bluuebunny/crossref_metadata_2025_split huggingface dataset:
La territorialité chez la Rousserolle verderolle Acrocephalus palustris
Authors: Dowsett-Lemaire Françoise 
Published: November 2022

Le comportement territorial de la Rousserolle verderolle Acrocephalus palustris a été étudié dans une population marquée de quelques dizaines de couples nichant dans la vallée liégeoise (Belgique) .
Liées à l’exploitation d’une végétation herbacée dense, les Verderolles occupent des territoires groupés de petites dimensions (quelques ares en moyenne) qui contiennent des sites potentiels de nid (lig. 1 et 4). Le couple se forme lorsqu’une femelle s’arrête pour sélectionner un site de nid. La plupart des couples continuent à défendre un territoire jusqu’à la naissance des jeunes, c’est-à-dire jusqu’à une époque où les tentatives d’installation de nouveaux venus sont presque terminées. Les couples tardifs cessent de défendre un territoire relativement plus tôt dans le cycle. L’essentiel de la nourriture pour les jeunes est recherché en dehors du territoire initial (fig. 1 C) ; dès avant ce stade, les excursions extraterritoriales sont fréquentes, surtout chez les mâles.
Outre leurs congénères, la Rousserolle effarvatte A. scirpaceus est la seule espèce locale que les Verderolles expulsent systématiquement de leur territoire.
Le rôle principal de défense du territoire revient aux mâles (dont le chant plein a une fonction territoriale), mais les femelles prennent une certaine part dans la défense du canton surtout en cas d’absence (temporaire ou non) de leur partenaire.
La dimension du territoire occupé à un moment donné dépend de l’époque de l’installation, de la position du territoire par rapport aux cantons voisins, du tempérament des oiseaux, du type de végétation contenu dans le territoire, et du stade du cycle. Les territoires des mâles cantonnés en début de saison (mi-mai) sont plus grands que ceux des individus arrivant au milieu ou vers la lin de la période principale des installations (fin mai). En moyenne, le territoire s’étend nettement lors de la formation du couple, puis sa surface décroît jusqu’à la fin de l’incubation (fig. 5). La dimension moyenne du territoire est inversement proportionnelle à la densité locale des sites de nid. Au cours de la saison exceptionnellement sèche de 1976, les sites de nid étaient plus dispersés et la densité des couples (10,6 couples/ha) a été la plus basse observée en quatre ans.
La possession par le mâle d’un territoire riche en sites de nid est sans doute indispensable à la réussite de la formation du couple. Pendant les parades nuptiales, le territoire protège le couple contre les interférences des mâles voisins. Enfin, plusieurs faits d’observation suggèrent que la territorialité contribue à limiter la densité de la population nicheuse.
Le cycle saisonnier des lipides de réserve chez deux espèces de rongeurs du Sénégal
Authors: Hubert B. , Demarne Yves 
Published: November 2022

The seasonal cycle of lipid deposition has been studied for two consecutive years in populations of Mastomys erythroleucus and Taterillus gracilis from a sahelo-sudanian woodland in Senegal.
At the beginning of the dry season young Mastomys, 2 to 3 months old, feed mostly upon the temporarily superabundant seeds and store fat. These fat deposits, largely made of oleic acid, are used during the long dry season, when food is scarce. During the rains, Mastomys diet changes, as does the nature of their lipid stores which then contain a larger percentage of linoleic acid. This last fatty acid is quite likely provided to the animals by Cucumis melo seeds, which are frequently consumed by Mastomys at this time of the year, when breeding takes place.
The seasonal cycle of fat deposition in Taterillus gracilis is similar to that of Mastomys erythroleucus, but less marked. The diet of this gerbilid is also more varied, and its breeding season spread over a longer time interval.
The above observations were made at the end of the 1975-1977 rodent outbreak in Northern Senegal. However, fat deposits remained very substantial in January 1976, at the time when population densities reached their peak values. Similarly, the rodents still maintained sizable fat deposits during the “crash” period, from August 1976 to the end of 1977. In the present situation, at least, population fluctuations were clearly not dependent upon the nutritional status of the rodents studied.
Les conséquences d’un supplément alimentaire sur la dynamique des populations de rongeurs au Sénégal. II. Le cas de Taterillus pygargus en zone sahélienne
Authors: Poulet A. , Couturier Guy , Hubert B. , Adam François 
Published: November 2022

Un aliment artificiel à base de céréales fut distribué pendant les neuf mois de la saison sèche 1976-1977 sur 2,25 ha d’une savane sahélienne du Nord-Sénégal, qui supporte une population du Gerbillidé Taterillus pygargus.
Les résultats d’une série de piégeages avec marquages et recaptures multiples sur la surface approvisionnée et sur une surface témoin montrent que les conséquences du supplément nutritionnel furent d’une part une prolongation de la saison de reproduction, d’autre part une concentration d’individus pendant la première partie de la saison sèche, de novembre à janvier ; mais, le très fort déclin qui affecta la population de Taterillus dès le mois de décembre 1976 ne fut pas modifié par la présence du supplément alimentaire : l’origine de la mortalité ne pouvait donc être une raréfaction de la nourriture disponible.
Le peuplement herpétologique d’un massif du Haut-Languedoc. II. Influence de quelques facteurs sur la répartition des reptiles
Authors: Livet F. 
Published: November 2022

The plant community structure and the influence of some climatic factors on the distribution and population density of the reptiles of the Caroux-Espinouze mountain range (Southern France) are discussed. Fixed transects counts were used to estimate species distribution and abundance.
The activity of the Mediterranean species is influenced more by wind speed and temperature than that of more northern species, e.g. Vipera aspis.
The climate of the area, which is intermediate between the Mediterranean and the Atlantic climates, exerts a strong influence on the population density of the reptile species in question. The structure of the reptile community may vary from year to year depending upon short term climatic fluctuations.
The structure of the plant communities also influences the structure of the reptilian communities, and the population density of the species concerned. Heathland communities with a closed canopy growing on a deep soil harbour the denser and more diverse reptile communities of the area. This may be correlated with the availability of numerous shelters, including rodent burrows, and of many prey species ; behavioural thermoregulation may also be facilitated. Species diversity and population density decrease in more open heathland communities, meadows and forests.
Three groups of species can be distinguished on the basis of their range of habitats : (1) those with a wide range : Elaphe longissima, Lacerta viridis, Malpodon monspessulanus, Natrix maura ; (2) those with a moderate range of habitats : Vipera aspis, Elaphe scalaris, Anguis fragilis, Coluber viridiflavus, Natrix natrix, Lacerta muralis ; and (3) those with a narrow range of habitats : Psammodromus algirus, Lacerta lepida and L. vivipara.
Les particularités démographiques et socioécologiques du Coliou strié dans le Nord-Est du Gabon. II. Stratégies adaptatives de l’espèce
Authors: Decoux Jean-Paul 
Published: November 2022

The observations carried out from 1973 to 1977 on a population of speckled mousebirds (Colius striatus) at Makokou, Gabon, have been summarized in a previous paper (Rev. Ecol., Terre Vie, 36, 1982 : 37-78). An attempt is made here to integrate the available data into a meaningful whole, in order to demonstrate the adaptiveness of the tactics adopted by this amazing bird.
None of the remarkable behavioural traits and ecological characteristics of the Speckled mousebird would be understandable without consideration of its unusual physiology and nutrition. A low metabolic rate and a vegetarian diet allow this bird a good deal of «free time» to develop play activities, even among subadults and adults.
Extensive social cooperation between members of the same population is the most striking feature of the breeding biology of Colius striatus ; this cooperation enables the species to maximize its breeding potential.
Among sedentary breeders, the long-lasting pair-bond and the frequent presence of subadult and adult «helpers at the nest» probably contribute to increase the expectation of life of fledged individuals. The existence of a «reserve of potential breeders», made of young bachelor males and satellite adult females, also allows the speckled mousebirds to adapt quickly their demographic strategy to rapidly changing environmental conditions. They cannot therefore be easily classified either among r or K-strategists.
Nomadic groups also enable the species to colonize unstable habitats, such as clearings around human settlements, or gaps in the mature rain-forests. On the whole Colius striatus is a highly adaptable bird, behavioural flexibility being the rule at the individual as well as at the population level. Occasional cases of communal nesting and even polyandry are extreme examples of this flexibility of behaviour.
Production et consommation de graines en milieu Sahélo-Soudanien au Sénégal : bilan général
Authors: Gillon Dominique , Adam François , Hubert B. , Kahlem G. 
Published: November 2022

La production annuelle de graines par la végétation herbacée et leur consommation par les oiseaux, les rongeurs et les fourmis Messor galla ont été étudiées au cours de 3 années successives. La production annuelle de graines a varié de 286 kg/ha à 1 061 kg/ha, les oiseaux en auraient consommé 6 % à 26 %, les rongeurs 1 % à 15 % et les fourmis 0,4 % à 2 % selon les années. Au total, 1/3 à 2/3 des graines produites auraient été consommées si on tient compte de l’impact des insectes endophytophages qui se développent dans les graines de l’espèce dominante Cassia tora (Leguminosae).
Globalement, pendant la période d’étude, les quantités de graines n’ont pas semblé un facteur limitant pour les populations granivores et, réciproquement, l’impact des granivores n’a pas paru compromettre le renouvellement de la strate herbacée l’année suivante. Cependant, les différents groupes granivores effectuant des choix parmi les graines disponibles, il est probable qu’il y a compétition pour certaines graines particulièrement recherchées et que leur impact influe sur l’équilibre entre les espèces herbacées.
Ces 3 groupes granivores, systématiquement éloignés (oiseaux, rongeurs, fourmis), utilisent certes la même source de nourriture, limitée en quantité et variable dans le temps, mais ils diffèrent quant à leur mode d’utilisation spaciale et temporelle de cette même ressource.
Habitat et comportement du poisson amphibie Periophtlamus koelreuteri africanus Eggert à Tuléar. Comparaison avec le P. sobrinus Eggert sympatrique
Authors: Brillet Charles 
Published: November 2022

La présente note apporte des informations sur l’écologie et le comportement du Poisson amphibie Periophtalmus koelreuteri africanus Eggert et compare ces données à celles recueillies sur un autre Périophtalme sympatrique, P. sobrinus Eggert.
Ces deux espèces, de tailles différentes, qui partagent les mêmes banquettes de vase en certains points des mangroves, se distinguent l’une de l’autre par plusieurs traits éthologiques.
Bien qu’on puisse les rencontrer toutes deux en mangrove (où la densité de population de P. Sobrinus est infiniment supérieure), P. koelreuteri s’adapte aussi à un substrat plus rocheux, ce dont sobrinus est incapable.
Les deux espèces creusent un terrier, mais la structure de cet abri est différente : une seule galerie d’accès surmontée d’un unique rempart de vase pour koelreuteri, deux remparts et deux galeries chez sobrinus.
Dans le domaine de l’utilisation de l’espace et des relations entre individus, il apparaît que P. koelreuteri africanus fréquente un domaine très vaste aux alentours de son terrier. Peu agressif, il ne semble pas défendre un véritable territoire avec la détermination dont fait toujours preuve P. sobrinus.
Allocation de ressources et effort de reproduction : le cas des lézards
Authors: Pilorge Thierry , Barbault R. 
Published: November 2022

The concept of reproductive effort and the problems associated with its measurement in lizards are reviewed and discussed. Many authors use indices such as the Relative Clutch Mass (R.C.M.) which are of limited value.
Though not yet in common use, the energy budget approach looks promising, especially since field radioisotope techniques are now available.
The role of the energy stored in fat deposits, and of that invested in tail regeneration, is discussed. Both seem able to influence reproductive patterns in lizards.
The demographic component of the reproductive effort (i.e. whether the energy is allocated to a few or many offspring), and the relationships between reproductive strategies and environmental and genetic factors, are also considered.
Structures de population et tables de survie des buffles, topis et cobs de Buffon au Parc National des Virunga, Zaïre
Authors: Mertens H. 
Published: November 2022

Les structures de population et les tables de survie de trois espèces d’ongulés sauvages ont été établies à partir de recensements terrestres et par l’étude des échantillons de crânes recueillis tout au long d’une année dans la plaine sud du Parc des Virunga au Zaïre.
Les résultats sont commentés et comparés à ceux d’autres études effectuées dans l’Est Africain.
Quelques caractéristiques du comportement social pouvant expliquer certaines constatations sont également communiquées.
Variations de la densité et de la taille corporelle en fonction de l’abondance et de la composition du peuplement de proies dans trois populations de lézards vivipares du Mont Lozère
Authors: Khodadoost Mehrdad , Pilorge Thierry , Ortega Alfredo 
Published: November 2022

Body size and density have been compared with the abundance and the size of invertebrates found in the environment in three populations of the common lizard, Lacerta vivipara J. This comparison leads to the following results :
1) There is no relationship between the density level of the lizard populations and the abundance of the invertebrates sampled.
2) There is a positive relationship between the average body size of females in each population and the abundance of prey in the biotope.
3) There is also a positive relationship between female average body size and the average body length of invertebrates.
4) The smaller size of males in one of the populations with regard to the other two stresses the importance of other factors than the trophic variables considered here.
Some hypotheses are formulated to try to explain these results. Nevertheless, it is obvious that other factors must be taken into consideration — physical structure of the environment, predation, etc. — to understand the differences observed among these populations
Valeur ornithologique des étangs à roselières de la Brenne (Indre)
Authors: Trotignon J. , Williams Tony 
Published: November 2022

The use of reedbeds by birds was studied from 1981 to 1985 in La Brenne, central France.
There are about nine hundred ponds in the Brenne, most of them used for fish-farming. Most of these waterbodies harboured in the past reedbeds of varying sizes. Since 1935, however, reeds were purposefully eradicated by farmers from most of the ponds, and no more than twenty now have reedbeds of any size. In the meantime, Purple Herons, Bitterns, and Marsh Harriers steadily declined in numbers. There are now less than 100 pairs of Purple Herons, 10 to 20 singing male Bitterns, and 70 to 85 nesting pairs of Marsh Harriers, left in the Brenne.
A systematic sampling of passerines was carried out during the post-breeding period. Birds were caught in mist nets set along transects through the reed beds, from open water to dry surrounding areas. Reed Warblers, Savi’s Warblers, Fantailed Warblers, and Bearded Tits, were mostly found in the wettest part of the beds. In drier areas, where willows often grew, these birds were much scarcer, making way for hedgerow and woodland passerines.
Gestion forestière et écologie des populations de chouette de Tengmalm (Aegolius funereus) dans l’est de la France
Authors: Joveniaux Alain , Durand Guy 
Published: November 2022

A breeding population census of the Tengmalm’s Owl was carried out, from 1984 to 1986, in six different areas of Bourgogne, Jura and Haut-Vercors, France. The total area surveyed was 100 km2. The largest number of breeding territories found in 1984 was 71. Breeding densities averaged 0.6 pair per km2, with a maximum of 1.3 pair per km2. Altogether, 47 nests were found by systematically checking tree holes and nest boxes. The Tengmalm’s Owl population studied displayed wide population fluctuations in relation to rodent population cycles (Clethrionomys glareolus and Apodemus sp.). Tengmalm’s Owl very often uses Black Woodpecker’s nests to breed ; such nest sites are particularly numerous in large Beech trees, within old mature forest.
To keep patches of unlogged mature forest (1-2 ha), at a density of one patch per 100 ha, would certainly help preserving a self-sustaining population of Tengmalm’s Owl in our study area.
Incidences de la structure d’un bocage sur l’avifaune au cours d’un cycle annuel (Autunois/Charolais)
Authors: Notteghem Patrice 
Published: November 2022

The avifauna of hedges, and its seasonal variations, was studied throughout a yearly cycle in the Autunois, central France. Fifty-nine species were identified during 38 counts carried out along a network of 4,486 m of hedgerows. The results of these counts were compared with those of counts made on 39 circular study plots (100 m diameter) of farmland (bocage) centered upon the hedges studied.
The total number and the diversity of birds found on each plot was strongly correlated with certain characteristics of the hedges, i.e. their physiognomy, stratification, and volume of vegetation. Plots containing treeless hedges which were trimmed every year had a less abundant, and a less varied, avifauna.
Dynamique de population du goéland argenté en Bretagne application à la gestion de l’espèce
Authors: Migot Pierre 
Published: November 2022

The population dynamics of the Herring Gull population of Brittany is briefly summarized. Following its steady increase between 1955 and 1978, the population started levelling off, but began colonizing new sites further south.
The number of fledglings per pair was 1.3 ± 0.2 in 1983-84. The yearly survival rate of adult breeders was 0.91 ± 0.02, and the survival rate of birds during their first year of life was 0.71 ± 0.10.
Démographie comparée d’une population de perdrix bartavelle (Alectoris graeca saxatilis) et d’une population d’hybrides (A. g. saxatilis x A. rufa rufa) dans les Alpes-Maritimes
Authors: Bernard-Laurent Ariane 
Published: November 2022

The demography of two partridge populations was compared during 4 years in southern French Alps : a population of Rock partridge Alectoris graeca saxatilis living at high elevations and a population of hybrids between Rock partridge and Red-legged Partrige A. rufa rufa inhabiting middle elevations. Spring densities and reproductive success were higher in the hybrid population. Survival rates were estimated for chicks and older birds from telemetry data collected in the hybrid population. Raptor predation was the major cause of death throughout the year, but during winter mammalian predation and starvation also occured. Starvation, provoked by deep snow, contributed to the low survival rate recorded from November to April (34 %). Radio-telemetry was useful in studying the recruitment of young males to the breeding segment of the population, the double nesting of certain hybrid females, and the incubation by the hybrid male of one of the two clutches.
Counts in May and August and radio-tracking must be continued at least for two additional years to confirm these preliminary results. Moreover rock partridges should also be radio-tracked at high elevation to study their behavior, reproductive success and survival, and to compare the dynamics of hybrid and non-hybrid populations.
Influence de la lumière sur le choix de l’habitat et le comportement sexuel des Pipridae (Aves : Passeriformes) en Guyane française
Authors: Théry Marc 
Published: November 2022

The influence of spatial and temporal patterns of illumination on habitat selection and courtship performances of male manakins were studied for 23 months in French Guiana. Seven sympatric species were studied in a pristine lowland rain forest and along forest edges. The relationships between light intensity, structure of the ornamental feathers, location of courtship arenas in « lek » species, and courtship postures, were given particular attention.
The courtship arenas of all the species studied were not established at random in the forest. They must meet definite conditions for each species : a certain degree of « openness », the presence of perches of a given diameter and inclination, and a certain level of illumination at set times of the day. The male displays of three lek species Manacus manacus, Pipra erythrocephala and Corapipo gutturalis were shown to coincide in time with definite light intensity levels on their respective arenas. The same is quite likely the case for Pipra pipra. As for the most vividly coloured of the six species, Pipra serena, it does display in more shady habitats, but around forest gaps or in the swamp forest. The males of the non-dimorphic manakins, Schiffornis turdinus and Tyranneutes virescens, do not possess ornamental feathers ; the first do not form « leks », and the latter has a very different kind of display.
Among the typical « lek » species, males apparently use their courtship arenas only when these are properly illuminated to enhance the brightness of their own colour markings. When the ornamental feathers are located on the upper parts of the body, the males display on perches in understorey trees or vines ; such is the case for Pipra erythrocephala and P. pipra. When the colour markings are located on the underparts of the body, as in Manacus manacus and Corapipo gutturalis, the males display on cleared courts on the forest floor or on fallen logs. Pipra serena whose feathers colours are due to light diffraction, is the only species to display in the shade of the understorey.
Dormancy and germination in Cistus clusii (Cistaceae) : Effect of biotic and abiotic factors
Authors: Castro Jorge , Romero-García Ana Teresa 
Published: November 2022

Nous avons analysé des traitements pour améliorer la germination de Cistus clusii (Cistaceae), en essayant de simuler les facteurs abiotiques et biotiques propres à l’habitat naturel de cette espèce. L’accroissement des taux de germination est obtenu par scarification chimique (comme celle qui aurait lieu après le passage des graines à travers le tractus digestif des mammifères), et sous un choc thermique similaire celui qui arrive lors des incendies. Dans ce dernier cas, tant l’intensité que la durée d’exposition au traitement sont déterminants.
L’étude de la capacité germinative, après une période de refroidissement des graines, suggère qu’en plus de la dormance imposée par les enveloppes, il y aurait chez cette espèce une dormance physiologique embryonnaire. Ces résultats améliorent les connaissances d’ensemble sur les processus de dormance caractéristiques des semences des Cistaceae.