bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some epidemiological consequences of drastic ecosystem changes accompanying exploitation of tropical rain forest
Authors: Cooper J.I. , Tinsley Thomas W. 
Published: November 2022

Les auteurs donnent quelques exemples des conséquences épidémiologiques inattendues de la modification drastique de l’écosystème forestier tropical humide par les activités humaines.
L’homme est exposé aux effets débilitants, voire mortels, d’agents infectieux auxquels certains animaux sauvages servent de réservoirs et chez lesquels ils n’entraînent que des affections bénignes, voire inapparentes. Les relations complexes existant entre parasites et arbovirus d’une part, réservoirs et vecteurs d’autre part, sont illustrées par les cas bien connus de la fièvre jaune et de la maladie de Kyasanur.
Les végétaux cultivés peuvent aussi être infectés par des virus ou des ravageurs divers, normalement inoffensifs pour les populations de plantes sauvages. Des exemples en sont donnés dans le cas des plantations de Cacaoyers attaquées par des virus, des champignons et des insectes.
Les nouveaux complexes pathogènes ainsi créés peuvent avoir des conséquences désastreuses tant pour l’homme que pour ses cultures vivrières ou industrielles.
Quelques données sur la dynamique de population chez Octodon degus (Rongeur Hystricomorphe) du Chili central
Authors: Le Boulengé Eric , Fuentes Eduardo r. 
Published: November 2022

This paper reviews data on the population ecology of Octodon degus, an hystricomorph rodent endemic to Chile. It is based upon personal field observations as well as on data from the literature.
Field work was carried out on two sites located at «Los Dominicos», 20 km east from Santiago, using capture-recapture methods. The first site (A) is covered by a moderately dense stand of various trees and shrubs. The second site (B) is more open, with grasslands crossed by a line of Muehlenbeckia hastulata. Grid size was 2400 m2 on site A and 600 m2 on site B. For density estimations an area 25 m wide in site A, and 13 m wide in site B, was added to the trapping areas around the grid, corresponding to the average distance between successive captures of the species in the two habitats.
On site A, population density varied from 49 individuals/ha in February to 39 individuals/ha at the end of March and 73 individuals/ha in October-November. The lowest densities are probably to be found in June-July, at the onset of the reproductive season. On site B, densities ranged from 259 individuals/ha in February to 192 individuals/ha in April. On both sites the monthly disappearance rate was about 40 % during the period from end of the summer to the following spring. Some data are also given on sex-ratio and age-ratio.
Octodon degus, a diurnal grass-eater, can withstand neither high temperatures nor high altitude, but appears to be well adapted to life in grasslands. It lives in small social groups within a complex network of tunnels and paths, centered upon a stable burrow system located under a pile of rocks or shrubs. In summer time, when water is scarce, the Octodon supplement their vegetarian diet with fresh droppings of cattle or horses, or with bark of Acacia caven. Birds of prey apparently exert a strong predation pressure upon the Octodon populations, and some of the morpholo- gical, physiological and behavioural characteristics of the species are probably adaptive in this context. Such might be the case for the observation posture and alarm call of the adults, the sharpness of vision for objects located above the animal, and the autotomy of the tail.
Régime alimentaire de quelques oiseaux de rivage sur deux milieux lagunaires des Iles-de-la-Madeleine, dans le golfe Saint-Laurent, Québec
Authors: Doyon Denise , Mcneil Raymond 
Published: November 2022

During the 1970 and 1971 summers, the food availability and food preference of 11 species of North American shorebirds were investigated in two fall migration transit habitats on the Magdalen Islands in the Gulf of St. Lawrence.
The data, presented in percentages, are analysed according to three different and complementary methods : the numbers method, the average weights method, and the frequency of occurrence method. The value of the two lagoon habitats as a food source is discussed in function of the differences and resemblances in the gut contents of the shorebirds.
The results of the present study may serve as indexes for selecting and preserving the more suitable habitats for shorebirds during fall migration on the Atlantic coast of eastern North America.
Observations sur la reproduction et la dynamique des populations de quelques Anoures tropicaux. I. Ptychadena maccarthyensis et Ptychadena oxyrhynchus
Authors: Barbault R. , Trefaut Rodrigues M. 
Published: November 2022

The populations of two frogs, Ptychadena maccarthyensis and P. oxyrhynchus, were studied over a four-year period in the Lamto savanna (Ivory Coast), where the climate is characterized by a dry season lasting from December to February, and a rainy season from March to November.
P. oxyrhynchus breeds from February to May, while P. maccarthyensis does not breed before March but can continue to do so until October.
Consideration of size-frequency histograms constructed from sequential samples in the two populations shows that the two species reach sexual maturity 8 to 9 months after metamorphosis, when the females attain a length of 43 mm for P. maccarthyensis and 59 mm for P. oxyrhynchus. There is very little overlap in adult size, either between sexes or species. Average clutch size is 1333 eggs in P. maccarthyensis and 3476 eggs in P. oxyrhynchus. The laying of a second clutch of eggs during the year has not been observed. However there is a strong probability that this does in fact occur, particularly in P. maccarthyensis which has a long breeding season.
Fecundity is high in the two species studied. The mortality rate is high for eggs and young individuals, especially during dry years. Adult mortality is low.
Méthodes de détermination de l’âge chez le chat haret des îles Kerguelen
Authors: Pascal Michel , Castanet Jacques 
Published: November 2022

The different methods of age determination used in the study of mammals are compared, using a sample (N = 292) of feral cats (Felis catus L.) from the Kerguelen islands as an example.
“Skeletal growth marks” in bone and cementum have already been used successfully on several species of Mammals. In our case, emphasis has been especially put on the critical use and discussion of these methods of “skeletochronology”.
No direct comparisons with animals of known age being possible, we had to rely on circumstancial evidence to demonstrate the value of the method. Bone tissue (jaw) and dental cementum were both used and compared. A critical study of the histological patterns shown by the tissues allows a functionnal interpretation. Wide zones of fast deposited tissues (warm season deposits) alternate with narrow annuli (narrow “rest lines” here called LAC = lignes d’arrêt de croissance) which are cool season marks.
The results have been cheked against other methods of age determination, such as body weight, dry weight of the eye lens, and tooth succession. A good correlation has been found between the results from these different techniques.
Seven age groups have been found and the best age resolution for adults fall to six months.
Les peuplements de Fourmis et les peuplements d’ Acridiens du Mont Ventoux. II. Les peuplements de Fourmis
Authors: Du Merle Paul , Marro Jean-Pierre , Mazet René 
Published: November 2022

The composition of the ant communities and the relative frequency of each species are described, as well as their ecological and altitudinal amplitudes. The richness and/or the composition of the communities differs from one vegetation zone to another. All the communities show a very hierarchical structure. The Shannon eaver index of evenness is roughly equal in all communities. The communities are very varied, but three species are predominant over the mountain : Lasius niger, Tetramorium caespitum and Formica lemani.
Of the environmental features, temperature is the most important, producing a marked altitudinal zonation of species and communities. The effects of aridity are important among certain species, leading to vertical discontinuities in their ranges. The vegetation cover affects species dependant on particular plants ; these species have been considerably affected by reafforestation, especially on the lower parts of the southern slopes, leading to a notable increase in L. niger. At the summit, the main limiting factor is temperature on the northern slope ; and the dessicating effects of the winds on the southern slopes.
Importance, répartition et tendance évolutive des populations de grands herbivores et de l’autruche dans le parc national de Waza, Cameroun
Authors: Esser J. D. , Van Lavieren L. P. 
Published: November 2022

Un dénombrement aérien des grands herbivores et des autruches du Parc National de Waza a été effectué en utilisant un échantillonnage stratifié sur transects. On a divisé le parc en cinq «strates» différentes suivant les types de végétation et la densité des animaux. Les estimations d’effectifs de sept espèces sont présentées, ainsi que des cartes montrant la répartition spatiale et la densité des grands mammifères et de l’Autruche. Ces résultats sont comparés avec ceux d’un recensement précédent et avec d’autres estimations d’abondance.
Les effectifs des damalisques, hippotragues et autruches montrent un déclin important. Les reduncas, autrefois très communs dans le parc, sont devenus très rares ; de plus, les cobes onctueux ont complètement disparu de la région, aucun n’ayant été observé pendant le recensement.
Les effectifs des éléphants et des girafes semblent stationnaires ou même en légère croissance. La population de cobes de Buffon, l’herbivore le plus abondant du parc est elle aussi en diminution, moins rapide cependant que celle des damalisques et des hippotragues.
Les causes possibles de cette diminution de la grande faune sauvage du Parc National de Waza sont discutées. L’action directe et indirecte des activités humaines paraît prépondérante.
Une approche synécologique des milieux humides savoyards et de leur avifaune
Authors: Tournier Hubert , Lebreton Philippe 
Published: November 2022

Une étude a été conduite de la répartition qualitative de 78 espèces d’oiseaux dans 25 milieux humides de Savoie, déterminés par leur structure végétale. Cette matrice de données a été analysée par la technique des coefficients d’affinité (Jaccard, Czekanovski ) et celle, plus moderne, de l’analyse factorielle des correspondances.
Les milieux jugés à travers leur avifaune s’ordonnent selon un axe paludicole principal, sur lequel se greffent deux axes latéraux d’eau libre, courante et stagnante. Correspondant à la notion de série de végétation et déterminée par elle, se dégage la notion de séquence ornithologique.
Diverses relations ont été établies concernant le nombre d’espèces aviennes en relation avec le nombre de strates végétales, ainsi que la répartition de l’avifaune en espèces migratrices et/ou plus généraux de structure des peuplements aviens en relation carnivores. Le présent travail est donc un apport aux problèmes, plus généraux de structure des peuplements aviens en relation avec leur milieu.
Le concept de niche écologique illustré par le cas de populations congénériques sympatriques du genre Acrocephalus
Authors: Henry Claude 
Published: November 2022

The niche overlap between Reed Wablers and Sedge Warblers during the breeding season is discussed.
At that time of the year Reed Warblers are “generalists”, feeding upon more than fifty arthropod taxons. However 80 % of this insectivorous diet is made of 22 species only, 2 to 11 being caught the same day. Within a given prey category, some species are caught by Reed Warblers and not by Sedge Warblers. Most of the prey taken are 1 to 4 mm long (modal value : 3.2 : range 0.5 to 22 mm).
Sedge warblers are also generalist insectivores, 26 taxons being represented in their diet, 6 to 17 being caught the same day. Prey taken are the same as that caught by Reed Warblers, although some prey items are not taken by the latter species. Prey size distribution is bimodal ; the first modal value is 3 mm, the second 9 mm (range : 1-24 mm).
The Morisita index is used to estimate niche overlap between the two species. Total overlap index is 0.93 for taxons, and 0.97 for prey size. The niches of the two warblers cannot therefore be separated on the basis of their respective diets. The two species, however, build their nests in different habitats, the Reed Warbler in Phragmites beds and the Sedge Warbler in Carex beds, close to water. Both also forage outside their nesting habitat, in willow groves, wheat and barley fields.
The high predation pressure exerted upon the nestlings of both species might explain the choice of their nesting sites.
Niche écologique et diversité spécifique des espèces sympatriques dans le genre Cercopithecus
Authors: Gautier-Hion A. , Gautier Jean-Pierre 
Published: November 2022

It is difficult to separate the ecological niches of three sympatric species of Cercopithecus living in North-East Gabon on the basis of the niche parameters usually studied by prima-tologists : their habitats are very similar, their activity rhythms are the same and the vegetation layers they frequent overlap broadly.
The three species have a very similar diet at the times of the year when food is readily available. The inter-specific differences in diet only become apparent during the “lean season”. At that critical period of the yearly cycle, the two species (C. nictitans and C. pogonias) whose habitat is the most similar, are also those whose diet is the most different. Food preferences between C. nictitans and C. cephus on one side, C. pogonias and C. cephus on the other side are not so marked, but C. cephus tends to forage in the lowest layers of the forest vegetation and in the areas where foliage density is the highest.
The three sympatric Cercopithecus species appear to feed upon the same kinds of fruits. They differ however in their preferred animal prey.
The three Cercopithecus species concerned also frequently live in “mixed groups” in the same area. Such an inter-specific association does not appear to reduce the niche breadth of the participating species, and no competition was observed. The formation of mixed groups of sympatric forest monkeys might then be considered as an adaptative strategy to optimize the utilization of available forest resources, three closely related but complementary species being more efficient resource-users than a single “generalist” one.
Préférences alimentaires chez Quéléa Quelea quelea (L.)
Authors: Manikowski Stanislaw , Da Camaha-Smeets Michèle 
Published: November 2022

Three hypotheses are advanced to explain the damage to crops caused by Quelea quelea :
1) non-availability of wild gramineous seeds, which are usually the normal quelea food ;
2) ready availability and ease of access to crops ;
3) marked preference for crops.
Cage experiments on food choices among some of the most frequently eaten seeds (both cultivated and wild) and the size of these seeds, demonstrate quelea’s preference for seeds of the size of millet. Since seeds of this size are scarce in the quelea habitat, this suggests that quelea would tend to damage crops, even if wild grass seeds were abundant.
Morphologie, croissance individuelle et dynamique des populations de la Tortue verte (Chelonia mydas L.) au Banc d’Arguin (République Islamique de Mauritanie)
Authors: Le Toquin A. , Galmel E. , Trotignon J. 
Published: November 2022

The carapace morphology and growth of the Green turtle (Chelonia mydas L.) has been studied in a large (n = 177) sample of animals collected by the Imragen fishermen on the Banc d’Arguin (Islamic Republic of Mauretania). The frequency of anomalies of the scales decreases with age in this species, possibly due to a differential mortality between normal and abnormal individuals.
The mathematical relation between length and width of the carapace is discussed and the Mauretanian data are compared with those of other areas. There are obvious differences in the shape of the carapace between different breeding populations of green turtles, which quite likely correspond to genetic differences between various breeding populations. The Mauretanian green turtles are quite similar to those breeding on the eastern coast of South-America.
Seven age classes can be recognized on the basis of the carapace length.
A growth curve of the Mauretanian population of Chelonia mydas L., based upon von Bertalanffy equation, is proposed. The rate of growth decreases sharply after the first breeding season. Sexual maturity takes place at 5.5 years of age, but age at first reproduction apparently varies from one population to the other, probably depending upon fishing pressure. The number of «bachelors» (mature individuals not taking part in reproduction) is apparently greater in areas with the smallest fishing pressure.
Recherches sur les écosystèmes des réserves biologiques de la forêt de Fontainebleau. VII. Structure et fonctions des peuplements de houx (Ilex aquifolium L.)
Authors: Clabault G. , Lemée G. , Bichaut N. , Legay B. , Pontailler J.Y. 
Published: November 2022

Holly bushes form an important structural unit in some natural reserves of the Fontainebleau forest (60 km S.E. of Paris). Due to the high stem density of the holly, its great basal area and the longevity of its leaves (about two years), the biomass and the global productivity of the mature beech-oak forest are appreciably increased.
This additional production brings about a large immobilisation and important turn-over of nutrients. Holly plays an important role as potassium accumulator and magnesium cycle accelerator.
The leaf litter, falling alternately from holly and trees, is appreciably increased in volume and its mineral and nitrogen contents are enriched. During the first months following leaf drop, decomposition of the holly litter is very rapid.
The actual evolution of holly populations tend to be extended by the peripheral formation of suckers and by seedlings. Under the bushes, deep shade and thick litter accumulation inhibit any regeneration. The progressive substitution of old oaks by beeches is unfavorable to holly. The presence of holly stands could represent a preterminal stage of this forest succession.
Organisation spatio-temporelle des activités individuelles et sociales dans une troupe de Cercopithecus cephus
Authors: Quris R. , Gautier Jean-Pierre , Gautier Jean-Yves , Gautier-Hion Annie 
Published: November 2022

A monospecific troop of Cercopithecus cephus was followed for five months using the radio-tracking method. Temporal and spatial distribution of the activities is described.
Two peaks of locomotion are found in the first half of the morning and the second half of the afternoon. Phytophagy follows the same rhythm, while feeding on prey and resting increase at mid-day. Strong daily variations are shown in forest type usage according to the activity performed. The more open and tallest forest is chosen during the night and for fruit gathering, while the densest and lowest one is significantly preferred for resting. Parallel daily variations are found in the forest level usage : resting, insect hunting and social interactions occur at levels lower than locomotion and fruit gathering.
The total time spent feeding does not differ between the age classes, however the time spent feeding on insects decreases with age while phytophagy increases. The young are found at significantly lower levels than the adults. The adult male stays higher than the other troop members, especially when resting.
Inter-individual distances are lowest between females and young, while the adult male has a more peripheral position. Troop cohesion is higher at the end of the day.
Physiological, behavioral and environmental constraints which might influence such activity rythm and differences between age classes are discussed.
Détermination de l’âge par pesée du cristallin chez le Lérot Eliomys Quercinus (L.)
Authors: Baudoin Claude , Abdi Hervé 
Published: November 2022

Dans le but d’étudier la composition de populations naturelles de Lérots en Franche-Comté, nous avons utilisé le poids sec de cristallin pour estimer l’âge des animaux.
La croissance pondérale du cristallin est rapide durant les 6 premiers mois de vie chez les 55 Lérots (29 ♂ ♂, 26 ♀ ♀) nés et maintenus en captivité, puis elle est ralentie entre 6 mois et 1 an. Ce ralentissement s’accentue au-delà de 1 an. La croissance est alors très lente sans toutefois s’arrêter.
Sur un échantillon de 24 animaux âgés de 1,5 à 6 mois, nous avons montré que le poids de cristallin dépend linéairement de l’âge. La valeur estimée du poids de cristallin s’exprime par la
formule Y = 27,448 X + 70,801. Les limites supérieure et inférieure de l’estimation sont calculées.
Par la méthode de prédiction inverse (Sokal and Rohlf, 1969), nous avons ensuite calculé l’âge estimé de 41 Lérots (17 ♂ ♂ et 24 ♀ ♀) capturés dans la nature. La comparaison de l’âge calculé par cette méthode à l’âge estimé au moyen d’autres critères montre une bonne concordance entre les données.
L’analyse des résultats a également permis de mettre en évidence un ralentissement de la croissance pondérale du cristallin en cours de l’hibernation chez les Lérots vivant dans la nature en Franche-Comté. Une autre méthode (analyse factorielle des correspondances) est utilisée pour ordonner les individus après leur première hibernation (Baudoin et Abdi, 1981).
Capacités prédatrices et budgets d’activité chez l’Aigle pêcheur Haliaeetus vocifer
Authors: Thiollay Jean-Marc 
Published: November 2022

Ten pairs of Fish Eagles Haliaeetus vocifer taken among a dense population in Uganda, were followed at the end of the breeding season to compare the time and energy budgets of breeding and non breeding adults.
Fish are usually obtained by diving from a waterside tree. If unsuccessful, the bird searches in flight, an energy-expensive but very rewarding method. The additional food necessary to feed the young is provided mainly by the male through fishing flights. Another source of increase in energy expenditure related to breeding activities is the more active territorial defense by adults with young than without young. The food consumption of the former is higher than that of the latter ; but the difference is smaller than the increase of the energetic cost of breeding (42 % and 64 % for 1 and 2 fledged young). Thus brood size seems to be limited by the ability of the parents to feed their young and maintain a territory of adequate size or quality, even in the optimal conditions studied.
Immature birds suffer heavily from the adults’ territorial behaviour, which forces them to make extensive flights and confines them to marginal food sources. This may explain their high mortality rate (83 % during the first four years).