Wednesday, December 26, 2012

Inspired by Beatrix Potter

The Morgan Library in New York is currently showing some fabulous letters and art by one of my greatest heros, Beatrix Potter. Potter was especially fond of rabbits, and two of her pets, Peter and Benjamin are the inspiration for her most famous story, "The Tale of Peter Rabbit".

As a testament to the power of artificial selection, rabbits like the Flemish giant can weigh up to 20kg (about 50 pounds).
Flemish Giant Rabbit

Beach mice are subspecies of oldfield mouse (Peromyscus polionotus) that have evolved pale fur to match the pale sand they live on. Hopi Hoekstra and her lab have worked out exactly which mutations in which genes are responsible for this adaptive colouration.


Choctawhatchee beach mouse (Peromyscus polionotus allophrys)
As a Victorian, Potter wouldn't have seen these North American mice in the genus Peromyscus, but I think she would have liked them, with their enormous eyes and relatively infantile proportions.

Tuesday, December 25, 2012

Evolutionary tricks

The superb fairy-wren (Malurus cyaneus) is a diminutive Australian songbird with some evolutionary tricks that are even more spectacular that the male's plumage.


Male superb fairy-wren (Malurus cyaneus)

Fairy-wrens are parasitised by cuckoos, so one would expect fairy-wren parents to have evolved ways to distinguish their own offspring from cuckoo chicks in the nest. One way fairy-wren mothers seem to do this, is to teach their chicks a special password before the chicks have hatched. Cuckoo eggs are laid later, so their chicks probably don't have time to learn this special password. At any rate, once they hatch, only the fairy-wren chicks are able to reproduce the password in their begging calls, so they get fed, while the cuckoo chicks are often rejected.

Another endearingly complex aspect of fairy-wren biology, is that in spite of their being socially monogamous, about 2/3 of a single clutch are fathered by males other than a female's social mate. What's more, males can be seen courting neighboring females with flowers, while females don't respond to these cuckolding attempts till just before dawn, when they sneak off for a spot of what biologists so fetchingly call "extra-pair copulation". Not surprisingly, sperm competition in these fairy-wrens is superbly high.

References
Colombelli-Negrel, D., Hauber, M. E., Robertson, J., Sulloway, F. J., Hoi, H., Griggio, M. & Kleindorfer, S. 2012. Embryonic Learning of Vocal Passwords in Superb Fairy-Wrens Reveals   Intruder Cuckoo Nestlings. Current Biology, 22, 2155–2160.

Rowley, I., and E. Russell. 1997. Fairy-Wrens and Grasswrens: Maluridae. Oxford Univ. Press, Oxford.

Monday, December 17, 2012

Animal Acknowledgements

To all who helped, directly and indirectly in producing Dr. Tong, THANK YOU!

A subset of people are depicted below, sans surnames:






Monday, December 3, 2012

Turkey season


The wild turkey (Meleagris gallopavo) is essentially a very heavy New World chicken. Benjamin Franklin rather sweetly favoured the turkey as a national symbol, and a much more fitting representative of America than the cowardly bald eagle. Having been chased by turkey toms, I agree with the great man that these birds are not wanting in spirit.


Pre-Nancy, post-Nancy
These bizarre head ornaments on the tom turkey are the result of sexual selection, though why turkey hens find that fleshy growth over the beak (a snood), dangling in all its multicoloured splendor, is beyond me. The skin on a tom's head changes colour, depending on his mood, and accounting for its Japanese name,  shichimenchō (シチメンチョウ / 七面鳥), which means seven-faced bird.


In memoriam: Farish A. Jenkins Jr.

Farish Jenkins Jr. was one of those people who radiated such energy and excellence that even as a baby, he sits ramrod straight, staring directly at the camera with the same intelligent, engaging expression that anyone who knew him later would recognise as the Farish they love and respect.

I know Farish best as a fellow lover of wild Africa, which is why a sable antelope bull is my tribute to his unfailing gallantry, courage, strength, poise, vigour and, of course, the immaculate form that characterised everything he did, from the smallest email, to his renowned sartorial perfection.




One of the things many people love best about Farish, is his ability to make others feel very special. He always seemed so genuinely honoured and excited to know you, that it inspired you to be as worthy as possible of his trust and respect. On our second meeting, Farish discovered that I had worked on zebras as an undergraduate, and immediately decided I was fit to lead a safari to northern Tanzania for the Harvard Museum of Natural History. His very popular annual trip had been oversubscribed, and who could be a better substitute than a 1st-year graduate student who just happened to love Africa too?

Shortly after I returned from this safari, Farish appeared with a massive print of a spotted hyena clan I had photographed luxuriating in a muddy road in the Ngorogoro crater, and asked if I would do him the honour of signing the picture before he hung it in his office. He always made a point of telling me if he had used any of my photographs in his legendary course on vertebrate evolution, even though he must have had more than enough beautiful images in his own collection. One of my favourites is associated with the spectacle of Farish, even more animated than usual, bounding into my office in high glee, to show me photographs of novel elephant behavior from his latest safari. With Farish radiating excitement, and chortling irrepressibly, I stared at a massive bull with a formidable erection, leaning over a tree stump. Farish's expression, when I realised what the elephant was enjoying from the stump, is one I shall always remember fondly -- it was so full of infectious, impish delight.

Farish is renowned for his insistence on doing everything impeccably. What his nephew aptly referred to, during the memorial service, as his "timeless" way of dressing, is symbolic of his perfectionism. The first time I saw Farish in anything other than a three-piece suit was on a Sunday afternoon, in Harvard Yard. His first words after greeting me, were full of apology for being so shabbily dressed in a fleece (heaven forfend!) and jeans-- he had been pruning trees. 

Farish transformed a shooting lesson into a memorable visit to the New Hampshire farm that he and his wife Eleanor lovingly restored. We met at 0830h precisely for the drive up, and upon arriving, were proudly introduced to the lovely Eleanor, and shown about the farmhouse, which overlooks a field bordered by about 50 apple trees, each a different heirloom variety, all lovingly planted and pruned by Farish. Exquisite bluebird boxes that he built and erected are dotted about the lawn. The enormous barn is dominated by an ancient and beloved John Deer tractor, and a blackboard with the year's apple crop and the number of gallons of cider they yielded. In the basement, he has everything so shipshape and spic-and-span that even the nails and screws are organised by size. Ever the superb and thorough teacher, Farish produced several gleaming revolvers, a Glock from a policeman friend, two rifles inherited from his grandfather, and a shotgun for the lesson.

Like Farish, I'm an early riser, and was up before dawn the next day, to walk his trails and look for birds. Hearing a turkey, I thought "that's interesting, it's rather late for the turkey mating season", and went to investigate, only to stumble upon a terrifying apparition in camouflage, pointing a big shotgun at me. Later, Farish was tickled pink to hear that one of the hunters he allows on his property had almost bagged a Harvard graduate student with his artificial turkey mating calls. I shall always be grateful to Farish and Eleanor for this special weekend at the home he loved, when he knew that his time was limited. No one, not even Farish, thought the end would come quite so soon.


There are many excellent obituaries that convey the acme of excellence Farish invariably achieved in everything he did, and his ability to inspire others to attempt their very best, and to relish life with the same zeal as himself. 

There is also a very moving and inspiring video of Farish giving his thank you speech at a celebratory meeting in his honour. Like everyone else there, I am so very glad we had the chance to celebrate Farish, with Farish.

In lieu of flowers, contributions may be made to the Farish A. Jenkins, Jr. Fund - to support the field work of students in evolutionary biology; c/o The Museum of Comparative Zoology 26 Oxford Street, Harvard University, Cambridge, MA 02138; or Focus on Tanzanian Communities, c/o Thomson Safaris, 14 Mount Auburn Street, Watertown, MA 02472. Info@fotzc.org

Saturday, August 25, 2012

Chinese Donkey

A foray into Chinese brush painting


And earlier, on printer paper: Auctioned in Japan as part of an earthquake relief effort



Monday, August 6, 2012

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.


Tuesday, July 24, 2012

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.

Thursday, July 5, 2012

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:

Tuesday, June 5, 2012

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)





Monday, May 21, 2012

Almost Cain and Abel

Some quick sketches from watching this enchanting webcam: Cornell Herons


Harassed parent scratching chin
Is this a crack I see before me?

Eggs about to hatch

Great Blue Herons (Ardea herodias) nest in rookeries, and lay 2-6 eggs. Parents share incubation duties, with males taking the day shift, and females the night shift.



Unlike many other birds, herons and egrets (and birds of prey) start incubating the moment the first egg has been laidresulting in a large firstborn, and a succession of increasingly puny chicks, as each hatchling has to compete with its older, heftier siblings. Some heron chicks are more equal than others.






Goneril and Regan

While great egret (Casmerodius albus) chicks actively stab their siblings to death, great blue herons may simply starve their younger siblings by outcompeting them when food is scarce. This raises the question of why herons and egrets evolved to have more offspring than they can reliably support. One idea is that by creating an age and size disparity in offspring, parents can allow for environmental unpredictability at minimal cost. If times are good, then all the chicks survive, and if times are hard, the runts perish, but being the youngest, they've had the least invested in them anyway.


 

Spotted hyenas also appear to be siblicidal, which could explain why females have evolved bizzare mimetic penises that make childbirth a nightmare -- but that's another story.

For an excellent account of familial conflict, I highly recommend "More than Kin and Less Than Kind" by Douglas Mock.
Other sources: