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.