bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship between fire and basal scarring on Afzelia africana in Benoue National Park, Cameroon
Authors: STARK M. A. 
Published: April 2008

SummaryAfzelia africana Sm. is a common, somewhat fire‐tolerant tree species in Benoue National Park, Cameroon, but Afzelia woodland is decreasing and being invaded by the fire‐tolerant tree species Monotes kerstingii Gilg. Basal scarring was severe and chronic on 74% of the Afzelia africana trees sampled. A strong positive correlation was found between basal scar width and height (r=0.693), and an average 4.5% (range 1.6–6.8%) of all Afzelia trees in each stand were dead or dying. The majority of basal scars faced south and south‐west. Growth ring analysis of Afzelia africana trees revealed that Benoue National Park has two distinct fire histories.RésuméAfzelia africana Sm. est un arbre quelque peu pyrorésistant commun dans le Parc National de Bénoué (Cameroun) bien que les forêts à Afzelia soient en dimunution et envahis par une autre espèce résistante au feu, Monotes kerstingii Gilg. Des cicactrices basales sont importantes et chroniques sur 74% des arbres échantillonnés. On a calculé une correlation fortement possitive (r=0.693) entre la largeur et la hauteur des cicatrices basales; une moyenne de 4.5% (limites de 1.6‐6.8%) de tous les Afzelia dans chaque station étaient mourants ou morts. La Majorité des cicatrices basales étaient située vers le sud et le sud‐ouest. L'analyse des anneaux de croissance dans les troncs d'Afzelia a révélé deux périodes distinctes de feux au Parc National de Bénoué.
Foraging site selection by three raptors in relation to grassland burning in a montane habitat
Authors: BARNARD PHOEBE 
Published: April 2008

SummaryFactors affecting the use of flight‐hunting areas by three common raptors (rock kestrel Falco tinnunculus L., jackal buzzard Buteo rufofuscus (Forster), and black‐shouldered kite Elanus caeruleus (Desfontaines)) were analysed in a montane grassland area. Seasonal variation in foraging site selection was examined, based on five habitat parameters: regrowth time since burn, cover density, grass height, rockiness and slope. Kestrels and buzzards moved into recently burnt areas to hover, while kites hovered over undisturbed grassland. Increased small mammal and large insect availability characterized newly burnt savanna and are suggested as reasons behind the habitat change by two of the three raptors. An increase in the use of rocky grassland by kestrels and buzzards coincided with the availability of juvenile skinks in this patchily‐distributed habitat.RÉSUMEÉLes facteurs influencant l'utilisation de terrain de chasse par trois rapaces communs (Crécerelle des rochers, Falco tinnunculus L., Buse‐chacal, Buteo rufofuscus (Forster) et Milan àépaules noires, Elanus caeruleus (Desfontaines)) ont été analysés dans une zone de prairie montagneuse. On a examiné la variation saisonnière du fourrage sur le site choisi selon cinq paramètres:temps de repousse après brulis, densité de couverture, hauteur de l'herbe, caractère rocailleux et pente. Des crécerelles et des buses se sont rendues au‐dessus des endroits récemment bru&#x030c;lés pour planer tandis que les milans survolaient des prés n'ayant pas connu de perturbation. La savanne frai&#x030c;chement bru&#x030c;lée se caractérise par une plus grande disponibilité en petits mammifères et grands insectes, ce qui expliquerait le changement d'habitat de deux des trois rapaces. Une utilisation accrue des prairies rocheuses par les crécerelles et les buses correspondait à la présence de jeunes scinques dans cet habitat clairsemé.
Population status of the hippopotamus on the Luangwa River, Zambia
Authors: TEMBO A. 
Published: April 2008

SummaryHippopotamus (Hippopotamus amphibius L.) were censused by both ground and aerial surveys along a 165 km stretch of the Luangwa River, Zambia. Total numbers of 6293 and 6544 were estimated for 1982 ground and 1983 aerial counts, respectively. The 1982 density was 38 hippopotami per river km for the whole study area, with a total of 343 hippopotamus schools. The ratio of calves to adults in the ground counts was 0.048: 1. The population growth for the whole study area since 1970 shows an annual increase of 7%. Hippopotamus densities in Luangwa are now twice those recorded in Uganda when a management cull was initiated there in the 1950s.RÉSUMEÉLes hippopotames (Hippopotamus amphibius L.) furent dénombrés par recensements terrestres et aériens le long d'une portion de 165 km de la Luangwa River en Zambie. Les nombres totaux de 6.293 et 6.544 furent estimés pour les comptages terrestres de 1982 et les comptages aériens de 1983 respectivement. La densité de 1982 était de 38 hippopotames par kilomètre de rivière pour toute la zone d'étude, avec un total de 343 groupes d'hippo. La proportion jeunes/adultes par observations terrestres était de 0,048. L'accroissement de la population pour toute la zone d'étude depuis 1970 présente une croissance annuelle de 7%. Les densités d'hippopotames dans la Luangwa sont à présent deux fois plus importantes que celles enregistrées en Uganda lorsqu'une gestion limitative (cull) fut entamée dans les années cinquantes.
Is the black‐headed weaver a pest?
Authors: KASOMA P. M. B. 
Published: April 2008

SummaryIn central Uganda, the black‐headed weaver is most abundant near human habitations. It feeds mainly in or near cultivations. Two hundred and forty hours were spent observing food items taken by this weaver in the wild near Kampala from March 1979 to May 1980. Crops and/or stomachs of 201 black‐headed weavers caught monthly from April 1980 to April 1981 were analysed. Field observations showed that insects made up 21.2% of total food items and plant material 78.8% but gut analysis showed that the mean percentage relative frequency of insects in the diet varied; in some months birds took more insects than plant material (numerically) and in other months the reverse occurred. Plant material was mostly seeds of the grass Rotboellia exaltata L. f. and maize grains (41.7% and 15%, respectively, according to the field observations; 62.7% and 76.3%, respectively, from the gut content analysis). Other grass seeds were eaten in very small amounts. Weed seeds (forbs) and nectar were also occasionally taken. Animal material was mostly insects but included some spiders. Of all 201 crops and/or stomachs examined, beetles were present in 78.7%, followed closely by ants (60.4%). A small scale survey, carried out in July 1981, concluded that damage to maize was slight.RÉSUMEÉDans le centre de l'Uganda, le tisserin à těte noire est très abondant près des habitations humaines. Il se nourrit principalement dans les cultures ou à leurs abords. Nous avons passé 240 heures à observer les types de nourritures de ce tisserin sur le terrain près de Kampala depuis mars 1979 jusqu'à mai 1980. Les jabots et/ou estomacs de 201 tisserins à těte noire, capturés chaque mois depuis avril 1980 jusqu'à avril 1981, furent analysés. Les observations de terrain montrent que les insectes constituent 21,2% du régime total et les matériaux végétaux 78,8%, mais I'analyse intestinale montre que le pourcentage moyen de fréquence relative des insectes varie; à certains mois les oiseaux prennent plus d'insectes que de matériaux végétaux et à certains autres c'est l'inverse. Les matériaux végétaux sont le plus souvent des graines de la graminée Rotboellia exaltata L. f. et des graines de mais (41,7% et 15% respectivement selon les observations de terrain et 62,7% et 76,3% respectivement selon l'analyse du contenu intestinal). Les graines d'autres graminées sont consommées en très petite proportion. Les graines des ‘forbs’ et le nectar sont aussi consommés occasionnellement. Parmi les animaux consommés on trouve surtout des insectes mais aussi quelques araignées. Parmi les 201 jabots et/ou estomacs examinés, 78.7% contenaient des scarabées et 60,4% des termites. En juillet 1981, une étude à petite échelle conduit à la conclusion que les déga&#x030c;ts au mais étaient légers.
Seasonal reproduction of white‐eared kob in Boma National Park, Sudan
Authors: FRYXELL J. M. 
Published: April 2008

SummaryThe reproductive phenology of migratory white‐eared kob in Boma National Park, southern Sudan, was investigated during 1981‐83. Calf production occurred during the late wet season (September‐December), well after the period of peak food abundance. Lactation continued throughout the dry season, when forage was in short supply. As a consequence, lactating females had lower fat reserves than either non‐lactating females or males. The observed calving phenology may (i) allow females time to replenish fat reserves prior to lactation and (ii) reduce the risk of predation on new‐born young.RÉSUMEÉLa phénologie reproductive du cobe de Buffon àoreilles blanches migrateur dans le Parc National de Boma, dans le sud du Soudan, fut étudiée durant les années 1981 à 1983. La naissance des jeunes se produit à la fin de la saison des pluies (septembre à décembre), bien après la période d'abondance maximale. L'allaitement se poursuit tout au long de la saison sèche, alors que le fourrage n'est pas suffisant. En conséquence, les femelles allaitantes ont moins de réserves de graisse que les autres femelles ou que les mäles. La phénologie de reproduction observée pourrait laisseu aux femelles le temps de se constituer des réserves de graisse avant la lactation et réduire le risque de prédation sur les nouveaux‐nés.
Waterbuck (Kobus ellipsipyrmnus) population dynamics: the testing of an hypothesis
Authors: MELTON D. A. 
Published: April 2008

SummaryResults of a previous study on the waterbuck {Kobus ellipsipyrmnus (Ogilby)} in the Umfolozi Game Reserve prompted the hypothesis that interspecific competition was the ultimate factor responsible for the decline of this population. Subsequent removal of many of the putative competitors allowed for the testing of this hypothesis. The present study confirms that the waterbuck population was declining, but the link between calf mortality and competition is de‐emphasized. It appears that competition may have acted only secondarily to aggravate tick‐induced calf mortality.RÉSUMEÉLes résultats d'une étude précédente sur le waterbuck (Kobus ellipsiprymnus (Ogilby)) dans la Réserve de Faune d'Umfolozi suggéraient l'hypothèse qu'une compétition interspécifique était le facteur ultime responsable du déclin de cette population. En supprimant ultérieurement de nombreux compétiteurs potentiels, on a pu tester cette hypothèse. La présente étude confirme que la population de waterbuck était en diminution, mais le lien entre la mortalité juvénile et la compétition est moins mis en évidence. Il semble que la compétition peut avoir agi secondairement pour aggraver la mortalité juvenile induite par les tiques.
Patterns of intra‐African small raptor spring migrations in the Taru Desert, Kenya
Authors: ANNE O. , RASA E. 
Published: April 2008

SummaryLittle is known about the movements of small African raptors in East Africa. The northward migration is reported here for four species that follow each other sequentially from January to March through the Taru Desert, a thick belt of Commiphora woodland behind the Kenyan Coast. Arrival and departure dates over a period of 6 years and estimations of numbers present are given, together with equivalent data for four species of European falcon. The movements of the African species appear to be associated with seasonal abundance of their prey.RÉSUMEÉOn sait peu des déplacements des petits oiseaux de proie africains en Afrique de l'Est. On décrit ici la migration vers le nord pour quatre espèces qui se succèdent de janvier à mars en passant par le Désert de Taru, une épaisse bande forestière àCommiphora le long de la cěte kenyane. Les dates de děparts et d'arrivées sur une période de 6 ans et les estimations de populations présentes sont donntés, ainsi que les indications équivalentes pour quatre espèces de faucons européens. Les mouvements des espèces africaines paraissent associés a l'abondance saisonnière de leure proie.
Seasonal reproduction of the springhare (Pedetes capensis) in southeastern Zimbabwe
Authors: KOFRON CHRISTOPHER P. 
Published: April 2008

SummaryFemale springhares in a population in southeastern Zimbabwe experienced seasonal reproduction during the study period from November 1983 to November 1984. In general, only adult springhares comprised the population from November to February. Adult females were pregnant during December, January and February, and subsequently they bore their young during March. Length of gestation was about 79 days. Later, some females experienced a second pregnancy. In the majority of females, pregnancy and birth of young was restricted to the wet season when food was readily available. During the dry season when food was sparse, only a small portion of females in the population reproduced. Adult males appeared able to reproduce throughout the year. Juvenile springhares first emerged from the burrows during May approximately 9 weeks after birth, and they attained sexual maturity at an age of about 8 months.RÉSUMEÉCette étude, couvrant la période novembre 1983‐novembre 1984, eut pour objet l'étude de la reproduction saisonnière chez les femelles de lièvres sauteurs d'une population au su‐est du Zimbabwe. En général, la population ne comprend que des adultes entre novembre et février. Les femelles adultes sont prégnantes en décembres, janvier et février et ensuite elles mettent bas leur jeune en mars. La durée de gestation est d'environ 79 jours. Plus tard, certaines femelles ont une seconde portée. Pour la majorité des femelles, la grossesse et la mise bas se déroulent durant la saison des pluies au moment où la nourriture est disponible en abondance. Durant la saison sèche, lorsqu'il y a moins de nourriture, une faible proportion des femelles se reproduisent. Les ma&#x030c;les adultes semblent ětre capables de reproduire tout au long de l'annee. Les lièvres sauteurs juvéniles émergent du terrier durant le mois de mai, environ neuf mois après la naissance, et atteignent leur maturité sexuelle à l'a&#x030c;ge de huit mois environ.
Dry season diurnal activity of elephants in Lake Manyara National park, Tanzania
Authors: KALEMERA M. C. 
Published: April 2008

SummaryThe daytime activities of elephants (Loxodonta africana (Blumembach)) in the Acacia tortilis woodland of Lake Manyara National Park Tanzania were monitored over two consecutive dry seasons in 1981 and 1982. The two methods used to assess the activity pattern were the point sample technique, with one sample involving several elephants, and the continuous observation method. A variant of the latter, the 5‐min interval method, was used with observations on one focal elephant each time. Activities were analysed with respect to time of the day and tree density in the study area. Chi‐squared tests showed that there was no variation of activities with respect to various Acacia tortilis density categories. Elephants descend the escarpment every morning so that walking is a pronounced activity at this time. They rest in the woodland around noon and visit the lake shore in the evening before most of them return up the escarpment.RÉSUMEÉLes activités diurnes des éléphants (Loxodonta africana Blumenbach)) dans les forěts d'Acacia tortilis du Pare National du Lac Manyara en Tanzanie furent observées durant deux saisons sèches consécutives en 1981 et 1982. Les deux méthodes utilisées pour évaluer les types d'activités furent la technique de l'échantillonnage ponctuel, avec un échantillon comprenant plusieurs éléphants, et la méthode d'observation continue. Une variante de cette dernier̀e, la méthode des intervalles de 5 minutes, fut utilisée pour observations d'un éléphant principal à chaque fois. Les activiteś furent analysées en fonction d l'heure et de la densité arbres dans la zone d'étude. Des tests de Chi‐carré montrent qu'il n'y a pas de variation des activités en fonction des différentes catégories de densités d'Acacia tortilis. Les éléphants descendent l'escarpement tous les matins de telle sorte que la marche est une activité majeure à ce moment. Ils se reposent dans les zones boisées a l'heure de midi et visitent le bord du lac dans la soirée avant que la majorité d'entre eux neretourne à l'escarpement.
Mima mounds in Kenya–a case of mistaken identity
Authors: MARTIN G. H. G. 
Published: April 2008

SummaryEarth mounds at seven sites in upland areas of Kenya were examined. Termite activity was recorded from 91% of mounds and the major termite genus present was Odontotermes.Generally, signs of the mole rat, Tachyoryctes splendens were few and were present on only 18% mounds.All termite activity was mound‐centred but only at Kiserian were mounds obvious centres for mole rat activity. At Molo, where Tachyoryctes were abundant, neither mounds nor much sign of termite activity were observed.The data are discussed in relation to the work of Cox and Gakahu. No convincing evidence was found to support the conclusion made by these workers for a mole rat origin of large earth mounds. The weight of the data suggests that a termite origin for these mounds is more likely.
Carbon isotopes as indicators of elephant diets and African environments
Authors: van der MERWE NIKOLAAS J. , THORP JULIA A. LEE , BELL RICHARD H. V. 
Published: April 2008

SummaryStable carbon isotope ratios have been successfully used to assess modern animal diets and to reconstruct prehistoric diets of animals and humans (Vogel & van der Merwe, 1977; van der Merwe & Vogel, 1978; Burleigh & Brothwell, 1978; Vogel, 1978a; DeNiro & Epstein, 1978; Tieszen et al., 1979; Tieszen & Imbamba, 1980; Chisholm, Nelson & Schwarcz, 1982; Tauber, 1981). We have used 13C/12C ratio measurements of bone collagen to study the diets of African elephants in twelve wildlife refuges. These represent most of the habitats in which elephants live, including such diverse plant communities as primary rain forest, savanna woodland and desert. The δ13C values were found to have a simple linear relationship with tree density in most cases. When translated into relative amounts of dietary browse (C3 plants) and graze (C4 plants), the grass content is seen to be systematically under‐represented, presumably due to inefficient metabolism. This does not affect the relationship between elephant diet and tree density, which has implications for the study of elephant‐woodland interactions, and for reconstructions of past African environments.
Distribution of small rodents and shrews in a lowland rain forest zone of Nigeria, with observations on their reproductive biology
Authors: IYAWE J. G. 
Published: April 2008

SummaryThis paper describes the habitat preferences of small rodents and shrews from April 1984 to March 1985 in four types of vegetation in a lowland rain forest zone of Nigeria. The vegetation types were high forest, scrub, farmlands and teak plantations in Ogba Forest Reserve, Nigeria.A collection of 359 small mammals, consisting of six species of small rodents and four species of shrews, was made in the study area. The small rodents and their percentage composition were Mus musculoides (26.2%), Praomys tullbergi (16.2%), Mastomys natalensis (7.0%), Lophuromys sikapusi (4.5%), Lemniscomys striatus (2.5%), and Arvicanthis niloticus (1.1%). The shrews were Crocidura nigeriae (19.5%), C. crossei (12.3%), C.grandiceps (7.8%) and C. ftavescens manni (3.1%).The vegetational distribution of the small rodents and shrews is discussed. In the high forest, seven species of small mammals were caught; these were Crocidura nigeriae, C. crossei, C.grandiceps, C.flavescens manni, Mus musculoides, Praomys tullbergi and Lophuromys sikapusi. Mus musculoides, Crocidura nigeriae and Praomys tullbergi were more abundant in the high forest.All the species of small mammals recorded in the study area, except Arvicanthis niloticus, were found in the scrub. In the farmlands, all ten species of small mammals were trapped. Mus musculoides was the commonest species in the farmlands. Three species of shrews, Crocidura crossei, C. grandiceps and C.flavescens manni, and also two species of small rodents, Mus musculoides and Mastomys natalensis were caught in the teak plantation.The reproductive data for Mus musculoides, Crocidura nigeriae and Praomys tullbergi show that breeding in these species occurs throughout most months of the year. Fecundity appears to be maximal in the wet season in Mus musculoides and Crocidura nigeriae and in the dry season in the case of Praomys tullbergi.
Fire behaviour and the invasion of Acacia sieberiana into savanna grassland openings
Authors: SABIITI ELLY N. , WEIN ROSS W. 
Published: April 2008

SummaryFollowing the recent decline in browsing and grazing pressures and changed fire regimes in Queen Elizabeth National Park, Uganda, Acacia thickets have encroached on grassland habitats important for grazing mammals. The objective of this research was to test experimentally the effects of fire behaviour, using simulated and natural fuel loading conditions, on A. sieberiana seedling and sapling regeneration.A high fire intensity (3200 kW m‐1) in natural fuels stimulated high seedling emergence (172 seedlings m‐2) compared to 6 seedlings m‐2 without fire. Also a highly significant linear regression was established between percentage top‐kill of seedlings and fire intensities. High fire intensities during late dry season fires were more effective in controlling sapling height growth than early dry season fires of low intensities. A conceptual diagram was developed to show the major factors and possible pathways leading to successful invasion by A. sieberiana into grassland openings of the savanna.
The feeding ecology of the African lily trotter Actophilornis africanus (Gmelin) at Lake Naivasha, Kenya
Authors: TAYLOR CHRIS , HARPER DAVID 
Published: April 2008

SummaryThe only feeding habitats available to African lily trotters, Actophilornis africanus (Gmelin), at Lake Naivasha are mats of the alien water fern, Salvinia molesta Mitch. This has replaced the native floating leaved water lily beds. Lily trotters were able to use these mats, taking invertebrate food items from the surface or turning plants over and pecking at the rootlets. Pecking rates and turning rates responded to the nature of the available food, with pecking rates high and turning rates low when terrestrial arthropods were found on the mat surface. Both pecking rates and turning rates were low when large aquatic food items, such as the swamp worm (Alma emeni Michaelsen), were available. Pecking rates and turning rates were both high when the predominant food items were aquatic insect larvae. The largest of these (hydrophilid larvae) were taken in preference to the smaller but commoner chironomid larvae. Colonization of the mats of S. molesta by invertebrates was low if the mats were affected by wind action but higher if they were constrained by enclosure or stranding; mats with higher invertebrate densities supported more feeding lily trotters.