Birding in "the polar bear capital of the world"

Churchill, Canada is a tiny town perched on the wind-blown edge of Hudson Bay, and most famously known for its polar bears, that attract flocks of tourists every autumn. Less well known are the birds that breed on the arctic tundra, beloved of a limited subset of enthusiasts that appear in town in the summer, just before the polar bear season begins.

When we appeared, Churchill was clearly waiting. The cluster of containers that constitute buildings in this town looked quiet, and driving further afield for birds, we would come upon surreal sights of enormous white "tundra buggies" and strings of huskies chained a few feet apart, waiting for the tourists to arrive.

The breeding birds, however, are in full swing, as can be seen from this frantic parent, its beak crammed with food for its offspring.

Boreal Chickadee (Poecile hudsonicus)

Beyond the town, the tundra is just as beautiful as one might expect, with melting sea ice creating channels for beluga whales to swim past, and massive, fluffy grey arctic hares. I took a lot of photos. As we were there during the summer solstice, there wasn't much night to speak of, which resulted in some very frantic birding, with abortive attempts to find an elusive yellow rail between the dusky hours of midnight and 2am, and a mad dash to catch the "dawn chorus" at 2:30am.

Some of the very special birds we did manage to see, are the arctic tern (Sterna paradisaea), with its striking red-lipsticked beak, best known for its grueling yearly migration between the Arctic and Antarctic.

Another tundra beauty is the willow ptarmigan (Lagopus lagopus), which turns completely white in the winter to match the snow. In the summer, males have the glowing red wattles above their eyes, presumably highly attractive to their much more tastefully decorated hens.

 

The gray jay (Perisoreus canadensis) is one of my favourites, because it is what biologists call a "cooperative breeder", where individuals forgo their own reproduction to help others raise offspring. Like many avian cooperative breeders, most gray jay helpers at the nest are sons from previous clutches, though daughters will also remain to help.

A very clever namesake

Cauchy, below, has the same name as an eminent French mathematician, and several concepts and theorems, particularly in infinitesimal calculus and complex analysis.

Cauchy and Bevo the bull

This particular Cauchy is still learning some rather basic concepts, but he is adept at attacking his beloved bull, Bevo.

How to become an endangered species

2015 update: I did some experiments and found that little bee-eaters, African hosts of another deadly brood parasitic bird, are also remarkably maladapted when it comes to avoiding parasitism.

I recently made a pilgrimage to see a very special bird, the Kirtland's warbler (Setophaga kirtlandii), one of the rarest and most endangered wood warblers. 

Male Kirtland's warbler in all his breeding glory

This wee creature has decidedly unfortunate tastes in where to breed. It is both fussy and unaesthetic, nesting only in the scrubbiest, shabbiest stands of young jack pines (Pinus banksiana) that grow in vast stands on sandy soil in northern Michigan. The success of Smokey Bear, the US Forest Service's campaign to stop wildfires, allowed all the jack pines to grow big and strong, leaving almost no young trees for the warblers to nest amongst. 

Cowbird egg (the big one) in a Kirtland's warbler nest

To make matters worse, human development has greatly expanded the range of the brown-headed cowbird (Molothrus ater), a brood parasite that lays its eggs in the nests of other species, thereby dispensing with the bother of incubation and childcare. The Kirtland's warbler was not historically exposed to cowbirds -- named for their habit of following bison (and subsequently cows) to eat insects disturbed by the moving herds. Without having evolved in tandem with the cowbirds, Kirkland's warblers are hopeless when faced with a cowbird egg in the nest. Instead of tossing the foreign egg or chick out, these tiny birds proceed to care for their parasitic offspring, which grabs all the food and starves its smaller warbler foster siblings to death. By the time they are fully grown, cowbirds are 3-5 times heavier than their foster parents.

Courting cowbirds

With habitat loss and intense parasitism by cowbirds, the Kirtland's warbler almost went extinct about 50 years ago. However, it has since become one of the best conservation successes in America. The U.S. Department of Agriculture Forest Service and the Michigan Department of Natural Resources began logging jack pines to simulate the disturbance caused by wildfires, and to produce large enough (at least 160 acres) areas of short young jack pine to suite the Kirtland's warblers. In addition, they trapped and killed thousands of cowbirds. As a result of these ongoing efforts, the Kirtland's warbler has now expanded its breeding range to bits of Wisconsin and Ontario.

The Kirtland's warbler is now the subject of considerable local attention, partly because it is an eco-tourist (or at least mad birder) attraction. There is a Warbler's Way Inn, and until recently, a Kirtland's warbler festival. The jack pine habitat is protected, so one is forced to join a tour to see birds. That said the tour was excellent, and well worth waking up at 2am and driving for 3 hours to see several male Kirtland's singing with gusto.

For more information:

Michigan Department of Natural Resources

University of Michigan, Museum of Zoology

Troglodytidae

Wrens are one of the only bird families I can think of that are more spectacular and widespread in the New World, while also being present in the Old World. In addition to their unusual biogeography, wrens are highly diverse in appearance and behavior. 

Troglodytes troglodytes, Greek for cave-dweller, is the only Old World representative. This diminuitive species is highly polygynous, which means that each male has several mates, each of which he attracts by building wee nests in some nook or cranny of a rock, building or bush.

Eurasian wren (Troglodytes troglodytes)

In striking contrast, the giant wren, endemic to Chiapas, Mexico, is about twice as long and five times as heavy as the dumpy little wren of European legend and literature.

Giant Wren (Campylorhynchus chiapensis)

Another endemic to Mexico, though with a less restricted range, is the felicitously named happy wren. 

Happy Wren (Thryothorus felix)

Inca Wren (Thryothorus eisenmanni)

Other wrens are aptly named for the places to which they are endemic. The Inca wren is only found around Machu Picchu, while the snail-eating Zapata wren only occurs in Cuba's Zapata Swamp. 

Zapata wren (Ferminia cerverai)

 



Wrens are also known for their varied and surprisingly loud songs. The musician wren of Amazonia is the subject of legend, including one in which all other birds stop to hear it sing.

Musician wren (Cyphorhinus arada)

Two of my favourite North American wrens are named for their habitat:

Marsh wren (Cistothorus palustris)

Canyon wren (Catherpes mexicanus)