Tuesday, December 15, 2009

Autumn in Algonquin

Home, for me, is the Province of Ontario in eastern Canada (I was born in Toronto, and live now in nearby Mississauga). Those of us who hail from northeastern North America may not lay claim to the great wildlife spectacles of other regions (though we do have some dandies, including the spring bird migration at Ontario's Point Pelee), but we do have something shared with one other place on earth: the spectacular autumn spectacle of dying leaves blazing with reds, oranges and yellows before they shrivel and fall.

The reason why our fall colour show (and that of northeastern Asia) is so spectacular is that we share the greatest diversity of a single tree family, the maples (Aceraceae,now often lumped with the soapberries, horsechestnuts and buckeyes in the family Sapindaceae). While the leaves of many other temperate deciduous trees turn colour only because their chlorophyll disappears, revealing other pigments (such as the yellow carotenoids) that were hiding there all along, maples (and a few other plants, including sumacs and some oaks) actively synthesize new pigments, the anthocyanins, from sugar stored in the leaves, creating the rich reds, oranges and even purples that make our eastern forests blaze - especially in good years, when the trees produce higher sugar yields.

If you want to know more about the chemistry involved, there is a nice explanation here. Some very recent research suggests that anthocyanin production is actually, oddly enough, a defense mechanism against leaf-eating insects, and that this explains why Europe has less of an autumn show than we get in North America (see here if this sounds confusing). Alternatively, it has been proposed that anthocyanins act as a sort of sunscreen, protecting leaves so that they can stay on their trees (and manufacture more sugars) later into the season.

Maples are widespread across the northern hemisphere, but reach their peak of spcies diversity in eastern north America and eastern Asia. To demonstrate what I mean, consider that of the thirteen tree-sized maples on the continent only three occur widely in the west (mind you, even our eastern maple diversity pales beside the 60-odd species in China). Our most famous species, of course, is the sugar maple (Acer saccharum), one of the dominant trees of eastern forests, the bulwark of the maple sugar industry and the national symbol of Canada.

This is, I believe, mountain maple (Acer spicatum), one of the shrubbier species.

Here is a stand of white birch (Betula papyrifera) to show you how our autumn might look without maples (or anthocyanins): pretty, but pale....

Anyway, September 29, a dull and intermittently rainy day, found Eileen and I crossing east to west through the southern route of Algonquin Provincial Park, a long detour on our way home from Ottawa to Mississauga. I hadn't been to Algonquin for years, and Eileen had never been there at all, so it was something of a new experience for me and an entirely new one for my Malaysian wife.

As you can see, she enjoyed herself thoroughly!

We saw almost nothing in the way of animal life, but this impressive beaver lodge was a testament to the efforts of the species that, besides our own, has done the most to shape the Algonquin landscape.

Algonquin is beautiful any time of year - why has it taken me so long to get back here? - though it is not, I'm afraid, as pristine as it looks. According to the Wildliands League, only 22% of the park is actually protected from logging, though this is now to be increased to 35% under new action by the Ontario government.

Algonquin sits near the southern edge of the vast Canadian Shield, the largest expanse of exposed Precambrian rock on the planet; the roadside outcrop supporting this little maple tree may be a billion years old, or even two.

It also sits near the southern edge of the equally vast Canadian boreal forest, lying, strictly speaking, on the ecological boundary between the deciduous forests of the south and the coniferous forests to the north. The two worlds meet in this photograph.

Ferns add a delicate touch to the undergrowth; this looks rather like male fern (Dryopteris filix-mas) but I wouldn't bet on it...

If you look still lower, you can find lichens covering the rocks; I'll go out on a limb here and say, based on a quick perusal of the gorgeous book Lichens of North America by Irwin Brodo et al. (Yale University Press 2001), that this could be common goldspeck lichen (Candelariella vitellina). Corrections, please?

And here, nestled among leaves of red maple (Acer rubrum), is, I suspect, a clump of common antler lichen (Pseudevernia conoscians), fallen, like the leaves, from a tree - Brodo et al. say it grows on the trunks of conifers. They also say that this is the only Pseudevernia in North America with isidia, and they ought to know. Isidia, I gather, are very small bits of the top of the thallus (or body) of the lichen having to do with its complicated reproduction (since a lichen is a composite of a fungus and an alga living together, the two organisms have to reproduce in a way that disperses both partners as a unit - read all about it in Brodo, or here).

Tuesday, December 8, 2009

A Morning on the Coussouls

Though the Camargue area is famous for its wetlands, one of its most fascinating habitats is anything but - the dry, stony plains (or Peau de Meau) of the Coussouls de Crau, famous among birders as the only place in France where the Pin-tailed Sandgrouse, a desert bird if ever there was one, breeds. It was the sandgrouse that drew me to abandon my wife and parents on our European tour for a morning run to the reserve, and of course (it being August 30, well past the breeding season) I didn't see any.

I didn't know it at the time, but perhaps one of the reasons that I missed the sandgrouse was that only a few weeks earlier, the reserve had been devastated by a massive oil spill from a ruptured pipeline. According to the news story, some 4,000 cubic metres of crude oil spilled over five acres of ground - only a fraction of the 18,278-acre (7,400-ha) reserve, but enough to raise fears for the survival of both the sandgrouse and another specialty of the area I failed to find, the endemic Crau Grasshopper (Prionotropis hystrix rhodanica).

The reserve technically requires a permit from the nearby Ecological Museum to enter; the Museum was closed when I arrived the previous day. Anywayy, when I arrived the next morning there was no one in sight to check my permit (had I obtained one). The site was well provided with informative signs, and showed, thank heavens, no trace of oil.

On the way into the reserve, I came a cross a group of the famous Camargue wild horses, which are not really wild or even particularly feral (the gardians round them up at least once a year), but are certainly beautiful, and of very ancient lineage (though no one seems quite sure just how ancient).

The Coussouls are. technically, dry steppe, the only surviving remnant of this habitat in western Europe - arid, stony, treeless and perhaps a bit forbidding (though I found the place quite beautiful). The legal protection the Coussouls now enjoy is highly necessary; between 1983, when the reserve was first proposed, and its creation in 1990, 20% of the steppe habitat disappeared (Buisson and Dutoit 2006).

By late August, I imagine, most of the plants on the steppe are but dry remnants of their former selves; but some, like these globe thistles (Echinops sp?), are impressive even when dry.

This old farmhouse has been partially converted into a hide for watching the local birdlife (assuming, of course, that the local birdlife deigns to show up).

The hide did provide me with a view of this dragonfly, probably a female Keeled Skimmer (Orthetrum coerulescens), a common species identifiable by its yellow pterostigma (that's the little coloured bit out by the tip of the wing).

This drainage canal running along the edge of the reserve is a paradise for dragonflies and a well-known hotspot for odonate diversity. I ran into a pair of dragonfly-watchers near the end of my visit (and a good thing, too, as I am pretty much a beginner with this group, still feeling my way through the guidebooks).

Particularly common and obvious here is a beautiful damselfly, the Copper Demoiselle (Calopteryx haemorrhoidalis). It sems more like a creature of the rainforest than an inhabitant of a ditch beside a near-desert, though the genus itself is largely found in Europe and North America, where males defend territories along flowing waters and lure females with elaborate midair courtship dances.

Brambles (Rubus sanctus) add another splash of colour along the canal - besides being very tasty!

I'm being a little harsh on the birds; a few wonderful species did turn up, including two of Europe's most exotic: about half a dozen European Rollers (Coracias garrulus), and, on the way out, a (dead) treeful of European Bee-eaters (Merops apiaster), about forty of them, presumably getting ready to head off for Africa (this one hung around long enough for a photo).

Saturday, December 5, 2009

An Afternoon in the Camargue

I sometimes find myself, despite the title of my blog, doing some wandering that isn't particularly naturalist-related. That includes a trip I took through southern France with Eileen and my parents this August -- but in the course of squiring everyone through medieval towns, Renaissance castles and the like, I did manage, on August 29, a brief visit to one of Europe's few great wildernesses, the Camargue. That's my mother up above, admiring a bit of sedge along the Camargue roadside.

The Camargue is Europe's answer to the Everglades - or, perhaps more closely, to the Venezuelan llanos, with its bull-rearing, horse-riding gardians the French version of the llaneros of South America. It is a huge wetland, over 930 km² in extent, created as the Rhone splits into its delta before emptying into the Mediterranean. We only had time for a quick taste, a drive down the eastern edge of the vast briny lagoon at its heart, the Étang de Vaccarès, a nature reserve since 1927.

The shallow, briny lagoons of the Camargue are ideal habitat for perhaps the least likely of European birds, the Greater Flamingo (Phoenicopterus ruber). Some 20,000 pairs of them breed here, the only place you can find them in Europe outside of a few colonies in Spain. Unfortunately, driving down the east side of flamingo territory in the late afternoon meant that we saw the birds mostly in silhouette - not the ideal way to appreciate them.

Wetlands, of course, are wonderful places for dragonflies. I think that this one, a remarkably plain creature with lavender-blue eyes, is a female Southern Skimmer (Orthetrum brunneum), a species that ought to be pretty common in these parts, but I would be grateful to be told otherwise by any dragonflyologists out there.

Birds for the afternoon included this young European Shelduck (Tadorna tadorna)....

Lots of Black-headed Gulls (Larus ridibundus), by now out of breeding plumage...

An immature Red-backed Shrike (Lanius collurio)...

And this brood of juvenile Black-winged Stilts (Himantopus himantopus), not yet in the crisp black-and white plumage of their parents, and with legs yet to acquire the shocking pink of adults.

Saturday, November 7, 2009

Bahamas: Little San Salvador

After a day at sea, our ship reached its final new port on Friday April 10: The tiny island of Little San Salvador in the Bahamas. The island, which lies not far from the long, serpentine island of Eleuthera, is wholly owned by Holland America Lines. "Little San Salvador" isn't a terribly romantic name, so Holland America has renamed its property "Half Moon Cay". It took me a bit of research to find out the real name of the place. I'm not an employee of Holland America, so, Dear Readers, it'll be Little San Salvador on this blog.

Most of the cruise passengers never get past the shops just off the dock. That didn't include Eileen and I, of course, though the heat of the day did control our movements somewhat!

Fortunately, the good folks at Holland America (or someone) have provided a genuine Nature Trail for us to follow. Little San Salvador is protected, I am happy to say, as a Wild Bird Preserve, and its brackish interior lagoon has been designated as an important wetland by the Bahamas National Trust.

On the narrow, sandy strip between the island's south shore, where Holland America lands its passengers, and the interior lagoon, many of the plants are typical coastal species adapted to dealing with salt spray. This is a morning glory, one of a dozen species of the genus Ipomoea in the Bahamas -- almost certainly Ipomoea pes-caprae, the beach morning glory, a highly salt-tolerant species found on tropical beaches around the world. "Pes-caprae" means "goat's foot", and the cleft, two-lobed leaf does suggest a goat's hoof at least.

Nonetheless, as this and the next two photos show, the island is far from treeless; there is some genuine woodland, known as coppice, on the north shore, but it was out of reach for us. On the south shore the vegetation is sandy scrub, with a few emergents like these palms (I assume they are some sort of thatch palm (Thrinax) but I would be glad to be enlightened further!)

The scrub itself is pretty dense stuff, similar to the sort of thing you can see in the Florida Keys, with an undergrowth heavily laced with saw palmetto (Serenoa repens). It is, of course, bird habitat, and though it is not a rich as the coppice woodlands of the larger islands it still holds a few "Bahama specialties". Robert L. Norton reported 42 species from Little San Salvador (Fla. Field Nat. 21(1):16-17 (1993)), 36 of which he saw himself in a few hours. Probably only seven or eight of them, though, are land birds that actually breed there. For a visiting birder off a cruise ship, it is a question of quality, not quantity!

Here, singing away, is a Thick-billed Vireo (Vireo crassirostris), a bird missing from Norton's list. Finding it here should not be a surprise; it is widespread in the Bahamas. This is a species with a most peculiar range: it seems to be a small island specialist, missing from the larger land masses of the Antilles but present on a few widely scattered islets. Besides the Bahamas, it lives on the Caicos and the Caymans, but is only a rare stray to Cuba and South Florida. A population of vireos on the distant island of Providencia in the far southwest Caribbean was once also thought to be this species, but according to my graduate supervisor, and leading vireo expert, Jon C. Barlow (who, sadly, passed away recently), the Providencia birds are actually Mangrove Vireos (V. pallens).

Even more interesting are the ubiquitous Bananaquits. Bananaquits, of course, are widespread in the West Indies and indeed have a huge range in Central and South America. Nowhere, though, do they look the way they do in the Bahamas (compare the bird in these photos to the Virgin Islands Bananaquit in my last blog entry). You could be forgiven for thinking these almost entirely black-and-white little birds, patched with yellow on the chest, belonged to a different species altogether from their primarily grey-and-yellow, dark-throated compatriots elsewhere in their range.

The truth, apparently, is more interesting. You can read all about it in a study published in 2008, "The dynamic evolutionary history of the bananaquit (Coereba flaveola) in the Caribbean revealed by a multigene analysis" by Eva Bellemain, Eldredge Bermingham and Robert E Ricklefs (BMC Evolutionary Biology 2008, 8:240). It appears that the various populations of Bananaquit have a complex evolutionary history, involving a number of island-hopping colonizations and invasions.

Most island birds originally reached their homes from the mainland, but Bananaquits (or so their DNA tells us) actually evolved in the Bahamas and the Greater Antilles (their closest relatives, oddly enough, appear to be grassquits and West Indian "bullfinches"), and spread to the rest of their range, including the mainland, from there. The Bahamas birds apparently split from most of the others about 1.75-3.99 million years ago, but, oddly, they have genetic similarities to birds from islands off the Yucatan Peninsula (such a Cozumel) that otherwise look like "typical" birds from other areas. There are no Bananaquits on Cuba, which lies between the Bahamas and Mexico; were they there once, long ago -- and if so, what did they look like?

All this matters very little, of course, to a naturalist simply enjoying being among bold, tame birds with lots of personality. For that, one species even beats the Bananaquit: the Bahama Mockingbird (Mimus gundlachii) -- another bird with a peculiar range, by the way; other than in the Bahamas (and occasionally Florida, where I saw one in Key West many years ago), it shows up again in the dry southwest of Jamaica.

Bahama Mockingbirds are duller and streakier (though larger) than the Northern Mockingbird (M. polyglottos) so common in nearby areas like Florida and Jamaica, but is none the less charming for that.

On Little San Salvador, they are noisy and bold, and take full advantage of cruise visitors.

This one is checking us out at a picnic table, waiting to see if we will drop any tasty scraps. The birds will hop right onto the table to get them - behaviour which, I am sorry to say, annoyed some of our fellow passengers. Not all cruise passengers, alas, are naturalists.

And with that, I come to the end of our cruise -- a week-long trip that it has taken me seven months to get around to writing up. It' a sad thing, I know, when our lives conflict with or blogging duties -- I'll have to do better in future....!