Demography and life history of free-rangingPropithecus diadema edwardsi in ranomafana national park,madagascar

I conducted the first long- term study of the life history patterns of Propithecus diadema edwardsi—Milne- Edward’s sifaka— in the rain forests of southeastern Madagascar, beginning in 1986. I report behavioral observations on a total of 33 individuals from three groups over a 9- year span. We captured,marked, and released 21 individuals. Individual group size ranged from three to nine sifakas. Two breeding females lived in groups I and II until 1993. A newly formed group (III) had one breeding female. Age at first reproduction is 4 years for females and 5 years for males. Gestation length is 179 days (n =2). Most births occurred in June (n = 17), but infants were also born in May (n = 2) and July (n =2). Nine of 21 (43%) infants born died before the age of 1 year, and 15 (67%) died before the age of reproduction. One female bred in her natal group after the death of the resident male and the immigration of an adult male. Another two females disappeared at 4 and 5 years of age;they could have emigrated or died. All 5- to- 6- year- old males (n = 4) have emigrated from their natal groups to adjacent groups. Two have committed infanticide. Five or more individuals were killed by Cryptoprocta ferox.Despite high mortality and offspring dispersal, the number of individuals in the two main groups remained nearly the same over the 9- year study.     

Responses to recent climatewarming of Pinus sylvestris and Pinus cembra within their montane transition zone in the Swiss Alps

Abstract. Altitudinal and latitudinal distribution limits of trees are mainly controlled by temperature. Therefore climate warming is expected to induce upslope or poleward migrations. In the Swiss Central Alps, summers in the period 1982-1991 were on average 0.8 °C warmer than those of the period 30 yr before. We investigated whether populations of conifers at the montane Pinus sylvestris-Pinus cembra ecocline exhibit demographic trends in response to that warming. We found no evidence for this. Young seedlings of Pinus sylvestris, the species which is expected to expand its range upward in a warmer climate, were virtually absent from all sites, whereas large fractions of Pinus cembra populations were observed in the seedling and juvenile categories even below the present lower distribution limit of adult trees. This suggests that there are no major altitudinal shifts in response to the recent sequence of warmer summers. Germination and seedling survival trials with Pinus sylvestris suggest that temperature per se would not exclude this species even from establishing at the current treeline in the Swiss Central Alps. Similar results were found at the polar treeline. Phytotron tests of seedling survival showed much less drought resistance in Pinus sylvestris than in Pinus cembra which is in contrast to their phytogeographic distributions. Thus, the montane pine ecocline in the Swiss Central Alps seems to be stabilized by species interactions and may not be directly responsive to moderate climatic change, which needs to be taken into account in predictive attempts.     

植物生活史对策的进化

植物生活史对策的进化班勇（中国林业科学院林业研究所,北京１０００９１）ＥｖｏｌｕｔｉｏｎｏｆＬｉｆｅＨｉｓｔｏｒｙＳｔｒａｔｅｇｙｉｎＰｌａｎｔｓ￥ＢａｎＹｏｎｇ（ＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＦｏｒｅｓｔｒｙ,ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏ...     

Genetic diversity and structure of Pinus dabeshanensis revealed by expressed sequence tag-simple sequence repeat (EST-SSR) markers

Assessing patterns of genetic variation in rare endangered species is critical for developing both in situ and ex situ conservation strategies. Pinus dabeshanensis Cheng et Law is an endangered species endemic to the Dabieshan Mountains of eastern China. To obtain fundamental information of genetic diversity, population history, effective population size, and gene flow in this species, we explored patterns of genetic variation of natural populations, in addition to an ex situ conserved population, using expressed sequence tag-simple sequence repeats (EST-SSR) markers. Our results revealed moderate levels of genetic diversity (e.g., H_E = 0.458 vs. H_E = 0.423) and a low level of genetic differentiation (F_ST = 0.028) among natural and conserved populations relative to other conifers. Both contemporary and historical migration rates among populations were high. Bayesian coalescent-based analyses suggested that 3 populations underwent reductions in population size ca. 10,000 yr ago, and that two populations may have experienced recent genetic bottlenecks under the TPM. Bayesian clustering revealed that individuals from the ex situ population were largely assigned to the ‘red’ cluster. Additionally, our results identified private alleles in the natural populations but not in the ex situ population, suggesting that the ex situ conserved population insufficiently represents the genetic diversity present in the species. Past decline in population size is likely to be due to Holocene climate change. Based on the genetic information obtained for P. dabeshanensis, we propose some suggestions for the conservation and efficient management of this endangered species.     

Experimental manipulation of tail length in female barn swallows (Hirundo rustica) affects their future reproductive success

Previous studies have shown no significant effect of experimentaltail length manipulation in female barn swallows (Hirundo rustica)at the beginning of a breeding season on reproductive successor behavior during that breeding season. In the present study,we investigate if tail length manipulation had any effect onreproductive performance the following year, the so-called long-termeffect, in contrast to the short-term effects already studied.We found that females with experimentally elongated externaltail feathers at the beginning of a breeding season producedless offspring during the breeding season the following yearthan did females with shortened or unmanipulated tails. Theseresults suggest that tail elongation caused flight deficienciesthat deteriorated the condition of females and eventually reducedreproductive success. The finding of long-term effects but nosignificant short-term effects for female tail elongation suggeststhat female barn swallows have the ability to adjust immediateparental investment. Detrimental effects of long tails in femalesin terms of decreased reproductive success might explain whyfemale tails are not as long as those of males. Finally, femalesmated to long-tailed (sexually attractive) males decreased theirreproductive success the following year more than did femalesmated to short-tailed males, possibly owing to differentialparental effort causing a deterioration of their condition.     

日本志留纪至三叠纪牙形刺生物地层

本文系统地回顾了日本志留纪至三叠纪牙形刺研究的历史和现在的成果。志留纪牙形刺只有少数零星的报道,没有建立化石带;早泥盆世已建立了５个牙形刺组合,没有中、晚泥盆世的记录;石炭纪有８个牙形刺带,其中晚石炭世３个牙形刺带;二叠纪５个牙形刺带或动物群,其中,中、晚二叠世各１个带（动物群）;三叠纪可划分出１４个牙形刺带。     

Life history of a lacustrine ostracod

The ostracod Cypria turneri has one generation per year in Mirror Lake, New Hampshire. Juveniles hatch in January through May and reach maturity by August. The life history of this ostracod suggests that the turnover rate of the population is low.     

Ancestral and neo-sex chromosomes contribute to population divergence in a dioecious plant

Empirical evidence from several animal groups suggests sex chromosomes disproportionately contribute to reproductive isolation. This effect may be enhanced when sex chromosomes are associated with turnover of sex determination systems resulting from structural rearrangements to the chromosomes. We investigated these predictions in the dioecious plant Rumex hastatulus, which is composed of populations of two different sex chromosome cytotypes caused by an X-autosome fusion. Using population genomic analyses, we investigated the demographic history of R. hastatulus and explored the contributions of ancestral and neo-sex chromosomes to population genetic divergence. Our study revealed that the cytotypes represent genetically divergent populations with evidence for historical but not contemporary gene flow between them. In agreement with classical predictions, we found that the ancestral X chromosome was disproportionately divergent compared with the rest of the genome. Excess differentiation was also observed on the Y chromosome, even when we used measures of differentiation that control for differences in effective population size. Our estimates of the timing of the origin of neo-sex chromosomes in R. hastatulus are coincident with cessation of gene flow, suggesting that the chromosomal fusion event that gave rise to the origin of the XYY cytotype may have also contributed to reproductive isolation.     

The influence of environmental instability on the reproductive strategy of the critically endangered Acıgöl killifish (Aphanius transgrediens)

To investigate the variability in the reproductive tactics of Acıgöl killifish (Aphanius transgrediens), one of the most seriously threatened freshwater teleost species, this study compared its reproductive ecology in two contrasting habitats that differ substantially in terms of stability of environmental parameters, particularly salinity regime (stable vs. unstable). Fish were sampled monthly from October 2013 to September 2014 with the aim of testing whether the reproductive life-history response of fish to stable and unstable conditions differed. The reproductive effort (gonad weight) of both sexes did not differ significantly between the two habitats, but females in the unstable habitat had significantly lower fecundity and larger eggs. The relationship between fecundity and fish size was stronger in the stable habitat, whereas the relationship was quite variable and uncertain in the unstable habitat. Fish born in the unstable habitat reached their first maturity at a smaller size than those in the stable habitat. The gonado-somatic index and the duration of hydrated eggs showed that reproduction continued from February to May in both habitats; nonetheless, a second spawning event occurred during July and August in the unstable habitat, which included the reproductive contributions of YOY individuals and older generations. This study’s results suggest that A. transgrediens employs varying reproductive strategies against environmental instability in its restricted unique range. This may have further implications for the ways in which habitat-specific conservation methods are used.