Sharing the fast-food hot spots of shallow waterways with shy, stately cranes

In St. George's Bay, near my home on the northeast coast of Nova Scotia, Pomquet Island hosts a breeding colony of great blue herons, locally referred to as cranes. Many herons in the Maritimes migrate here in late March or early April from southern climes, and islands provide nesting trees, privacy and some protection from four-legged climbers like weasels, martins, squirrels and raccoons, searching for eggs and nestlings. Colonies also form near waterways in evergreens and hardwood trees in remote inland areas.

Great blue herons are large, blue-grey birds-standing four feet tall-with long legs, neck and bill. They wade in shallow waterways across Canada and up the Pacific coast to southern Alaska; they can be found stealthily hunting in Mexico's desert rivers and searching mangrove swamps in the Gulf of Mexico and the Caribbean.

Quietly stalking a shoreline, a great blue suddenly thrusts its neck, head and dagger-like bill to spear or grab unwitting animals. A modified sixth cervical vertebra of its skeleton allows it to coil its neck while stalking prey, or to draw it into a tight S shape in flight.

Great blues are normally shy in Atlantic Canada, but in more crowded parts of the southern US, some birds actually target anglers along saltwater and freshwater shorelines. They may sneak up to steal from anglers' knapsacks or buckets; other times a heron will grab and attempt to yank a fish being reeled ashore off the hook or snap the line, flying away with the prize.

In the Maritimes, herons find schools of alewife (also called gaspereau or kiack) and blue-backed herring when fish begin annual May migrations up rivers to spawn; local rivers remain fast-food hot spots until late June. If dry spring weather drops water levels in Gaspereaux Lake, in my neck of the woods, the outflow stops and alewife that spawned in the lake become trapped there, prevented from returning to sea. This prompts great blue herons to fly from Pomquet Island to the lake and back, a distance of 56 kilometres, air freighting gaspereau to hungry youngsters.

Three to five young normally hatch per nest. Before learning to fly, about 60 days later, the youngsters often spend vulnerable time on the ground. Would-be flyers often form queues, waiting their turn to practice-flap down makeshift runways routed through openings in the undergrowth or along shorelines. Once airborne, youngsters must quickly master the awkward matter of landing in tree-tops, a safe refuge from predators.

Dozens of young and adult great blue herons gather in lower Pomquet Harbour during late June, July and August. Staking out invisible territories, each heron wades the shallow flats, searching intently for animals with fins or legs. Deep, harsh croaking sounds of indignation often erupt between birds, prompting re-alignments of foraging territories. When the mud flats become exposed or covered in deep water, the herons cluster on the flats or along the shore, waiting for the tide to bring new angling opportunities. They remind me of church elders conferring outside after a particularly meaningful Sunday sermon. Meanwhile, perched atop white spruces on a distant shore, one or two bald eagles, the deacons of the harbour, scrutinize this congregation for the weak or the foolhardy.

Great blues eat a variety of animals. They sometimes roam lawns and flowerbeds near their watery habitat searching for snakes, mice, birds and bugs. I watched one ambitious great blue heron nab a rat in a hedge one day. The rat, screaming in protest, began chewing off pieces of the heron's bill. The bird walked quickly to water and, before the entire bill was turned into shrapnel, drowned the rat. Wading in shallow water for fish and amphibians must bring a special challenge for great blues in places like Florida, where alligators probably know their taste.

Young herons must learn to catch prey under water. Light bends as it enters and leaves the surface, meaning objects underwater are not where they appear to be. On several occasions I've watched young herons at a freshwater pond near our home take a pencil-sized stick and thrust it sideways with its bill, so the stick hits the water like a spear. It then tries to grab the stick at varied depths while it's still moving-thus honing its fishing skills.

The great blue is the largest and most numerous of the herons, but sharp-eyed folks can spot other members of the family. Tricolored herons and little blue herons are medium-sized slate-blue shoreline huggers. (Immature little blue herons are all white with dusky wing tips.) Green herons are small and short-legged, with bluish-green backs and deep, chestnut-coloured necks. All three are occasional visitors here, often blown up the Atlantic coast with storm systems. Black-crowned night-herons are stocky, short-legged members of the family; they have a breeding colony at Bon Portage Island, NS, and perhaps at other locations along the coast.

Our most reclusive herons are the American bittern and the least bittern, found in freshwater marshes and reedy lakes. They slip through the reeds along wetland edges, hunting for fish, frogs, snakes and even dragonflies. Heard more often than seen, American bitterns emit an odd pumping sound to proclaim breeding territories.

Years ago while travelling through Nova Scotia's remote interior, I found and photographed a Mi'kmaq petroglyph on a lakeshore. The beautiful rock carving depicted a great blue heron and a human, two fishermen sharing the lake in another time. A good tradition!