds are juveniles. And since most appear to leave Alaska directly for wintering grounds, it explains why we see only a fraction of the birds that occur in Alaska.

Of course, many additional unanswered questions are raised.  For example, are our birds the ones that do not attempt a trans-oceanic flight? If not, where do they go? The lack of winter and spring records in North America indicates that they must either perish, make a different trans-oceanic flight to the wintering grounds, or winter at some unknown location in the New World and make an even more remarkable trans-ocean flight up to the Siberian breeding grounds from there. (I think they likely make their way to the wintering grounds eventually). Are our birds the ones that did not sufficiently fatten up, either due to disturbances or other unknown causes, to make the great flight? Are the birds we see simply lost, or is this an established alternative migratory pathway? Or is it that our birds are ones that actually started out over the ocean but got blown off-course or forced to seek land due to unfavourable weather conditions? (Personally I think if this were the case we’d see larger numbers of birds involved, rather than the 1 or 2 birds usually seen at any given location or time). And why don’t adults use this same strategy? For this last question, the answer may very well have to do with molt as we see in other adult sandpipers (the juveniles having just grown a new set of flight feathers don’t have this same constraint); at any rate, adults appear to be a time-minimizing migrant.

As you can see, we’ve just barely skimmed the surface of the evolution of migratory pathways and strategies. The different life-history strategies even within a species can help us birders predict when and where to look for birds. And if you are successful in catching a glimpse of a bird such as the Sharp-tailed Sandpiper, take a moment away from admiring its beauty or rarity, and consider just how improbable it is that it’s here at all, and just how far it has yet to go.

1Lindström, Å., R.E. Gill Jr., S.E. Jamieson, B. McCaffery, L. Wennerberg, M. Wikelski, and M. Klaasen. 2011. A Puzzling Migratory Detour: Are Fuelling Conditions in Alaska Driving the Movement of Juvenile Sharp-tailed Sandpipers?. Condor 113: 129-139.

Posted in bird distribution, birds, science | Tagged , , , , , , | 2 Comments

Aves Playeras

Hi all. Sorry for the lack of recent postings to the blog. I’m currently in the thick of the 4th Western Hemisphere Shorebird Group conference at Simon Fraser University. Yesterday I gave a presentation on over-ocean flocking behaviour of Pacific Dunlin, and otherwise have been completely engulfed in shorebird talks, shorebird meetings, and shorebird communications. Plenty to talk about, and lots of blog posts lined up, but they’ll have to wait until next week. Gotta go, there’s a shorebird calling…

Posted in Uncategorized | 2 Comments

What’s the Teal-io

Every once in a while in birding, something completely surprises you. Sometimes it’s an assumption that you’ve always had, that you suddenly realize is completely false.  Sometimes it’s an epiphany about some field mark – maybe one that every other birder knows, that has somehow slipped past you for all this time.

For me, the Limpkin falls into the category of mistaken assumptions. The first time I saw one, I was amazed at how big it was. I had always just assumed that they were the size of a large rail.  So imagine my surprise to discover that the brownish heron standing beside a pond in the Yucatan was a Limpkin.

The surprisingly large Limpkin. Photo: Wikimedia Commons

Female Eurasian Teal and female Green-winged Teal fall into the second category for me. I had always just run under the assumption that they were indistinguishable, and left it at that.

But first a bit of background. Here in western Canada we have three regular species of teal: Green-winged, Blue-winged and Cinnamon. However, a fourth teal, the Eurasian (aka Common Teal), occasionally shows up from breeding grounds in Asia and western Alaska. Several years ago there was increased attention paid to the Green-winged and Eurasian teals as ornithological committees around the world split off Green-winged Teal (Anas carolinensis) from Eurasian Teal (Anas crecca) as two distinct species. There was much rumour and hype that the American Ornithologists’ Union would soon follow suit…they never did. At any rate, whether considered as two separate species as they are in many countries, or as different forms of the same species as here in North America, the stage was set for looking at our teal much more closely.

Fast forward to a birding trip I took to China. We were enjoying scoping out Eurasian Teal flocks in the hopes of turning up new and exotic species. The problem was that due to incessant hunting pressures, these birds rarely stuck around long enough for careful scrutiny. So it was, while watching the tail end of yet another teal flock, that it suddenly hit me what was different about these birds. The upper wing-bar (formed by the greater coverts) of Eurasian Teal is a different colour than on our Green-wingeds. The speculum of Green-winged Teal is bordered by a white trailing edge, and a (variably) buffish upper bar.  On Eurasian Teal both of these bars are white. This was good news, for now I could try to pick out a female Eurasian Teal back home in Canada.

Upon coming home and investigating this trait, I found out that it was, in fact, an already published field mark. This and a couple other field marks can be read about here. Now, I don’t think the wing bar difference is 100% reliable. That is, I’ve yet to encounter a Green-winged Teal with a completely white upper wingbar, but some Eurasian do seem to have buffish bars, especially nearer the body. Sibley’s guide states that there is much overlap in this feature, and undoubtedly integradation/hybridization (depending on your taxonomic viewpoint) complicates the matter somewhat. Some birds, as always, are best left unidentified. Nevertheless, this wing bar appears to be one of the main differences in separating the females of these species/subspecies, and knowing this is one more weapon in the birder’s identification arsenal.

To see this difference in some images of female Eurasian Teal in flight check out here, here and here. For images of Green-winged Teal check here and here.

Posted in bird identification, birds | Tagged , , , , , , | 1 Comment

Tussocky: not a town in Italy

Picture walking through the tundra. What did you see? A vast flat expanse, 24 hours of sunlight, a bounty of singing birds, and the buzz of mosquitoes? Well you’re almost correct…except for the bit about it being flat. Instead, raise your trail up a few metres, drop it down into a snowpile, then raise it back up. Repeat.

Somehow I manage to work in a variety of “flat” places that end up being anything but flat. The same thing happened to me on the Prairies. My visions of prancing through the flat grass and canola fields were suddenly shattered when I arrived on my Saskatchewan work site. Rolling hills as far as the eye can see. It turned out that Missouri Coteau wasn’t an architectural style.

Well, it’s true that history repeats itself, and I now find myself on the low arctic tundra near Nome, sweating and tripping over willow-fringed hillocks. I’m fairly certain that the term “rolling hills” describes the likelihood of rolling your ankles rather than the hill itself, and don’t let me catch you adding the term “gentle” to the descriptor! If all this weren’t enough, these miniature mountains of mayhem are covered in tussocks of grass. If you haven’t the pleasure of walking across tussocks, imagine a field full of bowling balls resting in cottage cheese, all on a layer of ice.

On one of my recent visits with the ground, I contemplated the grassy demon-bump that felled me. Tussock is a strange name, I thought. At first it sounds rather benign, but if you say it quickly and slightly slurred it can substitute nicely for any expletive you might otherwise use; for example, on your quick re-orientation from vertical to horizontal. “Oh tussock!”

Lapland Longspur on a Tussock

On reconsideration, tussocks may be the most aptly named thing on the tundra. Even the closest town to my camp has a rather anti-climactic etymology. Nome, despite my best guess, is not a native name meaning “place of waist-deep snow one day and chest-deep puddle the next”. In fact, it doesn’t mean anything at all. A series of cartographical type-set errors converted “? Name” to “C. Name” and finally “C. Nome”. But it’s not just towns that have confused names. As I type this Tree Swallows zip past, far from any tree, and Eastern Yellow Wagtails call out from one of the westernmost points in the Americas. Meanwhile the ubiquitous warbling of the Lapland Longspurs ring out, far from the Lapland region of Finland and Sweden.

An Eastern Yellow Wagtail in the West

As always, things are more contoured than they at first appear. Well, I’ve now packed my sandwich and am prepared to head back into the not-so-flat wilds of Alaska. I just need to remember to keep my wits about me and watch my ste….whoooaaaaa…..oh tussock!

Posted in Alaska, birds, Habitat | Tagged , , , , | 4 Comments

Gulls, garbage, glory

5 species of scavenger scour for tasty morsels

Landfills are wonderful, exciting places.  I personally try to visit them often, and it’s a different experience every time.  I’ve had the fortune to bird garbage dumps from 60 degrees N to 55 degrees S. The only place potentially more exciting is a sewage lagoon, but short of finding one of those the lure of a new bird at the landfill of the southernmost city in the world was too much to bear. With a few hours to spare during our last day in Ushuaia back in 2009, I decided to take the question of “Who doesnt like the garbage dump?” to the streets.  My first survey came up negative.  Angie [my partner] does not like landfills.  So, she stayed behind.  From there though, responses only got more positive.  Taxi drivers like landfills; perhaps more to the point, they like dumb tourists who are willing to pay to get a ride to the landfill.  This particular driver didn’t seem as shocked by the prospect of going to the dump as the lady in the tourist office was when I asked how to get there.  At any rate, he seemed to be familiar with the place (which would be expected since they are so wonderful) and took me directly to the birdiest vantage point. My next respondents all checked the “extremely like” box of the questionaire.  Turkey Vultures find waste wonderful.  Black-chested Buzzard-Eagles like the landfill. Even the humble Bar-winged Cinclodes basks in the basurero.

A White-throated Caracara battles a Black-chested Buzzard-Eagle for aerial supremacy.

Perhaps most enthusiastic, 3 species of caracara (including my lifer White-throated Caracara) delight in the dump.  After a while I realized my survey was biased to those respondentswho were already inclined to respond favourably.  So I took my extremely scientific and unflawed survey to the forest.  However, I could find nothing there.  Probably because they were all enjoying their afternoons in some sunny corner of the landfill I could not reach.  I thereby conclude, beyond the smallest percentile of a doubt, that not only are dumps marvelous places to spend a few hours, but they are also signifcantly more important in conserving biodiversity than, say, a nice riparian stretch of river, or an old-growth forest.

Posted in birds, Habitat | Tagged , , , , , | 1 Comment

From Astrapia to Zosterops

I like bird books. A lot. Some say it’s wonderful to have an extensive ornithological library at your fingertips. Others say “you bought them, you move them into the new place”. While it’s true that a Rubbermaid tote full of books is a heavy beast, most of the contained weight is from all the dreams and hopes that lie on each page. Will I ever see a Subdesert Mesite in person? I don’t know, but at least I can read about it for now.  Well, ok, I may not have the time right now to read about it, or any of the other Malagasy wonders, but one day when I want to I know I can. It’s in that spirit that the pilgrimage to find yet another bookshelf has become an annual event in our house. The Helm guides to specific bird families are all together on one bookcase, while the regional field guides live on another. Recently, however, there has been a disturbance in the force. With shelf space at a premium in our rental suite, I’ve had to sit back in silent protest while things like “The Birds of Northern Melanesia” get replaced with titles such as “Panda Bear, Panda Bear, What do you see?”.  I’ll tell you one thing right now, that panda bear does not see Zosterops vellavella, or any other Melanesian endemics (though admittedly he does rack up an intriguing species list)!  Sure, children’s literary classics are all fine and dandy, but I can’t help think that maybe a few of these books need to be rewritten. There’s nothing new in learning that “A” is for apple, but think of all the fun that ensues learning that “A” is actually for Astrapia. And please, “The Cat in the Hat” has been done to death, but the “Emu in the Shoe” is sure to educate and entertain the whole family!

Posted in birds, books | Tagged , | Leave a comment

The Status is not Quo

Hello world and welcome to my blog. It’s a blog about birds, and about watching birds and about watching the watchers that watch birds. Beyond that I don’t yet know what it will become, but I hope you’ll join me as this blog takes flight. And if you’ve just been blown in accidentally by a wind-storm or rode in from an ocean-faring vessel, welcome, there’s a feeder with the highest quality seed out back and plenty of cover to stay a while. Just pay no attention to that guy behind the curtains with the binoculars.

Posted in Uncategorized | Tagged , , | Leave a comment