Penguins are one of the most dis-tinctive and charismatic bird orders. Supremely adapted for flipper-propelled diving, they are the most aquatic of all birds and hold the records for the deepest and longest dives. A new study by Theresa Cole and a large team of researchers (Nature Communications, doi: 10.1038/ s41467-022-31508-9) provides unprecedented insights into how they adapted to a life at sea.
Thanks to their dense bones and aquatic habitats, penguins are well represented in the fossil record. In addition to the 19 extant species, nearly 50 other penguin species are known from fossil or sub-fossil remains. Cole’s team combined data from fossil species with genomic evidence from all extant and recently extinct penguins to infer their evolutionary history.
By comparing the genomes of penguins with those of other birds, the researchers were able to identify the genes responsible for a suite of marine adaptations. These include genes that enhance dive duration by promoting oxygen storage in the muscles and by improving tolerance to low blood oxygen concentrations. Penguins also have
lost the gene for green cones in their retina and have blue-shifted their colour vision to enhance visual acuity in extremely low light levels.
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Denne historien er fra September/October 2022-utgaven av 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.
footloose IN FYNBOS
The Walker Bay Diversity Trail is a leisurely hike with a multitude of flowers, feathers and flavours along the way.
Living forwards
How photographing birds helps me face adversity
CAPE crusade
The Cape Bird Club/City of Cape Town Birding Big Year Challenge
water & WINGS
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.
