The unhurried mangrove
TO most people, mangrove swamps are places to be avoided. Dark, sinister, muddy, they choke the estuaries and quiet bays, useless, lonely, smelly, spoiling the foreshores. Mention of being alongside them brings worn-out jokes: ``Beware of the crocodiles and man-eating crabs.'' But since coming to live beside a mangrove-lined bay on the central coast of New South Wales, Australia, I have learned to know its strange beauty and variety, the constant movement of life on all levels, the seasonal changes, the ge ntle rhythm of the tides. The mangrove trees in our bay are Avicennia marina, so-called gray mangrove, common to the east coast. They grow in a variety of forms, twisting and contorting to reach their share of sun and air. Individually, they assume unusual shapes, molded by wind and tidewaters. The new growth is richly green, young trees softening the hoary gray of the older trunks.
In late summer clusters of small, pale, starry flowers appear. Close up they are as pretty as any of our wildflowers. Some trees are laden with these tiny blossoms, which persist well into autumn, attracting insects and birds. Slowly the seeds form. Mangroves are unhurried trees, not given to rush or wild behavior. Even the wind merely ripples their canopy. The seeds begin as little knobs, then during the winter months the fertile ones grow into large green pods, similar to broad beans. In late spring b oth seed and pod fall into the rich ooze below and split open like green butterflies. A root grows and the little plant washes with the tide, finally settling to become a new tree. Last summer I gathered some of these floating treelets and laid them in a gap in the swamp. Now many new mangrove trees are reaching to the sun.
When the tides flow in under the trees, a busy aquatic life comes with them. The waters rise gently but swiftly, rippling over the weed and bringing schools of tiny fish, silver flashes in the shallow water. A great many of our fish species use the shallows for a breeding ground, a very necessary part of our ecology.
Toadfish, or puffer fish as they are sometimes called, dart in the little creeks, feeding off the fresh mud. Small crabs emerge from their holes, and the larger, edible crabs go underground to wait for low tide. Jellyfish float in, eels and octopuses pay a visit, and larger fish come close to feed on the fringes of the reeds.
When the tide goes out, leaving its gifts of weed and driftwood, the birds move in. The swamp floor is a hunting ground for the stately ibis, stalking in the open spaces beneath the trees, its long black beak probing in the soft mud. The elegant heron hunts along the little creek edge, and in the shadow, invisible until they move, soft brown doves forage for food. The shy and swift banded rail slips among the roots, tail twitching, its breast feathers glowing warmly as it moves through a patch of sun.
The trees themselves are full of life. Flocks of red-browed finches live in the branches, falling like leaves on the soft earth, searching for seeds. A superb blue wren flashes through the canopy, followed by his harem. Rosellas nest yearly in hollows in the trunks of the older trees. Mangrove warblers dart among the branches, seeking insects, calling in their lovely song. A flock of crested pigeons uses a dead branch for its daylight perch, sharing it with a black-faced cuckoo shrike and a group of str ay starlings. Currawongs flit and live among the protective branches. A bittern occasionally suns itself on a mangrove branch. Its startling ``boom'' sounds over the dense canopy.
Water birds live along the outer perimeter. Cormorants dry their wings, dreaming on a low branch. Herons perch like old men meditating; ibis, plump white feather pillows, rest awkwardly in the tree forks. Spoonbills and egrets wade in the mud flats, black swans and ducks feed, nest, and call, pelicans patrol the shallows, and in bad weather, silver gulls move into shelter and scavenge for food.
In summer, crab spiders sling their webs between mangrove tree branches and orb spiders spin their lovely orbs of silk, soon untidy with prey parceled up or rejected. Dragonflies on iridescent wings hover among the leaves; water flies skim the incoming tides. The cheerful wanderer, the meadow argus and common orchard, and rarely the brilliant blue triangle butterflies flit around the mangrove flowers, attracted by the nectar.
On warm evenings clouds of tiny flying insects rise on the air currents. Flocks of swallows dart and swoop among them, feeding on the fresh bounty from the swamp. Swifts spiral in the thermals, catching the tips of the rising insect clouds. This is the time when the summer sun blazes down on the waters of the bay. The mangrove trees absorb the glare, their green canopy keeping the shoreline cool, breaking down the dazzling light. They break the hot west winds, and in their dappled shade, samphires flour ish, a delicacy for the galahs and other parrots and cockatoos.
Mangrove swamps may look uninviting. They are really a place of natural rebirth; refuge and home for many creatures; a gentle return to the beginnings of life; a peaceful haven and a source of constant joy and wonder.