摘要:

SummaryThe decrease in woody vegetation in Tsavo National Park has probably had adverse effects on woodland‐adapted herbivores, including the giraffe (Girafa camelopar‐dalis). In an ecological study we attempted to assess this species' density, habitat preference and utilization, and population dynamics, using mainly road strip counts and identification of individual animals.Population structure varied seasonally and locally, indicating differential distribution of sex/age classes. Records on individually known animals suggested an annual mortality rate ofc. 10% for adult plus subadult animals. Of fifteen newborn young, five (33%) survived to 1 year of age, four (27%) to 2 years; in young males mortality appeared to be somewhat higher than in females, but the adult/subadult sex ratio was near unity. The mean calving interval was 22.6 months.Overall mean density was about 0–2 animals/km2. Vegetation‐specific densities indicated a marked preference for woody vegetation generally, and some preference for riverine areas in the dry season. Data on seasonal distribution showed marked concentrations near rivers in the dry season and dispersal into deciduous woodlands away from rivers in the rainy season. The seasonal movements were correlated with, and presumably causally related to, rainfall and the condition of the vegetation; they involved distances of 20–30 km, rarely up to 50 km. Home ranges measured on average 160 km2, with maxima of 650 km2in males and 480 km2in females.The results are compared with those of other studies, and their implications for management are discussed. The future of the giraffe in Tsavo East National Park depends on the development of the woody vegetation inside the park, and probably also on the future pattern of land use outside, as some giraffes appear to move out of the park at times.RésuméLes dégâts effectués par les éléphants sur les arbres du Parc National Tsavo au Kénia ont probablement influencé négativement les herbivores adaptés aux habitats boisés, y compris la girafe (Girafa camelopardalis). Nous avons conduit une ttude écologique pour déterminer la densité, la préférence et utilisation d'habitat, et la dynamique de la population de cette espèce, en employant des recensements routiers et l'identification d'individus a l'aide de différences en configuration des tâches.La structure de la population varie entre saisons et localités, ce qui indique une distribution différente des classes d'âge/sexe. La mortalité annuelle des adultes était environ 10%. Entre 15 nouveau‐nés cinq (33%) atteignaient l'âge d'un an, quatre (27%) deux ans. La mortalité des jeunes mâles était un peu plus élevée que celle des femelles, mais le sex‐ratio des adultes/subadultes était prés de 1: 1. L'interval moyen entre deux mises‐bas était 22,6 mois.La densité moyenne était environ 0,2 animaux/km2, étant plus élevée dans les habitats bien boisés, et aussi prés des rivières en saison sèche. Les girafes se concentraient auprès des rivières en saison séche, se dispersant aux bois à feuilles caduques en saison des pluies. Ces déplacements saisonniers étaient en corrélation statistique et probablement aussi causale ‐ avec les quantités de pluie; ils se montaient à 20–30 km, rarement à 50 km. Les domaines vitaux mesuraient en moyenne 160 km2, avec un maximum de 650 km2pour les mâles et de 480 km2pour les femelles.Les résultats sont comparés avec ceux d'autres études et discutés en termes d'application pratique. L'existence continue des girafes au Parc National Tsavo dépend du développement de la végétation boisée dans le parc, et aussi de l'utilisation humaine d

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1978.tb00419.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

SummaryThe coat colour pattern of the Black and WhiteColobushas served for almost two centuries as the primary means of classifying the genus. Observations on aberrations in the coat colour pattern, particularly of the ‘white’Colobusof Mt. Kenya, suggest a simple hypothesis explaining the development of the coat colour in terms of dorsal and ventral fields, which have been blocked in these aberrant individuals. The basic differences in the species patterns within the genusColobusmay be viewed as the result of differing degrees of extension of these fields. The evident rarity of aberrations in coat colour underlines the uniqueness of the Mt. Kenya populations containing these ‘white’ individuals.RésuméLa couleur de la robe deColobusa servi de moyen principal pour classifier ce genre. Les remarques sur les anomalies dans la couleur de la robe, particulièrement les colobes ‘blancs’ du Mt. Kenya, suggèrent une hypothése qui explique le développement de la couleur de la robe sous form des champs dorsal et ventral, qui sont bloqués chez ces individus ‘blancs’. Les différences de base parmi les espèces du genreColobuspeuvent être envisagées comme le résultat de degrés différents de l'extension de ces champs. La rareté de ces anomalies dans la robe deCofubussouligne le charactère unique de la population du Mt. Kenya qui

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1978.tb00420.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

SummaryThe occurrence, chronology of breeding and wing‐moult, and feeding habits of the Pigmy GooseNettapus auritus, Knob‐billed GooseSarkidiornis melanotos, Spur‐winged GoosePlectropterus gambensis, Egyptian GooseAlopochen aegyptiacaand Red‐knobbed CootFulica cristataon the Kafue Flats in Zambia are described based on observations made between October 1970 and January 1974 at Lochinvar National Park and, from the air, over the central section of the Flats.The Pigmy Goose, Knob‐billed Goose, Egyptian Goose and Red‐knobbed Coot fed largely by grazing. They were most abundant between March and June, occurring in greatest numbers at Lochinvar. Egyptian Geese occasionally nested on the flood‐plain at Lochinvar between August and January, but there was no proof of the other species nesting there. Many Pigmy Geese and male Knob‐billed Geese moulted on the lagoon at Lochinvar between March and June; small numbers of Egyptian Geese and Red‐knobbed Coot also moulted in the Park, the former between February and May, the latter in June and July.The Spur‐winged Goose fed mostly by grazing and grubbing. Numbers on the Flats were greatest between June and November when 60,000–90,000 moved downriver as the floods subsided. Many bred between January and March in the fringing zone and moulted on the floodplain between May and July.A hydroelectric scheme, completed in 1975, may benefit the Pigmy Goose and Red‐knobbed Coot but har

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1978.tb00421.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

SummaryThe spleen weights increase with age inRousettus aegyptiacusfor the first 6 months. The size of the adrenal cortex estimated by adrenal weight behaves in a similar way as the spleen weights. The spleen weights decline as the bats mature while the adrenal weights continue to increase with age.Both the spleen and adrenal weights are variable in pregnant bats. The pregnant animals have heavy adrenals and small spleens on average. Since the pregnant bats are heavy, their relative spleen and adrenal weights are different from the absolute weights, but more so in the latter than in the former.The spleen inRousettusresponds to stressful environments differently from the way it does in rodents under similar situations.

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1978.tb00422.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1978.tb00423.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1978.tb00424.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1978.tb00425.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1978.tb00426.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Book reviewed in this article:Rangeland Management and Ecology in East Africa. Ed. by D. J. Prattand M. D. Gwynne. Hodder and StoughtonLarge Mammals and a Brave People: Subsistence Hunters in Zambia. By StuartA. Marks. Foreword by J. DesmondClark.

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1978.tb00427.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

ISSN:0141-6707    

DOI:10.1111/j.1365-2028.1978.tb00428.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY