MIDDLE ISLAND’S HIDDEN TREASURES
Reprinted with permission from "Seasons: The Environment and Nature Magazine", Autumn 1992, published by the Federation of Ontario Naturalists.
On this wild isle in the Erie Archipelago, isolation is salvation for a rare wealth of species
Lake Erie was as smooth as glass when I launched my canoe into the waters off the southern tip of Pelee Island. Several islands were visible on the horizon, but I was bound for only one - Middle Island, Canada's southernmost possession.
I soon encountered flocks of Bonaparte's gulls and common terns hovering over schools of fish. A light breeze sprang up, sending cat's-paws rippling across the water, and I quickened my strokes. Lake Erie is fickle and the deceptively calm waters of its shallow western basin can quickly whip into choppy, metre-high waves. With a couple of kilometres still to go, I realized how important a refuge these 21 islands of the Erie Archipelago must have been to early natives crossing a stormy lake in their fragile bark canoes.
As I neared the island, about an hour after setting out, I was assaulted by the powerful odour of fish-eating birds. My landing was loudly protested by hundreds of gulls nesting on the shinglestrewn north shore. It was early May and the hackberry woods were alive with song. Colourful warblers moved through the understorey, pausing to feed before the short hop north to Pelee Island and Point Pelee. Catching the "cheery-cheery-cheery" of a Kentucky warbler, I turned to look for the skulker, but was distracted by a scarlet tanager, flickering like flame among the leaves of a black maple. Clumps of wild hyacinth had pushed through the mat of phlox carpeting the forest floor, their blooms creating a blue and white mosaic. Nearby, an exquisite southern plant called Miami-mist had just opened its delicately fringed mauve petals.
I almost stumbled into a deep crevice, its walls slippery with mosses, lichens and liverworts. As I caught myself, a red fox emerged from the crack in the bedrock. It stared at me, as startled as I was, then bounded off through the dense ground cover of appendaged waterleaf. It had no doubt wandered here over the winter ice and would be marooned until the lake froze up again.
After pushing through an almost impenetrable thicket of staghom sumac, roughleaf dogwood and Kentucky coffee trees that had overtaken an abandoned airstrip, I emerged at the south shore. Blue ash and hop-trees grew near the edge, their roots running through cracks in the limestone cliffs. Suddenly, one of the "roots" quivered - a perfectly camouflaged Lake Erie water snake raced across the ledge, disappearing into a fissure.
Pandemonium reigned at the shoreline as squealing herring gulls, disturbed by my arrival, wheeled overhead. Their nests were everywhere, perched precariously on narrow cliffside ledges or nestled in tree roots. Some even lay unprotected on the flat limestone shelf by the water's edge where the first big wave would wash them away. I sat quietly and the gulls soon returned to their activities: bonding, bathing, repairing nests, incubating eggs. Offshore, hundreds of cormorants, .mergansers and a fishing boat were working the rich waters. Black-crowned night-herons and great blue herons flew by, vanishing into the hackberry forests where their flimsy stick nests were hidden.
This uninhabited naturalist's paradise lies at a latitude of 41°N, farther south than the French Riviera. As its name suggests, Middle Island is positioned about halfway between the Ontario and Ohio shorelines. From the air, the 19-hectare island is tadpole-shaped, its body a forested rocky dome rising a few metres above the lake, its tail a shifting sand-and-gravel spit trailing out to the west. A dilapidated two-storey hotel in the midst of a small clearing is the only obvious sign of humans passing through. It's a remnant of an unlikely past in which the island hosted a procession of visitors, from journeyers to runaways and renegades. Now, only wild things live here.
Tiny Middle Island supports a wealth of flora and fauna, much of which is unusual in Canada thanks to the peculiar combination of conditions here - a thinly soiled limestone substrate and an almost maritime climate. The southern location and island situation give rise to a slightly retarded spring, sparse precipitation, abundant sunshine and a long frost-free season.
The island's host, western Lake Erie, is a fertile basin that encourages a high diversity and abundance of fish. It's not surprising, then, that Middle Island's most conspicuous inhabitants are its colonially nesting birds. Offering undisturbed habitat and easy access to plentiful food, the island is a perfect place for these fish-eaters to breed.
By far the most abundant are herring gulls; pairs nest in almost every available spot on the limestone cliffs and shelves that ring the island, and many more have settled on the lawn around the old hotel. In 1981, researchers counted 992 nests, making this site one of Lake Erie's largest gull colonies.
Hundreds of great blue herons and a few great egrets nest in the tall hackberries and cottonwoods. Black-crowned night-herons first arrived in 1981, when 400-500 pairs established a colony in smaller hackberries and staghorn sumacs. Most likely, they had relocated from Fish Point on Pelee Island, whose night-heron colony had been abandoned the year before. Recently, double-crested cormorants began nesting here, probable refugees from another dwindling Pelee Island colony. Fortunately for these birds, Middle Island was there to welcome them with an alternative nesting site.
Other species haven't fared so well. In the 1930s, up to 25 bald eagles at a time could be seen on the island, drawn by the lake's good fishing. Some reportedly bred here until a couple of decades ago, but now they are gone, likely victims of the chemical pollution that has infiltrated the Great Lake food chain, causing reproductive failure, among other problems, in bald eagle populations. Common terns have disappeared too; a century ago, they crowded the gravel spit.
Besides being an oasis for luckier birds, Middle Island is home to several rare southern trees and flowering plants characteristic of the Carolinian zone. The hackberry tree is particularly conspicuous and the western part of the island contains an almost pure stand of them. Toward the northeast, black maple becomes more common, and just south of this is a large grove of hoptrees. Scattered throughout are black walnut, sycamore, blue ash, and Kentucky coffee tree, imparting a distinctively southern flavour to the island.
Instead of the sugar maple/beech woods that typify richer soils elsewhere in southwestern Ontario, hackberry forest is the climax here. Blue ash and chinquapin oak also thrive in these conditions, growing to a size not commonly found on the Canadian mainland. One blue ash is believed to be the country's largest, and some of the hop-trees grow to a height of more than seven metres.
Several flowering plants, harboured by these communities, are at or near the northern limit of their range and are rare or absent on mainland Canada. At last count, the island has 56 significant plant species, either rare for the region or province, or for the nation. Species whose Canadian ranges are restricted to the Erie islands include creeping chervil, Miami-mist, wild hyacinth and a sedge (Carex divulsa). A distinct variety of smartweed (Polygonum pensylvanicum vaT. eglandulosum), endemic to the Erie islands, seems to be undergoing a rapid evolution in its isolation. Middle Island is the only known Canadian site for this plant.
Some of the birds and animals, too, are representative of more southern habitats. The rollicking "teakettle-teakettle" of the Carolina wren and the croaking calls of the yellow-billed cuckoos are distinctive sounds of Middle Island woodlands. Southern migrants such as Louisiana waterthrush and hooded warbler pass through regularly in spring. Hackberry butterflies are common, and occasionally giant swallowtails can be found near hop-trees.
Middle Island's origins date back to the middle Devonian period, 350 million years ago. A series of primordial inland seas left sedimentary layers containing many fossil plants, fishes and invertebrates. The abundant crinoids, brachiopods, trilobites and fish vertebrae found in the limestone foundation have prompted one paleontologist to claim that Middle Island's rock houses the richest fossil collection in the Erie Archipelago. One of the more spectacular fossils is a concentrically ringed colonial coral three metres in diameter lying on a north shore ledge.
A series of continental glaciations over the last million years shaped the island's bedrock, and left a thin layer of glacial till and deep striations in its wake. There is a well-preserved groove 23 metres long on the southeast shore where a large boulder may have been dragged under an ice sheet two kilometres thick.
Elsewhere, exposed limestone is riddled with parallel faults and cracks, and numerous karst crevices run through the woodland floor. Some crevices are as deep as six metres and one runs for more than 300 metres, almost a third of the island's length.
Middle Island didn't actually become an island until 4,300 years ago when lake levels rose, submerging most of the hard dolomitic limestone ridge that runs from Ohio's Mar. blehead Peninsula to Point Pelee. Kelley's, Middle and Pelee islands are the above.water exposures of this submarine ridge that separates Lake Erie's western basin from its much deeper eastern portion. These islands, along with Bass and Sister Islands, stretch like stepping.stones across the lake.
For birds, this chain of islands provides a convenient migration corridor. The migration is particularly noticeable in spring when the islands act to funnel birds across Lake Erie north to Point Pelee. On a clear day, migrants are never out of sight of land, and in inclement weather, they rest and refuel on the islands. Middle Island is an important link in this "island hop" - despite its small size and limited coverage by birders, more than 150 species of birds have already been recorded on the island.
Migrating monarch butterflies also island.hop and are plentiful in fall. Even the movement of plant species, both north and south, is facilitated by the strings of islands.
For hundreds of years, humans, too, have been making use of these natural stepping-stones. Early natives used the islands in voyages across Lake Erie and as temporary hunting and fishing camps. An archeological team investigated the island in 1982, spurred on by rumours of burial mounds. Though no mounds were discovered, the team unearthed pieces of ceramic, flaked stone, animal and human bone and notched limestone cobble netsinkers. One campsite appeared to have been continually reoccupied for several centuries. The transients probably survived by hunting, fishing and gathering nuts, berries and eggs from the bird colonies. Most of the evidence points to use around A.D. 1000-1500, but one site contained remains that may date back to 500 B.C.
Later migrants included American slaves, Civil War army deserters, and escaped Confederate prisoners of war, all of whom are said to have used Middle and Pelee islands in their flight north to Canada.
The first Europeans to spend any time on the island were lighthouse keepers. Built in 1872 because too many ships were being lost on nearby reefs (at least two schooners lie wrecked just offshore), the lighthouse was manned by a series of keepers until 1918. It burned to the ground in later years, but part of the stone foundation remains.
The island gained infamy during the Prohibition Era, when it became a transfer point and haven for rumrunners. Until alcohol was legalized in the United States in 1933, the archipelago's links were critical to the small boats smuggling Canadian liquor and beer to Ohio. A Prohibition gangster, Joe Roscoe, purchased a share of Middle Island and built the hotel that became the centre for much of the rumrunning activity. The comfortable seven-bedroom "clubhouse" had electricity, cozy fireplaces, and large screened-in verandas affording marvellous views of the lake. The basement, which had been carved from solid bedrock, held a casino, complete with gambling wheel.
After Prohibition, the hotel attracted a more conventional clientele - charter fishermen working the nearby reefs and vacationers seeking outdoor and indoor pleasures, such as the kitchen's fine pheasant dinners. As many as 200 tourists a day visited the island, coming by tourboat or plane, and, in winter, the more adventurous drove their cars over the frozen lake. Icefishing and pheasant hunting were popular activities.
But times have changed, leaving behind the days of euchre games and barbecues around the giant picnic table under the shady coffee trees. Deserted years ago, the hotel has suffered from neglect and vandalism. Its verandas have collapsed and not a pane of glass remains unbroken. Rumours of the lost fortune of Al Capone (an alleged visitor to the hotel), stashed somewhere in the walls, may have inspired some of the vandals. Barn swallows are the building's inhabitants now; they whip incessantly through the rooms, their mud nests hanging from lightbulb sockets, ceiling beams and pipes.
Today, the only human visitors are curious boaters and a few researchers. The island offers rich opportunities for field study into topics such as migration, island biogeography, habitat succession, and the effects of pollution. The Canadian Wildlife Service, for example, has been monitoring the levels of organic hydrocarbons in gull eggs since 1974. Ohio State University organizes regular educational and research trips to explore the island's rich biota. And the unusual fossils and rock formations are a treasure trove for paleontologists and geologists.
In 1982, a Parks Canada study recognized the island's special features and recommended that it be designated a Natural Site of Canadian Significance and a Canadian Landmark. Its educational, aesthetic and historical interest, as well as its strategic position as an island link and migratory stopover, qualified it overwhelmingly for inclusion in Essex County's list of Environmentally Sensitive Areas and as an ANSI (Area of Natural and Scientific Interest). The Carolinian Canada protection program lists the island as one of 38 critically important sites. Despite this, neither the Canadian government nor the Ontario Ministry of Natural Resources (MNR) has attempted to acquire or protect it. With reserves on Pelee and Easter islands, MNR feels the region's habitats are sufficiently represented.
Though Carolinian Canada agrees that Middle Island is not in any immediate danger, it wants to devise a stewardship plan in cooperation with the current owner, an American. He enjoys the island's wildness and, since buying it in 1976, has allowed nature to take its course. Slowly, the few traces of human influence are being erased as the airfield becomes choked with vegetation, the hotel gradually crumbles, and the woodlands progress toward a climax forest.
It was getting dark as I prepared to leave, but I lingered on the pebbly spit for one last look. On nearby South Bass Island, the beacon atop the 100-metre Perry Monument swung around in lazy circles; dozens of lesser reef- and channel-marker lights twinkled and flashed in reds, greens and whites, guiding freighter and pleasure boats through the shoal waters. Glowing swaths of sky marked the locations of Detroit, Windsor, Toledo and Sandusky.
The view emphasized the fact that, despite its pristine and tranquil setting, Middle Island lies in the midst of one of the continent's most heavily industrialized and populated areas. Beer cans, plastics and even medical syringes litter its shores, and it is not hard to find the odd gull or heron with a fishing lure caught in its beak or foot. The western rim of Lake Erie is home to millions of people, more and more of whom are discovering the archipelago's recreational delights. Most of the islands are, unfortunately, almost fully settled with cottages, marinas, farms and vineyards, and development is encroaching upon the others.
Isolated at the far eastern edge of the archipelago, Middle Island has largely escaped these pressures, and its wildlife continues to breed here in a relatively healthy and natural environment. I hope we have the foresight and wisdom to keep it so. For as I paddled away, looking back at the moonlit trees and rocky shores, I could think of no finer symbol to mark Canada's sovereignty at her southernmost point than this wild and special place.
Y. Robert Tymstra is a naturalist and Photographer living in Sarnia.
Erie Snakes: A Long Tale of Destruction
The Erie Archipelago was once so filled with snakes that early explorers dubbed the area "les lies aux Serpentes." In 1754, a French soldier spent a night on one of the islands and recorded in his journal that his party "killed 130 rattlesnakes before they dared to sleep." In 1878, W.H. Ballou, an early naturalist, observed:
Numerous enormous black water snakes darting through the water...sunning themselves in heaps, knots, and gnarls...Rattlesnakes were plentiful and caused annoyance for early settlers...so thick were they it is avowed that a man couldn't walk without treading on three or four of the varmints at every step...
By the 1950s, the timber rattlesnake was extirpated from the archipelago and other snake species were not faring much better. Pigs had been released on some islands (including Middle Island) to eradicate snake populations. Collectors took their toll, as well - in July 1949, 200 garter snakes were removed from Middle Island. The following year a researcher found only one. Water snakes were similarly captured in large numbers until they, too, were almost wiped out. One of the captives was 159 centimetres long, one of the largest water snakes on record.
Although nowhere near their former abundance, snakes are still an important element of the island's fauna. Garter and brown snakes are common and sometimes a few fox snakes appear. A small percentage of the garter snakes here are jet black instead of striped. This phenomenon, called melanism, is primarily restricted to the islands and shores of Lake Erie. Researchers believe that this colouring increases heat gain, an important advantage in the cold springs, although it may make the snakes more apparent to predators.
The Lake Erie water snake, a race of the northern water snake, is endemic to the shores and islands of western Lake Erie and can still be found sunning on the rocks in small numbers. Richard King, a graduate student of Purdue University, Indiana, studied their colour patterns and found that mainland snakes are generally cross-banded whereas the islands contain a high frequency of intermediate and unbanded all-grey individuals.
The unbanded morph camouflages well with the pale grey limestone and is dominant on isolated Middle Island. Perhaps this is an example of natural selection in action. The banded individuals may be more easily spotted by predators, leaving greater numbers of unbanded snakes to reproduce their successful genes.
Nevertheless, King believes that the extinction of Lake Erie water snakes could be imminent. In 1984, he estimated that only 25-30 adults are surviving on Middle Island. Though the snakes are protected under Ontario's Endangered Species Act, loss of suitable habitat to development, especially on neighbouring islands, threatens their continued existence. It is for these creatures and others that the preservation of places like Middle Island is so important Here, numerous crevices by the lake's edge give them ample shelter and easy access to their main prey of mudpuppies and bottom-dwelling fish.
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