bluuebunny/crossref_metadata_2025 huggingface dataset:
A review of ivory exploitation and elephant population trends in Africa
Authors: SPINAGE C. A.
Published: April 2008

A brief review of published data is presented, outlining the intensive exploitation of African elephants for ivory. Records suggest that this began in the early seventeenth century in western Africa, and that hunting pressure was sufficient to eliminate, or drive out, populations over wide areas. In eastern Africa intensive exploitation ensued between 1840 and 1890, leading to a sudden collapse of the ivory supply from over‐exploitation. Subsequent protection has apparently enabled surviving elephants to enter an exponential phase of population increase. Elephant population cycles, if they can be shown to have occurred, are probably reflections of over‐exploitation, followed by population recovery when hunting was no longer profitable. If cycles of scarcity and abundance were a natural feature of elephant populations, then they could have been masked by the intensity of hunting.
Density, distribution, population structure and social organization of the black rhinoceros in Masai Mara Game Reserve
Authors: MUKINYA JOHN G.
Published: April 2008

Black rhinoceros were studied in the Masai Mara Game Reserve from May 1971 to August 1972. Data were gathered on their density, distribution, population structure, social organization, feeding habits and daily activities.

The study area, its vegetation, and the study methods are described briefly. Rhino occupied thirteen separate distribution areas, their distribution being influenced by food availability, water, cover and the presence of human and domestic animals. The number of rhino in each distribution area were within the range of one to thirty‐one (densities 0–04 to 0–24/km2), giving a mean density in the rhino‐occupied area (749 km2) of 0–14/km2 and in the whole study area (1530 km2) of 0–07/km2.

Of the 108 rhino in the population, 73% were adult and 27% were immature. At least one adult and one immature were found in nearly all distribution areas. Adult rhinos formed one age class while the immatures were divided into three age classes. Sex ratio and mortality were investigated.

Social units and their home range sizes in relation to density and distribution are discussed. Some aspects of social organization, feeding habits and daily activities will be discussed in a later paper.

In conclusion, recommendations for rhino management based on preservation of habitat, particularly cover, more sources of water and human settlement are discussed. Suggestions for further lines of research are also discussed.
Seronera bull problem: The trees
Authors: CROZE HARVEY
Published: April 2008

(1) The impact of groups of bull elephants on the wooded–grassland of the Seronera area of the Serengeti National Park, Tanzania, is examined.

(2) Elephant use of trees occurs contagiously. At use loci in the woodlands, removal of canopy–forming acacia has been as high as 6% per annum.

(3) However, from a survey of the whole Seronera woodland community, the loss of large trees has been 2–5% per annum.

(4) It is argued that the regeneration potential is adequate to compensate loss due to elephant activity, and that large acacia will not disappear because of elephants.

(5) Management action is discussed and recommendations made.
Seasonal variation in water turnover by oryx and eland on the Galana Game Ranch Research Project
Authors: KING J. M. , KINGABY G. P. , COLVIN J. G. , HEATH B. R.
Published: April 2008

Measurement of total body water and water turnover was based on the single injection dilution principal using tritiated water.

Under a daylight grazing regime the water turnover varied from 24 to 98 ml/kg/day in oryx and 42 to 121 ml/kg/day in eland. This large seasonal variation was most highly correlated with heat load expressed as solar radiation or mean ambient temperature. Lack of correlation between water turnover and dry matter intake, and low correlation with dietary moisture may have been due to difficulties in measuring these parameters accurately.

When preformed water was calculated by subtraction of drinking and metabolic water from total turnover, it was found to have a positive correlation with turnover rate and a negative correlation with water drunk. Thus high water turnover was not associated with high drinking requirements in either species.

The relationship between climate, pasture and water turnover, could be upset by changes in the activity of the animal from the normal day grazing pattern.

The results obtained from the domestic game animals were used to explain how wild oryx and eland could exploit a hot, semi‐arid environment without drinking. To achieve this, the wild animal must obtain most of its nutritional requirements between evening and morning, and its water requirements during the period of maximum relative humidity between midnight and dawn.
Wet season movements of individual wildebeests of the Serengeti migratory herd
Authors: INGLIS JACK M.
Published: April 2008

Sixteen wildebeest were marked with radio transmitters and tracked for varying lengths of time during the period between late November, 1971, and mid‐July 1972. They were repeatedly radiofixed from an aircraft prior to, during and after their annual wet season visit to the Serengeti Plain. Fix‐to‐fix tracks of animals showed that each hurried to the Plain at the onset of the rains, performed oscillatory movements over an individually distinct, elliptically shaped, fractional part of the Plain area, and departed into the woodland as the Plain dried out. Average fix‐to‐fix rate of travel approximated 3–75 km/day. Large aggregations of animals, armies, were smaller and more restless in the woodlands than on the Plain. Smaller aggregations included within armies, troops, varied in size as a function of activity. They were small when feeding and large when marching. Troops averaged larger in the woodlands mostly because they were more often marching there than on the plain. The tracked animals were equally successful in finding green forage in the presence of water in both habitats. The item in shortest supply appeared to be the presence of green forage in the woodlands and of water on the Plain. It is concluded that structural attributes of the woodlands, by lowering the security level of animals, played a part in making the Serengeti Plain attractive to the animals.
The ecology of the lechwe, Kobus leche kafuensis Haltenorth, in Lochinvar National Park, Zambia, as affected by the Kafue Gorge hydroelectric scheme. Herbage digestibility in free‐living antelope
Authors: REES W. A.
Published: April 2008

A method of collecting rumen fluid from free‐living antelope is presented, together with the in vitro procedure used to try to estimate the digestibility of the herbage grazed by them. Modifications to this procedure are suggested, which it is thought would allow the calculation of a meaningful equation relating these data to digestibility estimates obtained by a chemical method.
The vegetation of the Samburu–Isiolo Game Reserve
Authors: BARKHAM J. P. , RAINY M. E.
Published: April 2008

(1) Communities were identified in the field from presence/absence records of species using a form of progressive approximation. These communities were then mapped from aerial photographs of the Reserve area and boundaries were later checked on the ground. The quantitative characteristics of the communities were described in terms of cover and frequency.

(2) The data were subjected to standard computer analyses and these results are used in an assessment of the validity of the original subjective techniques.

(3) A hypothetical scheme is suggested which explains the principal lines of vegetation variation in terms of water availability and soil salinity. A number of related vegetation catenae may be recognized in addition to an east–west trend of increasing tree cover which is attributed to decreasing salinity along the riverine strip.

(4) It is concluded that the effects of grazing and burning regimes are superimposed upon those of the physical environment and that further rapid changes in vegetation composition will take place within the next few decades.
The nutritive values of some major food plants of lechwe, puku and waterbuck along the Chobe River, Botswana
Authors: VONRICHTER W. , OSTERBERG R.
Published: April 2008

The feeding preferences of lechwe, puku and waterbuck and the nutritive values of the major food plants show a correlation. Within their habitat the species show preference for the plants with the highest crude protein value. The preferred habitats of the species, although overlapping to a certain extent, prevented all three species from using the food plants with the highest protein values at all times. Puku and waterbuck, for example, utilized plants which were clearly inferior to the plant growth available to lechwe in August.
Food habits of Chanler's mountain reedbuck in a Rift valley ranch
Authors: IRBY L. R.
Published: April 2008

During 1971‐72 contents from the rumens of twenty‐two Chanler's mountain reedbuck (Redunca fulvorufula chanleri Rothschild) collected in the Arthur Cole Ranch near Gilgil, Kenya were examined. Frequency of occurrence of monocots averaged 99.5% of identifiable fragments. Frequency of occurrence of monocots in the ground stratum of the vegetation averaged 94% in the areas where mountain reedbuck were collected. Of the 11 grass classifications (seven to species and four to genus) considered reliably identifiable in rumens, three (Themeda triandra, Hyparrhenia spp., and Cymbopogon pospischilii) were taken more frequently than was expected from their occurrence in the vegetation, six (Aristida spp., Cynodon spp., Eragrostis spp., Harpachne schimperi, Microchlva kunthii, and Tragus berteronianus) were taken less frequently, and two (Bothriochloa insculpta and Enneapogon schimperanus) were taken in approximately the same ratio as they occurred in the ground stratum of the vegetation.
Estimates of the population size of some ungulate species in the Rwenzori National Park, Uganda
Authors: ELTRINGHAM S. K. , DIN N. A.
Published: April 2008

Random sample counts were made from the air of kob, topi, warthog and waterbuck in the Rwenzori National Park, Uganda in 1971 and 1972. Estimates of the total populations varied widely and the means for each species were 12 301 (kob), 4932 (topi), 1530 (warthog) and 3563 (waterbuck). The kob and topi figures are considered as fair approximations to the true totals. The warthog total is thought to be much too low but the degree of inaccuracy could not be assessed. The waterbuck total is also considered to be too low and the application of a groundlair correction factor gives a total of 4454. The distribution of the animals over the park was unequal and the most heavily populated areas are identified for each species. There were significant differences between the species in their distribution over the various sectors of the park. A relationship between the rainfall and the number of animals counted was not established except in the case of the waterbuck which showed a positive correlation with rain falling in the month prior to the count. The densities determined from these surveys fell within the range of those found by other workers from ground counts.

En 1971 et 1972, des comptages aériens, échantillons au hasard, se sont effectués au Parc national Rwenzori (Ouganda) des cobes de Buffon, damalisques, phacochéres et cobes defassa. Les estimations ont varié mais les moyennes pour chaque espéce ont été 12 301 cobes de Buffon, 4932 damalisques, 1503 phacochéres et 3563 cobes defassa. On croit que les nombres totals des cobes de Buffon et des damalisques sont corrects approximativement. Cependant le chiffre pour les phacochkres êst certainement trop bas mais on ne peut pas evaluer I'erreur. Le chiffre 4500 peut etre une juste estimation des damalisques. La distribution des animaux dans le parc n'ont pas été uniforme et les régions les plus préferées sont indiquées pour chaque espéce. Les differences entre la préférence des espèces divers pour les habitats favoris sont significatives. Une corrélation entre la quantité de la pluie et les nombres des animaux n'ont ktabli que pour les damalisques où on peut déterminer une correlation positive avec la pluie pendant le mois qui précède le recensement. Les densités déter‐minées dans ces dknombrenients aCriens se confornient assez bien avec les resullals des comptages terrestres des autres chercheurs.
Weights and measures of Ugandan pelicans with some seasonal variations
Authors: DIN N. A. , ELTRINGHAM S. K.
Published: April 2008

Samples of White and Pink‐backed Pelicans from the Rwenzori National Park, Uganda were weighed and measured. The results are given below as mean values in the order of male and female White Pelicans and male and female Pink‐backed Pelicans. Only a few measurements were taken of female White Pelicans. Further details given in the Tables include sample size, standard deviation and range. Linear measurements (cm): total body length:— 177.3, 136.7, 146.9, 134.0; tail length:—18.1, ‐, 17.2, 16.6; tarsometatarsus:— 14.2, ‐, 9.6, 8.7: cu1men:— 41.8, 31.4, 35.7, 30.5; lower mandible:— 49.3, ‐, 40.3, 34.6; wing span:— 285.8, 246.4, 233.9, 224.2; wing length:— 136.5, ‐, 112.9, 105.8; standard wing length:— 70.2, ‐, 60.5, 56.0; chord:— 70.8, ‐, 35.5, 34.3; aspect ratio:— 4.0, ‐, 6.6, 6.6; weights (gm unless stated otherwise): total weight (kg);— 11.45, 7.59, 5.97, 4.92; adrenal (mg):— 647.2, 531–0, 401.2, 352.4; heart:— 100.1, ‐, 49.9, 39.5; kidney:— 40.9, ‐, 23.6, 23.4; liver:—258.2, 176.5, 128.5, 110.4; lung:— 60.3, –, 29.1, 30.0; pancreas:— 15.2, ‐, 7.1, 5.3; pectoralis major:— 731.9, ‐, 389.0, 313.9; pectoralis minor:— 51.8, ‐, 27.6, 24.3; pituitary (mg):— 40.6, 39.1, 37.4, 37.5; spleen:— 12.7, ‐, 12.3, 10.1. There was no significant difference between the species in the proportional weights of the organs. Seasonal variations were found in the weights of testes, ovaries, oviducts and fat deposits. Changes in weight of the reproductive organs of the Pink‐backed Pelican showed a clear correlation with the breeding cycle. The testes of the migratory White Pelican appeared to be inactive while the birds were in the park. The amount of fat laid down could be directly related to seasonal fluctuations in the food supply. The degree of development of the head crest was greatest during the breeding season in the Pink‐backed Pelican and during the second quarter of the year in the White Pelican. 58.6% of the White Pelicans showed traces of colouration on the breast.
Range movements of giraffe in the Luangwa Valley, Zambia
Authors: BERRY P. S. M.
Published: April 2008

The range movements of a small population of giraffe in the Luangwa Valley in eastern Zambia were studied over a period of 44 years. The majority of the adults of both sexes were found to move over distances in excess of 40 km though only two, both males, moved farther than 50 km. The average home range size was 82 km2 for males and 68 km2 for females respectively though these figures are regarded as conservative. Twelve crossings of the Luangwa River by adult males only were recorded during the study.

Les mouvements étendus d'une petite population des girafes étaient étudiés pendant 44 anntes dans la Vallée Luangwa en Zambia d'est. La majorité des adultes, mâles et femelles, était trouvée aller une distance linéaire plusque 40 km quoique deux seule‐ment des mâles s'éloigmaient plus que 50 km. La moyenne grandeur de l'étendue domestique était 82 km2 dans les mâles et 68 km2 dans les femelles respectivement bienque ces chiffres sont considerés plus près des minimums. Douze traversées de la rivière Luangwa par des mâles seulement étaient rapportées pendant l'étude.
Overbrowsing of Capparis tomentosa bushes by goats in Rwenzori National Park, Uganda
Authors: MUSOKE M. B.
Published: April 2008

Several human settlements within or bordering the park were surveyed. Goats were present in most villages and browsed most intensely between 09.00 and 12.00 hours. Bushes were browsed during the rainy season and, by the peak of the dry season, many Capparis tomentosa bushes close to human settlements were severely over‐browsed. As the browse close to the settlements decreased, especially during the dry season, the goats penetrated the park.

Plusieurs installations humaines à l'intérieur ou au bord du parc furent suivies. II y a des chévres dans la plupart des villages, qui broutent surtout entre 9 et 12 h. Les bosquets sont broutés durant la saison des pluies et, au plus fort de la saison she, de nombreux bosquets de Capparis tomentosa proches des villages sont gravement surpaturés. Au moment où les feuillages proches des colonies humaines diminuent— spécialement durant la saison sèche—Ies chèvres pénètrent dans le parc.
Seasonal defoliation of thickets by larvae of Belenois aurota
Authors: KENYI J. M.
Published: April 2008

Eruptions of Belenois aurota Fabricius occur about the middle of every year in the park. Varying numbers of eggs are laid. Females lay eggs on the upper surface of Capparis tomentosa leaves which are selectively browsed by the larvae. Defoliation is at a maximum in July and August. The average generation time for B. aurota was found to be 30 days. The thicket defoliation alters the habitat and diversity of some plant species in the park.

Réumé

Des explosions démographiques de Belenois aurota Fabricius ont lieu à peu près à la moitié de chaque année dans le parc. Un nombre variable d'oeufs sont pondus. Les femelles pondent leurs oeufs sur la face supérieure des feuilles de Capparis tomentosa qui sont broutées sélectivement par les larvaes. La défoliation est maximale en juillet et août. La durée moyenne d'une génération chez B. aurota a été estimée á 30 jours. La défoliation des fourrées altère l'habitat et la diversité de quelques espèces de plantes dans le parc.
Food preference and carcass composition of the grass cutter(Thryonomys swinderianus)in captivity
Authors: YI S. S. AJA , TEWE O. O.
Published: April 2008

Some aspects of the biology of the grass cutter, otherwise known as the cane rat, in captivity are studied. Wild rats tend to be gregarious and take about 28 days to adapt to their new surroundings, Cannibalism and burrowing are completely absent.

Cane rats show a high preference for elephant grass (Pennisetum purpureum). Sweet potato (Ipomea batatas) is also highly favoured while other concentrates, from commercial livestock rations, are not consumed to any remarkable degree. It is a herbivore.

Carcass characteristics compare favourably with domesticated livestock species. Mature live weight ranges from 4300 g to 6832 g. An average dressing out percentage of 63.8% was obtained. The carcass is low in fat and comparatively high in protein. Mineral content of tissues are similar to mutton in many respects.

Quelques aspects de la biologie de 1'Aulacode en captivité sont étudiés. Les aulacodes sauvages tendent àêtre grégaires et mettent environ 28 jours pour s'habituer à leur nouvel environnement. Il n'y a pas de cannibalisme et les animaux ne creusent pas. Les aulacodes montrent une nette préférence pour les herbes àéléphant (Pennisetum purpureum). La patate douce (Ipomea batatas) est aussi consommée préfé‐rentiellement alors que d'autres concentrés provenant d'aliments commerciaux pour bétail, ne sont pas particulièrement consommés. L'aulacode est un herbivore. Les caractéristiques de sa carcasse est avantageusement comparée avec les espèces de bétail domestique. Le poids vif de l'adulte varie de 4300 g et 6832 g. On a obtenu un tuax de mortalité moyen de 63,8%. Les carcasses sont faibles en graisses et com‐parativement riches en protéines. Le contenu minéral des tissus est similaire à ceux du mouton en de nombreux points.
Photosynthetic systems, carbon isotope discrimination and herbivore selectivity in Kenya
Authors: TIESZEN L. L. , IMBAMBA S. K.
Published: April 2008

The flora of the lowlands of East Africa possesses both C3 and C4 plants with nearly all grasses being C4. These photosynthetic systems discriminate differently against 13C. We have utilized the ‘label’ provided by the δ13C values to initiate studies of energy flow and vegetation utilization by East African herbivores. Preliminary data are reported here to illustrate the usefulness of this technique and to suggest its potential role in the numerous plant‐herbivore studies already under way in East African systems.

The δ13C values from faecal samples of East African herbivores allows us to estimate their immediate dependency on plant growth forms. Buffalo, zebra, waterbuck and wildebeest select 90–100% of their food at Amboseli from C4 plants (mainly grasses); elephant, Grant's and Thompson's gazelle, warthog and ostrich were more generalized feeders; and dik‐dik and giraffe were nearly wholly dependent on C3 plants (trees and shrubs). A similar pattern was found at Samburu, but in the Aber‐dares the generalized feeders were nearly exclusively dependent upon C3 vegetation.

RÉSUMEÉ

La flore des plaines d'Afrique de l'Est comporte des plantes de type C3 et C4 dont presque toutes les graminées sont C4. Ces systèmes photosynthétiques classent différemment par rapport à |dL 13C. Nous avons utilise le “label” fourni par des valeurs de 13C pour entammer des études sur le flux éné rgetique et l'utilisation de la végétation par les herbivores d'Afrique de l'Est. Les données préliminaires sont rapportées ici pour illustrer l'utilité de cette technique et suggérer sa valeur potentielle dans les nombreuses études plantes‐herbivores déjà en cours dans les écosystèmes Est‐Africains.

Les valeurs de δ13C provenant d'échantillons de féces d'herbivores Est‐Africains nous permettent d'estimer leur dépendance directe des formes de croissance des plantes. Le buffle, le zèbre, le waterbuck et le gnou à Amboseli selectionnent 95 à 100% de leur naurriture parmi les plantes C4 (principalement des graminées); les éléphants, les gazelles de Grant et de Thompson, le phacochère et l'autruche sont plus omnivores; le dik‐dik et le girafe dèpendent presqu'à 100% de plantes C3 (arbres et arbustes). Un schéma semblable a été trouvéà Samburu, mais, dans les Aberdares, les omnivores dépendent presqu exclusivement de la végétation de type C3.
The feeding behaviour of a tame impala Aepyceros melampus
Authors: DUNHAM K. M.
Published: April 2008

The bite sizes and bite rates achieved by a tame impala feeding on ten woody browse species were recorded. Mean bite mass was positively correlated with mean leaf mass while mean bite rate was negatively correlated with mean bite mass. The bite rate when feeding on Acacia tortilis was less than expected from the bite size because the impala caught its tongue and lips on the small, curved thorns. This supports the theory that Acacia species are at least partially protected from the effects of ungulate browsing by the presence of thorns, combined with a very small leaf size.

RÉSUMEÉ

Les tailles et pourcentages des coups de dents provoqués par une impala apprivoisée se nourrissant de dix espàces végétales ligneuses ont été releves. L'importance moyenne du coup de dents est directement proportionnel avec la masse moyenne de la feuille alors que le pourcentage moyen des coups de dents est inversement proportionnel avec l'importance moyenne des coups de dents. Lorsque l'impala se nourrit d'Acacia tortilis, le pourcentage des coups de dents est inférieur à celui attendu d'aprés la taille des coups de dents parce qu'elle se blesse la langue et les lèvres sur les petites epines recourbées. Ceci confirme la théorie selon laquelle les espéces d'Acacia sont au moins partiellement protégées des effets du broutage des ongulés par la présence des épines en combinaison avec la très petite taille des feuilles.
Pugu Forest Reserve: biological values and development
Authors: HOWELL K. M.
Published: April 2008

The Pugu Forest Reserve, a small 22 km2 reserve near Dar es Salaam, is one of the last remaining vestiges of lowland coastal forest in Tanzania and contains a unique flora with twelve endemic species and one endemic genus. The Pugu Forest Reserve is the type locality for several species of invertebrates. The herpetofauna of the forest is unusual and recent collections have yielded two species not previously recorded for coastal Tanzania. The forest is the southernmost point in the range of an endemic East African coastal bird, the Sokoke pipit, and a number of bird species with unusual or restricted distributions are found in the forest. The mammals of the forest have not yet been studied in detail but many of the larger species formerly occupying the area are no longer present. It is suggested that the small portions of natural vegetation remaining within the Pugu Forest Reserve should be given total protection under a Nature Reserve conservation status and that this status be extended to a number of natural habitats, not only forests, which are in danger of destruction in Tanzania.

La Réserve Forestière de Pugu, une petite réserve de 22 km2 pres de Dar es Salaam, est un des derniers vestiges de la forêtst côtière de Tanzanie et contient une flore unique dont douze espèces endémiques et un genre endémique. La Réserve Forestière de Pugu est un habitat adaptéà différentes espèces d'invertébrés. L'herpétofaune de la forêt est peu commune et de récentes récoltes ont révélé deux espèces non encore rapportées de Tanzanie côtiere. La forêt est le point le plus méridional de la distribution d'un oiseau côtier est‐africain, le pipit de Sokoke, et un certain nombre d'espèces d'oiseaux peu communs ou a répartition restreinte est trouvé dans cette forêt. Les mammifères de la forêt n'ont pas encore étéétudiés en détail mais de nombreux grands mammifères ayant occupé la région ont disparu. Il est suggéré que les petites portions de végétation naturelle restant dans la Réserve Forestière de Pugu devraient être totalement protégées sous un statut de conservation et que ce statut devrait ětre étendu à un certain nombre d'habitats naturels, non seulement forestiers, qui sont menacés de destruction en Tanzanie.
The influence of environmental changes on an isolated topi(Damaliscus Zunatus jimela Matschie)population in the Ishasha Sector of Rwenzori National Park, Uganda
Authors: YOACIEL S. M. , ORSDOL K. G. VAN
Published: April 2008

Numbers of topi, Damaliscus lunatus jimela (Matschie), in the Ishasha Sector of Rwenzori National Park declined by c. 50% between 1975 and 1978. Concurrently, there was a marked reduction in the home range of the population. The part played by a number of environmental factors in bringing about these changes in the population is examined. Poaching pressure, lion predation and changes in the vegetation structure in the region are described. The possible effects of these factors on the topi population are discussed. The sensitivity of the topi population, which is essentially an insular one, to such factors is emphasized and possible ways of counteracting the effects are suggested.

Le nombre de topis, Damaliscus lunatus jimela (Matschie), dans le secteur d'lshasha au Parc National de Ruwenzori a étés réduit d'environ 50% entre 1975 et 1978. Dans le même temps, il y eut une réduction marquée du domaine vital de la population. La part jouée par un certain nombre de factuers de l'environnement sur ces changements dans la population est examinée. La pression de braconnage, la prédation léonine et les changements dans la structure de la végétation de cette région sont décrits. On discute des effets possibles de ces éléments sur la population de topis. La sensibilité de la population de topis—qui est essentiellement insulaire—à de tels facteurs est soulignée et l'on suggère des solutions possibles pour contrecarrer ces effets.
Companion preference in an eland herd
Authors: UNDERWOOD R.
Published: April 2008

Data on the size and structure of eland social groups are presented and discussed. Associations between known animals, except for calves, were usually weak. Companion preference was probably based mainly on age/sex class. Bulls were peripheral to most groups, had fewer companions than most cows and lost those companions more quickly.

For all classes, companion preference varied seasonally. In the dry season, a loose network of adult cow associations was probably the basis of most groups, while nursery herds were the nucleus of large rainy season aggregations. Such seasonal changes in group size may be linked with food requirements. The population of about eighty animals was probably a single, diffuse social unit. A proposed model of group formation fails to explain the observed data.

RÉSUMEÉ

Des données sur l'importance et la structure des groupes sociaux d'elands sont présentées et discutées. Les associations entre animaux identifiés sont généralement faibles, sauf chez les jeunes. Les préférences d'association sont probablement basées surtout sur les classes d'ǎge et de sexe. Les mǎles restent en périphéric de la plupart des groupes, s'associent moins volontiers à d'autres individus que les femelles et perdent plus rapidement leurs compagnons.

Les préférences de compagnie varient selon les saisons pour toutes les classes d'ǎge. Durant la saison sèche, un réseau d'associations labiles de femelles adultes est probablement la base de la plupart des groupes, alors que les hardes de jeunes sont le noyau des grands aggrégats durant la saison des pluies. De tels changements saison‐niers dans les dimensions des groupes peuvent ětre attribués aux exigences alimentaires Le groupement d'environ 80 animaux est sans doute une unite sociale isolée et diffuse. Un modèle proposé de formation de groupe manque pour expliquer ces données.
On surveying ungulate groups
Authors: UNDERWOOD R.
Published: April 2008

The size and structure of groups of seven species of ungulates were recorded over a 2‐year period. The size of the group did not significantly correlate with its distance from the observer when first sighted. Large groups were more likely than small ones to be grazing or lying when first seen. For impala and zebra, grazing groups tended to be further from the observer than lying or moving ones. ‘Terrain screening’ is suggested as the main factor affecting sighting distance at Kyle.

La taille et la structure des groupes de sept espèces d'ongulés ont été notées pendant deux ans. La taille du groupe n'est pas significativement liée à la distance qui le sépare de l'observateur au moment où il le découvre. Les grands groupes śont plus souvent en train de paturer ou couchés que les petits au moment où ils sont observés pour la première fois. Chez les impales et les zèbres, les groupes occupés à manger ont tendance à se trouver plus loin de l'observateur que les groupes couchés ou marchant. On suggère qu'un écran de terrain était le plus important facteur influençant la vue à distance à Kyle.
Elephant feeding behaviour in Ruaha National Park, Tanzania*
Authors: BARNES R. F. W.
Published: April 2008

Elephants were observed in an area of woodland and bushland during two dry seasons and the intervening wet season. In the wet season elephants ate mainly grass while in the dry season they ate mainly woody browse. The quality of food eaten was higher in the wet season than in the dry. Most vegetation damage was caused in the dry season. Browsing bulls tended to move from plant to plant less frequently than did cows. There were within‐season differences in the diversity of browse eaten, within‐season and between‐season variations in the use of individual tree and shrub species, and between‐season differences in defaecation rates.

Des éléphants ont été observés dans une zone de forêts et de buissons durant deux saisons seches et la saison des pluies intermédiaire. Pendant la saison des pluies les éléphants mangent principalement de l'herbe alors que pendant la saison sèche ils mangent surtout des éléments ligneux. La qualité de la nourriture prise en saison des pluies est meilleure qu'en saison sechre. Les plus grands dégats causés a la végétation le sont en saison sèche. Les mâes qui se nourrissent ont tendance à aller d'une plante à l'autre moins souvent que ne le font les femelles. I1 ya à I'intérieur d'une même saison des différences dans la diversité des aliments choisis, des variations intra‐ et intersaisonniéres dans I'usage d'espèces d'arbres et d'arbustes et des différences intersaisonnières dans le rythme des défécations.
Bush pig (Potamochoerus porcus) polychromatism and ecology in Kibale Forest, Uganda
Authors: GHIGLIERI M. P. , BUTYNSKI T. M. , STRUHSAKER T. T. , LELAND LYSA , WALLIS S. J. , WASER P.
Published: April 2008

Bush pigs of Kibale Forest, Uganda, exhibit at least four pelage colour morphs. Two predominant morphs resemble the western subspecies, Potamochoerus porcus porcus, and the eastern/southern subspecies, P. porcus koiropotamus. Kibale Forest may be a zone of secondary contact between subspecies. Alternatively, the Kibale population could be intermediate between clinal extremes. Group size ranged from one to eleven pigs with a mean of 32. One‐third of those bush pigs sighted were immature. Observations were also made on activity and food habits.

Les potamochères de la Forêt de Kibale (Uganda) présentent quatre types de pelage. Les deux morphologies prédominantes ressemblent à la sous‐espèce occi‐dentale, Potamochoerus porcus porcus, et la sous‐espèce orientale et du sud, P.p. koiropotamus. La Forêt de Kibale semble être une zone de sympatrie pour ces sous‐esmeces. L'organisation sociale est variable; la taille du groupe varie d'un à onze individus avec une moyenne de 3.13. 34% des potamochères observés sont immatures. L'alimentation diurne n'est pas rare.
Density and biomass of the large herbivore community in Kainji Lake National Park, Nigeria
Authors: MILLIGAN K. , AJAYI S. S. , HALL J. B.
Published: April 2008

Ground and aerial surveys were used to determine the abundance and distribution of the large herbivore community in the Borgu sector of Kainji Lake National Park, Density estimates of thirteen species, assessed during dry season road counts, indicated about five individuals per km2 in the upland savanna regions and about three times this number in the Olli river valley. Hartebeest and roan antelope comprised 60% of the upland savanna density while kob comprised 74% of the Olli river valley density. Total populations for the reserve, assessed during dry season aerial surveys, indicated that hartebeest and roan antelope were the two most abundant species, with about 2700 and 2200 individuals, respectively. The only other species with estimated populations greater than 500 were elephant and grey duiker. Total populations during the wet season, assessed during an aerial survey, indicated considerably fewer animals than during the dry season.

Densities of the six most abundant species during the 1970–1976 period did not appear to have changed significantly, with the exception of elephant and roan antelope which were more abundant. Biomass density for the large herbivore populations in the upland savanna and for the Olli valley were almost the same being approximately 1200 kg/km.

RÉSUMEÉ

Des comptages terrestres et aériens ont été menés pour déterminer l'abondance et la distribution de la communauté de grands herbivores dans le secteur de Borgu, au Lake Kanji National Park. Des estimations de densité pour traze espèces par comptages routiers durant la saison sèche donnaient environ cinque individus au km2 dans la savane d'altitude et environ trois fois plus dans la vallee de la rivière Olli. Le bubale et l'antilope roanne représentent 60% de la densité en savane d'altitude alors que le cob compte pour 74% dans celle de la vallée de la rivière Olli. Des comptages aériens de toute la population de la réserve effectué en saison sèche, indiquent que le bubale et la roanne sont les deux espèces les plus abondantes avec environ 2700 et 2200 individus respectivement.

Les seules autres espèces dont les populations sont estimees à plus de 500 individus sont l'éléphant et le céphalophe gris. L'ensemble de la population, durant la saison des pluies et estimé par comptage aérien, indique la présence d'un beaucoup plus petit nombre d'animaux que pendant la saison sèche. Les densités de population des six espèces les plus abondantes entre 1970 et 1976 ne semblent pas avoir changé significativement, à l'exception de l'eléphant et de l'antilope roanne qui étaient moins abondants. La biomasse des populations de grands herbivores est presque la měme dans la savane d'altitude que dans la vallée de 1'0lli: elle est d'environ 1200 kg/km2.
Secondary compounds in the diet of Colobus angolensis
Authors: MORENO‐BLACK G. S. , BENT E. F.
Published: April 2008

Four of the most important dietary items of Colobus angolensis in Kenya were tested for the presence of secondary compounds. Phytochemical screening tests found tannins, saponins and alkaloids to be present. Current theories concerning the relationship between social structure and resource availability for herbivorous primates are discussed. It is proposed that the presence of secondary compounds in the diets of primates may be more ubiquitous than previously assumed and adaptive behavioural patterns more individualized for geographical localities and species.

RÉSUMEÉ

Quatre de plus importants éléments du régime du Colobus angolensis au Kenya sont analysés pour déceler la présence de composés secondaires. Des tests phytochimiques révèlent la présence de tanins, de substances saponifiables et d'alcalorides. Les théories ‘courantes’ sur la relation entre la structure sociale et l'accès aux ressources chez les primates herbivores sont discutées. On propose que la présence de composés secondaires dans la régime des primates peut ětre plus généralisable que supposé antérieurement et que les schémas de comportement adaptatif sont plus particuliers selon les endroits et les espèces.
The flooding tolerance of some Nigerian ornamental plants
Authors: KINAKO P. D. S. , ONUEGBU B. A.
Published: April 2008

An ecological study of the flooding tolerance of two ornamental plants–Caesalpinia pulcherrima and Crotalaria retusa–indicated that flooding had a significant adverse effect on the growth and development of the species but C. retusa was more tolerant of inundation than C. pulcherrima. Morphological development in C. retusa was reduced by 26.94% and that of C. pulcherrima by 47.11% after the plants had been subjected to 5 weeks of flooding. Metabolic activities as indicated by the amount of acids of Kreb's cycle present in root samples of control and flooded plants, were reduced by 45.71% in C. retusa, and 76.87% in C. pulcherrima, the less flooding‐tolerant species. The poor development of the affected plants is attributed mainly to the reduced level of metabolic activities brought about by inundation. The flooding tolerance assessment method used in the study was found to be sensitive and reliable and is thus considered appropriate for screening of plant species for a variety of conservation work such as river bank, flood plain and reservoir margin plantings.

Une étude écologique sur la tolérance de deux plantes d'ornament–Caesalpinia pulcherrima et Crotalaria retusa‐ai l'inondation a montré un effet inverse significatif sur la croissance et le développement des espéces, C. retusaétant plus tolérante ai l'inondation que C. pulcherrima. Le développement morphologique de C. retusa est réduit de 26.9% alors que celui de C. pulcherrima l'est de 47.1% aprés 5 semaines d'immersion. Les activités métaboliques–mises en évidence par la quantité d'acides du Cycle de Krebs dans les racines des plantes expérimentales et de contrôle–ont été réduits de 45.7% chez C. retusa et de 76.9% chez C. pulcherrima, la moins résistante des deux. Le faible développement des plantes affectées est attribué principalement ai la réduction du niveau d'activité métaboliques provoquée par l'inondation. La méthode d'évaluation de tolérance á l'inondation, utilisée dans cette étude, s'est révélée sensible et fiable; on peut donc la considérer comme appropriée ai la sélection des espeices végétales pour les plantations de bordure lors d'une série de trav̀aux de conservation tels que berges de riviéres, plaines immergées et réservoirs d'eau.
Feeding ecology and the evolution of body size of baboons
Authors: DEMMENT MONTAGUE W.
Published: April 2008

The total metabolic requirement (kcal day‐1) of herbivores increases as a fractional power of weight while gut capacity increases approximately linearly. Because MR/GC ratio (metabolic requirement/gut capacity) decreases with body size, foods can be retained within the gut progressively longer in larger herbivores. Since digestibility (proportion of intake not appearing in the faeces) is related to retention time, digestibility of foods will be a function of size. Small animals respond by eating rapidly digesting foods. Since high quality foods (i. e. rapidly digesting) are rare and low quality, abundant, larger sized animals (constrained by their higher metabolic requirement) must eat higher fibre diets. In the middle body sizes, the constraints of the MR/GC ratio have been sufficiently relaxed to allow the evolution of structures which selectively delay the passage of fibrous foods (i. e. ruminoreticulum).

Sexual selection is considered a factor responsible for larger male body size. This paper argues that male size is constrained by competition with ruminant species who are more efficient at digesting the types of foods required of greater male size. Female size is viewed as reduced below that of the male to absorb the energetic costs of lactation. The extent of the reduction is constrained by the increasing loss of digestive capacity with decreasing size.

Les besoins métaboliques totaux (kcal jour‐1) des herbivores augmentent en relation fractionnelle avec le poids du corps tandis que la capacité stomacale suit ± linéairement. Puisque le rapport MR/GC (besoins métaboliques/capacité stomacale) diminue avec la taille du corps, les aliments peuvent être retenus dans l'estomac progressivement plus longtemps chez les plus grands herbivores. Etant donné que la digestibilité (proportion de I'aliment qui n'apparaît plus dans les feces) est liée au temps de rétention, la digestibilité des aliments sera fonction de la taille. De petits animaux répondent en mangeant une nourriture rapidement digérée. Sachant qu'une nourriture de bonne qualité (vite digérée) est rare, et une de moins bonne, abondante, les plus gros animaux (contraints par leurs besoins métaboliques supérieurs) doivent manger un régime plus fibreux. Dans les tailles moyennes, les exigences du rapport MR/GC ont été suffisamment adoucies pour permettre une évolution de structures qui propose sélectivement le passage aux nourritures fibreuses (p. e. ruminoreticulum).

La sélection sexuelle est considérée comme le facteur déterminant chez les animaux de plus grandes tailles. Cet article prétend que la taille du mâle est limitée par la compétition avec des espèces ruminantes qui digèrent plus efficacement les types de nourritures qui sont aussi celles du plus grand mâle. La taille de la femelle serait ainsi inférieure à celle du mâle en raison du coût énergétique de la lactation. Le supplément de la réduction de taille est lié lui à la perte de la capacité digestive à cause de la diminution de taille.
The structural organization of the carotid arterial system of the giraffe (Giraffa camelopardalis)
Authors: KIMANI JAMES KIRUMBI
Published: April 2008

Carotid arteries in the giraffe were removed and their structural organization studied with light microscopy. It has been shown that the carotid artery has a largely muscular structure in the adult except for the carotid baroreceptor area located at the carotid‐occipital junction. The fetus carotid has an elastic structure in its caudal portion and a musculo‐elastic structure in its cranial portion. It is proposed here that the muscular structure of the carotid arterial system constitutes part of the structural mechanism by which this animal autoregulates its cranial circulation particularly when it bends the neck down. Pertinent to this suggestion is the fact that the elevated distal carotid pressure does not cause a significant increase in cerebral blood flow.

Les artères carotidiennes de la girafe ont été disséquées et leur organisation structurel structurelle étudiées au microscope. On a montré que l'artère carotidienne a une forte structure musculaire chez l'adulte sauf dans la zone baroréceptrice de la carotide située à la jonction carotido‐occipitale. Le fetus carotidien a une structure élastique dans sa portion caudale et une structure musculoélastique dans sa portion crâniale. II est proposé que la structure musculaire du système artériel carotidien constitue une partie des mécanismes structurels par lesquels cet animal régit lui‐même sa circulation crâniale, en particulier lorsqu'il penche le cou. Une confirmation de cette suggestion réside dans le fait que la pression carotidienne distale n'entraine pas d'augmentation significative du flax sanguin cérébral.
Nocturnal ecology of the springhare, Pedetes capensis, in Botswana
Authors: BUTYNSKI T. M.
Published: April 2008

The springhare, Pedetes capensis, was studied in the Kalahari Desert, Republic of Botswana, from August 1971 to August 1974 inclusive. Night censuses totalling 253 h provided data on springhare habitat selection, social grouping, activity pattern and the effect of moonlight and weather on activity.

Utilization of dry lakebeds (pans) by springhares was 2.3‐3.4 times greater than on the surrounding habitats. Springhares were strictly nocturnal. The population, as a whole, exhibited one activity peak every 24 h. Group size and distance from burrows were directly related to time after sunset. Low temperatures and moderate to heavy precipitation both reduced springhare activity, while moonlight reduced the distance to which springhares moved out onto pans.

Except for adult males, all sex/age classes of springhares participated in group formation to the same extent. Apparently little social cohesion existed within groups. Territoriality was not observed but may occur in the area immediately around the burrow.

Le lièvre sauteur (Pedetes capensis) fut étudié dans le désert du Kalahari, au Botswana, de août 1971 à août 1974. Un total de 253 heures de recensements nocturnes a fourni des données sur le choix de l'habitat chez le lièvre sauteur, son organisation sociale, ses types d'activités et l'effet du clair de lune et du temps sur celles‐ci. L'utilisation du fond des lacs esséchés (pans) par ces animaux est de 2.3 à 3.4 fois plus important que les habitats avoisinants. Les lièvres sauteurs sont strictement nocturnes. L'ensemble de la population présente une activité maximale toutes les 24 heures. La taille du groupe et la distance au terrier sont en relation directe avec le temps écoulé après le coucher du soleil. Des températures basses ou modérées ainsi que les grosses précipitations réduisent l'activité des lièvres sauteurs, alors que le clair de lune limite la distance que l'animal parcourt sur les pans.