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1.
Prosimian and anthropoid females are generally thought to have divergent reproductive patterns, characterized by circumscribed and situation-dependent receptivity. This dichotomy underpins the traditional view that nonreproductive mating serves a social function in anthropoid females, distinguishing them from prosimians which, like most other mammals, mate only when conception is most probable. Circumscribed estrous cycles differ from anthropoid menstrual cycles by the presence of menstruation, and greater flexibility in timing and longer duration of receptivity in the latter. The degree to which sexual behavior is tightly synchronized to periovulatory events in Propithecus verreauxi was assessed via the behavioral, hormonal, and social correlates of reproduction in a free-ranging population. I collected data from two social groups before and during the 1990–1991 and 1991–1992 breeding seasons at Beza Mahafaly, Madagascar. I also conducted 644 focal-animal hours and collected 485 fecal samples from five marked females in the Vaovao and Vavy Masiaka social groups. Estrus was behaviorally characterized by 0.5–96-h periods of receptivity when females were motivated and willing to mate, the latter not always coincident with periovulatory events. Females exhibited age- and rank-related asynchronous receptivity, and in some cases, periovulatory synchrony within groups. Sifaka were not pair-bonded. Most females mated with multiple males, temporally ordering partners based on male residence and age. Mating was limited by male mate-guarding and sexual aggression by males, female mate competition, and aversions to mating with certain partners. It was facilitated by surreptitious copulations, positive mate choice, and the availability of non-resident mating partners.  相似文献   

2.
In 1987, a long-term study of the demography of Lemur catta was begun in southern Madagascar. Eighty-five ringtailed lemurs were captured, marked, and released. Adult age classes were estimated using patterns of dental attrition. Including young, 155 individuals from nine groups were identified and monitored over 18 months. The study population of the reserve remained stable, with a growth rate of 0.98. Group sizes ranged from nine to 22 individuals (mean 14). Home ranges were larger (32 ha) and population densities lower (135/km2) than those for previously studied populations, and there was a relationship between habitat quality (e.g., no. of large trees) and these factors. At the beginning of the study, there were more adult males than females, but the sex ratio reached 1.00 by the last census. Females first gave birth at 3 years of age, and 80% or more of the females gave birth in 2 consecutive years. Fifty-two percent of the infants died in the first year and, given preliminary findings, only 40% of those born reach adulthood. Age-specific fertility patterns were similar to those reported for anthropoid primates. Forty-seven percent of the adult males migrated or were missing within a year. This included 78% of the 3–4 year olds and 38% of older age classes. No females were observed to migrate. One group split during the study. Demographic patterns are discussed and related to patterns in other populations of ringtailed lemurs as well as in anthropoids.  相似文献   

3.
Observations of antipredator behavior in two troops of free-rangingLemur catta were made during a 13-month study ofL., catta feeding ecology. Both responses to and frequency of encounters with other species were recorded. Ringtailed lemur antipredator calls differentiated between terrestrial and avian predators. L. catta responded to the Madagascar harrier hawk (Polyboroides radiatus) and the Madagascar buzzard (Buteo brachypterus) in a specific manner that differed from their reaction to the other bird of prey in the reserve, the Black kite (Milvus migrants) and to potential mammalian and reptilian predators. Encounters with avian predators peaked during the birth season and when infants were being weaned. These periods coincide with previously observed nesting periods for the Harrier hawk and the buzzard, and with times when their offspring are fledged. Both were periods whenL. catta infants might have been especially vulnerable to prédation.  相似文献   

4.
Observations of reproductive behavior in free-ranging Lemur catta were carried out during one annual cycle. Variability in the behavior of female ringtailed lemurs during parturition appears to be mainly a function of the female's parity and thus her experience. Females within a troop show estrous asynchrony and characteristically mate with more than one male. Females also exhibit proceptive behavior toward and mate with some males from other troops and with transferring males. The potential for a male to monopolize mating opportunities during a female's short estrous period is therefore limited. Male mating strategies in ringtailed lemurs can be seen as adaptations to female mate choice during a highly restricted breeding season. In this species the dominance hierarchy does not break down with regard to the order of mating. The highest ranking male (central male) mates first and shows precopulatory guarding and longer postejaculatory guarding, which may increase his chances of siring the offspring. Subsequent mating partners have developed various counterstrategies to mitigate mating order effects.  相似文献   

5.
Studies of primate diets usually focus on differences that distinguish species or populations. However, variation in diet can occur at a more local level of groups within a population, especially in a non-homogeneous habitat. I compared dietary variation in food composition and toughness across groups of 2 lemur species in Beza Mahafaly special reserve, Madagascar. Beza Mahafaly contains an 80-ha reserve (Parcel 1) that, while small, hosts a dense population of Lemur catta (ring-tailed lemurs) and Propithecus verreauxi verreauxi (sifakas). Microhabitats in the eastern vs. western sides of the parcel are structurally and floristically distinct. Sifakas in this parcel have small, discrete home ranges and are morphological folivores. For these reasons, I expected that the 6 groups studied would eat a different menu of food plants but with similar toughness values. Ring-tailed lemurs have comparatively large, overlapping home ranges, and I expected that the 5 study groups would eat similar foods. Despite living in different microhabitats across the parcel, sifakas exhibit high dietary uniformity both in dietary plant species composition and the toughness of the foods. Food selection in sifakas operates on two distinct levels. Sifaka groups share many key food species that appear independent of local abundances, but the ranking of the foods within each group appears related to availability. Ring-tailed lemur groups are more heterogeneous in the composition of their diets relative to sifakas, though the time spent feeding on individual foods reveals a marked preference for the fruits of Tamarindus indica by all groups. Food toughness is consistent across the parcel with the exception of the most western group. Ring-tailed lemurs are highly specific feeders, but indiscriminate nibblers. Sifakas are targeted, balanced feeders. There does not appear to be a consistent microhabitat effect operating across species. Differences within sifaka and ring-tailed lemur populations in food composition and toughness, however, correspond to an east-west microhabitat gradient. Measures of dietary flexibility must take into account not only the plant species consumed and the different parts eaten but also their associated food properties and proportion of time spent feeding on them.  相似文献   

6.
The dry spiny forest of southern Madagascar is a highly unpredictable environment in terms of the amount and distribution of rainfall. The region is also subject to marked El Niño oscillations. One of the inhabitants of the region is Microcebus griseorufus (Kollman, 1910), the reddish-grey mouse lemur. During the 4 yr of the study, the focal population underwent marked fluctuations in size and exhibited a relatively long reproductive season: September–May. Subjects used daily torpor and expressed opportunistic seasonal fattening when food availability was high. They fed mainly on gum, especially during periods of drought. The estimated sex-ratio of the population is 54% female. Young males dispersed. Females and less frequently, males, associated in same-sex pairs that sometimes joined to form larger sleeping groups. I observed both erratic and resident males, the latter sometimes associated with females in sleeping groups. Mating occurred from September to January and involved mate-guarding. Individual female home ranges (N?=?14) overlapped with, on average, 2.8?±?0.3 male home ranges (range 2–5), whereas individual male home ranges (N?=?12) overlapped with 4.7?±?0.4 female home ranges (range 2–7). Female estrus was not synchronized, even within the female pairs, allowing alloparental care. Gestation lasted 52 d in 1 female, and litter size could be as high as 3; 20 reproductive females out of 37 adult females raised only 1 or 2 young per year.  相似文献   

7.
Increasing evidence supports the idea that endemic avian and mammalian predators have profoundly impacted primate populations in Madagascar (Goodman, S. M. Predation on lemurs. In S. M. Goodman, & J. P. Benstead (Eds.), The natural history of Madagascar (pp. 1221–1228). Chicago: University of Chicago Press, (2003).). The role in regulating lemur populations of the 3 introduced mammalian carnivorans —small Indian civets (Viverricula indica, Desmarest 1804), domestic dogs (Canis lupus familiaris, Linnaeus 1758), and invasive wildcats (Felis silvestris, Schreber 1775)— is less clear, but recent evidence suggests that the latter 2 are becoming important predators of diurnal lemurs. We report evidence for invasive wildcat predation on sifaka (Propithecus verreauxi verreauxi) in Parcel 1 at Beza Mahafaly Special Reserve, Madagascar, including skeletal remains of apparent Propithecus sifaka victims, observations of wildcat predatory behavior, and behavioral responses of the lemurs in the presence of wildcats.  相似文献   

8.
Insects that vector pathogens are under constant surveillance in Australasia although the repertoire of genetic markers to distinguish what are often cryptic mosquito species remains limited. We present a comparative assessment of the second exon–intron region of the acetylcholine esterase 2 gene (ace-2) and the mitochondrial DNA cytochrome c oxidase I (COI) using two closely related Australasia mosquitoes Culex annulirostris and Culex palpalis. The COI revealed eight divergent lineages of which four were confirmed with the ace-2. We dissect out the nuclear chromosomal haplotypes of the ace-2 as well as the exon–intron regions by assessing the protein’s tertiary structure to reveal a hypervariable 5’-exon that forms part of an external protein loop and displays a higher polymorphic rate than the intron. We retrace the evolutionary history of these mosquitoes by phylogenetic inference and by testing different evolutionary hypotheses. We conclude that DNA barcoding using COI may overestimate the diversity of Culex mosquitoes in Australasia and should be applied cautiously with support from the nuclear DNA such as the ace-2. Together the COI and ace-2 provide robust evidence for distinct cryptic Culex lineages—one of which correlates exactly with the southern limit of Japanese encephalitis virus activity in Australasia.  相似文献   

9.
Connections between species diversity and genetic diversity   总被引:7,自引:1,他引:7  
Species diversity and genetic diversity remain the nearly exclusive domains of community ecology and population genetics, respectively, despite repeated recognition in the literature over the past 30 years of close parallels between these two levels of diversity. Species diversity within communities and genetic diversity within populations are hypothesized to co‐vary in space or time because of locality characteristics that influence the two levels of diversity via parallel processes, or because of direct effects of one level of diversity on the other via several different mechanisms. Here, we draw on a wide range of studies in ecology and evolution to examine the theoretical underpinnings of these hypotheses, review relevant empirical literature, and outline an agenda for future research. The plausibility of species diversity–genetic diversity relationships is supported by a variety of theoretical and empirical studies, and several recent studies provide direct, though preliminary support. Focusing on potential connections between species diversity and genetic diversity complements other approaches to synthesis at the ecology–evolution interface, and should contribute to conceptual unification of biodiversity research at the levels of genes and species.  相似文献   

10.
Coprophagy occurs in a number of animal species, including nonhuman primates. During the 2003-2004 dry seasons at the Beza Mahafaly Special Reserve, Madagascar, we observed wild ring-tailed lemurs (Lemur catta) consuming dried fecal matter from three different species. Ring-tailed lemurs consumed human feces on 12 occasions, cattle feces twice, and feral dog feces once. Coprophagy in this population may be a behavioral adaptation that provides animals access to energy and nutrients and may be an important nutritional source for older, and/or dentally impaired individuals during the dry season.  相似文献   

11.
12.
Bamboo is an important member of the giant grass subfamily Bambusoideae of Poaceae. In this study, 13 bamboo accessions belonging to 5 different genera were subjected to morphological evaluation and sequence-related amplified polymorphism (SRAP) analysis. Unweighted pair-group method of arithmetic averages (UPGMA) cluster analysis was used to construct a dendrogram and to estimate the genetic distances among accessions. On the basis of morphological characteristics, the 13 accessions were distinctly classified into 2 major clusters; 3 varieties, PPYX, PGNK, and PLYY were grouped as cluster A, and 10 accessions were categorized under cluster B. Similarity coefficients ranging from 0.23 to 0.96 indicated abundant genetic variation among bamboo varieties. Approximately 38 SRAP primer combinations generated 186 bands, with 150 bands (80.65%) showing polymorphisms among the 13 accessions. Based on SRAP analysis, 13 bamboo accessions were grouped into 3 major clusters. Five species comprised Cluster I (PASL, PLYY, PTSC, SCNK, and BMAK), which belongs to genus Phyllostachys. Cluster II consisted of 5 varieties, PASL, PLYY, PTSC, SCNK, and BMAK; Cluster III included 3 varieties, PGNK, PLSY, and BMRS. Comparison of the results generated by morphological and SRAP analyses showed that the classification based on SRAP markers was more concordant to the taxonomic results of Gamble than that performed using morphological characters, thus suggesting that SRAP analysis is more efficient in evaluating genetic diversity in bamboos compared to morphological analysis. The SRAP technique serves as an alternative method in assessing genetic diversity within bamboo collections.  相似文献   

13.
The genus Linum L. (Lineacea) has over 15 species, subspecies or ecotypes in Iran. These species show extensive geographical distribution and form many local populations throughout the country. Linum album is herbaceous medicinal plant containing important lignans such as podophyllotoxin (PTOX) and 6-methoxy podophyllotoxin (MPTOX), which have antiviral and anticancer properties. Studying the genetic and morphological diversity of different geographical populations produces detailed knowledge about population divergence and identification of the infra-species taxa if at all they are present. Moreover, the populations that differ in their genetic content and structure may also differ in their chemical and medicinal properties. The present study considers morphological and genetic diversity analyses of 20 L. album geographical populations by using nuclear ISSR markers, genome size, and cytogenetic characteristics. These populations differed significantly in many of their quantitative morphological characters and in some of their qualitative features. They also differed significantly in their molecular characteristics and genome size. Details of morphological and molecular variations are reported and discussed.  相似文献   

14.
Chemical deterioration of teeth is common among modern humans, and has been suggested for some extinct primates. Dental erosion caused by acidic foods may also obscure microwear signals of mechanical food properties. Ring-tailed lemurs at the Beza Mahafaly Special Reserve (BMSR), Madagascar, display frequent severe tooth wear and subsequent tooth loss. In contrast, sympatric Verreaux's sifaka display far less tooth wear and infrequent tooth loss, despite both species regularly consuming acidic tamarind fruit. We investigated the potential impact of dietary acidity on tooth wear, collecting data on salivary pH from both species, as well as salivary pH from ring-tailed lemurs at Tsimanampesotse National Park, Madagascar. We also collected salivary pH data from ring-tailed lemurs at the Indianapolis Zoo, none of which had eaten for at least 12 hr before data collection. Mean salivary pH for the BMSR ring-tailed lemurs (8.098, n=41, SD=0.550) was significantly more alkaline than Verreaux's sifaka (7.481, n=26, SD=0.458). The mean salivary pH of BMSR (8.098) and Tsimanampesotse (8.080, n=25, SD=0.746) ring-tailed lemurs did not differ significantly. Salivary pH for the Indianapolis Zoo sample (8.125, n=16, SD=0.289) did not differ significantly from either the BMSR or Tsimanampesotse ring-tailed lemurs, but was significantly more alkaline than the BMSR Verreaux's sifaka sample. Regardless of the time between feeding and collection of pH data (from several minutes to nearly 1 hr), salivary pH for each wild lemur was above the "critical" pH of 5.5, below which enamel demineralization occurs. Thus, the high pH of lemur saliva suggests a strong buffering capacity, indicating the impact of acidic foods on dental wear is short-lived, likely having a limited effect. However, tannins in tamarind fruit may increase friction between teeth, thereby increasing attrition and wear in lemurs. These data also suggest that salivary pH varies between lemur species, corresponding to broad dietary categories.  相似文献   

15.
Eighty-five sifakas (Propithecus verreauxi) have been captured, marked, released, and monitored between September 1984 and August 1988 at the Beza Mahafaly Special Reserve in southwest Madagascar. Estimates are presented of the age and sex structure of this population and of age-specific fertility and survival. Using data from this and other studies, it is shown that sifaka tertiary sex ratios do not depart significantly from 50:50, but that they do differ significantly from those of haplorhine primates, which have strongly female-biased tertiary sex ratios. Two demographic mechanisms that could give rise to this distinction are considered: 1) intermittently male-biased birth cohorts among sifakas and 2) different patterns of survivorship in haplorhines and sifakas.  相似文献   

16.
Hessen  Dag O.  Rueness  Eli K.  Stabell  Marianne 《Hydrobiologia》2004,519(1-3):73-84
This study presents a first circumpolar screening of the taxonomic and genetic diversity of the crustacean Lepidurus arcticus, belonging to the ‘living fossil’ order Notostraca. Sequencing of a 484 bp segment of the mitochondrial 12S rDNA from 48 populations revealed two distinct haplogroups, each consisting of separate haplotypes. Alignment with published sequences of other species of Lepidurus clearly revealed that all of the studied populations were distinctly different from other species. Some major geographical patterns for distribution of haplogroups and haplotypes were identified, perhaps the most remarkable being the difference in distribution of haplogroups between the neighbouring Svalbard and Bear Island where a larger number of populations were studied. On the Norwegian mainland both haplogroups co-occurred in the same areas, however, and strong conclusions of the distributional pattern are yet premature. The distribution of similar haplotypes over wide geographical ranges suggests high dispersal abilities by Lepidurus. Morphological taxonomic criteria assign all surveyed populations to L. arcticusin spite of a pronounced morphological plasticity. Analysis of major morphological features such as length:width ratio of cephalothorax, the cephalothorax:abdominal length ratio, size of supra-anal plate and eye morphology revealed some distinctive population specific properties. The two major haplogroups differed significantly with regard to the relative size of the supra-anal plate, which also is a standard taxonomic criterion. This first genetic screening of a limited number of populations suggests that a subtler genetic diversity will be revealed when including more populations over a larger geographic area as well as a finer geographical resolution.  相似文献   

17.
Cladistic and taxonomic treatments of the same plant group usually exhibit a mixture of congruences and incongruences. The question arises in the case of the incongruences as to which version is right and which is wrong. Many cladists believe that cladistics is a superior approach and gives the best results. There are several conceptual and methodological differences between cladistics and taxonomy that cause incongruence. One important conceptual difference is the use of different criteria for grouping: order of branching vs. similarity and difference (clades vs. taxa). Another is the policy regarding paraphyletic groups: to ban them in cladistics but ignore the ban in taxonomy. These two differences automatically lead to some incongruences. One approach is not right and the other wrong; each is operating by its own standards. However, when cladists apply the paraphyly rule to a taxonomic system and conclude that it needs revision to eliminate paraphyly, as cladists often do, they are judging the taxonomic system by a wrong standard. Several differences between the two schools in the use and handling of characters can also cause incongruence. First consider phenetic characters. Taxonomy uses a very wide range of these, whereas phenetic cladistics sets restrictions on the selection of characters, which deprive it of potentially useful evidence. Taxonomic systems generally rest on a broader empirical foundation than phenetic cladistic systems. Next, consider molecular cladistics, which is the leader in the use of DNA evidence. Two sources of incongruence between molecular cladistics and taxonomic systems can come into play here. First, the molecular evidence used in cladistics comes mainly from cytoplasmic organelles, whereas taxonomic systems are based on characters that are determined mainly by the chromosomal genome. More generally, the database in a molecular cladogram is, in itself, too narrow to serve as a foundation for an organismic classification. In cases of incongruence, the molecular evidence can be a reliable indicator of taxonomic relationships sometimes, misleading other times, and may afford no clear basis for a systematic decision. In this situation, it is helpful, indeed necessary, to integrate the molecular evidence with the phenetic evidence and bring more characters to bear on the question.  相似文献   

18.
An expanded matrix of morphological characters for the genus Aramigus (Coleoptera: Curculionidae), which includes numerous polyploid parthenogenetic lineages, was compared and combined with a published matrix of mitochondrial DNA (mtDNA) characters. The matrix of morphological characters provides little resolution of the A. tessellatus and A. uruguayensis species complexes but does resolve previously unresolved relationships among other morphologically defined species (A. globoculus + A. intermedius, A. curtulus + A. planioculus). The morphological and mtDNA characters are significantly incongruent (0.435 < or = IM < or = 0.463; IMF = 0.0735), according to the tests of Farris et al. (P = 0.010) and Templeton (P < 0.005), probably because of hybrid origins of polyploid parthenogenetic lineages. For the few sexual lineages included in both matrices, morphology and mtDNA provide congruent estimates of phylogeny. In spite of recent injunctions against combining data sets that are incongruent because of differing histories, the results of the combined analyses were used to select one of the most-parsimonious mtDNA trees as the best estimate of maternal-lineage genealogy and to reconstruct the evolution of parthenogenesis under the assumption that transitions from sexuality to parthenogenesis are irreversible. Where cytogenetically justified, as in weevils, the irreversibility assumption is useful for producing conservative estimates of the age of parthenogenetic lineages in spite of potential sampling bias against sexuals.  相似文献   

19.
Like most of Madagascar's endemic primates, ring‐tailed lemurs (Lemur catta) face a number of threats to their survival. Although habitat loss is of greatest concern, other anthropogenic factors including environmental contamination may also affect lemur health and survival. In this study, we examined ring‐tailed lemurs from the Beza Mahafaly Special Reserve (BMSR), southern Madagascar for exposure to organochlorine (OC) pesticides and metals and examined differences in contaminant concentrations between sexes and among age groups, troops, and habitats. A total of 14 pesticides and 13 metals was detected in lemur blood (24 individuals) and hair (65 individuals) samples, respectively. p,p′‐DDT, heptachlor, aldrin, heptachlor epoxide, endrin aldehyde, and endrin were among the most prevalent pesticides detected. Surprisingly, the persistent metabolite of p,p′‐DDT, p,p′‐DDE, was not detected. The most commonly detected metals were aluminum, zinc, boron, phosphorus, silicon, and copper, whereas metals considered more hazardous to wildlife (e.g. arsenic, cadmium, lead, selenium, vanadium) were not found above detection limits. Overall, concentrations of OC pesticides and metals were low and similar to those considered to be background concentrations in other studies examining the ecotoxicology of wild mammals. Few inter‐sex, ‐age, ‐troop, and ‐habitat differences in contaminant concentrations were observed, suggesting a uniform distribution of contaminants within the reserve. Several statistically significant relationships between lemur body size and contaminant concentrations were observed, but owing to the lack of supportive data regarding contaminant exposure in wild primates, the biological significance of these findings remains uncertain. Results of this study document exposure of ring‐tailed lemurs at BMSR to multiple OC pesticides and metals and provide essential baseline data for future health and toxicological evaluations of lemurs and other wild primates, especially those in regions with expanding agricultural and mining operations. Am. J. Primatol. 71:998–1010, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

20.
The butterfly genus Zizina in New Zealand has a complex taxonomic history due to the presence of morphological intermediates between the two species, the endemic Z. oxleyi and the introduced Z. labradus, in a putative hybrid zone on the east coast of the South Island of New Zealand. This makes species identification in the field problematic, particularly as the presence of hybrids has not been confirmed. We address this uncertainty through morphological and molecular analyses. Specimens were collected from a range of locations in New Zealand, as well as from Australia, and measurements were made of male genitalia and ventral wing coloration. Two mitochondrial genes (COI, ND5) and three nuclear gene fragments (28S, ITS2 and wingless) were also sequenced for a selection of individuals, and the presence of Wolbachia species in genomic DNA was tested. The two species were separable in morphological space, although there was some overlap, and the contact zone appeared to be around Kaikoura on the east coast of the South Island. Furthermore, specimens from the putative hybrid zone could be classified as Z. oxleyi using morphological characters individually, but not when these were used in a principal component analysis. Molecular analysis showed that there was a mean sequence divergence of 2.0% between two clades for COI, and 4.1% for ND5, but suggested that the contact zone between them was in the north‐west of the South Island. However, there was only a single clade for each of the three nuclear markers. It is thought that this incongruence between morphological and molecular markers is indicative of hybridization which is more extensive than previously thought. However, the possibility that recent speciation has occurred or is occurring is not ruled out.  相似文献   

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