237 research outputs found
Morphological identification of sibling species: the case of West African <i>Mastomys</i> (Rodentia: Muridae) in sympatry
Phylogeny and biogeography of African Murinae based on mitochondrial and nuclear gene sequences, with a new tribal classification of the subfamily
New records of bats (Mammalia : Chiroptera) and karyotypes from Guinean Mount Nimba (West Africa)
New bats were recorded from various habitats on the Guinean side of Mount Nimba during two surveys in 2008 and coupled
with a cytotaxonomic survey. A total of 152 specimens comprising 15 species in 12 genera from five families were collected,
of which 13 individuals were karyotyped. The most numerous species was Rhinolophus guineensis followed by four fruit bats
(Epomops buettikoferi, Lissonycteris angolensis, Roussettus aegyptiacus, Nanonycteris veldkampii). We confirm the presence of
Hipposideros lamottei in the mine adits at 1500 m as well as the exceptional diversity of this habitat. First standard karyotypes
are provided for Epomops buettikoferi and Nanonycteris intermedia. We also document for the first time karyotypes for West
African populations of Mops thersites, Lissonycteris angolensis and Roussettus aegyptiacus, and cytogenetical comparisons with
the existing literature are provided. We add five new species to the list of Guinean Nimba and two to the whole Nimba list
(including Liberian side), which now stands at 42 species. This confirms the importance of Mount Nimba as a hotspot of
diversity and the necessity to protect it.http://www.tandfonline.com/loi/tizo20hb2014Zoology and EntomologyMammal Research Institut
Seasonal variation of the diet of the Little Owl (Athene noctua) (Scopoli, 1769) in the extreme South-East of the Algerian Sahara (Djanet, Algeria)
From the autumn 2007 to the spring 2008,
we studied the diet of the Little Owl Athene noctua in the area of Djanet, situated in the extreme South-East
of Algeria. The analysis of 128 pellets enabled us to identify 80 species belonging to 6 classes, 12 orders
and 32 families, preyed upon by this raptor. Considering the number of preys, insects (relative abundance,
ARÂ = 70.1 %) were dominant, followed by rodents (ARÂ = 17.1 %) ; the most selected ones were Mesostena
angustata (ARÂ = 18.4 %) and Brachytrypes megacephalus (ARÂ = 17.4 %). Insects dominated whatever the
season (ARÂ = 47 % in autumn, 79 % in winter, 63.6 % in spring). In terms of biomass, rodents were dominant
with 9 species, two of them being new for the area. The Little Owl exihibit a diversified diet (E = 0.7) in this
Algerian area of Central SaharaNous avons Ă©tudiĂ© de l'automne 2007 au printemps 2008 le rĂ©gime alimentaire de la ChevĂȘche d'AthĂ©na (Athene noctua) dans la rĂ©gion de Djanet, situĂ©e dans l'extrĂȘme sud-est de l'AlgĂ©rie. L'analyse de 128 pelotes de rĂ©jection nous a
permis de reconnaßtre 80 espÚces-proies réparties en 6 clas-ses, 12 ordres et 32 familles. En nombre de proies, les Insectes (abondance relative, AR = 70,1 %) se sont avérés le plus consommés, suivis par les Rongeurs (AR = 17,1 %) ; les plus sélectionnés étaient Mesostena angustata (AR =
18,4 %) et Brachytrypes megacephalus (AR = 17,4 %). Les insectes dominĂšrent quelle que soit la saison (AR=47 % en automne, 79 % en hiver, 63,6 % au printemps). En termes de biomasse, les rongeurs dominaient avec 9 espĂšces dont deux nouvelles pour la rĂ©gion. La ChevĂȘche d'AthĂ©na a un rĂ©gime
alimentaire diversifié (E =0,7) dans cette région algérienne du Sahara central
Edaphic preferences and pullulation in Meriones shawii (Mammalia, Rodentia) in Tiaret region (Algeria).- In order to better control pullulations of M. shawii in cultivated fields in the Tiaret region
In order to better control pullulations of M. shawii in cultivated fields in the Tiaret region
(Algeria), we studied the edaphic preferences of this rodent in two zones of low and high relative density
of active burrows at the beginning of cereal tillering (March). By using index method to estimate relative
abundance (census of active burrows) and pedological analysis of soil granulometry, rates of total and active
CaCO3, organic matter and humidity, we searched for correlations between soil characteristics and abundance
level. The level of the rodent population is higher when the amounts of sand and total CaCO3 in the
soil are high and humidity less than 15 %. On the other hand, the abundance is low and even null when the
amounts of clay, active CaC03 and humidity are high. Thus this study confirms for the first time in Algeria,
in cultivated fields, M. shawiiâs preference for low-humidity sandy soils with high total CaCO3 ; these
soils would be more suitable to the species for digging out burrows, thence its higher abundance there. We
found no clear relation between the organic matter rate in the soil and the pullulation level. Further studies
are required for a better understanding of the role of irrigation and of the demographic cycle of M. shawii
in order to better predict and control the relative population abundance of this rodent in the cereal fields.
These results confirm recent works that highlighted the importance of edaphic factors to explain burrowing
rodentsâ pullulationsAfin de mieux contrĂŽler les pullulations de Meriones shawii dans les champs cultivĂ©s de la rĂ©gion de Tiaret (AlgĂ©rie), nous avons Ă©tudiĂ© les prĂ©fĂ©rences Ă©daphiques de ce rongeur dans deux zones, l'une de faible, l'autre de forte
densité relative des terriers occupés à la période du début du tallage (mars). à l'aide de méthodes indiciaires (comptage du nombre de terriers actifs) et de méthodes pédologiques d'analyse de la granulométrie du sol, du pourcentage de CaCO3 total et actif, du taux de matiÚre organique et
d'humidité, nous avons recherché les corrélations entre nature du sol et niveau de pullulation. Les sols possédant des taux de sable et de CaCO3 total élevés mais des taux d'humidité inférieurs à 15 % sont corrélés significativement avec les nombres élevés de trous En revanche les taux
d'argile, de CaC03 actif Ă©levĂ©s et d'humiditĂ© supĂ©rieure Ă 15 % sont Ă©galement trĂšs corrĂ©lĂ©s mais avec des nombres de trous faibles. Ainsi, les sols sableux, Ă faible humiditĂ© et avec un taux de calcaire total plus Ă©levĂ© seraient favorables Ă la construction de terriers par M. shawii, d'oĂč
un taux de pullulation plus élevé. Cette étude confirme pour la premiÚre fois en Algérie et en milieu cultivé, la nette préférence de M. shawii pour les sols à texture limonosablonneuse bien pourvus en calcaire total et à faible humidité. Il n'y a pas de relation nette entre le taux de
matiÚre organique du sol et le degré de pullulation. Par contre, il reste à tester le rÎle de l'irrigation des sols et suivre le cycle démographique pour comprendre les pullulations de cette espÚce. Ces résultats confirment cependant plusieurs travaux récents concernant l'importance du sol
comme facteur explicatif de certaines pullulations de rongeurs creuseurs de terriers
Morphological, genetical and ecological discrimination of sympatric Coastal Guinea Mastomys (Mammalia : Rodentia) species (West Africa) : implications for health and agriculture
Cytogenetic
and molecular tools have shown the existence of two sibling species of the multimammate rat in
Coastal Guinea : M. erythroleucus and M. huberti from Mankoutan locality. Here we present the study of
the unique population of M. huberti ever recorded in Guinea, distant from 350 km from the closest locality
in Senegal and representing the southernmost point of the speciesâ disjunct distribution. In order to clarify
its ecological preferences and define its degree of sympatry with M. erythroleucus, we have searched for
morphological and morphometric criteria allowing reliable identification of the species in Coastal Guinea.
Discriminant Factorial Analyses (DFA) were performed on external and skull measurements for respectively
108 and 106 previously genetically typed individuals. All discriminant analyses showed that the 100 % rate
of good classification is never attained. Misclassifications of 55.6 % of the specimens were obtained in the
field by using external fur colour and aspect whereas the error score ranged from 4.5 to 8 % by using DFA
on external measurements. Furthermore, DFA on skull measurements gave 100 % of correct classification
for M. huberti - which is characterized by a smaller size - against 96.97 % for M. erythroleucus. In the same
time, we were able to define the local specific habitat of each species. In Mankountan, M. huberti is never
found into houses but prefers wet rice fields, while M. erythroleucus is found both in houses and cultures as
well as in wet rice fields where it is found in syntopy with M. huberti at the end of the dry season. In Yerende,
a hundred kilometres from Mankoutan, we only caught M. erythroleucus both in houses and fields. This
study once again highlights the importance of a deep taxonomic knowledge of small mammalsâ diversity for
sanitary and agricultural risks evaluation but also confirms the problems of identification encountered with
rodent sibling species living in sympatryLes analyses cytogénétiques et moléculaires ont mis en évidence la présence de deux espÚces jumelles de Mastomys en Guinée Maritime: M. ervthroleucus et M. huberti dans la localité de Mankoutan. Il s'agit de la premiÚre étude de
la seule population de M. huberti rencontrée en Guinée située à 350 km de la population la plus proche du Sénégal, à l'extrémité Sud de l'aire de distribution disjointe de l'espÚce. Afin de définir ses préférences écologiques, nous avons recherché des critÚres morphologiques et
morphométriques pour identifier les deux espÚces de Mastomys afin de mieux définir leur degré de sympa-trie. Des Analyses Factorielles Discriminantes (AFD) effectuées sur les caractÚres externes et crùniens de 108 et 106 individus ayant fait l'objet d'analyses moléculaires (cyt.b) et /ou
cytogénétiques, provenant de deux localités proches, montrent que l'on ne peut jamais discriminer avec 100 % de certitude les spécimens en 'peau' et 'crùne'. Le taux d'erreur de détermination des deux espÚces atteint 55,6 % pour la coloration et l'aspect du pelage sur le terrain, il oscille
entre 4,5 et 8 % en AFD sur les mesures externes. Cependant avec les mesures crùniennes traitées par AFD, les M. huberti se distinguent à 100 % par une taille légÚrement plus faible, contre 96,97 % chez M. erythroleucus. ParallÚlement, nous avons pu préciser l'habitat spécifique aux deux
espĂšces dans la mĂȘme localitĂ©. Ainsi, Ă Mankountan, M. huberti n'est jamais rencontrĂ© dans les maisons et prĂ©fĂšre les champs de riz inondĂ©s. M. erythroleucus est prĂ©sent Ă la fois dans les maisons et dans les champs, quelquefois dans les riziĂšres inondĂ©s oĂč, Ă la fin de la saison sĂšche, il
se retrouve en syntopie avec M. huberti. La localité de Yerendé située à 100 km de Mankountan n'a livré que des M. erythroleucus, présents à la fois dans les maisons et les champs. Cette étude montre l'importance d'une connaissance approfondie de la systématique et de la diversité des petits
mammifÚres nuisibles pour l'évaluation des risques sanitaires et agricoles et confirme les difficultés d'identification morphologique des espÚces jumelles chez les rongeurs
RĂ©gime alimentaire de Crocidura pachyura (KĂŒster, 135) (Mammalia, Soricidae) dans plusieurs localitĂ©s dâAlgĂ©rie
Le rĂ©gime alimentaire de Crocidura pachyura (KĂŒster, 1835) a Ă©tĂ© Ă©tudiĂ© grĂące Ă lâanalyse des contenus stomacaux de 95 spĂ©cimens collectĂ©s sur le terrain de juin 2007 Ă septembre 2008 et de mars 2012 Ă mai 2014. Ces individus ont Ă©tĂ© collectĂ©s au moyen de piĂšges Sherman et de pots-enterrĂ©s dans 8 localitĂ©s dâAlgĂ©rie du Nord et du Centre, du niveau de la mer Ă 1390 m dâaltitude (Tigzirt, Boukhalfa, Ouadias, El Misser, Darna, Tala Guilef, Zeralda et Reghaia). On trouve 99 proies diffĂ©rentes distribuĂ©es dans 7 taxons dâinvertĂ©brĂ©s (Clitellates, NĂ©matelminthes, Gastropodes, Arachnides, CrustacĂ©s, Myriapodes et Insectes), un vertĂ©brĂ© (Squamate) et des plantes indĂ©terminĂ©es, notamment des graines. Les invertĂ©brĂ©s reprĂ©sentent 77,05 % du rĂ©gime alimentaire et les insectes sont les proies les plus frĂ©quentes avec 54,3 %. Crocidura pachyura se nourrit de petites proies de taille infĂ©rieure Ă 17 mm (moyenne 4 mm) et la diversitĂ© des proies (indice de diversitĂ© de Shannon-Weaver) varie de 1,58 Ă 4,88 (moyenne de 2,4). La comparaison avec les travaux similaires effectuĂ©s en AlgĂ©rie et en Europe sur C. russula montre quelques diffĂ©rences de rĂ©gime, surtout en ce qui concerne les proportions des proies ColeoptĂšres, HymĂ©noptĂšres et DiptĂšres.Ecological information, including food habits, on African shrews is scarce. The aim of this study was to describe the diet of Crocidura pachyura (KĂŒster, 1835) in Algeria. Its diet was studied by analysing stomach contents of 95 shrews collected in pitfall and Sherman traps, from June 2007 to September 2008 and from March 2012 to May 2014, in eight localities of North-Central Algeria, from the sea level until 1390 m (Tigzirt, Boukhalfa, Ouadias, El Misser, Darna, Tala Guilef, Zeralda and Reghaia). The diet was composed of 99 different prey taxa distributed in seven invertebrate classes (Clitellata, Nematelminthes, Gastropoda, Arachnida, Crustacea, Myriapoda and Insecta), one vertebrate (Squamata) and plants, particularly seeds. The most important components of the diet were invertebrates: their contribution was 77.05 % of the overall diet composition. Insects were the most frequent prey with 54.3 %. Crocidura pachyura feeds on small preys lower than 17 mm (average 4 mm) and the diversity index of Shannon-Weaver varied between 1.58 and 4.88 (average 2.4). Comparisons with similar studies in Algeria and Europe for C. russula showed some differences especially for Coleoptera, Hymenoptera and Diptera proportions
Hantavirus in African Wood Mouse, Guinea
Hantaviruses are rodentborne, emerging viruses that cause life-threatening human diseases in Eurasia and the Americas. We detected hantavirus genome sequences in an African wood mouse (Hylomyscus simus) captured in Sangassou, Guinea. Sequence and phylogenetic analyses of the genetic material demonstrate a novel hantavirus species, which we propose to name "Sangassou virus.
Mastomys natalensis and Lassa Fever, West Africa
PCR screening of 1,482 murid rodents from 13 genera caught in 18 different localities of Guinea, West Africa, showed Lassa virus infection only in molecularly typed Mastomys natalensis. Distribution of this rodent and relative abundance compared with M. erythroleucus correlates geographically with Lassa virus seroprevalence in humans
Shrews (Mammalia, Eulipotyphla) from a biodiversity hotspot, Mount Nimba (West Africa), with a field identification key to species
In this study, we collected 226 shrew specimens originating from 16 localities on the Guinean and
Liberian sides of Mount Nimba. We surveyed all major vegetation zones from 400 to 1600 m above
sea level (asl), including forest and savannah habitats. We recorded 11 species, whose identifications
were confirmed by genetic analyses and classical morphometrics. Furthermore, we provide cytogenetic
data for five of these species. The shrew community at Mount Nimba is composed of a mix of both
savannah- and forest-dependent species, which is related to the peculiar position of Mount Nimba
situated at the transition between lowland rainforest to the south and Guinean woodlands to the
north. We recorded 11 species of shrews in syntopy in lowland rainforest, seven in edaphic savannah and mountain forest, and five in high-altitude savannah at 1600 m asl. Based on morphometric
analyses, we show that these syntopic species separate along a size axis, allowing species to occupy
different ecological niches, which we speculate allows them to access different food resources. We also
highlight that Crocidura theresae Heim de Balsac, 1968 from Mount Nimba has a different karyotype
from that described in CĂŽte dâIvoire. Finally, we develop a novel identification key for shrews from
Mount Nimba using external characters and standard body measurements, allowing it to be used
in the field on live specimens. In total 12 shrew species are now known from Mount Nimba, which
highlights its exceptional position as a tropical African biodiversity hotspot.https://sciencepress.mnhn.fr/en/periodiques/zoosystemadm2022Mammal Research InstituteZoology and Entomolog
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