摘要:

Oatley, T. B. 1982. The Starred Robin in Natal, Part 2: Annual cycles and feeding ecology.Ostrich53:193-205 Young Starred RobinsPogonocichla stellatadisperse from their birthplace and evidently seldom return. Other immature Starred Robins move into the forests during April andMayto form recruits to the local population. In addition to local dispersal, there is a notable altitudinal migration by some adults and immatures.

ISSN:0030-6525    

DOI:10.1080/00306525.1982.9634573

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0030-6525    

DOI:10.1080/00306525.1982.9634574

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Oatley, T. B. 1982. The Starred Robin in Natal, Part 3: Breeding, populations and plumages.Ostrich53: 206–221 The female Starred RobinPogonocichla stellataconstructs a domed nest of moss and dead leaves usually on sloping ground and well concealed in the herb layer. The normal clutch is three eggs laid on consecutive days. Incubation usually starts with the laying of the third egg. The mean size of 138 eggs was 22 x 16 mm. The female incubates the eggs for 16 to 18 days and intermittently broods the young for the fist five of the average 14-day nestling period. Both sexes feed the young from the time of hatching and parental care lasts for some 42 days after leaving the nest. Eggs are laid from October to December with 63% of clutches started in November. Data on sex ratios indicate a surplus of adult males in the population and annual survival rates are estimated at 0,84 for males and 0,76 for females. 51% of eggs laid in 60 nests give rise to fledged young. About 21.3% of eggs laid produce adults. The level of brood parasitism by cuckoos is relatively low. Most adult mortality occurs outside of the breeding seasons. Chilling and overnight starvation from January to March when incidence of late afternoon thunderstorms is highMaycause significant mortality. The subadult plumage appears to confer crypsis and enable the immature bird to reside in adult territories without harassment. AdultsMaybenefit through an effective reduction in competitive stress.

ISSN:0030-6525    

DOI:10.1080/00306525.1982.9634575

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0030-6525    

DOI:10.1080/00306525.1982.9634576

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Clark, A. 1982. Some observations on the behaviour of the Threebanded Plover.Ostrich53:222-227. The behaviour of the Threebanded PloverCharadrius tricollariswas studied at two localities in the Transvaal over the years 1973–1982. Descriptions of behaviour cover feeding, voice and displays associated with the breeding season. Comparisons are made with the displays described for otherCharadriusplovers.

ISSN:0030-6525    

DOI:10.1080/00306525.1982.9634577

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0030-6525    

DOI:10.1080/00306525.1982.9634578

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Griffiths, A. M. 1982. Reactions of some seabirds to a ship in the Southern Ocean.Ostrich53:228-235. The reactions of 31 species of seabirds (mainly Procellariiformes) to a moving and a stationary ship were investigated in the Southern Ocean. Birds were categorized according to the distance at which they were seen from the moving ship. The proportions of individuals of each species following the ship, as opposed to flying past it, were calculated. Few species allow accurate censuses of their abundance. The time spent following by individual birds is discussed with respect to “turn-over rates” of ship-following species. Species strongly attracted to the ship were scavengers. Food is believed to be the prime factor influencing the attraction of seabirds to ships, although albatrossesMayhave followed to use air currents generated by the ship. Within an hour of the ship stopping most species had increased in abundance. The implications of assessing avian abundance and biomass from a stationary ship are discussed.

ISSN:0030-6525    

DOI:10.1080/00306525.1982.9634579

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0030-6525    

DOI:10.1080/00306525.1982.9634580

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Silbernagl, H. P. 1982. Seasonal and spatial distribution of the American Purple Gallinule in South Africa.Ostrich53:236-240.

ISSN:0030-6525    

DOI:10.1080/00306525.1982.9634581

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0030-6525    

DOI:10.1080/00306525.1982.9634582

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor