Unpredictable environments, opportunistic responses: Reproduction and population turnover in two wild mouse lemur species (Microcebus rufus and M. griseorufus) from eastern and western Madagascar

Abstract

Small-bodied, nocturnal mouse lemurs (Microcebus) are widespread across diverse forest habitats in Madagascar. They are strict seasonal breeders and can, depending on the habitat and species, undergo daily or prolonged torpor to minimize energy expenditure during periods of food and water scarcity. Duration of reproduction, number of litters per season and timing of births vary across individuals and species. The "polyestry-seasonality" hypothesis proposes that the duration of reproduction and number of litters per year are positively correlated with rainfall but negatively correlated with longevity, whereas the "hypervariability" hypothesis suggests that the duration of reproduction is negatively correlated with the degree of predictability of food resources. We test these hypotheses in two mouse lemur species inhabiting contrasting habitats, the brown mouse lemurs, Microcebus rufus, from Ranomafana (a less seasonal and more climatically predictable habitat) and the gray-brown mouse lemurs, M. griseorufus, from Beza Mahafaly (a more seasonal and less climatically predictable environment). We use capture/mark/recapture techniques and records of female reproductive status. We found evidence of polyestry at both study sites but faster population turnover and longer duration of the reproductive season at Beza Mahafaly. The "polyestry-seasonality" hypothesis is not supported but the "hypervariability" hypothesis could not be rejected. We conclude that reproductive output cannot be tied to climatic factors in a simple manner. Paradoxically, polyestry can be expressed in contrasting habitats: less seasonal forests where females can sustain multiple reproductive events, but also highly seasonal environments where females may not fatten sufficiently to sustain prolonged torpor but instead remain active throughout the year by relying on fallback resources. Am. J. Primatol. 77:936-947, 2015. © 2015 Wiley Periodicals, Inc.

A biogeographical perspective on the variation in mouse lemur density throughout Madagascar

“…), by less abrupt habitat zones than exist in the western dry forests (Goodman & Ganzhorn ), and by lower seasonality, which results in more constant food availability and higher levels of environmental predictability (Table ; Blanco et al. ). Less predictable habitats characteristic of western dry forests tend to favour species with faster life‐history strategies that exhibit high levels of ecological flexibility (Dausmann , Vuarin & Henry ).…”

“…Population densities in mouse lemur species are likely to be driven largely by food availability and climate, but life-history theory may also offer clues as to how many individuals an area can support. The eastern humid forests are characterised by heavier precipitation (1500-6000 mm per year vs. 500-2000 mm per year in the western dry forests; Ganzhorn et al 2006), by less abrupt habitat zones than exist in the western dry forests (Goodman & Ganzhorn 2003), and by lower seasonality, which results in more constant food availability and higher levels of environmental predictability (Table 1; Blanco et al 2015). Less predictable habitats characteristic of western dry forests tend to favour species with faster life-history strategies that exhibit high levels of ecological flexibility (Dausmann 2014, Vuarin & Henry 2014.…”

“…(), 4 Muldoon and Goodman (), 5 Blanco et al. (), 6 Dausmann (), 7 Vuarin et al. (), 8 Zimmerman et al.…”

Geogenetic patterns in mouse lemurs (genus Microcebus ) reveal the ghosts of Madagascar's forests past

“…Field observations indicate that for eastern humid-forest species, age at first reproduction in wild populations is 10-12 mo, with females undergoing estrus and reproduction annually thereafter. Two litters per year can be common for some species and wild populations but is rare in other species and localities (45,71). Captive data for M. murinus at the Duke Lemur Center show that two litters in a single year has occurred only once in 101 litters.…”

Comparative analyses of two primate species diverged by more than 60 million years show different rates but similar distribution of genome-wide UV repair events

“…To study whether repair patterns are unique to the organism of interest we aimed to compare human and a deeply diverged non-human primate. Gray mouse lemur (Microcebus murinus) stands out as a promising model organism candidate because of its small body size, short gestation time (2 months) and fast sexual maturation (6-8 months) (Blanco et al 2015;Ezran et al 2017). A near chromosome level reference genome for the gray mouse lemur was recently sequenced and assembled (Larsen et al 2017).…”