Ode to a water rail

Splay-footed, struts near-silent,
Leaving reeds untroubled,
Elusive but for its piglet squeal,
Broadcast through the evening marsh,
Over coot and goose
And squabbling gulls,
The dabchick ducking, diving,
The moorhen picking, darting,
As starlings chatter into roosts,
But the rail-cry cuts across them all.