5 research outputs found
Discovery of Macrotarsomys bastardi at Beza Mahafaly Special Reserve, southwest Madagascar, with observations on the dynamics of small mammal interactions
We report the presence of Macrotarsomys bastardi, Bastardâs big - footed mouse, at the Beza Mahafaly Special Reserve in southwestern Madagascar. Despite years of fieldwork, including field research targeting the nocturnal mammals, this species had never been reported here previously. A program of intensive and random capture of nocturnal mammals was established over a period of one year (October 2006 to September 2007). We monitored the relative abundances and microhabitat preferences of small-bodied nocturnal mammals in three forests at Beza, as reflected in trapping success both on the ground and at heights of one to two meters in the trees. Three species are common at Beza (although they have different apparent habitat preferences): Microcebus griseorufus, Rattus rattus, and Echinops telfairi. Endemic rodents appear to be rare. Possible interactions between introduced rodents (rats and mice) and endemic species of rodents (Macrotarsomys and Eliurus) are also discussed.RĂSUMĂ AprĂšs plusieurs annĂ©es de recherches dans la RĂ©serve SpĂ©ciale de BezĂ Mahafaly au Sud - ouest de Madagascar, y compris les recherches sur les mammifĂšres nocturnes, la prĂ©sence de Macrotarsomys bastardi (famille des Nesomyidae) est signalĂ©e pour la premiĂšre fois dans cet endroit. Une sĂ©rie dâĂ©chantillonnage et une sĂ©ance de capture intensive des espĂšces nocturnes ont Ă©tĂ© organisĂ©es durant une annĂ©e dans trois forĂȘts diffĂ©rentes de cette rĂ©gion (entre octobre 2006 et septembre 2007). Les piĂšges avaient Ă©tĂ© installĂ©s sur le sol ou sur des branches Ă une hauteur comprise entre un et deux mĂštre(s) pour Ă©valuer lâabondance relative et la prĂ©fĂ©rence pour des microhabitats des micromammifĂšres nocturnes. Trois espĂšces, ayant chacune des prĂ©fĂ©rences particuliĂšres pour un type dâhabitat, sont frĂ©quentes Ă BezĂ Mahafaly, Ă savoir Microcebus griseorufus, Rattus rattus et Echinops telfairi. Les rongeurs endĂ©miques sont rares (Macrotarsomys et Eliurus), fait qui pourrait sâexpliquer par leur interaction avec les rongeurs introduits (rats et souris) qui est discutĂ© ici
Antipredator Vocalization Usage in the Male Ring-Tailed Lemur <b><i>(Lemur catta)</i></b>
Paternity in wild ring-tailed lemurs (Lemur catta): Implications for male mating strategies
In groupâliving species with male dominance hierarchies where receptive periods of females do not overlap, high male reproductive skew would be predicted. However, the existence of female multiple mating and alternative male mating strategies can call into question singleâmale monopolization of paternity in groups. Ringâtailed lemurs (Lemur catta) are seasonally breeding primates that live in multiâmale, multiâfemale groups. Although established groups show male dominance hierarchies, male dominance relationships can break down during mating periods. In addition, females are the dominant sex and mate with multiple males during estrus, including group residents, and extraâgroup malesâposing the question of whether there is high or low male paternity skew in groups. In this study, we analyzed paternity in a population of wild L. catta from the BezĂ Mahafaly Special Reserve in southwestern Madagascar. Paternity was determined with 80â95% confidence for 39 offspring born to nine different groups. We calculated male reproductive skew indices for six groups, and our results showed a range of values corresponding to both high and low reproductive skew. Between 21% and 33% of offspring (3 of 14 or three of nine, counting paternity assignments at the 80% or 95% confidence levels, respectively) were sired by extraâtroop males. Males siring offspring within the same group during the same year appear to be unrelated. Our study provides evidence of varying male reproductive skew in different L. catta groups. A single male may monopolize paternity across one or more years, while in other groups, >1 male can sire offspring within the same group, even within a single year. Extraâgroup mating is a viable strategy that can result in extraâgroup paternity for L. catta males
Genetic evidence for male and female dispersal in wild Lemur catta
Lemur catta has traditionally been considered a species with male-biased dispersal; however, occasional female dispersal occurs. Using molecular data, we evaluated dispersal patterns in 2 L. catta populations in southwestern Madagascar: Tsimanampesotse National Park (TNP) and BezĂ Mahafaly Special Reserve (BMSR). We also investigated the genetic differentiation between the populations and dispersal partner relatedness. Results showed minor genetic differentiation between the populations (ÏŽ(ST) = 0.039), which may indicate gene flow historically occurring in this region, made possible by the presence of L. catta groups between the sites. Different patterns of sex-biased dispersal were found between the sites using corrected assignment indices: male-biased dispersal in TNP, and a lack of sex-biased dispersal in BMSR. Observational evidence of female dispersal in BMSR supports these results and may imply intense female resource competition in and around BMSR, because small groups of 2-3 females have been observed dispersing within BMSR and entering the reserve from outside. These dispersing groups largely consisted of mothers transferring with daughters, although we have an aunt-niece pair transferring together. Genetic data suggest that males also transfer with relatives. Our data demonstrate that dispersal partners consist of same-sexed kin for L. catta males and females, highlighting the importance of kin selection