White-backed Duck diving behaviour
The White-backed Duck is an ab-errant whistling duck that shares several morphological features with the stiff-tailed ducks (Oxyurini) because of their shared reliance on diving for feeding. White-backed Ducks eat vegetable matter, especially waterlily seeds, collected from the bottom of shallow wetlands. Clark (1969, Wildfowl 20: 71–74) reported that dive durations increase with water depth, lasting 12 to 14 seconds in water 0.3 metres deep, 15 to 20 seconds in water 0.6 to 0.9 metres deep, and 25 to 30 seconds in water approximately two metres deep. Recovery intervals between dives range from four to 12 seconds, increasing with dive duration and depth, giving a dive efficiency (the ratio of dive duration to recovery period) in the order of 2 to 3.
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Esta historia es de la edición May/June 2018 de African Birdlife.
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EXPLORING NEW HORIZONS
Keith Barnes, co-author of the new Field Guide to Birds of Greater Southern Africa, chats about the long-neglected birding regions just north of the Kunene and Zambezi, getting back to watching birds and the vulture that changed his life.
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CAPE crusade
The Cape Bird Club/City of Cape Town Birding Big Year Challenge
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WATER IS LIFE. As wildlife photographer Greg du Toit knows better than most.
winter wanderer
as summer becomes a memory in the south, the skies are a little quieter as the migrants have returned to the warming north. But one bird endemic to the southern African region takes its own little winter journey.
when perfect isn't enough
Egg signatures and forgeries in the cuckoo-drongo arms race
Southern SIGHTINGS
The late summer period naturally started quietening down after the midsummer excitement, but there were still some classy rarities on offer for birders all over the subregion. As always, none of the records included here have been adjudicated by any of the subregion's Rarities Committees.
flood impact on wetland birds
One of the features of a warming planet is increasingly erratic rainfall; years of drought followed by devastating floods. Fortunately, many waterbirds are pre-adapted to cope with such extremes, especially in southern Africa where they have evolved to exploit episodic rainfall events in semi-arid and arid regions. But how do waterbirds respond to floods in areas where rainfall - and access to water - is more predictable? Peter Ryan explores the consequences of recent floods on the birds of the Western Cape's Olifants River valley.
a star is born
It’s every producer’s dream to plan a wildlife television series and pick the right characters before filming.
