|
The southern black tit or simply black tit (''Parus niger'') is a species of bird in the tit family Paridae. It occurs chiefly in tropical and subtropical savanna woodland, in a semicircular arc from Angola to Eastern Cape Province in South Africa.〔(Simulated distribution map for ''Parus niger'' )〕 It prefers woodland dominated by broad-leaved trees, most importantly miombo, ''Combretum'' species, and ''Burkea africana''.〔(''Parus niger'' (Southern Black Tit) )〕 It is especially common in the woodlands of western Zimbabwe, where densities can reach as high as fifty birds per square kilometre.〔 The southern black tit, unlike parids of the Northern Hemisphere or other local species, is almost entirely monotone in colour and sexually somewhat dimorphic,〔Newman; Kenneth; ''Newman's Birds of Southern Africa''; p. 328. ISBN 1868727351〕 with the female being greyish and the male very distinctly blue-black in colour. It can be distinguished from the white-winged tit and Carp's tit by having no white rim in its tail〔Harrap, Simon; ''Tits, Nuthatches and Treecreepers''; p. 80. ISBN 1408134586〕 and is around in total length including the tail.〔 Like all tits, it feed chiefly on insects, and is a voracious consumer of wasps in its favoured habitat; however, it has unusually for a parid been known to take nectar and fruiting figs.〔 The breeding system of the southern black tit has been intensively studied and is often regarded〔Skutch; Alexander Frank (author) and Gardner, Dana (illustrator) ''Helpers at birds' nests : a worldwide survey of cooperative breeding and related behavior'' pp. 139-142. Published 1987 by University of Iowa Press. ISBN 0877451508〕 as a classic example of the differences in breeding strategies between warm regions with unpredictable rainfall and cold regions with severe winters. Unlike the great tit or blue tit which can provision up to twenty-five nestlings per year in unassisted pairs, the southern black tit, living on a much poorer food supply,〔Wiggins, David A.; “Low reproductive rates in two ''Parus'' species in southern Africa”; in ''Ibis'', 143 (2001) pp. 677-680〕 can as an unassisted pair seldom provision even ''one'' nestling in a breeding season.〔 As a result, most males must stay in the parental territory for several years to help rear the usually three nestlings that each breeding female produces under favourable conditions. An interesting feature of the southern black tit is that the breeding female, who incubates continuously during the fifteen days of incubation and is fed by her mate and the helpers, will mimic venomous snakes when she feels threatened to prevent depredation of the nest.〔MacLean, Gordon; ''Roberts’ Birds of Southern Africa'' (Sixth Edition); p. 481. ISBN 9780620175838〕 Breeding occurs during the summer wet season, but its initiation is very varied and the number of broods reared is dependent on how consistent rainfall is. Although the species has been recovered from ringing on only a few occasions and data about survival and longevity are thus useless,〔(Southern Black Tit )〕 it is practically certain that the adult mortality rate is much lower than the 70 to 75 percent mortality of closely related parids in Europe and North America.〔Peach, Will J., Hanmer, Dale B. and Oatley, Terence B.; “Do southern African songbirds live longer than their European counterparts?” in ''Oikos'' 93: 235–249.〕 ==References== 〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Southern black tit」の詳細全文を読む スポンサード リンク
|
