Author
Pia Braune
Bio: Pia Braune is an academic researcher from University of Veterinary Medicine Hanover. The author has contributed to research in topics: Lemur & Golden-brown mouse lemur. The author has an hindex of 2, co-authored 2 publications receiving 165 citations.
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TL;DR: These findings provide the first empirical evidence for nocturnal primates in a natural environment that olfactory signals represent an important mechanism to regulate the distribution of different groups in space, whereas acoustic signals control intra-group cohesion and coordination.
Abstract: In order to remain stable, dispersed social groups have to solve two fundamental problems: the coordination of movement and cohesiveness within a group and the spacing between the groups. Here, we investigate mechanisms involved in intra-group coordination and inter-group spacing using the golden brown mouse lemur, Microcebus ravelobensis, as a model for a nocturnal, solitary foraging mammal with a dispersed social system. By means of radiotelemetry and bioacoustics we studied the olfactory and vocal behaviour during nocturnal dispersal and reunion of five sleeping groups.
122 citations
TL;DR: These findings provide the first empirical evidence for the hypothesis that loud calling has evolved as a key mechanism for regulating space use and cohesiveness in dispersed pair-living primates.
Abstract: Dispersed pair-living primates provide a unique model for illuminating the evolution of mechanisms regulating spacing and cohesiveness in permanently cohesive groups. We present for the first time data on the spatiotemporal distribution and loud-calling behavior of the Milne Edwards' sportive lemur, known to forage solitarily during the night, but to form stable male-female sleeping groups during the day. Data include radio-tracking observations of sleeping associations, and focal follows of pair partners during dispersal in the evenings and reunions in the mornings. Male-female pairs forming stable sleeping associations during the day were pair-bonded. They used sleeping sites and home ranges exclusively, and exchanged loud calls at potentially restricted resources during dispersal in the evenings and during reunion in the mornings. Direct agonistic conflicts between pairs and others were rare. The acoustic analysis of loud calls revealed nine major call types. They carry signatures for sex and pair identity, and provide the substrate for signaling and the potential for recognizing pair ownership. Thus, pairs use loud call exchanges as a vocal display for signaling territory ownership, thus limiting direct aggressive encounters between neighbors and strangers. Altogether, our findings provide the first empirical evidence for the hypothesis that loud calling has evolved as a key mechanism for regulating space use and cohesiveness in dispersed pair-living primates.
59 citations
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TL;DR: It is pointed out that decision-making for moving collectively can be reached by a combination of different rules, i.e. individualized and self-organized ones for any species, context and group size.
204 citations
01 Jan 2003
TL;DR: It is advocated that it will be valuable for researchers to consider analyzing the independent effects of habitat loss and fragmentation to determine whether it is the overall loss of habitat or the separation of habitat into smaller pieces (hereafter termed “habitat fragmentation per se”) that actually causes negative effects on primates.
Abstract: and/or keywords. This search revealed a total of 227 papers. We randomly selected 100 of these papers and identifi ed the ways in which habitat fragmentation effects are being assessed. Evaluating and Measuring Habitat Fragmentation Habitat may be broadly defi ned as “the range of environments suitable for a given species” (Hall et al. 1997 ). For primates this generally refers to broad vegetation types, such as tropical rain forest and tropical dry forest (Arroyo-Rodríguez and Mandujano 2009 ). Because native vegetation is important for many species, numerous researchers have equated “habitat” with native vegetation (Fischer and Lindenmayer 2007 ; Arroyo-Rodríguez and Mandujano 2009 ). Habitat fragmentation is a landscape-scale process in which continuous habitat is broken apart into smaller pieces (fragments) scattered within a matrix of nonhabitat. This implies the loss of habitat and its subdivision (fragmentation) into a variable number of fragments (Fahrig 1999 ; McGarigal and Cushman 2002 ; Fahrig 2003 ). However, habitat loss can occur without the subdivision of habitat (Fig. 2.2 ), and therefore, we advocate that it will be valuable for researchers to consider analyzing the independent effects of habitat loss and fragmentation to determine whether it is the overall loss of habitat or the separation of habitat into smaller pieces (hereafter termed “habitat fragmentation per se”; sensu Fahrig 1999 , 2003 ) that actually causes negative effects on primates. This can only be done through landscape-scale studies, that is, by using landscapes as the independent units of observation (McGarigal and Cushman 2002 ; Fahrig 2003 ; Arroyo-Rodríguez and Mandujano 2009 ). By using fragments as the unit of analysis (hereafter named “fragment-scale studies”), researchers cannot differentiate between the effects of the habitat loss and the breaking apart of habitat, as both processes can result in smaller and more isolated fragments (Fahrig 2003 ; Fig. 2.2 ). Most fragmentation measures (e.g., mean fragment isolation, total amount of edge, number of fragments) are strongly related in a nonlinear manner to the amount of habitat within a landscape, in such a way that below a certain threshold of habitat area, small changes in the extent of the habitat lead to big changes in these measures (Neel et al. 2004 ). For this reason, it is often diffi cult to determine the separate effects of habitat loss and fragmentation. For instance, studies with plants (ArroyoRodríguez et al. 2009 ) and animals (Andrén 1994 ; Pardini et al. 2010 ) suggest that species diversity in a fragment of a given size may vary in landscapes with different habitat amount. Actually, the effects of fragmentation per se are thought to be relatively more important below certain thresholds of habitat amount remaining in the landscape (Andrén 1994 ; Fahrig 1997 , 1998 ; With and King 2001 ). Below this threshold of habitat amount, the probability of persistence of populations drops signifi cantly. Given the crucial management implications that these thresholds have for primate conservation, we urgently need to analyze the response of primates under different scenarios of habitat loss and fragmentation. This cannot be done through fragment-scale studies; it requires studies at the landscape scale. 2 Assessing Habitat Fragmentation Effects on Primates...
166 citations
TL;DR: Elements of both biogeographic models are combined in a new hypothesis that aims to explain the speciation process leading to the present distribution of mouse lemurs in Madagascar.
152 citations
TL;DR: In this paper, the authors describe the type of information contained in the acoustic structure of contact calls, and then they consider the function of contact call in animals' social lives, particularly their function as identity advertisements.
Abstract: The focus of acoustic communication studies differs between birds and primates due to differences between the avian and primate social structures. Contact calls exist in almost all species independent of social structure, indicating their importance for animals. Contact calls contain various types of information about the sender. They function to keep groups cohesive or to help reunite visually separated individuals. In this review, we first describe the type of information contained in the acoustic structure of contact calls, and then we consider the function of contact calls in animals' social lives, particularly their function as identity advertisements.
139 citations
TL;DR: Evidence is provided for cooperative nursing and adoption by plural-breeding females in a nocturnal primate, the gray mouse lemur, in which females forage solitarily during the night, but form day-time sleeping groups with one to two other females.
Abstract: Lactation imposes substantial physiological costs on mothers and should therefore not be directed towards foreign offspring. Such allonursing, however, is common in mammal species that share roosts. Hypotheses to explain allonursing among such plural breeders include misdirected parental care, milk evacuation, brood parasitism, reciprocity, and kin selection. The necessary behavioral data, in combination with data on kinship and kin recognition, have rarely been available to distinguish among these explanations, however. In this study, we provide evidence for cooperative nursing and adoption by plural-breeding females in a nocturnal primate, the gray mouse lemur (Microcebus murinus), in which females forage solitarily during the night, but form day-time sleeping groups with one to two other females. We observed 34 resident females in an 8 ha study area in Kirindy Forest, Madagascar, over three consecutive annual breeding seasons and determined genetic relationships among all members of this population. Five sleeping groups of adult females were filmed inside their roosts during one breeding season after females gave birth. The composition of groups changed substantially across years, but they always consisted of close maternal relatives. All females within a group gave birth to one to three infants. They regularly transferred only their own offspring among roosting sites, demonstrating an ability to discriminate between their own and other’s offspring, but they regularly groomed and nursed related offspring other than their own and adopted related dependent young after their mother’s death. Kin selection may therefore be the main selective force behind cooperative breeding among these closely related females with a high mortality risk, providing each of them with family insurance.
127 citations