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Primates are adept at dealing with fluctuating availability of resources and display a range of responses to minimize the effects of food scarcity. An important component of primate conservation is to understand how primates adapt their foraging and ranging patterns in response to fluctuating food resources. Animals optimize resource acquisition within the home range through the selection of resource‐bearing patches and choose between contrasting foraging strategies (resource‐maximizing vs. area‐minimizing). Our study aimed to characterize the foraging strategy of a folivorous primate, Verreaux's sifaka (Propithecus verreauxi), by evaluating whether group home range size varied between peak and lean leaf seasons within a seasonally dry tropical forest in Madagascar. We hypothesized that Verreaux's sifaka used the resource maximization strategy to select high‐value resource patches so that during periods of resource depression, the home range area did not significantly change in size. We characterized resource availability (i.e., primary productivity) by season at Kirindy Mitea National Park using remotely‐sensed Enhanced Vegetation Index data. We calculated group home ranges using 10 years of focal animal sampling data collected on eight groups using both 95% and 50% kernel density estimation. We used area accumulation curves to ensure each group had an adequate number of locations to reach seasonal home range asymptotes. Neither 95% home ranges nor 50% core areas differed across peak and lean leaf resource seasons, supporting the hypothesis that Verreaux's sifaka use a resource maximization strategy. With a better understanding of animal space use strategies, managers can model anticipated changes under environmental and/or anthropogenic resource depression scenarios. These findings demonstrate the value of long‐term data for characterizing and understanding foraging and ranging patterns. We also illustrate the benefits of using satellite data for characterizing food resources for folivorous primates. Research Highlights: While seasonal leaf availability (characterized using Enhanced Vegetation Index) differed between peak and lean leaf seasons, we found no significant variation in home range and core area sizes of Verreaux's sifaka groups at Kirindy Mitea National Park, Madagascar.Our findings suggest Verreaux's sifaka use a resource‐maximizing strategy.Home range area estimates are improved when an asymptote analysis is used to ensure an adequate number of location samples and when temporal requirements are imposed to avoid concentrated sampling. [ABSTRACT FROM AUTHOR]

Simple Summary: Lemur hunting and consumption is widespread in Madagascar. Understanding what drives this phenomenon is key to conserving lemurs and protecting human livelihoods. Current research shows poverty to be a primary driver of lemur hunting and consumption, but no study has employed a composite poverty metric that includes health, education, and living standards. Our study employs such a metric, along with income, to investigate, for the first time, poverty as a driver of lemur hunting and consumption in and around Kirindy Mitea National Park, Madagascar. We document alarming levels of poverty and lemur hunting and consumption among the study community but find no relationship between the variables. Because nearly all households in the study community were impoverished, possible explanations include the following: (1) poverty is not a driver of lemur hunting and consumption in Kirindy Mitea National Park, or (2) a relationship could not be found due to the socio-economic similarity of households in our study community. We consider both interpretations in light of the current literature and offer recommendations for future research. If human and non-human primates are to continue to co-exist in and around Kirindy Mitea National Park, immediate investment in poverty eradication is required, and conservationists should test the efficacy of livestock interventions locally. The futures of human and nonhuman primates are closely tied in protected areas. Understanding this interconnectedness is especially urgent in Madagascar, one of the world's most impoverished biodiversity hotspots. Yet, no study has evaluated the relationship between poverty and lemur hunting and consumption using a composite poverty metric that includes health, education, and living standards. To address this gap, and to inform primate conservation practice and policy, we administered annual surveys to 81 households over six consecutive months (September 2018 to March 2019) in a village on the border of Kirindy Mitea National Park, Madagascar. We observed extreme deprivation scores across multiple dimensions of poverty and identified ninety-five percent of households as 'impoverished'. Of these, three-quarters (77%) of households were identified as being in 'severe poverty'. One-fifth (19%) of all households hunted lemurs and half (49%) of households consumed lemurs. While poverty eradication is an urgent need in communities around Kirindy Mitea National Park, our findings show no relationship between poverty and lemur hunting and consumption, perhaps due to the lack of variance in poverty. Our results highlight the need to investigate other contributory factors to lemur hunting and consumption locally. Because food insecurity is a known driver of lemur hunting and consumption among the study community, and because domestic meats can be preferred over protected species, we recommend testing the efficacy of livestock interventions near Kirindy Mitea National Park. [ABSTRACT FROM AUTHOR]

Primates acquire gut microbiota from conspecifics through direct social contact and shared environmental exposures. Host behaviour is a prominent force in structuring gut microbial communities, yet the extent to which group or individual‐level forces shape the long‐term dynamics of gut microbiota is poorly understood. We investigated the effects of three aspects of host sociality (social groupings, dyadic interactions, and individual dispersal between groups) on gut microbiome composition and plasticity in 58 wild Verreaux's sifaka (Propithecus verreauxi) from six social groups. Over the course of three dry seasons in a 5‐year period, the six social groups maintained distinct gut microbial signatures, with the taxonomic composition of individual communities changing in tandem among coresiding group members. Samples collected from group members during each season were more similar than samples collected from single individuals across different years. In addition, new immigrants and individuals with less stable social ties exhibited elevated rates of microbiome turnover across seasons. Our results suggest that permanent social groupings shape the changing composition of commensal and mutualistic gut microbial communities and thus may be important drivers of health and resilience in wild primate populations. [ABSTRACT FROM AUTHOR]

Socioecological theory predicts that larger groups are able to gain better access to resources because of their numerical advantage in intergroup contests. Nevertheless, the numerical superiority hypothesis has received mixed support, perhaps due to the collective action problem and sex differences in strategies and payoffs. We tested the numerical superiority and the collective action problem hypotheses using 141 intergroup encounters in a 7-year dataset on 5 groups of Verreaux's sifaka (Propithecus verreauxi) at Ankoatsifaka Research Station in Kirindy Mitea National Park in western Madagascar. Contrary to the numerical superiority hypothesis, larger groups were not more likely to supplant smaller groups, nor was success determined by participation of a larger number of one sex. Consistent with a collective action problem, group size negatively affected participation. Notably, the sexes differed in which factors predicted individual participation. Male participation, which may serve to defend mating opportunities with resident females and signal competitive ability to neighboring groups, was greater than female participation, though we did not detect any strong predictor of male participation. Female participation was more likely during the lactation season, when food resources were scarce, than during the mating season. Contrary to previous studies, which argued that mothers with infants avoid intergroup conflicts because of the risk of infanticide, our study suggests that maternal energetic stress due to lactation and food scarcity increases the benefits of defending resources and instead drives mothers to participate in intergroup encounters. Thus, individual reproductive payoffs provide the private incentives needed to induce collective action. [ABSTRACT FROM AUTHOR]

ABSTRACT Cyclones, which change tree communities and alter forest structure, are thought to have had a significant selective pressure on the flora and fauna of Madagascar. Very little information, however, is available on the actual impact of cyclones on Malagasy ecosystems. On 21 January 2009, Cyclone Fanele made landfall on the western coast of Madagascar with sustained winds of 185 km/h. We examined the immediate effects of the cyclone on tropical dry forest structure in the Kirindy Mitea National Park. In July and August 2009, we measured the height, diameter at breast height (dbh), and damage for 1361 trees in nine 25 × 25 m plots. We found that: (1) over 95 percent of trees experienced some sort of damage, including 8.8 percent mortality; (2) understory and emergent trees experienced significantly higher mortality than canopy trees; and (3) stem density was reduced 9.2±4.5 percent and biomass was reduced 13.4±8.1 percent after the cyclone. Dbh was the best predictor of trunk damage and mortality. This extensive alteration of forest structure will have a substantial short- and long-term impact on the biotic communities of western Madagascar. [ABSTRACT FROM AUTHOR]

The size and composition of a social group can influence the reproductive success of its members. I examined the hypothesis that residents actively try to manipulate group size and composition in Verreaux’s sifaka ( Propithecus verreauxi verreauxi). I collected behavioral data from 21 individuals in 5 social groups from November 2000 to March 2002 in the Kirindy Forest (C.F.P.F.) of western Madagascar. I investigated the affiliative and agonistic behaviors of resident males and females toward other group members to determine whether residents attempt to manipulate the costs and benefits of group membership. I also examined 3 cases of immigration attempts and 1 case of emigration. As expected, group members facilitated the residency of subordinate members of the opposite sex. For example, females sought out the subordinate males, responded to their calls, and even groomed them more. However, intrasexual relationships were also important for establishing or maintaining residency. The data, in conjunction with the observations of immigration and emigration events, suggest that resident individuals of both sexes attempt to influence group size and composition. I suggest that single–male groups are not the norm in Propithecus verreauxi verreauxi because females encourage, and males do not discourage, multiple males to reside in the group to increase group stability and to reduce the risk of infanticide. [ABSTRACT FROM AUTHOR]

Male primates in species with pronounced secondary sexual adornments can exhibit reversible or irreversible bimorphism, i.e., striking variation in the degree to which males express the adornments. Verreaux’s sifaka ( Propithecus verreauxi verreauxi) use scent marking as a form of communication and exhibit sex differences in scent glands. Some males exhibit a pronounced brown staining around their sternal gland, whereas others do not. We studied morphological and behavioral characteristics of males in 6 social groups in Kirindy Forest, Madagascar, from November 2000 to March 2002 to evaluate the hypotheses that the bimorphism in male sifaka chest status represents alternative mating tactics and is a badge of status. Males are clearly divided into 2 categories: clean and stained chests, with rare, but informative, intermediate males. The chest staining probably results from the males scent marking with their sternal glands, because stained-chested males scent marked significantly more often than clean-chested males. Though sample sizes are small, chest status did not appear to depend on body size. Chest status is reversible and related to dominance rank. In each group, only 1 male, the dominant, was stained-chested, whereas all other (subordinate) males were clean-chested. These findings suggest that stained chests are visual and olfactory signals of dominance rank and that clean chests signal lack of competitive intent. Thus, this bimorphism may reflect alternative mating tactics used by males to maximize their reproductive success based upon their social environment. [ABSTRACT FROM AUTHOR]

Male and female interests can either be in conflict or serve as a basis for exchange. Communication is thus an important aspect of intersexual relationships. Verreaux's sifaka (Propithecus verreauxi verreauxi), like many prosimians, uses chemical signals as one form of communication. The goals of this study were to determine 1) if males and females exhibit sex differences in their scent-marking behavior, and 2) if scent-marking is an example of mating conflict or cooperation. All occurrences of scent-marks, scent-mark context, and scent-mark style were collected on 23 sifaka in the Kirindy Forest of western Madagascar for 7 months (September 2001-March 2002). Scent-mark rates were collected using continuous focal animal sampling from November 2000-March 2002. Home-range data were collected using monthly censuses and instantaneous focal sampling throughout those 17 months. The pressures of behavioral ecology seem to have shaped scent-marking in sifaka: the sexes exhibited significantly different scent-marking behavior. Results from this study are consistent with the hypotheses that 1) females scent-mark to advertise their presence and mark their resources, 2) clean-chested males use scent-marks as between-group communication to advertise their presence, and 3) stained-chested males use scent-marks as a form of olfactory mate-guarding. Scent-marking does not appear to be a "service" that males provide to females, because overmarking limits female communication rather than adding to the overall number of scent-marks. Scent-marking behavior is a crucial aspect of the mating conflict and for understanding intersexual relationships in sifaka. [ABSTRACT FROM AUTHOR]

The study of how animals adapt their behaviors depending on weather variables has gained particular significance in the context of climate change. This exploration offers insights into endangered species' potential threats and provides information on the direction to take in conservation activities. In this context, noninvasive, cost-effective, and potentially long-term monitoring systems, such as Passive Acoustic Monitoring (PAM), become particularly appropriate. Our study investigates the relationship between weather variables and the vocal behavior of Indri indri, the sole singing lemur species, within Madagascar's Maromizaha New Protected Area. Using PAM, we explore the factors shaping the vocalization patterns of this primate species in response to some environmental factors in their natural habitat. Analysis of an extensive audio data set collected across different years revealed the differential influence of temperature and precipitation on Indri indri vocal activity. We found that rainfall negatively influenced the emission of the vocalizations while warmer temperatures correlated with a greater emission of songs. The various environmental factors we considered also affected the timing of vocal emissions, showing the same pattern. Furthermore, our study confirms, once again, the strength of PAM as a valuable tool for studying vocal animal communication quickly, giving us information about long-term behavioral patterns that would be difficult to get in other ways. This research gives us further valuable information about how indris use vocalizations in their environment and how they adjust to environmental changes., (© 2024 The Author(s). American Journal of Primatology published by Wiley Periodicals LLC.)

Objectives: Unidirectional dominance-related signals can be used to communicate submission (an immediate behavioral response) or subordination (the status of an established relationship). Subordination signals are defined as emitted during peaceful interactions and are hypothesized to be critical for the evolution of social complexity and robust power structures because they reduce uncertainty in social relationships. The chatter vocalization in Verreaux's sifaka (Propithecus verreauxi) is a unidirectional submissive signal. I tested the hypothesis that chatter vocalizations can signal subordination and thereby reduce agonism in a dyad., Materials and Methods: I examined 780 chatters from 18 dyads collected over 881 observation hours on four groups of sifaka in Kirindy Forest, Madagascar., Results: Sifaka emitted 63% of chatters in the peaceful context. Peaceful chatters significantly predicted grooming rate, fighting rate, reconciliation, and proportion of wins in a dyad but did not predict time in proximity. Dyad-type significantly predicted the frequency of peaceful chatters, with intrasexual dyads exhibiting chatters in peaceful contexts more often than intersexual dyads., Discussion: Sifaka communicate both submission and subordination with chatter vocalizations. Subordination signaling increased tolerance and affiliation. It reduced conflicts and the probability dominant individuals usurped resources. Moreover, intrasexual power may be more institutionalized than intersexual power in sifaka. The finding of complex and cognitively demanding social communication in a lemur with low levels of cooperation (1) challenges previous assumptions that the evolution of social complexity is dependent on frequent triadic interactions and high levels of cooperation, and (2) highlights the need for taxonomic diversity in studies of social complexity., (© 2019 Wiley Periodicals, Inc.)

The gut microbiomes of mammals appear to mirror their hosts' phylogeny, suggesting host-driven microbial community assembly. Yet, much of this evidence stems from comparative studies of distinct wild or captive populations that lack data for disentangling the relative influences of shared phylogeny and environment. Here, we present phylogenetic and multivariate analyses of gut microbiomes from six sympatric (i.e., co-occurring) mammal species inhabiting a 1-km 2 area in western Madagascar-three lemur and three non-primate species-that consider genetic, dietary, and ecological predictors of microbiome functionality and composition. Host evolutionary history, indeed, appears to shape gut microbial patterns among both closely and distantly related species. However, we also find that diet-reliance on leaves versus fruit-is the best predictor of microbiome similarity among closely related lemur species, and that host substrate use-ground versus tree-constrains horizontal transmission via incidental contact with feces, with arboreal species harboring far more distinct communities than those of their terrestrial and semi-terrestrial counterparts.

Evaluation of the health, prevalence, and incidence of diseases in wild populations is a critical component of wildlife management. In addition, the establishment of reference physiologic parameters can Verreaux's sifaka (Propithecus verreauxi) from Kirindy Mitea National Park, Madagascar, during two field captures incontribute to the assessment of population risks. Complete medical evaluations were performed on 33 wild June 2010 and June 2011. Each animal received a complete physical examination: weight, body temperature, heart rate, and respiratory rate were recorded, and ectoparasites collected. Blood samples were collected for complete blood cell count, differential white blood cell count, hemoparasite examination, serum biochemical profile, fat-soluble vitamin analysis, trace mineral analysis, and toxoplasmosis and viral serology. Fecal samples were collected for bacterial culture and endoparasite examination. Significant differences exist between age classes for neutrophil and lymphocyte count, alkaline phosphatase, and creatinine values. Parasites detected were Callistoura sp., Bertiella lemuriformis, and Dipetalonema petteri. This publication reports the first complete biomedical evaluation of the P. verreauxi and provides a basis for hematologic and biochemical comparisons of P. verreauxi in the wild.