Saturday, February 12, 2011

Water birds, weirs and what ifs

click photo to enlarge
Freshwater birds, by and large, prefer calm water. Most ducks, waders, herons and smaller species find their food, raise their young and spend their days around slow moving rivers or open expanses of water. There are exceptions of course. Dippers only frequent quickly running rivers and streams, and grey wagtails, though they are found in a range of waterside locations, prefer the quicker stretches of a river. Common sandpipers aren't averse to such locations either. I've seen adult red breasted mergansers with a brood of fluffy chicks bouncing down a steep and stony Lakeland beck, but for most of the year these birds too will choose the calmer reaches of rivers, lakes and even the sea. Certainly common ducks such as the mallard generally favour ponds, meres, lakes and sluggish rivers.

Where a river has a weir the water above the drop is often flat and calm. I've watched mallard and tufted duck as well as coot and moorhen feeding in such places, dabbling or diving as the pull of the water slowly draws them to the tipping point, then paddling away from the edge as they get too close. I've often wondered if at such times, a bird that is distracted by the prospect of a tasty morsel, ever loses its sense of where it is relative to the weir and is drawn over the edge. It's not something I've ever seen happen. Until the other day when we were at Cogglesford Mill in Sleaford.

I took a photograph at this location a few weeks ago, and as I stood at the same spot again I saw a pair of mallard being pulled towards the falling water. The male kept out of harms way, but the female drifted over the edge. However, rather than dropping into the foaming water below, she extended her wings, flapped them very purposefully and in combination with walking on the water, got herself back to swimming again. Unfortunately, by the time I raised my camera to my eye this scene was played out. But I did get this shot with the still disturbed water going over the weir's edge and the female heading for a safer spot.

photograph and text (c) T. Boughen

Camera: Canon
Mode: Aperture Priority
Focal Length: 100mm
F No: 7.1
Shutter Speed: 1/40
ISO: 200
Exposure Compensation: -1.33 EV
Image Stabilisation: On