Most of the birds that feed along Sydney’s shores are coloured in shades of brown. Mottled brown is surprisingly effective camouflage out on the open mud and sandflats. The expression ‘little brown bird’ seems purpose designed for waders and shorebirds.
Amongst this dappled horde there are a few exceptions, birds that replace boring beige with stark patterns of black and white.
A trip to Lake Illawarra featured the most delicate of the pied shorebirds, the Black Winged Stilt. ‘Stilt’ is a wonderfully apt name for these birds, whose diminutive black and white bodies float above improbably long pink legs.
The legs are so long that stilts can appear a bit awkward, tangled legs criss crossing as they stalk over shallow seagrass beds.
Black Winged Stilts often preen or sleep on a single leg while standing in the shallows, the body seemingly levitating above the water.
When they fly the long legs dangle far behind the body and tail.
The bill is long and thin. They don’t often probe into the sediment like other waders, but instead use the bill like a pair of tweezers, darting down to snatch a prawn, shrimp or fish. Stilts move in slow motion, carefully picking their way over the flats and relying on stealth to approach their prey. Perhaps the sharply contrasting blocks of black and white plumage help by breaking up the outline of the stalking bird.
Pied Oystercatchers share the stilt’s colour scheme, right down to having brightly coloured legs (although red rather than the stilt’s pink). The bodies are a similar size and both species are inhabitants of the mud and sandflats. There the similarities end. Where stilts are all delicacy and quiet, Pied Oystercatchers are the rambunctious bulldozers of Sydney’s coasts.
My morning spent paddling around the southern shores of Botany Bay must have coincided with a peak in territorial squabbles amongst the local Pied Oystercatcher population. Pairs were working the flats, using their heavy chisel like bills to pry open oysters from the beds by the low tide. Every few moments the feeding birds would be disturbed by the arrival of more oystercatchers. The original pair would arch their heads downwards, open bills, emit a grating call and chase after the new arrivals. Most of the time the intruders would retreat, but some turned the tables, chasing off the originals.
Not all of the disputes were resolved on the ground, with some continuing in aerial chases. I watched an oystercatcher dive bomb an opponent so vigorously that its outswept wing dipped below the water, almost tumbling it out of the sky.
Near one of the groups of squabbling oystercatchers was a nesting colony of Little Terns. The terns are pearly white with a black cap and eyes. From below they look all white. Tern colonies are always a hive of activity, even when the birds are sitting on eggs. There is always someone returning to the colony proudly grasping a fish in its bill, and event that always seems to demand a couple of laps to ensure that everyone gets to admire the catch.
On this occasion one of the reasons for perpetual activity was a pair of Australian Ravens. Ravens are common on coasts, searching the shore for the endless variety of dead stuff that arrives with every tide. I watched first one and then the other fly over and around the Little Tern colony. The tern’s response was the same, every bird in the colony rising in an attempt to drive off the much larger bird. After completing their circuit the ravens returned to perch near the edge of the colony. I couldn’t help wondering if they were looking for signs of eggs or chicks that might make the tern’s bombardment worthwhile.
Between the brawling Pied Oystercatchers, the ever vigilant Little Terns and the plaintive calls of Eastern Curlew there was no doubt that the mud and sandflats are one of the most productive wildlife habitats around Sydney. And, at least from the relative comfort of my kayak seat, an enjoyable place to watch wildlife.
Odds and sods