77 research outputs found
Distribution et abondance des mouches piqueuses (Glossinidae, Stomoxys et Tabanidae) dans deux parcs nationaux du Gabon.
11 pagesInternational audienceIn order to minimize risks of pathogen transmission with the development of ecotourism in Gabon, a seasonal inventory has been performed in five contrasted biotopes in Ivindo (INP) and Moukalaba-Doudou (MDNP) National Parks. A total of 10,033 hematophagous flies were captured. The Glossinidae, with six different species identified, was the most abundant group and constitutes about 60% of the captured flies compared to the Stomoxys (6 species also identified) and Tabanidae with 28% and 12%, respectively. The Glossinidae showed a higher rate of capture in primary forest and in research camps. In INP, the Stomoxys showed a higher rate of capture in secondary forest and at village borders, whereas in MDNP the Stomoxys were captured more in the savannah area. Thus, each fly group seemed to reach maximum abundance in different habitats. The Glossinidae were more abundant in primary forest and near research camps while Stomoxys were more abundant in secondary forest and savannah. The Tabanidae did not show a clear habitat preference.Afin de minimiser les risques de transmission de pathogènes avec le développement de l’écotourisme au Gabon, un inventaire saisonnier a été mené dans cinq biotopes caractéristiques des parcs nationaux de l’Ivindo (PNI) et de Moukalaba-Doudou (PNMD). Au total, 10 033 mouches hématophages ont été capturées. Les Glossinidae, avec 6 espèces différentes identifiées, constituaient le groupe le plus abondant avec 60 % de mouches capturées, suivi des Stomoxys (6 espèces différentes identifiées) et des Tabanidae avec respectivement 28 % et 12 %. Les glossines ont été majoritairement capturées en forêt primaire et au niveau des camps de recherche. Au PNI, les stomoxes ont été majoritairement capturés en forêt secondaire et en périphérie des villages. Alors qu’au PNMD, ces stomoxes ont été majoritairement capturés au niveau des savanes. Ainsi, chaque groupe de mouches semble être inféodé à un type de milieu. Les glossines préfèrent la forêt primaire et camps de recherche, alors que les stomoxes préfèrent la forêt secondaire et la savane. Les tabanides ne dégagent aucune préférence particulière pour un type de milieu
Deleterious effects of thermal and water stresses on life history and physiology: a case study on woodlouse
We tested independently the influences of increasing temperature and decreasing moisture on life history and physiological traits in the arthropod Armadillidium vulgare. Both increasing temperature and decreasing moisture led reproductive success to decrease. While the density of immune cells decreased and the β-galactosidase activity increased with increasing temperature and decreasing moisture, which suggests a negative impact of these stressors on individual performance, increased temperature and decreased moisture affected differently the other biomarkers conjuring different underlying mechanisms depending on the stress applied. Our findings demonstrate overall a negative impact of high temperature and low moisture on woodlouse welfare. Changing temperature or moisture had slightly different effects, illustrating the need to test further the respective role of each of these key components of climate change on organisms to predict more reliably the future of our ecosystems
Touchy matter: the delicate balance between Morgan’s canon and open-minded description of advanced cognitive skills in the animal
A recommendation – based on reviews by Valérie Dufour and Alex Taylor – of the article: Farrar, B. G. (2020). Evidence of tool use in a seabird? PsyArXiv, 463hk, ver. 5 recommended and peer-reviewed by Peer Community In Ecology. doi: 10.31234/osf.io/463h
Optimal foraging in a changing world: old questions, new perspectives
A recommendation of : Calcagno V, Hamelin F, Mailleret L, and Grognard F. How optimal foragers should respond to habitat changes? On the consequences of habitat conversion. bioRxiv 273557 (2018), ver. 4 peer-reviewed and recommended PCI Ecology.International audienc
Butinage collectif chez l'abeille Apis mellifera L.: étude théorique et expérimentale
Ce travail de thèse a porté sur le comportement de butinage coopératif chez l’abeille. Dans un environnement hétérogène où les ressources alimentaires sont distribuées de manière discrète, la collecte de nectar chez cet insecte social met en jeu non seulement des processus individuels d’orientation et d’apprentissage, mais aussi des processus collectifs reposant sur une communication vibratoire et phéromonale intense entre les membres de la colonie qui agissent de façon coordonnée. Pour rendre compte de ces phénomènes, j’ai adopté une double approche théorique et expérimentale. A partir des données recueillies lors d’expérimentations conduites au laboratoire, j’ai étudié certaines transitions entre les différents comportements impliqués dans le butinage (modèles à risques proportionnels). J’ai en outre développé un modèle mathématique (système dynamique non linéaire) du comportement de butinage. Les propriétés de ce modèle ont été étudiées et nous avons dégagé plusieurs prédictions théoriques. Ce travail m’a d’une part conduit à reconsidérer le langage de l’abeille dans un contexte d’écologie comportementale et à proposer un scénario de l’évolution de la communication de la distance chez les apoïdes. D’autre part, les protocoles expérimentaux et les outils d’analyse statistique développés dans cette thèse ont été utilisés pour évaluer l’impact de produits phytosanitaires (pesticides, entomotoxines issues de plantes transgéniques) sur le comportement de butinage collectif des abeilles
A dynamic game theoretical model predicts variance in choosiness when mate availability fluctuates
RésuméInternational audienc
Pairing patterns in relation to body size, genetic similarity and multilocus heterozygosity in a tropical monogamous bird species.
9 pagesInternational audienceThe relative influence of genetic and phenotypic quality on pairing status and mating patterns in socially monogamous species remains poorly documented. We studied social status and pairing patterns in relation to genetic similarity and multilocus heterozygosity (MLH) estimates from 11 microsatellite markers, and both tarsus length and wing chord (as a measure of competitive ability in territorial defence) in a socially monogamous tropical bird species where individuals defend territories year-round, alone or in pairs, the Zenaida dove, Zenaida aurita. Tarsus length and wing chord did not differ between unpaired territorial birds and paired ones in either sex, whereas paired females, but not paired males, tended to be more heterozygous than unpaired ones. Among 84 pairs, we found no evidence for assortative mating for tarsus length, wing chord, MLH or genetic similarity. However, within pairs, male wing chord was positively related to female MLH and female tarsus length was positively related to male MLH, with no evidence for local effects, suggesting assortative mating by individual quality. Although the observed pattern of mating in Zenaida doves may be the product of mutual mate choice, further assessment of this hypothesis requires direct investigation of both mating preference in each sex and lifetime reproductive success in relation to body size and MLH
Sexing birds using discriminant function analysis: a critical appraisal.
9 pagesInternational audienceDiscriminant function analysis (DFA) based on morphological measurements is a quick, inexpensive, and efficient method for sex determination in field studies on cryptically monomorphic bird species. However, behind the apparent standardization and relative simplicity of DFA lie subtle differences and pitfalls that have been neglected in some studies. Most of these concerns directly affect assessment of the discriminant performance, a parameter of crucial importance in practice because it provides a measure of the quality of an equation that may be used in later field studies. Using results from 141 published studies and simulations based on a large data set collected on adult Zenaida Doves (Zenaida aurita), we assessed the effects of sexual dimorphism, sample size, and validation methods on discrimination rates. We compared the three most common methods used to estimate the proportion of correctly classified males and females by DFA: resubstitution, jackknife, or sample splitting. Results from simulations indicate that these procedures may lead to opposite conclusions, especially when the sample size is small. In particular, the resubstitution techniques appear to be overoptimistic, and we therefore recommend that DFA accuracy be estimated by the jackknife cross-validation procedure. In addition, we show that most previous studies failed to present DFA accuracy with 95% confidence intervals, which hampers comparisons among studies. Finally, our results suggest that large sample sizes should be preferred over repeated measurements of the same individuals, because random measurement error is likely to have only a weak effect on the accuracy of the discriminant rate
- …