The status and distribution of three species of Sternula terns on the eastern coast of Africa and in the western Indian Ocean, with two species new for Mozambique
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引用次数: 0
Abstract
Summary. The status of three Sternula terns in southern and eastern Africa and the Indian Ocean is updated based on observations in Mozambique during October 2009–August 2021. Damara Tern S. balaenarum and Saunders's Tern S. saundersi, both new to Mozambique, were found at the San Sebastian Peninsula in August 2018 and have been recorded regularly since. Damara Tern arrived in May, numbers were lower June–July, with a peak of 100+ in August–October. Breeding plumage was assumed by late October and all departed in early November; those aged were all adults. Observations of ringed birds suggested they originated from colonies in South Africa. Numbers of Damara Tern reached the Key Biodiversity Area designation threshold population for the site in 2020. These are the first records of large numbers of Damara Tern in the Indian Ocean, whilst timings suggest the species is partly transient at the site and may also occur further north. Saunders's Tern was recorded at San Sebastian in all months except March and April, with 5–80 regularly present, and peak numbers perhaps in October–December. Birds were observed in a range of plumages in all months, from non-breeding, transitional to full breeding. Courtship feeding was observed in September–November suggesting at least some attempt to breed locally, although disturbance is high. Birds in non-breeding plumage may stem from Northern Hemisphere breeding localities. Little Tern S. albifrons was a numerous migrant in southern Mozambique in October–May, peaking in April when large numbers were observed during pelagic trips to the continental shelf edge, and at onshore roost sites including San Sebastian. Smaller numbers fed in coastal lagoons and freshwater lakes. Three Little Terns had been colour-ringed in Israel.
总结。根据2009年10月至2021年8月在莫桑比克的观测资料,更新了南部和东部非洲以及印度洋的三种Sternula燕鸥的状况。Damara Tern S. balaenarum和Saunders's Tern S. saundersi都是莫桑比克的新物种,于2018年8月在圣塞巴斯蒂安半岛被发现,此后一直定期记录。达玛拉特恩于5月抵达,6月至7月数量较少,8月至10月达到100多只的峰值。繁殖羽毛在10月下旬出现,11月初全部离开;那些上了年纪的都是成年人。对环鸟的观察表明,它们起源于南非的殖民地。2020年,达马拉燕鸥的数量达到了该地点的关键生物多样性区指定阈值。这是印度洋上大量达马拉燕鸥的第一次记录,同时时间表明该物种在该地点部分是短暂的,也可能在更北的地方出现。除了3月和4月外,圣塞瓦斯蒂安的所有月份都有桑德斯燕鸥的记录,定期出现5-80只,10 - 12月可能是高峰。从非繁殖期、过渡期到繁殖期,所有月份的鸟类都有不同的羽毛。在9月至11月期间观察到的求偶喂养表明,尽管干扰很大,但至少有一些尝试在当地繁殖。非繁殖期羽毛的鸟类可能来自北半球繁殖期的地方。10月至5月,小燕鸥在莫桑比克南部大量迁徙,4月达到高峰,在前往大陆架边缘的远洋旅行中,以及在包括圣塞瓦斯蒂安在内的陆上栖息地,观察到大量的小燕鸥。少数在沿海的泻湖和淡水湖中觅食。三只小燕鸥在以色列被戴上了彩圈。