Costs and Potential Benefits of Parental Care in the Nocturnal Fat-Tailed Dwarf Lemur (Cheirogaleus medius)

Abstract

Parental care should evolve only if fitness benefits exceed fitness costs. In Cheirogaleus medius, a small nocturnal lemur of western Madagascar, we found the peculiar situation of considerable parental care by both sexes, combined with an extremely high rate of extra-pair young (EPY). In this paper, we try to elucidate the costs and benefits of parental care in C. medius, and we discuss hypotheses as to why males might actively participate in raising young, especially with regard to the high rate of EPY. The study was carried out in the dry deciduous forest of western Madagascar between 1996 and 2001. The most important components of parental care in C. medius are babysitting and guarding of the young. Observational data suggest that thermoregulatory demands during the first days after birth and defence from predators may be the driving factors selecting for this infant care behaviour. The reproducing individuals of both sexes incur considerable energetic costs by this behaviour, resulting in reduced fat stores and body condition in comparison to non-reproducing individuals. The reason why males also care for EPY remains elusive. We propose that males might not be able to detect individual relatedness and that they would jeopardise the survival of their own young if they gave no parental care. Alternatively, they might gain advantages other than direct fitness from raising EPY, for example if caring behaviour increases their chances in further reproduction, or if EPY are fathered by close kin.

Neutral versus adaptive genetic variation in parasite resistance: importance of major histocompatibility complex supertypes in a free-ranging primate

“…The hibernating C. medius is only active during the rainy season (about November/December to April). A detailed description of the forest and trapping conditions is given elsewhere (Ganzhorn and Sorg, 1996;Fietz 1999a, b;Fietz and Dausmann, 2003). Briefly, captures were carried out for four consecutive nights per month using 200 Sherman traps (7.7 Â 7.7 Â 30.5 cm), which were placed in 50-m intervals at the intersections of a grid system of trails.…”

“…We used a fat-tailed dwarf lemur population (Cheirogaleus medius; cheirogaleidae, primates) of the dry deciduous forest of western Madagascar as a model, which has been the focus of long-term population and behavioural ecological investigations (Fietz and Ganzhorn, 1999;Fietz et al, 2000;Fietz and Dausmann, 2003;Dausmann et al, 2004Dausmann et al, , 2005. The main objectives of our study were: (1) to examine associations between microsatellite variability and the diversity of a functionally important region of an immune gene (MHC class II DRB exon2) with parasite burden and (2) to identify possible parasite-driven selection acting on the MHC under natural selection conditions.…”

Tree Hole Utilisation by the Hairy-Eared Dwarf Lemur (Allocebus trichotis) in Analamazaotra Special Reserve

“…Four species use leaf nests exclusively (Microcebus griseorufus , Microcebus myoxinus , Mirza coquereli and Mirza zaza) [Kappeler, 1998;Kappeler et al, 2005;Génin, 2008]. Tree holes are used exclusively or in combination with leaf nests by the majority of species (Cheirogaleus major , Cheirogaleus medius , Microcebus berthae , Microcebus murinus , Microcebus ravelobensis , Microcebus rufus and Phaner pallescens) [Martin, 1973;Wright and Martin, 1995;Radespiel, 1998;Schmid, 1998;Müller, 1999a;Schmelting, 2000;Schwab, 2000;Fietz and Dausmann, 2003;Radespiel et al, 2003;Schülke and Kappeler, 2003;Dammhahn and Kappeler, 2005;Dausmann et al, 2005;Rasoazanabary, 2006;Lahann, 2007Lahann, , 2008; Deppe et al, 2008]. Although the hairy-eared dwarf lemur (Allocebus trichotis) has previously been observed to use tree holes and the characteristics of a few of these cavities have been reported, it is important for the survival of this enigmatic species to gather additional information on this aspect of its habitat needs [Meier and Albignac, 1991;Rakotoarison et al, 1997;Goodman and Raselimanana, 2002].…”

“…Although the hairy-eared dwarf lemur (Allocebus trichotis) has previously been observed to use tree holes and the characteristics of a few of these cavities have been reported, it is important for the survival of this enigmatic species to gather additional information on this aspect of its habitat needs [Meier and Albignac, 1991;Rakotoarison et al, 1997;Goodman and Raselimanana, 2002]. Apart from being used as diurnal resting shelters, cheirogaleids also use these sleeping sites for birthing, to raise and/or cache young and for torpor or hibernation during the dry season [Wright and Martin, 1995;Kappeler, 1998;Schmid, 1998;Fietz, 1999Fietz, , 2003Müller, 1999a, b;Fietz and Dausmann, 2003;Dausmann et al, 2005;Eberle and Kappeler, 2006;Rasoazanabary, 2006]. The advantages proposed to be driving the use of such shelters include protection against predators, energy saving through thermoregulatory advantages, less ectoparasitism and better survival of altricial young [Kappeler, 1998;Radespiel, 1998;Schmid, 1998;Radespiel et al, 2003;Dausmann et al, 2005;Lahann, 2008].…”

“…Tree holes in particular have been proposed to be better for antipredator defence and thermoregulation [Schmid, 1998;Radespiel et al, 2003;Lahann, 2008]. However, the antipredator advantage of using tree holes has been questioned as several authors reported predation events where animals were removed from their sleeping site during the day [Wright and Martin, 1995;Schmelting, 2000;Schülke and Ostner, 2001;Fietz and Dausmann, 2003]. Furthermore, the risk of predation in 'low-quality' sleeping sites (i.e.…”