Context.
Rapid rotation is a common feature of early-type stars but remains a challenge for models. Nevertheless, we need to understand its effect on stellar evolution in order to interpret the ...observed properties of numerous stars.
Aims.
We wish to provide more observational constraints on the properties of fast rotating stars, especially their oscillation modes.
Methods.
We focus on the nearby star Altair which is known to be a very rapidly rotating star with an equatorial velocity recently estimated at 313 km s
−1
. We observed this star with the high-resolution spectropolarimeter Neo-Narval over six nights, with one night of interruption, in September 2020.
Results.
We detect significant line profile variations on the mean line profile of the spectra. Their time-frequency analysis shows that these variations are induced by gravito-inertial waves propagating at Altair’s surface with azimuthal wavenumbers of the order
m
= 10 − 15. With a preliminary computation of the eigenspectrum using the most recent concordance model of Altair we carried out a first modelling of the observed waves.
Conclusions.
Altair was known as the brightest
δ
Scuti star. We now see that it is the brightest hybrid oscillating star with gravito-inertial waves and acoustic waves being excited. Clearly, more observations and more advanced models are needed to explain the observations in greater details.
Habitat loss and overexploitation are the most severe threats to wild animals in Central Africa. One mammalian group under pressure from hunting is the Pholidota (pangolins), with three species of ...pangolin inhabiting the region. While local uses of pangolins have been investigated in several Central African countries, data originating from the Republic of the Congo are lacking. To address this knowledge gap, we conducted a semistructured questionnaire survey in 65 rural communities around the Odzala‐Kokoua National Park. Our research focused on collecting baseline information on local knowledge of species ecology, and perceived economic values and uses of pangolins in local communities. We identified significant differences in our data corresponding to respondents' sociocultural and demographic profiles in the surveyed villages. Recognition of pangolins was high (98.2%), we recorded 22 traditional medicinal or cultural uses of pangolins by respondents, and the taste of pangolin meat was ranked highly (71.3%). Respondents based along the northern boundary of the park were more familiar with pangolins and the market value of their meat and scales, which could be due to better quality roads in the area and proximity to Cameroon. We then provide guidelines for further research to better understand the dynamics of local use, needed for conservation policy and actions.
Our research focused on collecting baseline information that revealed the knowledge about species ecology and perceived market value and uses of pangolins by local communities. We identified significant differences in this data corresponding to the respondents' sociodemographic and cultural status across the surveyed villages around the Odzala‐Kokoua National Park in the Republic of the Congo.
Identifying the consequences of tropical forest degradation is essential to mitigate its effects upon forest fauna. Large forest-dwelling mammals are often highly sensitive to environmental ...perturbation through processes such as fragmentation, simplification of habitat structure, and abiotic changes including increased temperatures where the canopy is cleared. Whilst previous work has focused upon species richness and rarity in logged forest, few look at spatial and temporal behavioural responses to forest degradation. Using camera traps, we explored the relationships between diel activity, behavioural expression, habitat use and ambient temperature to understand how the wild free-ranging Bornean banteng (Bos javanicus lowi) respond to logging and regeneration. Three secondary forests in Sabah, Malaysian Borneo were studied, varying in the time since last logging (6-23 years). A combination of generalised linear mixed models and generalised linear models were constructed using >36,000 trap-nights. Temperature had no significant effect on activity, however it varied markedly between forests, with the period of intense heat shortening as forest regeneration increased over the years. Bantengs regulated activity, with a reduction during the wet season in the most degraded forest (z = -2.6, Std. Error = 0.13, p = 0.01), and reductions during midday hours in forest with limited regeneration, however after >20 years of regrowth, activity was more consistent throughout the day. Foraging and use of open canopy areas dominated the activity budget when regeneration was limited. As regeneration advanced, this was replaced by greater investment in travelling and using a closed canopy. Forest degradation modifies the ambient temperature, and positively influences flooding and habitat availability during the wet season. Retention of a mosaic of mature forest patches within commercial forests could minimise these effects and also provide refuge, which is key to heat dissipation and the prevention of thermal stress, whilst retention of degraded forest could provide forage.
The orangutan is the world's largest arboreal mammal, and images of the red ape moving through the tropical forest canopy symbolise its typical arboreal behaviour. Records of terrestrial behaviour ...are scarce and often associated with habitat disturbance. We conducted a large-scale species-level analysis of ground-based camera-trapping data to evaluate the extent to which Bornean orangutans Pongo pygmaeus come down from the trees to travel terrestrially, and whether they are indeed forced to the ground primarily by anthropogenic forest disturbances. Although the degree of forest disturbance and canopy gap size influenced terrestriality, orangutans were recorded on the ground as frequently in heavily degraded habitats as in primary forests. Furthermore, all age-sex classes were recorded on the ground (flanged males more often). This suggests that terrestrial locomotion is part of the Bornean orangutan's natural behavioural repertoire to a much greater extent than previously thought, and is only modified by habitat disturbance. The capacity of orangutans to come down from the trees may increase their ability to cope with at least smaller-scale forest fragmentation, and to cross moderately open spaces in mosaic landscapes, although the extent of this versatility remains to be investigated.
In our most recent study, we found that in Tanzania infection with Treponema pallidum (TP) subsp. pertenue (TPE) is present in four different monkey species. In order to gain information on the ...diversity and epidemiological spread of the infection in Tanzanian nonhuman primates (NHP), we identified two suitable candidate genes for multi-locus sequence typing (MLST). We demonstrate the functionality of the MLST system in invasively and non-invasively collected samples. While we were not able to demonstrate frequent interspecies transmission of TPE in Tanzanian monkeys, our results show a clustering of TPE strains according to geography and not host species, which is suggestive for rare transmission events between different NHP species. In addition to the geographic stability, we describe the relative temporal stability of the strains infecting NHPs and identified multi-strain infection. Differences between TPE strains of NHP and human origin are highlighted. Our results show that antibiotic resistance does not occur in Tanzanian TPE strains of NHP origin.
Despite its wide distribution in continental Africa, the serval (Leptailurus serval Schreber) has received relatively little scientific attention so far. We did camera‐trapping in the forest–savannah ...mosaic of the Odzala‐Kokoua National Park, Republic of Congo. The park's savannahs represent the northernmost extension of the savannahs of the Batéké Plateaux, a large ecoregion of open habitat in Central Africa. During 8 months of camera‐trapping, we recorded 51 individuals. Almost two‐thirds of individuals recorded belonged to the servaline morph, with a pattern mutation of small “freckled” spots. Using maximum likelihood (ML) and Bayesian spatially explicit capture–recapture methods serval density was 7.7–9.8 individuals/100 km². ML analyses favoured a model with trap placement and gender as covariates. Serval males were largely nocturnal whereas females were mainly diurnal. Differences in activity patterns were likely related to the occurrence of spotted hyaenas (Crocuta crocuta Erxleben). Spotted hyaenas were highly nocturnal and, consequently, had a higher overlap in activity patterns with male servals. Our study provided the first robust density estimates for this medium‐sized carnivore in Central Africa. To achieve sufficient precision in density estimates, we recommend that future studies also include individual and trap placement covariates in analyses.
Résumé
Malgré sa large distribution en Afrique continentale, le serval (Leptailurus serval Schreber) n'a jusqu'ici attiré que relativement peu l'attention des scientifiques. Nous avons fait du piégeage photographique dans la mosaïque forêt‐savane du Parc National d'Odzala‐Kokoua, en République du Congo. Les savanes du parc représentent l'extension la plus au nord des savanes du Plateau des Batéké, une vaste écorégion d'habitat ouvert en Afrique centrale. En huit mois de piégeage photo, nous avons enregistré 51 individus. Près des deux‐tiers des individus enregistrés appartenaient au morphe servalin avec une mutation du pattern en petites taches. En utilisant la méthode du maximum de vraisemblance (ML) et la méthode bayésienne spatialement explicite de capture‐recapture, nous avons déduit une densité de servals de 7.7–9.8 individus/100 km². Les analyses ML privilégiaient un modèle avec placement de pièges et sexe comme covariantes. Les servals mâles sont surtout nocturnes alors que les femelles sont plutôt diurnes. Les différences des schémas d'activités étaient probablement liées à la présence d'hyènes tachetées (Crocuta crocuta Erxleben). Les hyènes tachetées sont principalement nocturnes et, par conséquent, avaient des schémas d'activité qui chevauchaient davantage ceux des servals mâles. Notre étude a apporté les premières estimations solides pour ce carnivore de taille moyenne en Afrique centrale. Pour atteindre une précision suffisante dans l'estimation de densité, nous recommandons que les prochaines études incluent aussi des covariantes individuelles et de placement de pièges dans les analyses.
Western lowland gorillas (Gorilla gorilla gorilla) are Critically Endangered and show continued population decline. Consequently, pressure is mounting to better understand their conservation threats ...and ecology. Gastrointestinal symbionts, such as bacterial and eukaryotic communities, are believed to play vital roles in the physiological landscape of the host. Gorillas host a broad spectrum of eucaryotes, so called parasites, with strongylid nematodes being particularly prevalent. While these communities are partially consistent, they are also shaped by various ecological factors, such as diet or habitat type. To investigate gastrointestinal symbionts of wild western lowland gorillas, we analysed 215 faecal samples from individuals in five distinct localities across the Congo Basin, using high‐throughput sequencing techniques. We describe the gut bacterial microbiome and genetic diversity of strongylid communities, including strain‐level identification of amplicon sequence variants (ASVs). We identified strongylid ASVs from eight genera and bacterial ASVs from 20 phyla. We compared these communities across localities, with reference to varying environmental factors among populations, finding differences in alpha diversity and community compositions of both gastrointestinal components. Moreover, we also investigated covariation between strongylid nematodes and the bacterial microbiome, finding correlations between strongylid taxa and Prevotellaceae and Rikenellaceae ASVs that were consistent across multiple localities. Our research highlights the complexity of the bacterial microbiome and strongylid communities in several gorilla populations and emphasizes potential interactions between these two symbiont communities. This study provides a framework for ongoing research into strongylid nematode diversity, and their interactions with the bacterial microbiome, among great apes.
Despite being heavily exploited, pangolins (Pholidota: Manidae) have been subject to
limited research, resulting in a lack of reliable population estimates and standardised
survey methods for the ...eight extant species. Camera trapping represents a unique opportunity
for broad-scale collaborative species monitoring due to its largely nondiscriminatory
nature, which creates considerable volumes of data on a relatively wide
range of species. This has the potential to shed light on the ecology of rare, cryptic and
understudied taxa, with implications for conservation decision-making. We undertook a
global analysis of available pangolin data from camera trapping studies across their range
in Africa and Asia. Our aims were (1) to assess the utility of existing camera trapping efforts
as a method for monitoring pangolin populations, and (2) to gain insights into the distribution
and ecology of pangolins. We analysed data collated from 103 camera trap surveys
undertaken across 22 countries that fell within the range of seven of the eight
pangolin species, which yielded more than half a million trap nights and 888 pangolin
encounters. We ran occupancy analyses on three species (Sunda pangolin Manis javanica,
white-bellied pangolin Phataginus tricuspis and giant pangolin Smutsia gigantea). Detection
probabilities varied with forest cover and levels of human influence for P. tricuspis, but were low (<0.05) for all species. Occupancy was associated with distance from rivers for M.
javanica and S. gigantea, elevation for P. tricuspis and S. gigantea, forest cover for P. tricuspis
and protected area status for M. javanica and P. tricuspis.We conclude that camera traps are
suitable for the detection of pangolins and large-scale assessment of their distributions.
However, the trapping effort required to monitor populations at any given study site using
existing methods appears prohibitively high. This may change in the future should
anticipated technological and methodological advances in camera trapping facilitate
greater sampling efforts and/or higher probabilities of detection. In particular, targeted
camera placement for pangolins is likely to make pangolin monitoring more feasible with
moderate sampling efforts.
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