bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recherches écologiques sur une savane sahélienne du Ferlo septentrional , Sénégal : Données quantitatives sur les Ténébrionides
Authors: Gillon Dominique , Gillon Yves 
Published: November 2022

Principaux constituants de la biomasse des insectes de la strate herbacée du Ferlo septentrional, les Ténébrionides sont étudiés quantitativement au niveau spécifique.
Pimelia senegalensis, Vieta senegalensis, Zophosis trilineata, Zophosis quadrilineata et Diodontes porcatus sont les principaux représentants de la famille. Ils en constituent 85 % des effectifs et 92 % de la biomasse.
Les adultes, seuls échantillonnés, de la majorité des espèces ne se rencontrent que pendant la saison des pluies, mais certains vivent là toute l’année (Zophosis spp.), avec parfois même une préférence pour la saison sèche (Pachycera tagenioides, Storthocnemis abyssinicus). La plupart des espèces ne marquent leur prédilection pour un biotope que par des différences de densité. Beaucoup aiment les milieux ombragés riches en litière et en plantes non graminéennes. Trachymetus elongatus, et probablement aussi les Oncosoma, sont inféodés aux bas-fonds humides.
Enfin les variations spécifiques du rythme nycthéméral d’activité ont pu être appréciées pour les espèces présentes en janvier.
L’économie de l’eau chez un mollusque gastéropode terrestre xérophile : Leucochroa Candidissima (Draparnaud).
Authors: Bonavita Dominique 
Published: November 2022

Un des problèmes essentiels pour les Mollusques terrestres des milieux xériques est le contrôle de l’économie de leur eau. C’est le cas pour Leucochroa candidissima (Drap.) qui a été étudié en Provence Occidentale (France). Dans son milieu naturel, cet animal xérophile et sténohygre passe, au cours du cycle annuel, par deux périodes de vie latente (hiver et été) alternant avec deux périodes d’activité (printemps et automne). Ces dernières ne sont, en fait, qu’une succession de brèves phases d’activité entrecoupées de phases de repos sous épiphragme.
Les modalités de l’absorption de l’eau sont envisagées. Les variations du taux d’hydratation tissulaire constatées chez les animaux, coïncident avec le cycle saisonnier, mais présentent des amplitudes différentes selon les organes.
L’utilisation d’un traceur radioactif (oxyde de tritium ingéré par voie buccale) permet de préciser les modalités du stockage et des pertes de l’eau dans différents organes choisis (tube digestif, cœur-rein, sole pédieuse, hépatopancréas, bourrelet palléal).
Les différences de vitesse de perte d’eau constatées entre organes s’expliquent par l’existence d’une fonction accumulatrice
Méthode télémétrique d’enregistrement individuel des vocalisations. Application à Cercocebus albigena
Authors: Gautier Jean-Pierre , Deputte Bertrand 
Published: November 2022

A telemetric device has been designed which allows simultaneous though independent recording of the vocalizations of different individuals within the same social group.
Each animal carries around the neck a small microphone (F.M.) adjusted on a definite frequency. The receivers are tuners. The records can be made by multi-track recorders on magnetic tape or on paper recorder.
Such a technique allows a qualitative and a quantitative analysis of vocal behaviour to be made for each sex, age-and status categories, in response to specific stimulating situations.
Quelques données écologiques de la grenouille africaine Dicroglossus occipitalis
Authors: Micha J.-Cl. 
Published: November 2022

The geographical distribution of Dicroglossus occipitalis extends from Western to Central and Eastern Africa.
The study of the length-weight relationship of this amphibian does not show any significant difference amongst immatures, adult males and females. Nevertheless the females reach a greater length than the males.
The diet, established by qualitative and quantitative analysis, consist of terrestrial insects, myriapods, and fishes. The differences between the feeding habits of the younger and older Dicroglossus are not important, but the older individuals have more diversified feeding habits.
Dicroglossus occipitalis mate throughout the year under the climatic conditions of Bangui. However a peak occurs in June, July and August, at the beginning of the rainy season. The fecundity of this species is relatively low ; this fact might be explained by relatively large egg dimensions.
The density of the adult Dicroglossus is relatively low (2,7 -10 ind./are) compared with the density of tadpoles ; the same applies for the biomass.
Dicroglossus occipitalis do not meet the requirements of stock farming. As a matter of fact, this species of frog does not stand high stocking rates. It feeds essentially on mobile preys and does not accept inert artificial food.
Dépenses énergétiques des populations hivernantes de Pinsons du nord (Fringilla montifringilla) en relation avec leur milieu
Authors: Hémery Georges , Le Toquin Alain 
Published: November 2022

During the past few years the ecology of the populations of Bramblings (Fringilla montifringilla) wintering in western Europe has undergone a rapid and important evolution due in large measure to the cultivation of maize (Zea maïs). The results is an increasingly frequent formation of flocks containing several million individuals. From 1965 to 1972 studies have been made of a roost in Pau (Pyrénées-Atlantiques) which has regrouped up to twenty million Bramblings.
The purpose of the present study is to propose a general model relating the quantity of energy expended daily (QD) to the behaviour of wintering Bramblings and to the habitat variables.
In the first part of this study different levels of energy metabolism are defined in function of the conditions in which the measures of energy expended occur. The general relationships linking these types of metabolism to body weight, and the relationship 9 v/b of flight metabolism to basal metabolism are indicated.
In the second part of this paper the preceding general conclusions and the information concerning the daily cycle of activity are applied to the case of Bramblings wintering in the Pyrénées-Atlantiques. For example, in the month of December, an individual flying a distance of 80 km a day expends 28 kcal.
In the third part of this study the relationship between the amount of energy expended (QD), the distance flown each day between the roost and the feeding grounds (D), the photoperiod qp and the time given to each activity (Ti) are established. These relationships enable us to deal with the problem of the maximal distance of dispersion from the center of the roost. In particular, the time lost reaching the feeding grounds constitutes the principal factor limiting daily dispersal, whereas energy loss is relatively unimportant.
The last part of this paper proposes a general model (figure 9) for the total wintering area, giving the amount of energy expended (Qd) and the maximal quantity of energy assimilable (QA max) in relation to the population behaviour, the habitat characteristics, and the period of the year.
Introduction into the model of the variables D and VN (value of the food ingested = quantity of energy assimilable by unit of time present on the feeding grounds) allows us to relate the potential number of individuals which can be supported by a given area to the different forms of maize cultivation.
The sensitivity analysis indicates the preponderant role of the photoperiod in the determination of the QD. Finally, three examples of simulation are given.
Actogramme journalier de l’Hylochère (Hylochoerus meinertzhageni Thomas) au Parc National des Virunga, Zaire
Authors: Huart J.p. d' 
Published: November 2022

L’Hylochère a, depuis 1960, adopté une activité diurne au Parc National des Virunga, Zaïre.
Une brève description de ses mœurs et des «repères biologiques» de son territoire est donnée (bauge, réseau de pistes, saltlick, souille, unité sociale, hiérarchie).
Le rythme d’activité de l’Hylochère est introduit par un diagramme présentant les fréquences d’observation de compagnies par tranches de 30 minutes durant la journée. En exprimant le nombre d’observations en forêt comme pourcentage du total, cinq périodes de la journée sont nettement différenciées : trois périodes de présence en forêt et deux en savane.
L’actogramme est précisé par l’analyse détaillée de trois groupes d’hylochères qui ont été suivis à pied de 6 h à 18 h. La séquence chronologique de leurs occupations a été notée toutes les cinq minutes et représentée selon la méthode — légèrement modifiée — de Spinage (1968).
Un tableau récapitulatif donne les pourcentages de temps d’occupation de chaque individu, et ceux-ci sont discutés.
Par un test de chi-carré d’homogénéité des proportions : entre différents groupes ou individus, il ressort que la composition du groupe détermine les heures d’activité, mais non leur durée relative.
La marche et l’alimentation sont les deux activités principales et prennent environ 60 % de l’activité diurne.
Détermination de l’âge et de la longévité chez le Desman des Pyrénées (Galemys pyrenaicus)
Authors: Richard P. B. 
Published: November 2022

La recherche d’une méthode pratique et sûre pour déterminer l’âge du Desman des Pyrénées se heurte à plusieurs difficultés dont la principale est la méconnaissance de l’âge exact de certains des animaux capturés, qui aurait pu servir de mesure absolue.
En utilisant les mesures relatives de l’usure de certaines dents et de leur déchaussement en fonction de la date de capture, on obtient une répartition de la population en trois ou quatre groupes selon la saison ; les plus vieux, âgés vraisemblablement de trois ans, disparaissant au moment où apparaissent les plus jeunes, en mars et avril. Un animal bagué et repris en mars, avait au moins deux ans et demi. L’usure des dents est plus rapide et moins régulière que leur déchaussement, car l’animal vit très bien avec plusieurs dents usées jusqu’à la racine. Le déchaussement semble donc le meilleur caractère ; ce que confirme la statistique.
Cependant la corrélation des deux caractères dentaires au cours de l’année met en lumière la distribution et l’évolution des groupes d’âge.
Contribution à la connaissance des Ophidiens de la Grande Camargue
Authors: Guillaume Claude 
Published: November 2022

A check list is given of the 21 species of «herptiles » presently found living in the Camargue : 7 Amphibians, 1 Turtle, 7 Lizards and 6 Snakes.
The preferential biotopes of the four most abundant species of snakes are described. Elaphe scalaris is found in the «gallery forests» and vineyards. Malpodon monspessulaniis lives in all kinds of Camargue habitats, sand dunes excepted. Natrix maura is mostly found in rice fields and Natrix n. helvetica in fresh water marshes.
Ecologie des populations de rongeurs de Bandia (Sénégal) en zone sahélo-soudanienne
Authors: Hubert B. 
Published: November 2022

The rodent population of the Bandia forest, a dry deciduous woodland S.E. from Dakar, Senegal, has been studied from 1971 to 1973. Comparisons were made with adjacent areas under cultivation.
Out of the 17 species recorded in the area, five were present in large numbers : Mastomys erythroleucus, Tatera gambiana, T. guineae, Taterillus gracilis and T. pygargus.
Data are given on population density, size of the home range and breeding season of these dominant species. A multivariate analysis is made of the distribution of these rodents in relation to their habitat characteristics. Each species is shown to have its distinctive environmental preferences, including the two species of Taterillus which cannot be distinguished from each other morphologically.
Particular attention is given to the seasonal changes in population density, size of the home ranges and their modifications during the breeding season. All the species studied breed at the end of the rains (from September-October to January-March), and the populations consequently reach their lowest densities at the beginning of the next rainy season.
At any time of the year population densities of rodents are about 10 times larger in cultivated areas than in the forest itself. The same applies to the annual net production of rodents.
Recherches écologiques sur une savane sahélienne du Ferlo septentrional, Sénégal : Premières données sur Commiphora africana (Rich.) Engl.
Authors: Poupon H. 
Published: November 2022

Les biomasse et production primaire nette de Commiphora africana (Rich.) Engl., ont été mesurées dans la savane sahélienne du Ferlo, au Nord du Sénégal. Après avoir étudié la structure de la population sur une mise en défens de vingt-cinq hectares, comprenant cinq types d’éléments de relief, l’auteur cherche des relations liant le nombre de cernes à la longueur de la circonférence mesurée à la base du tronc.
L’évolution des biomasses aérienne et souterraine en fonction de l’âge des arbres montre que les jeunes individus développent rapidement leur système racinaire. Pour un arbre d’une vingtaine d’années la biomasse totale est également répartie entre les racines et l’appareil aérien.
Les productions caduques varient d’une année à l’autre et sont très sensibles aux conditions hydriques : faibles en année sèche (1972) elles n’atteignent pas en années pluvieuses des valeurs élevées car elles sont consommées par les sauterelles.
L’auteur donne, enfin, une évaluation de la productivité foliaire en 1973.
Sensibilité des milieux et impacts des activités humaines sur le massif du Ventoux
Authors: Guende Georges 
Published: November 2022

A map depicting the fragility of the environment has been drawn up (see Appendix), which distinguishes two main groups.
1) Areas of natural vegetation with low human influence. These include :
a) the mature forests. These are poorly represented (only 5300 ha) due to previous overexploitation ;
b) the pre-climax forest stages (mainly coniferous) covering about 1000 ha ;
c) “degraded” habitats (scrub and grassland), which are mapped in terms of their value as pasture. Scrub covers about 2800 ha, and grassland about 1200 ha.
These natural ecosystems make up about half of the non-cultivated areas.
2) Areas with severe human pressure. This pressure may be due to one of several activities. Extensive reafforestation has been carried out since about 1860 (much of the natural forest having been destroyed by then), so that the new forests now cover the other half of the non-cultivated areas. In addition to native species, the exotics Pinus nigra ssp. austriaca and Cedrus atlantica have been widely planted. The cultivated areas are restricted to the foot of the mountain, although sheep are grazed to much higher altitudes. The type of agriculture is related to the natural vegetation series being exploited, and in most places is tending towards monoculture (mainly of vines, fruit-trees or lavender). Other human pressures include housing, roads, military activities and tourism ; industry is very limited in extent.
The Mont Ventoux shows a fairly balanced relationship between man and his environment for several reasons.
1) Forest is by far the dominant vegetation type (covering about 75% of the massif).
2) The areas of non-climax and degraded vegetation are relatively restricted in extent, and have a considerable landscape value and economic importance.
3) The impact of forestry and agriculture is negligible, since these areas harmonise remarkably well with the natural landscape.
4) There has been no excessive development of other human activities, although the increasing number of holiday homes is a potential threat.
La niche écologique, mythe ou réalité ?
Authors: Blondel Jacques , Bourlière François 
Published: November 2022

The niche concept in ecology can be approached either empirically or theoretically. The emphasis is laid in this paper on the empirical approach, and the authors make use of their personnal field experience to illustrate the points discussed.
The usefullness of the Hutchinsonian concept of a multi-dimensonial niche is first emphasized, together with that of the distinction between the fundamental and the realized niche. Examples are given which will help to define and quantify a niche dimension in field conditions. Taking the spectrum of seed size eaten by four sympatric species of finches as an example, a number of concepts are discussed, such as the ecological profile of a species, the barycenter of its niche, niche breadth and niche overlap.
Niche packing and the number of niches in a given ecological universe are then discussed, together with the concepts of alpha-, beta-and gamma-diversity.
Niche regulation is also discussed at some length. The notion of a “ vacant niche” is shown to be a non-problem, and this is illustrated by some examples. It is pointed out that the mechanisms of niche regulation cannot be understood without reference to the concept of adaptive strategy, whether it be at the individual or demographic level. It is hard to understand how a species has developped its ecological niche without considering the nature of the selection pressures operating in more or less changing environments.
To sum up, it is suggested that although it will always remain difficult (if not impossible) to identify and quantify all the n-dimensions of the niche of a given species, the concept remains most useful to stimulate working hypotheses, some of which at least can be tested in field conditions.
Régénération et reconstitution de forêts naturelles à l'île de la Réunion
Authors: Miguet J.M. 
Published: November 2022

Although still densely forested, the vegetation of the island of La Reunion (Mascarenes) has been drastically modified by human intervention during the past three hundred years.
Little is left of the lowland coastal forest, except in the small reserve of Saint Philippe.
The hill forests still cover most of the mountain slopes between 700 and 1300 m above sea level, although some tree species have suffered from overexploitation in the past.
The open forest of the endemic tree, le Tamarin des hauts (Acacia heterophyila), is found between 1300 and 1800 m above sea level, in the highest ranges. The biology of this tree is described and the successful techniques devised by the Reunion Forest Service to ensure its regeneration after forest fires or landslides is described.
Evolution annuelle des effectifs et des biomasses des oiseaux antarctiques
Authors: Mougin Jean-Louis , Prévost J. 
Published: November 2022

An estimation is made of the population numbers of the Antarctic and sub-Antarctic birds, their biomasses and their food consumption at sea, and of their seasonal variations. The total populations of the 46 species represent a grand total of about 350 million birds and a biomass of ca 850,000 tons. Forty nine percent of this population and 36 % of this biomass are found in the sub-Antarctic zone, as against 51 % and 64 % respectively in the Antarctic zone. The penguins represent 52 % of the total bird population and 92 % of the total bird biomass. Some seasonal variations occur, the difference between maximum and minimum values not exceeding 20 % however. On the average, 80 % of the birds live offshore, as against 20 % on land.
The daily energy requirements are estimated to be of c 112 X 109 kcal, and the daily energy demands of c 160 X 109 kcal.
The monthly food consumption at sea is about 4.7 million tons, 61 % of which are crustaceans, 24 % squids and 14 % fish. Penguins are the major consumers. The amount of food consumed does not vary much from month to month, the monthly maximum being only 70 % higher than the monthly minimum in the Antartic zone, and 56 % in the sub-Antarctic zone.
Some hypotheses are formulated concerning competition for food between birds, seals and whales. There was probably no competition when whales were numerous in Southern Oceans, feeding on the huge summer planctonic production, little being left for birds and seals. The present situation is quite different, most of the summer production of plancton no longer being used on a large scale by mammals and birds.
L’évolution des peuplements d’oiseaux le long d’un gradient altitudinal dans l'Himalaya central
Authors: Thiollay Jean-Marc 
Published: November 2022

The breeding bird communities along an altitudinal gradient ranging from 100 to 5,000 metres, South of the Annapurna range, have been studied in central Nepal, from 30 May to 14 August 1977, and from 6 October to 5 November 1978. Two comparative surveys were also conducted between 2,500 and 5,500 m, during July and September-October 1978, in the Manang and Mustang valleys, on the northern slope of the main Himalaya range. For 1,892 observation periods of 20 minutes each, carried out at 31 different altitudinal levels, a total of 15,116 birds belonging to 344 species were recorded. Birds of prey, swifts, swallows, goatsuckers, and birds living along water-courses were not included in the counts. A grand total of 554 species was observed during our trips. Most of the counts were made under difficult conditions, especially during the monsoon.
Species richness, species diversity and population density, although remaining high throughout the elevation gradient, diminish very slowly from the tropical lowlands to the subalpine forests. This unusual feature apparently results from a high speciation rate of such families as the Timaliidae, the Muscicapidae, the Turdidae and the Sylviidae in the temperate and alpine zones. Community structure, and the size of the various trophic guilds, are more closely related to the availability of the various food categories than to vegetation structure per se. Frugivorous birds are prominent only in the tropical lowlands, and seed-eaters in the upper altitudinal levels. Terrestrial insectivores and arboreal gleaners are common at all levels, but flycatchers and bark-feeders disappear in the upper Rhododendron forest, where nectarivores reach their highest density.
The narrow distribution of most species, the altitudinal zonation of allopatric congeneric species, the high turnover rate of avian communities between adjacent altitudinal levels and the differences observed between similar habitats in different valleys are pointed out. These characteristics, together with some intraspecific differences in altitudinal distribution and habitat preferences among the localities studied, suggest a strong interspecific competition. The large number of species present at various altitudes most likely explains why “density compensation” and “competition release” were not apparent in the area studied.
Some information is also given on the breeding periods, clutch size and altitudinal migrations of birds observed along the Annapurna transect.
Observations on the ecology and behavior of the Giant River Otter Pteronura brasiliensis in Suriname
Authors: Duplaix Nicole 
Published: November 2022

L’écologie et le comportement de la Loutre géante du Brésil Pteronura brasiliensis ont été étudiés de juillet 1977 à mars 1978 au Suriname.
L’espèce est diurne et grégaire, formant des groupes familiaux durables qui défendent certaines portions de leur domaine vital contre les incursions de leurs congénères.
Pteronura brasiliensis est piscivore. Les modalités de reproduction et les déplacements saisonniers des poissons Characoides qui forment l’essentiel de son régime ont une influence profonde sur l’écologie de cette loutre. Pendant la saison des pluies, par exemple, les Pteronura suivent leurs proies dans la forêt inondée, abandonnant temporairement leurs «bivouacs » et tanières habituels.
La reproduction a lieu d’août à octobre. Les jeunes loutres restent avec leurs parents quand naît la portée suivante, peut-être même jusqu’à leur propre maturité. Le répertoire comportemental de Pteronura brasiliensis est décrit et comparé avec celui des Lutra solitaires.
Lutra enudris peut cohabiter avec Pteronura dans certains cours d’eau de Suriname. Ses mœurs solitaires, son activité surtout crépusculaire et la taille moyenne de ses proies, tout comme le fait qu’elle peut également habiter dans les marais côtiers et les petites rivières de la grande forêt, minimisent les chances d’une éventuelle compétition avec Pteronura.