bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seasonal variation in growth of Mastomys natalensis (Rodentia: Muridae) in Morogoro, Tanzania
Authors: LEIRS HERWIG , STUYCK JAN , VERHAGEN RON , VERHEYEN WALTER 
Published: April 2008

SummaryThe paper describes seasonal growth variation in a free living population of Mastomys natalensis (Smith, 1834) from Morogoro, Tanzania. Growth patterns are associated with rainfall patterns. Young animals enter a growth stop at the end of the dry season (October‐November) and growth is only resumed after the first heavy rains. Reproduction is more related to size than to age. If the heavy rains come early in the rainy season, animals start reproducing in the beginning of the year. The resulting young reach their maximal size without growth stop and start reproducing immediately. Possible causes for the growth stop are discussed. Growth phenomena are thought to explain at least partially the relation between rainfall and reproduction in Mastomys.RésuméCet article décrit la variation de croissance saisonnière d'une population de Mastomys natalensis (Smith, 1834) vivant en libertéà Morogoro, en Tanzanie. Les graphiques de croissance sont associés à ceux des chutes de pluie. Les jeunes animaux connaissent un arrêt de la croissance à la fin de la saison sèche (octobre‐novembre) et la croissance ne reprend qu'après les premières fortes pluies. La reproduction est plus liée à la taille qu'à l'âge. Si les fortes pluies surviennent tôt en saison des pluies, les animaux commencent à se reproduire au début de l'année. Les jeunes atteignent alors leur taille maximale sans avoir connu d'arrêt de croissance et commencent à se reproduire immédiatement. On pense que les phénomènes de croissance expliquent au moins partiellement la relation entre les chutes de pluie et la reproduction chez Mastomys.
The pattern and distribution of Brachylaena huillensis in semi‐deciduous dry forests in Kenya
Authors: KIGOMO BERNARD N. , SAVILL PETER S. , WOODELL STANLEY J. R. 
Published: April 2008

SummaryThe pattern of distribution, in space and time, of Brachylaena huillensis (Compositae) in two semi‐deciduous forests in Kenya was investigated. Results showed that seedlings and adults are distributed in patches, reflecting the distribution of female trees in the forest. Seedlings of different ages occur within the patches indicating that continuous establishment is ensured on sites under canopy. Other factors, however, seem to influence the degree of patchiness, and an investigation of these is needed.
Selectivity in large generalist herbivores: feeding patterns of African ungulates in a semi‐arid habitat
Authors: BEN‐SHAHAR RAPHAEL 
Published: April 2008

SummaryFeeding habits of free‐ranging wildebeest and zebra were monitored in a semi‐arid nature reserve, bordering the southwestern part of Kruger National Park, South Africa. The purpose of study was to distinguish and define the feeding niches of two roughage grazers that occur in similar habitat types. The monthly compositions of diets were evaluated by direct observations of feeding bouts over a period of two years when rainfall patterns were average and animal populations were stable. Other analyses evaluated the standing biomass of grass species in the reserve during the wet summer and dry winter seasons.A considerable overlap of grass species composition was found in the diets of wildebeest and zebra. Ordination of bi‐monthly records of the diet composition showed greater variations in scores of grasses in zebra diet in comparison to wildebeest. Seasonal patterns were more apparent in the wildebeest diet. Preference ranking of grass species indicated that zebra diet remained constant in winter and summer. Wildebeest diet however, alternated with seasons, showing high preferences during the winter months for grass species which were rejected during summer.The combined assessment of results from three separate statistical methods analysing temporal patterns and preferences in diet composition revealed contradictory trends. The solution, however, relied on the initial assumptions posed. Hence, wildebeest and zebra are essentially generalist feeders which show a limited amount of preference in their choice of diet.
Man determines the distribution of elephants in the rain forests of northeastern Gabon
Authors: BARNES R. F. W. , BARNES K. L. , ALERS M. P. T. , BLOM A. 
Published: April 2008

SummaryDropping counts were used to assess elephant abundance in the remote forests of northeastern Gabon where there are few people and no logging. Elephants prefer the secondary forest which grows on abandoned villages and plantations, but avoid roads and villages. Thus elephant distribution is governed by the distribution of both past and present human settlement, even in the remotest and least disturbed forests of equatorial Africa.RésuméOn a évalué l'abondance des éléphants en comptant les excréments, dans les forêts reculées du nord‐est du Gabon, là où il n'y a que peu de gens et aucun abattage d'arbres. Les éléphants préférent les forêts secondaires qui poussent dans les villages et les plantations abandonnés, mais évitent routes et villages. Donc, la distribution des éléphants est régie par la répartition des installations humaines présentes et passées, même dans les forêts les plus reculées et les moins troublées d'Afrique équatoriale.
Field immobilization of lions using disassociative anaesthetics in combination with sedatives
Authors: STANDER P. E. , MORKEL P. vdB. 
Published: April 2008

SummaryZoletil (CI‐744) proved to be a useful drug combination for lions during 64 immobilizations. The duration of Zoletil immobilizations were dosage dependent, but the onset of immobilization was similar for both low and high dosages. These characteristics were pragmatic in that low dosages of Zoletil were used for the initial dose, which was delivered by dart‐syringe. This practice facilitated either a short duration of immobility, or the possibility of adding an additional dose by hand, which prevented the loss of large amounts of Zoletil in the case of a dart failure. Ketamine and xylazine were used on 120 lions at dosages of 7.5 and 3.5mgkg‐l, respectively, and antagonized with 3.9mg kg‐1 Tolazoline. Disadvantages of the ketamine/xylazine combination were the inability to use lower dosages for short periods of immobilization and the large volumes required. Midazolam served as a practical drug for the capture of retiring and unapproachable lions, and significantly increased trapping success. Additional notes are presented on the use of Ro 15–3505 as an antagonist for Zoletil immobilization in lions.
A population survey of forest elephants(Loxodonta africana cyclotis)in northern Congo
Authors: FAY J. MICHAEL , AGNAGNA MARCELLIN 
Published: April 2008

SummaryFrom February to April of 1989 transects were run in four forested areas of northern Congo (Brazzaville) to census elephant populations using dung counts. A total of 401.0 km of line transects was completed during the survey. An overall extrapolated density of 0.7 elephants/km2was obtained with a variation from 0.3 to 0.9 elephants/km2. This study shows for the first time that elephants occur in high densities in a number of sites in northern Congo. When elephant dung density is plotted against distance from the nearest village for each transect a significant positive linear correlation results. Based on this correlation we hypothesize that the population of elephants in much of northern Congo is high. Local reports and our own observations indicate that elephant poaching is heavy in northern Congo and that the CITES ban on trade in African elephant ivory has had a limited effect on the level of poaching.
Evaluation of four survey methods for estimating elephant densities
Authors: JACHMANN H. 
Published: April 2008

SummaryAerial sample survey, foot survey, vehicle survey, dry‐season droppings count and wet‐season droppings count were used for estimating elephant (Loxodonta africana africana) densities on the Nazinga Game Ranch, Burkina Faso and evaluated against the results of an aerial total count. Results of all survey techniques except the dry‐season dropping count method had low accuracies relative to the aerial total count. It is concluded that the droppings count method was the best and most cost‐effective survey technique available for estimation of elephant densities.
Observations of tree growth, woodland structure and elephant damage on Colophospermum mopane in Luangwa Valley, Zambia
Authors: LEWIS DALEM. 
Published: April 2008

SummarySix samples of tagged Colophospermum mopane were monitored for five years in locations with varying soil characteristics but with similar elephant densities. Physiognomic variation among the samples was related to soil differences, which also correlated with different browsing habits by elephants. The impact of elephant browsing further influenced both the physiognomy and demography of C. mopane. Results from this study suggest that the influence of soils and elephants on C. mopane alter successional transitions from grassland to woodland. Soils that promote coppicing of C. mopane yield less stable woodlands when associated with elephants than soils promoting woodlands with large bolus, non‐coppicing trees. The dynamics of the latter are determined more by tree recruitment as influenced by such agents as other browsers or frequency and seasonality of bush fires. Implications for forest/elephant management are discussed.
Nigerian Man and Biosphere research plots in Guinea savanna: floristics and structure of the vegetation
Authors: MUOGHALU JOSEPH I. , ISICHEI AUGUSTINE O. 
Published: April 2008

SummaryA study was made of the vegetation of three plots used in the Nigerian Man and Biosphere Research Programme for Savanna Studies. The aim is to provide detailed information on the vegetation of the plots which may possibly contribute to an understanding of factors influencing savanna structure and relative abundances of forbs, grasses and woody species. Results show that there are differences in the species composition of the plots. There are more forb species than grass species in each plot. The woody basal areas and crown areas of the plots do not depend entirely on the density but also on the size of the woody species. There are differences in herbage yield in the plots that could be attributed to differences in soil properties, species composition and level of human and animal activities between the plots.
A preliminary report of an experiment on vegetation recovery of drought deciduous woodland in Kitui, Kenya
Authors: HAYASHI ICHIROKU 
Published: April 2008

SummaryThe drought‐deciduous woodlands in Kitui, Kenya are dominated by Commiphora africana and Acacia spp. including Acacia senegal, A. tortilis and A. mellifera. The 1990 density was 329 trees, 3571 shrubs and 1442 seedlings per hectare of Acacia species. Trees of Commiphora africana have survived because the tree is useless for firewood or timber. Only a few trees of Acacia species, which are useful for fuel, remained, because people cut the trees selectively. The dominant species in the shrub layer were Hermannia oliveri, Aspila mossambicensis and Solanum incanum, Chloris roxburghiana and Sporobolus fimbriatus became re‐established on the bare ground after one year's exclusion from livestock grazing. The average diameter increment of the trees was 0·5 cm per year with a standard deviation of 0·3 cm. The mean height of Acacia mellifera seedlings in the herb layer increased from 14·7 to 23·8 cm.RésuméLes forêts, décidues en saison sèche, de Kitui (Kenya), sont dominées par Commiphora africana et Acacia spp., y compris Acacia senegal, A. tortilis et A. mellifera. En 1990, la densitéétait de 329 arbres, 3571 buissons et 1442 jeunes plants d'acacias par hectare. Les arbres de Commiphora africana ont survécu parce qu'ils ne servent ni pour le feu ni pour la construction. Mais il ne reste que peu d'acacias, qui servent de combustible, parce que les gens coupent ces arbres sélectivement. Les espèces dominantes dans les buissons sont Hermannia oliveri, Aspila mossambicensis et Solanum incanum, Chloris roxburghiana et Sporobolus fimbriatus recolonisent en un an les sols dénudés par le bétail. L'augmentation annuelle moyenne du diamètre des arbres était de 0,5 cm. avec une déviation standard de 0,3 cm. La hauteur moyenne des jeunnes plants d'Acacia mellifera dans la couche herbeuse est passée de 14,7 à 23,8 cm.
Cassidinae beetles of the Kibale Forest, western Uganda; comparison between virgin and managed forests
Authors: NUMMELIN MATTI , BOROWIEC LECH 
Published: April 2008

SummaryCassidinae in forest floor vegetation were studied in five different forest habitats in Kibale Forest, Western Uganda, by monthly sweep net sampling during 23 months from July 1983 to May 1985 and in September 1986. The studied habitats were two virgin forest sites, two selectively logged sites and one exotic pine plantation. Altogether 22 Cassidinae species were found. The peak numbers of Cassidinae per sample were found in the early dry season after the long rains. The most common species in all sites was Cassida humerosa. There does not seem to be any Cassidinae species which are specialized for life in virgin forest. Several species occurring in the managed forest sites were not found in virgin forest. In logged forest sites and in the exotic pine plantation higher species numbers were caught than in virgin forest sites. The species composition of pine plantation differed significantly from those in all other sites. In a species‐wise factor analysis, the two logged sites were close to each other and to the pine plantation.RésuméDans cinq habitats différents de la forêt de Kibale, dans l'ouest ougandais, on a étudié les Cassidinae du sol forestier au moyen d'un filet, de juillet 1983 à mai 1985 et en septembre 1986. Les endroits étudiés étaient deux sites de forêt vierge, deux sites exploités pour le bois et une plantation de conifères exotiques. En tout, on a trouvé 22 espèces de Cassidinae. Les nombres maximaux de Cassidinae par échantillon ont été relevés en début de saison sèche après la grande saison des pluies. Partout, l'espèce la plus commune est Cassida humerosa. II ne semble pas exister d'espèce de Cassidinae qui soit spécialisée pour la vie en forêt vierge. Certaines espèces récoltées en forêt exploitée ne se retrouvent pas en forêt vierge. Dans les forêts exploitées et dans les plantations de conifères exotiques, on attrapait un plus grand nombre d'espèces qu'en forêt vierge. La composition des espèces dans la plantation de conifères différait significativement de celle des autres milieux. Dans l'analyse ayant trait aux espèces elles‐mêmes, les deux sites exploités étaient proches l'un de l'autre et de la plantation de conifères.
Aboveground standing crop, protein content and dry matter digestibility of a tropical grassland range in the Nairobi National Park, Kenya
Authors: KINYAMARIO JENESIO I. , MACHARIA JOSEPH N. M. 
Published: April 2008

SummaryEstimates of aboveground standing crop were carried out over a seven‐month period in the Nairobi National Park, Kenya. Standing crop varied according to the rainfall period, more during the growing season (March to June) than during the dry season months (January, February and July). Themeda triandra contributed most of the standing crop, followed by Pennisetum mezianum. Dicots, which ranked third, were found to be important plant constituents in this grassland. Percentage crude protein and rumen dry matter digestibility varied from month to month and between different plant categories. Both were highest during the growing season. Dicots maintained higher percentage crude protein and rumen dry matter digestibility than grasses. In most months percentage crude protein was below the critical level required for maintenance of the grazing animals. Standing stocks of crude protein for the whole sward were highest during the growing season months and lowest during the dry season months.RésuméDes estimations de la masse végétale aérienne ont été menées durant une période de sept mois au Parc National de Nairobi, Kenya. La quantité de végétation sur pied varie en fonction des périodes de pluies, davantage durant la saison de croissance (mars à juin) que durant les mois de saison séche (janvier, février et juillet). C'est Themeda triandra qui contribue le plus à cette masse végétale, suivie par Pennisetum mezianum. Les dicotylées, au troisième rang, sont aussi des constituants importants de cette savane. Le pourcentage de protéine brute et la digestibilité de matières sèches dans le rumen varient de mois en mois et diffèrent entre catégories de plantes. IIs sont tous deux le plus élevé durant la saison de croissance. Les dicotylées maintiennent un pourcentage de protéine brute et une digestibilité de matières sèches dam le rumen plus élevés que les graminées. Au cours de la plupart des mois, le pourcentage de protéine brute était inférieur au niveau critique requis pour le maintien des animaux brouteurs. Les stocks présents de protéine brute pour l'ensemble du tapis végétal étaient les plus élevés durant les mois de croissance et les plus bas durant les mois de saison sèche.
Breeding of the black‐headed village weaver (Ploceus cucullatus) and the chestnut‐and‐black weaver (P. nigerrimus) in Ile‐Ife, Nigeria
Authors: DIN N. A. 
Published: April 2008

SummaryThe variations in the breeding seasons of the black‐headed village weaver and the chestnut‐and‐black weaver were analysed in fifteen of the 30 colonies sighted at Ife and one colony on Ilesha Road, about 14 km to the east. Both species commenced large‐scale breeding during the first peak in rainfall and established numerous unproductive satellite colonies. The changes in gonad weights indicated bimodal and discontinuous off‐season breeding in the black‐headed village weaver but breeding in the chestnut‐and‐black weaver was mainly unimodal, with two peaks observed in only one colony. The mean nest completion time and commencement of a new nest was 11 h (range = 9–15 h) and 6 days (range = 3–13 days), respectively whereas in the chestnut‐and‐black weaver the corresponding figures were 9 h (range = 6–11 h) and 3 days (range = 2–4 days). Mate attraction displays in both species were restricted during early stages of nest construction but were heightened on completion, when females were responsive. The mean bout lengths of undernest and branch displays in the chestnut‐and‐black weaver were significantly (P < 0.05) longer than in the black‐headed village weaver. The pair bond formation and motivation of males to build a new nest were investigated.RésuméOn analyse les variations des saisons de reproduction du tisserin gendarme et du tisserin noir de Vieillot dans 15 des 30 colonies connues à Ife et une colonie sur Ilesha Road, à environ 15 kilomètres vers l'est. Les deux espèces ont commencéà se reproduire en grand nombre lors du premier pic de la saison des pluies et ont établi de nombreuses colonies satellites improductives. Les changements du poids des gonades indiquaient une reproduction hors‐saison bimodale et discontinue chez le tisserin gendarme mais la reproduction du tisserin noir de Vieillot était surtout unimodale, avec deux pics de reproduction dans une colonie seulement. Le temps moyen pour terminer un nid et en commencer un autre était de 11 h. (de 9 à 15 h.) et 6 jours (de 3 à 13 jours) pour le premier alors que pour le tisserin noir de Vieillot les chiffres correspondants étaient de 9 h. (de 6 à 11 h.) et 3 jours (de 2 à 4 jours). Les manifestations pour l'accouplement étaient limitées au début de la construction du nid mais devenaient plus vives lorsque celui‐ci se terminait et que les femelles devenaient plus réceptives. La durée moyenne des manifestations sous le nid et sur les branches était significativement plus longue chez le tisserin noir de Vieillot (P <0,05) que chez le tisserin gendarme. On a étudié la formation du couple et la motivation des mâles à construire un nouveau nid.
Forest elephants in a rainforest fragment: preliminary findings from a wildlife conservation project in southern Ghana
Authors: DUDLEY J. P. , MENSAH‐NTIAMOAH A. Y. , KPELLE D. G. 
Published: April 2008

SummaryData on the population status, foraging habits, and crop depredation activities of African forest elephants (Loxodonta africana cyclotis) were collected in conjection with a three‐month reconnaissance study of wildlife populations in the Kakum and Assin‐Attandanso Forest Reserves, Central Region, Ghana. There were no visual sightings of elephants; spoor data were used to derive group size, age class, and population density estimates. The resident elephant population contains an estimated 100–150 individuals, which is equivalent to a crude density of 0·3‐0·4 elephants/km2. Social group size estimates from fresh spoor data ranged from two to six elephants. Typical group size appears to be three or four although solitary individuals were not uncommon. The Kakum‐Assin elephants appear to be completely isolated from contact with other elephant populations. Elephant poaching is not a problem in the area at the present time. Elephants frequently cause major damage to food crops in farms bordering the two reserves, but do not damage orchard crops of oil palm (Elaeis guineensis), cocoa (Theobroma cacao), and orange (Citrus sinensis). Cows with small calves are not known to raid farms.RésuméOn a collecté des données sur le statut des populations d'éléphants de forêt africains, sur leurs habitudes alimentaires et les dommages causés aux récoltes lors de trois mois de recherches sur des populations sauvages dans les Réserves de Kakum et Assin‐Attandaso Forest, Central Region, au Ghana. Il n'y a pas eu de contact visuel avec les éléphants, les traces qu'ils avaient laissées ont servi à estimer la taille du groupe, les classes d'âge et les densités de population. La population locale d'éléphants doit s'élever à quelque 100–150 individus, ce qui correspond à peu près à une densité de 0,3‐0,4 élèphant/km2. D'après les traces fraîches, la taille du groupe social est estimée de 2 à 6 éléphants. La taille type d'un groupe semble être de 3 ou 4 mais les solitaires ne sont pas rares. Ces éléphants semblent être complètement coupés des autres populations. Le braconnage des éléphants n'est, pour le moment, pas un problème dans la région. Les éléphants causent souvent de sérieux dommages aux récoltes dans les fermes voisines des deux réserves mais pas aux vergers de palmiers à huile (Elaeis guineensis), ni au cacao (Theobroma cacao), ni aux orangers (Citrus sinensis). On ne rapporte aucun cas de femelles avec des jeunes qui s'attaqueraient aux fermes.