Female social dominance in two Eulemur species with different social organizations

Female social dominance is rare in mammals, but common in lemurs. We investigated social dominance in two Eulemur species; the polygynous crowned lemur (E. coronatus) and the monogamous red‐bellied lemur (E. rubriventer), using four and two social groups, respectively. We collected data on agonistic interactions and two types of affiliative behavior (grooming and maintaining spatial proximity). We used a combination of focal watches of individuals, instantaneous scan‐sampling of groups, and all‐occurrence of some behaviors in groups. We found that overall rates of agonistic interactions were higher in E. coronatus, and they also had more decided intersexual agonistic interactions than E. rubriventer. However, in both species the females won the vast majority of these agonistic interactions. E. coronatus females were groomed more often by males than vice versa, whereas no sex differences in grooming were observed in E. rubriventer. We found that males were responsible for maintaining spatial proximity in E. coronatus whereas in E. rubriventer, females were responsible. In one group of E. coronatus, the male was overweight and dominant to the female and this is the first observation of male dominance in a lemur species typically described as female dominant. We suggest that body weights in captivity be monitored for maintaining normal dominance relationships. Overall, agonistic behaviors were consistent with clear female social dominance in both E. coronatus and E. rubriventer. The affiliative behaviors also provided clear evidence for female dominance E. coronatus, but not for E. rubriventer. Zoo Biol 0: 1–14, 2007. © 2007 Wiley‐Liss, Inc.     

Normal nasal cavity and paranasal sinuses in brown lemurs Eulemur fulvus: computed tomography and cross-sectional anatomy

Background Far less is known about the normal anatomy of the nasal cavity of Eulemur fulvus; no computed tomography (CT) scan has ever been published. Methods Relevant CT scans were taken in the transverse, dorsal and longitudinal planes. These scans were compared with anatomical sections of heads. Results Computed tomography scans revealed almost all nasal structures, but cannot differentiate between the various layers of the nasal mucosa. Results show a double‐scroll arrangement of the ventral nasal concha. The dorsal nasal concha protrudes into the maxillary sinus, but no protrusion into the frontal sinus was observed. The ethmoturbinate I is completely closed back on itself and rostrally voluminous. Conclusions This work shows that at a clinical level, the integrity of the different turbinates can easily be appreciated from a simple CT scan. It will assist clinicians to evaluate pathological conditions that affect the nasal region.     

Characterization of 20 microsatellite marker loci in the red‐bellied brown lemur (Eulemur rubriventer)

Twenty nuclear microsatellite loci were isolated from a genomic DNA library derived from a free‐ranging red‐bellied brown lemur (Eulemur rubriventer), from the Ranomafana National Park, Madagascar. Population genetic parameters were estimated as baseline values from samples collected from populations harboured in the Ranomafana and Andringitra National Parks. The marker suite will be used in a future study on the population dynamics of this species.     

Organization of white adipose tissue in lemuridae

The gross anatomy of white adipose tissue was studied in seven carcasses representing three lemurid species (Lemur catta, Eulemur fulvus, E. mongoz) to validate in vivo methods of assessing fatness, and to contribute to a comprehensive database on the organization of adipose tissue in Mammalia. During the years preceding their deaths, subjects had been either caged or semi-provisioned under semi-captive conditions, and their body masses had been recorded several times annually. All specimens were as fat or fatter than anthropoid primates maintained for long periods under comparable conditions. At least eight superficial, four intra-abdominal, and two intermuscular adipose depots were described, all of which were comparable to those described previously for macaques and humans. All typical mammalian depots were present. Many superficial depots adhered tightly to the skin and/or underlying muscles. The superficial “paunch” depot on the outer ventral wall of the abdomen, characteristic of anthropoid primates, was found in all specimens. The existence of this depot in lemurs suggests that it evolved early in Primates. As in monkeys and humans, the paunch was very variable in size, massive in obese specimens but almost absent in moderately lean ones, confirming that extensive accumulation and selective depletion of adipose tissue at this depot is a special feature of Primates. In some obese specimens, adipose tissue on the ventral and lateral thorax and on the inner dorsal wall of the abdomen, extending around the kidneys and into the pelvic canal, was also massive. The investigation allowed for improvement of protocols for external measurement in ongoing research on growth, mass, and fatness in ringtailed and redfronted lemurs. Comparisons of subjects' ranges of body mass change during adult life with masses of adipose tissue found upon dissection suggested that much of lemurs' predictable seasonal change in body mass is due to changes in the mass of white adipose tissue. © 1995 Wiley-Liss, Inc.     

兀鹫在中国的分布

兀鹫(Gyps fulvus)隶属于隼形目(Falconiformes)鹰科(Accipitridae),被列入CITES附录Ⅱ,在国内几乎没有相应的研究。作者于2013年6月5日在西藏阿里地区改则县(33°6′52.2″N,85°39′9.18″E,海拔5 021 m)发现1只兀鹫。结合国内其他研究者的记录,此次发现增加了我们对兀鹫分布区的认识,表明了兀鹫在西藏的分布区可能被低估。根据以前研究者对兀鹫种群数量的估计值(100~300只)和平均群体大小(3只或4只或单只),以及本次的发现,我们认为兀鹫在新疆、西藏仍有未被发现的分布区,且在新疆、西藏的邻近省份可能存在其潜在分布区;此前兀鹫在西藏地区未有确切的观察记录或照片,本次记录可为西藏珍稀物种的保护提供依据。     

Colonization of ephemeral detrital patches by vagile macroinvertebrates in a brackish lake: a body size-related process?

The mechanisms regulating the build-up of invertebrate assemblages on ephemeral detritus patches are still poorly understood. Here, the daily colonization of decaying reed leaves by vagile macroinvertebrates was monitored in an brackish lake in Italy. The highly variable abundance patterns of dominant taxa were analysed by spectral and geostatistical techniques to test for nonrandomness and to further determine whether they were related to body size. Comparisons between two contrasting sites allowed an assessment of the generality of our observations. At both sites, the macroinvertebrate assemblage was dominated by three detritivorous taxa, i.e. the isopod Lekanesphaera monodi, the amphipod Microdeutopus gryllotalpa and the polychaete Neanthes caudata. Overall, their abundance patterns were characterised by short-term fluctuations of a nonrandom, autocorrelated nature. In addition, a significant covariation was observed between the average body mass of each taxon and the complexity of the respective abundance pattern, expressed by the fractal dimension D. The covariation was observed at both study sites, notwithstanding the diverging outcomes of bivariate pattern comparisons for similar-sized taxa. Our findings indicate that the size of macroinvertebrates is strongly related to the short-term dynamics of their abundance patterns on reed detritus, suggesting that the interaction between vagile consumers and ephemeral resource patches might be influenced by individual energetics. The implications of size-related constraints for the coexistence of species on decaying detrital patches are discussed.     

On the importance of body size in the colonisation of ephemeral resource patches by vagile consumers

A study on the colonisation of leaf detritus patches by vagile macroinvertebrates in a brackish lagoon is presented in the framework of a conceptual model where a body size-related constraint on patch use behaviour is explicitly considered. Abundance patterns of dominant macroinvertebrate taxa were characterised by short-term, non-random fluctuations, showing significant site-dependent variations. Yet, a site-independent covariation was observed between patterns’ fractal dimension and the average body mass of each taxon, indicating that, while the temporal scales characterising the colonisation patterns may be highly species-specific, cross-species generalisations are possible based on body size. The generality of these results was supported by literature data on temporal patterns of carcass colonisation by bathyal fish. The importance of size-related mechanisms in regulating the aggregation of vagile consumers on resource patches and, ultimately, their coexistence at both an inter- and intra-specific level, is discussed.     

Foraging site use and interspecific competition between bluegills and golden shiners

Synopsis Laboratory experiments examined the foraging performances of a dietary generalist, bluegill,Lepomis macrochirus, and a dietary specialist, golden shiner,Notemigonus crysoleucas, as they fed from devices simulating four foraging sites (bottom substrate, water column, submerged macrophytes, and water surface). Fishes foraged in monospecific and mixed-species groups of two and four individuals. For monospecific groups, foraging rates of bluegills did not differ among the four sites, but golden shiners had significantly higher rates on bottom and midwater sites than on plant and surface sites. The size of monospecific groups did not affect foraging rates of either species. In mixed-species trials, bluegills removed more food items than golden shiners from plant and surface sites in two- and four-fish groups and from bottom sites in two-fish groups. Bluegills' foraging performances improved with experience, golden shiners' performances did not. Experimental results are discussed with respect to interactions between bluegills and golden shiners in natural assemblages.     

Paternity Determination in Two Groups of Eulemur fulvus mayottensis: Implications for Understanding Mating Strategies

We used random amplified polymorphic DNA (RAPD) to determine paternity in two groups of brown lemurs (Eulemur fulvus mayottensis). We analyzed the results in relation to behavioral data on observed copulations, dominance relationships among adult males, and female behavior. The association between paternity determination and behavioral sampling shows that paternity determination is a crucial tool for understanding the mating strategies and reproductive success in the studied species. In brown lemurs, dominance relationships between males are correlated with reproductive success, but male social dominance could be altered by female choice as suggested by the ability of subordinate males to sire offspring in the presence of a dominant male.