Seasonality in daily movement patterns of mandrills revealed by combining direct tracking and camera traps

野生マンドリルの移動パターンを解明 --直接追跡法と自動撮影カメラ法を組み合わせて説得力のある結論を得る--. 京都大学プレスリリース. 2021-11-26.Movement is a fundamental characteristic of animals, but challenging to measure noninvasively. Noninvasive methods for measuring travel have different weaknesses, so multiple techniques need to be applied multiple techniques for reliable inferences. We used two methods, direct tracking and camera trapping, to examine the variation in time and seasonal differences in movement rates of mandrills (Mandrillus sphinx), an elusive primate that lives in large groups in central Africa. In a 400-km2 rainforest area in Moukalaba-Doudou National Park, Gabon, we tracked unidentified groups 46 times from 2009 to 2013. We systematically placed 157 terrestrial camera traps in the same area from 2012 to 2014 and recorded groups 309 times. Generalized additive mixed models (GAMMs) of the tracking data indicated that the group travel speed varied with time and season. In the fruiting season, the movement rate fluctuated with time in a bimodal pattern, whereas in the nonfruiting season, it increased monotonously with time. The predicted day range was longer in the fruiting season (6.98 km) than in the nonfruiting season (6.06 km). These seasonal differences suggest responses to changes in food resources and temperature. Camera-trap detection rates showed similar temporal and seasonal patterns to the tracking data, allowing us to generalize our findings to the population level. Moreover, cameras never detected mandrills at night, and we observed that they slept high in trees and hardly moved until the next morning, all suggesting their strict avoidance of nighttime movement. This study demonstrated the significance of the multiple-method approach in drawing robust conclusions on temporal patterns of animal movement.Le mouvement est une caractéristique fondamentale des animaux, mais il est difficile de le mesurer de manière non invasive. Les méthodes non invasives de mesure des déplacements présentent des faiblesses différentes, de sorte que nous devons appliquer plusieurs techniques à un même sujet pour obtenir des déductions fiables. Nous avons utilisé deux méthodes, le suivi direct et le piégeage photographique, pour examiner les variations temporelles et la différence saisonnière des taux de déplacement des mandrills (Mandrillus sphinx), un primate insaisissable vivant en grands groupes. Dans une zone de forêt tropicale humide de 400 km2 du parc national de Moukalaba-Doudou au Gabon, nous avons suivi des groupes non identifiés 46 fois entre 2009 et 2013. Dans la même zone, nous avons systématiquement placé 157 pièges photographiques terrestres de 2012 à 2014 et enregistré des groupes 309 fois. Les modèles mixtes additifs généralisés (GAMM) des données de suivi ont indiqué que la vitesse de déplacement des groupes variait en fonction du temps et des saison. Pendant la saison de fructification, la vitesse de déplacement fluctuait dans le temps selon un schéma bimodal, tandis que pendant la saison de non-fructification, elle augmentait de façon monotone avec le temps. Les distances journalières prédites étaient plus longues pendant la saison de fructification (6, 98 km) que pendant la saison de non-fructification (6, 06 km). Ces différences saisonnières suggèrent des réponses aux changements de ressources alimentaires et de température. Les taux de détection des pièges photographiques ont montré des tendances temporelles et saisonnières similaires à celles des données de suivi, ce qui nous permet de généraliser nos conclusions au niveau de la population. De plus, les caméras n’ont jamais détecté les mandrills la nuit, et nous avons observé qu’ils dormaient haut dans les arbres et ne bougeaient pratiquement pas jusqu’au lendemain matin, ce qui suggère qu’ils évitent strictement de se déplacer la nuit. Cette étude a démontré l’importance de l’approche à méthodes multiples pour tirer des conclusions solides sur les modes temporels de déplacement des animaux

Female Reproductive Seasonality and Male Influxes in Wild Mandrills (Mandrillus sphinx)

The correlates of variation in the number of males in primate groups form a long-standing question in primatology. We investigated female reproductive seasonality and the numbers of males in groups of wild mandrills (Mandrillus sphinx) in a 25-month camera-trap survey with 160 camera locations in Moukalaba-Doudou National Park, Gabon. We used 1760 videos to analyze group composition, including the presence of females with newborn infants and with sexual swellings, the number of males present in groups, and male spatial positioning in groups. Female reproduction was seasonal, with a peak in the number of newborns in the mid-rainy season and a peak in the number of females with sexual swellings in the early dry season. The number of males in the group increased in the dry season, with a much greater increase in the number of mature males (sevenfold) than in submature males (twofold). The peak number of mature males, but not submature males, in the group lagged significantly behind the peak in the number of females with sexual swellings, suggesting that submature males enter groups before mature males and/or that mature males stay in the group longer after the peak of females with sexual swellings. Mature, but not submature, males appeared frequently near females with sexual swellings. In conclusion, we found a clear relationship between the presence of receptive females and the number of males in the group, and evidence that male competitive ability influences male strategies

Evaluation of the role of Guenons and Mangabeys in seed dispersal in Moukalaba-Doudou National Park, Gabon

In order to gain knowledge on the quantity of seed dispersed and the contribution of small diurnal primates in the ecosystem, a preliminary study  on four species of monkeys was carried out in the northeastern part of the Moukalaba-Doudou National Park in Gabon. The aim was to identify the  species of fruits which are dispersed and the animal biomass in two large groups of monkeys namely mangabeys (Cercocebus torquatus and  Lophocebus albigena) and guenons (Cercopithecus cephus and Cercopithecus nictitans). Using the reconnaissance walking method, we followed old  tracks and dung piles were collected after direct observation of the little monkeys and in the sleeping site. The dung piles were washed, and the  seeds collected were identified. A total of 104 fecal samples from the four species of monkeys were collected. Seeds from 19 species of plants  were found in the dung piles. The majority of the seeds found in droppings were seeds of Cissus dinklagei and Musanga cecropioides.  Cercopithecus nictitans dispersed seeds of more plant species than the others. All the results obtained show that the monkeys disperse an average  of 1,114 seeds per day. In this study guenons disperses more fruit than the mangabeys who have a more varied diet. These results suggest that  monkeys of Moukalaba-Doudou disperse fewer seeds compared to monkeys in other sites in Africa.   Afin d’avoir une connaissance sur la quantité de graine dispersée et la contribution des petits primates diurnes dans l’écosystème, une étude  préliminaire sur quatre espèces de singes a été réalisée dans la partie nord-est du Parc National de Moukalaba-Doudou au Gabon. L’objectif était de  connaître les espèces de fruits dispersées et la biomasse animale chez deux grands groupes de singes à savoir les mangabeys (Cercocebus  torquatus et Lophocebus albigena) et les guenons (Cercopithecus cephus et Cercopithecus nictitans). En utilisant la méthode de la marche de  reconnaissance, nous avons suivi d’anciennes pistes et les tas de fumier ont été ramassés après observation directe des petits singes et dans les  dortoirs. Les crottes ont été lavées et les graines récoltées ont été identifiées. Un total de 104 échantillons fécaux des quatre espèces de singes a été  collectés. Les graines de 19 espèces de plantes ont été trouvées dans les excréments. Cercopithecus nictitans a dispersé plus d’espèces de  graines que les autres. La majorité des graines trouvées dans les déjections étaient des graines de Cissus dinklagei et Musanga cecropioides.  L’ensemble des résultats obtenus montre que les singes dispersent en moyenne 1114 graines par jour. Dans cette étude les guenons dispersent plus  de fruits que les mangabeys qui ont une alimentation plus variée. Ces résultats suggèrent que les singes de Moukalaba-Doudou dispersent  peu de graines en comparaison aux singes d’autres sites en Afrique.&nbsp

Etude de la Relation entre l’abondance des grands mammifères frugivores et celle des fruits dans le Parc National de Moukalaba-Doudou, Gabon

Au Gabon, les travaux portant sur les relations plantes animaux demeurent encore très lacunaires. Pourtant, cette connaissance est indispensable dans la compréhension des fonctionnements des écosystèmes forestiers, mais aussi sur le comportement alimentaire des mammifères. C’est dans ce cadre qu’une étude sur l’abondance des mammifères frugivores et celles des fruits a été conduite dans le Parc National de Moukalaba Doudou. Les données sur l’abondance des mammifères ont été recueillies à l’aide des caméras pièges, le long de 11 transects de janvier 2012 à janvier 2014. Quant aux fruits, ils ont été récoltés le long de ces transects sur une bande de 1 m de large de part et d’autre du transect. Au total, 2492 fruits repartis en 100 espèces ont été recensés au cours de cette étude. Le nombre de fruits recensés a varié en fonction des biotopes prospectés et des mois. Les caméras pièges ont permis d’identifier dix espèces de mammifères frugivores présents dans cette zone. Le test de corrélation P de Pearson (R= 0,2 ; df= 10, P= 0,5) a montré que la variation entre l’abondance des mammifères et celle des fruits reste indépendante.Mots clés : Abondance, fruits, mammifères, Parc National Moukalaba-Doudou, caméra piège, Gabon

Seasonal Change in Diet and Habitat Use in Wild Mandrills (Mandrillus sphinx)

霊長類最大の群れで暮らす、野生マンドリルの食生活 --季節的な「食糧難」への柔軟な対応--. 京都大学プレスリリース. 2017-12-19.Primates show various behavioral responses to resource seasonality, including changes in diet and habitat use. These responses may be particularly important for species living in large groups, owing to strong competition for resources. We investigated seasonality in diet and habitat use in wild mandrills (Mandrillus sphinx), which form some of the largest primate groups, in Moukalaba–Doudou National Park, Gabon. We used a fallen fruit census to measure fruit availability and camera trapping to measure visit frequency by mandrill groups on 11 line transects from January 2012 to November 2013, and collected mandrill feces for 25 months in 2009–2013 to assess their diets. Fruit availability varied seasonally, with a peak in December–February, and a scarce period in March–August. Relative volumes of fruit skin, pulp, and intact seeds in fecal remains varied with fruit availability, whereas feces contained as large a proportion of crushed seeds in the fruit-scarce season as in the fruit-peak season. The relative volumes of woody tissue (e.g., bark and roots) and the number of food types increased in the fruit-scarce season compared to in the fruit-peak season. Camera trapping revealed seasonality in habitat use. In fruit-rich seasons, mandrill visits were highly biased toward transects where fruit species that appeared in the majority of feces in a group were abundant. In contrast, in fruit-scarce seasons, visit frequencies were distributed more uniformly and the relationship with fruit availability was unclear. Our results suggest that mandrill groups in the study area respond to seasonal fruit scarcity by consuming seeds and woody tissue and by ranging more widely than in fruit-rich seasons. These flexible dietary and ranging behaviors may contribute to the maintenance of extremely large groups in mandrills

Estimating diurnal primate densities using distance sampling method in Moukalaba-Doudou National Park, Gabon

Objective: To complete data of diurnal primates, we have estimated the density of diurnal primates in the northeastern part of Moukalaba Doudou National Park (MDNP) in Gabon and then we compared the results from those obtained in other areas.Methodology and results: we estimated the densities of each species based on the conventional distancesampling approach. Sampling was done in two sessions along 14 line-transects including various types of vegetation. Cercocebus torquatus is the species most abundance with 62.37 ind.km-2, followed by Cercopithecus nictitans (33.26 individuals.km-2), Cercopithecus cephus (29.38 individuals.km-2) Lophocebus albigena (15.72 ind.km-2). The low density was observed in Cercopithecus pogonias (5.23 individuals.km-2). Those values are higher than Makokou with C. cephus, C. nictitans 25 ind.km-2and 30 ind.km-2 respectively. Those results are relatively high unlike to Lopé C. cephus (5.1 individuals.km-2) C. nictitans (19.2 individuals.km-2) C. pogonias (4.6 individuals.km-2) which have the same vegetation types. They are different from Loango Loango, C. cephus (13.33 individuals.km-2) C. nictitans (3.71 individuals.km-2) Cercocebus torquatus (15.89 individuals.km-2) which have a disturbed forest, which may affect monkey’s density.Conclusion and application: our results showed that the density of monkeys in MDNP is among the highest in Gabon. This can be explained by the lacking of colobine monkeys, which generally dominated in the African rainforest, and the different types of vegetation that we founded.Keywords: Moukalaba-Doudou, distance sampling, monkeys, density, compariso

Pharyngeal Communities and Antimicrobial Resistance in Pangolins in Gabon

ABSTRACT Wildlife can be a reservoir and source of zoonotic pathogens for humans. For instance, pangolins were considered one of the potential animal reservoirs of SARS-CoV-2. The aim of this study was to assess the prevalence of antimicrobial-resistant species (e.g., extended-spectrum β-lactamase [ESBL]-producing Enterobacterales) and Staphylococcus aureus-related complex and to describe the bacterial community in wild Gabonese pangolins. The pharyngeal colonization of pangolins sold in Gabon (n = 89, 2021 to 2022) was analyzed using culture media selective for ESBL-producing Enterobacterales, S. aureus-related complex, Gram-positive bacteria and nonfermenters. Phylogenetic analyses of ESBL-producing Enterobacterales was done using core-genome multilocus sequence typing (cgMLST) and compared with publicly available genomes. Patterns of cooccurring species were detected by network analysis. Of the 439 bacterial isolates, the majority of species belonged to the genus Pseudomonas (n = 170), followed by Stenotrophomonas (n = 113) and Achromobacter (n = 37). Three Klebsiella pneumoniae isolates and one Escherichia coli isolate were ESBL-producers, which clustered with human isolates from Nigeria (MLST sequence type 1788 [ST1788]) and Gabon (ST38), respectively. Network analysis revealed a frequent cooccurrence of Stenotrophomonas maltophilia with Pseudomonas putida and Pseudomonas aeruginosa. In conclusion, pangolins can be colonized with human-related ESBL-producing K. pneumoniae and E. coli. Unlike in other African wildlife, S. aureus-related complex was not detected in pangolins. IMPORTANCE There is an ongoing debate if pangolins are a relevant reservoir for viruses such as SARS-CoV-2. Here, we wanted to know if African pangolins are colonized with bacteria that are relevant for human health. A wildlife reservoir of antimicrobial resistance would be of medical relevance in regions were consumption of so-called bushmeat is common. In 89 pangolins, we found three ESBL-producing Klebsiella pneumoniae strains and one ESBL-producing Escherichia coli strains, which were closely related to isolates from humans in Africa. This points toward either a transmission between pangolins and humans or a common source from which both humans and pangolins became colonized

Phylogenetic Groups, Pathotypes and Antimicrobial Resistance of Escherichia coli Isolated from Western Lowland Gorilla Faeces (Gorilla gorilla gorilla) of Moukalaba-Doudou National Park (MDNP)

International audienceBackground: Terrestrial mammals in protected areas have been identified as a potential source of antimicrobial-resistant bacteria. Studies on antimicrobial resistance in gorillas have already been conducted. Thus, this study aimed to describe the phylogroups, pathotypes and prevalence of antimicrobial resistance of Escherichia coli isolated from western lowland gorilla's faeces living in MDNP. (2) Materials and Methods: Ninety-six faecal samples were collected from western lowland gorillas (Gorilla gorilla gorilla) during daily monitoring in the MDNP. Sixty-four E. coli isolates were obtained and screened for phylogenetic and pathotype group genes by polymerase chain reaction (PCR) after DNA extraction. In addition, antimicrobial susceptibility was determined by the disk diffusion method on Mueller Hinton agar. (3) Results: Sixty-four (64%) isolates of E. coli were obtained from samples. A high level of resistance to the beta-lactam family, a moderate rate for fluoroquinolone and a low rate for aminoglycoside was obtained. All E. coli isolates were positive in phylogroup PCR with a predominance of A (69% ± 11.36%), followed by B2 (20% ± 19.89%) and B1 (10% ± 8.90%) and low prevalence for D (1% ± 3.04%). In addition, twenty E. coli isolates (31%) were positive for pathotype PCR, such as EPEC (85% ± 10.82%) and EPEC/EHEC (15% ± 5.18%) that were obtained in this study. The majority of these MDR E. coli (DECs) belonged to phylogenetic group A, followed by MDR E. coli (DECs) belonging to group B2. (4) Conclusion: This study is the first description of MDR E. coli (DECs) assigned to phylogroup A in western lowland gorillas from the MDNP in Gabon. Thus, wild gorillas in MDNP could be considered as asymptomatic carriers of potential pathogenic MDR E. coli (DECs) that may present a potential risk to human healt

Phylogenetic Groups, Pathotypes and Antimicrobial Resistance of Escherichia coli Isolated from Western Lowland Gorilla Faeces (Gorilla gorilla gorilla) of Moukalaba-Doudou National Park (MDNP)

(1) Background: Terrestrial mammals in protected areas have been identified as a potential source of antimicrobial-resistant bacteria. Studies on antimicrobial resistance in gorillas have already been conducted. Thus, this study aimed to describe the phylogroups, pathotypes and prevalence of antimicrobial resistance of Escherichia coli isolated from western lowland gorilla’s faeces living in MDNP. (2) Materials and Methods: Ninety-six faecal samples were collected from western lowland gorillas (Gorilla gorilla gorilla) during daily monitoring in the MDNP. Sixty-four E. coli isolates were obtained and screened for phylogenetic and pathotype group genes by polymerase chain reaction (PCR) after DNA extraction. In addition, antimicrobial susceptibility was determined by the disk diffusion method on Mueller Hinton agar. (3) Results: Sixty-four (64%) isolates of E. coli were obtained from samples. A high level of resistance to the beta-lactam family, a moderate rate for fluoroquinolone and a low rate for aminoglycoside was obtained. All E. coli isolates were positive in phylogroup PCR with a predominance of A (69% ± 11.36%), followed by B2 (20% ± 19.89%) and B1 (10% ± 8.90%) and low prevalence for D (1% ± 3.04%). In addition, twenty E. coli isolates (31%) were positive for pathotype PCR, such as EPEC (85% ± 10.82%) and EPEC/EHEC (15% ± 5.18%) that were obtained in this study. The majority of these MDR E. coli (DECs) belonged to phylogenetic group A, followed by MDR E. coli (DECs) belonging to group B2. (4) Conclusion: This study is the first description of MDR E. coli (DECs) assigned to phylogroup A in western lowland gorillas from the MDNP in Gabon. Thus, wild gorillas in MDNP could be considered as asymptomatic carriers of potential pathogenic MDR E. coli (DECs) that may present a potential risk to human health