Thalasseus (Sterna) bergii
The Swift Tern, or Greater Crested Tern, usually inhabits the shallow tropical and sub-tropical waters of lagoons, estuaries, bays, harbours and open beaches where it feeds mainly on fish (up to 90% of its diet) as well as squid, crustaceans and insects. Adults have a wingspan of up to 1.2m and weigh up to 430g.
These terns are gregarious birds, nesting and roosting in fairly large and dense colonies, often mixed with gulls and cormorants, usually on offshore islands, reefs or sandbanks and occasionally on top of buildings. Nests are shallow scrapes in the bare sand or on rocks and often quite exposed. The breeding season in Swift Terns stretches from late summer through winter to early spring. Pairs are monogamous. Clutches consist of 1 or 2 eggs and are incubated for around 4 weeks by both parents. Chicks fledge at a little over a month old, but don’t become fully independent until they’re about 5 months old.
The IUCN considers the Swift Tern to be of least concern, estimating the total population at around a million birds, with an enormous distribution stretching from Namibia and South Africa along the Indian Ocean coasts of Africa, the Middle East and Asia, and into the Pacific Ocean far to the north-east of Australia. They occur along the entire South African coastline, though about 80% of the local population, estimated in the region of 25,000 birds and increasing, is found in the Western Cape during the breeding season.
I love the single tern sitting on a rock photo but the one in flight is brilliantly captured!
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Very kind of you, thanks very much!
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I think this bird looks particularly beautiful in flight.
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Absolutely, P J B – they are very aerodynamic!
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Verruklike foto’s!
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Baie dankie, Tannie Frannie!
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Dankie… nou het ek weer lekker gekuier!! 😉
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Ons is baie bly en dankbaar dat jy bietjie tyd by ons kom spandeer het, AJ!
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En om te dink… ek ken the blggers van die jaar! Dis vir my beslus ‘n eer om daar by julle te kuier!! 😉
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Die een foto teen blou lug en waar almal eenkant toe kyk, is pragtig! Mooi Dries!
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Baie dankie Dina – ek waardeer dit regtig!
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That tern has a special look compared to other terns I’ve seen. Both the beak and the feathers on the head.
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Many of the terns that visit our shores in summer are wearing their non-breeding plumage, making it extremely difficult for a novice like me to identify them. At least the swift terns, as you rightly say John, is easier to identify.
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I like the photos of them all facing the same way. Makes me smile. See? 🙂
janet
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I’ve wondered why all the members of the flock so often seem to be facing the same direction, but couldn’t find an answer anywhere. It does make them look like a squadron of fighter-jets lined up for take-off though!
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