The population dynamics of the voleClethrionomys rufocanus in Hokkaido, Japan

Population dynamics of the gray sided-vole,Clethrionomys rufocanus, in Hokkaido, Japan were described on the basis of 225 time series (being from 12 to 31 years long); 194 of the time series have a length of 23 years or longer. The time series were classified into 11 groups according to geographic proximity and topographic characteristics of the island of Hokkaido. Mean abundance varied among populations from 1.07 to 21.07 individuals per 150 trap-nights. The index of variability for population fluctuation (s-index) ranged from 0.204 to 0.629. Another index for population variability (amplitude on log-10 scale) ranged from 0.811 to 2.743. Mean abundance and variability of populations were higher in the more northern and eastern regions of the island. Most populations, except for the southernmost populations, exhibited significant direct density-dependence in population growth. Detection rate for delayed density-dependence varied among groups from 0% to 22.6%. Both direct and delayed density-dependence tended to be stronger in the more northern and eastern populations. The proportion of cyclic populations was higher in the northern-eastern areas than that in the southern-western areas. There was a clear gradient from the asynchronous populations in southwest, to the highly synchronized populations in the northeast.     

Social organization of the voleClethrionomys rufocanus and its demographic and genetic consequences: A review

Recent findings on the relationship between social interaction and demographic process in the gray-sided voleClethrionomys rufocanus are reviewed with reference to the findings in other microtine rodents. Social behavior was particularly focused on spacing and dispersal, and their effects on population dynamics are discussed. Female territoriality can limit a population abundance as a density-dependent factor, although its regulatory effect is controversial. Female philopatry and male-biased dispersal should bring about the clumped distribution of female relatives and genetically random distribution of males during the breeding season. The sexual difference in dispersal patterns can contribute to the mating behavior of the vole; promiscuous mating and low frequency of incestuous mating. However, effects of social structure, including kinship, on reproduction and survival of individuals still remains to be clarified. Molecular markers may help to solve these issues and provide new field of population ecology in microtine rodents.     

The biology of the voleClethrionomys rufocanus: A review

The biology of the gray-sided voleClethrionomys rufocanus in Hokkaido, concerning taxonomy, morphology, phylogeny, distribution, and natural history, is reviewed. Applied issues in forest management (damage, control and census) are also mentioned. AlthoughClethrionomys rufocanus of Hokkaido was originally identified as a distinct species,Evotomys (=nowClethrionomys) bedfordiae Thomas, 1905, current literature generally refers to the gray-sided vole of Hokkaido asClethrionomys rufocanus or asC. rufocanus bedfordiae (vernacular name, the Bedford’s red-backed vole). The gray-sided vole is the most common small mammal in Hokkaido. It inhabits open areas as well as forests, and mainly feeds on green plants. The gray-sided vole has a high reproductive potential; litter size: 4–7; gestation period: 18–19 days; maturation age: 30–60 days old. Although spring-born individuals usually attain sexual maturity in their summer/fall of birth, their maturation is sometimes suppressed under high densities. The breeding season is generally from April to October, but with some regional variation.Clethrionomys rufocanus has a rather specialized diet (folivorous), particularly during winter when it feeds on bamboo grass. Many predators specialize on the grey-sided vole in Hokkaido; even the red fox, which is a typical generalist predator, selectively feeds on this vole. Damage by voles’ eating bark used to be sever on forest plantations in Hokkaido. Censuses of small rodents have been carried out for management purpose since 1954.     

A molecular genetic analysis of the communal nesting of the ostrich (Struthio camelus)

The ostrich breeding system is complex and unique; communal clutches are laid by several females, although only one female, the major female, and the resident territorial male provide parental care. More eggs are laid in the nest than can be incubated and the major female ejects surplus eggs from the incubated central clutch. Microsatellite markers were used to analyse the parentage of communal nests in Nairobi National Park. This revealed that major females contributed a disproportionate number of fertile eggs to the central, incubated clutch and that multiple paternity and maternity within a nest were common; 68.9% of all incubated eggs on a nest were not parented by both the resident territorial male and the major female of that nest. All the males fertilized eggs on the clutches of neighbouring males. Unexpectedly, every major female with her own nest was also simultaneously a minor female with incubated eggs on neighbouring clutches. The relatedness between females laying in the same nest was not significantly different from the population average and significantly less than that between chicks hatched from the same nest.     

Multiple paternity in a natural population of a salamander with long-term sperm storage

Sperm competition appears to be an important aspect of any mating system in which individual female organisms mate with multiple males and store sperm. Post-copulatory sexual selection may be particularly important in species that store sperm throughout long breeding seasons, because the lengthy storage period may permit extensive interactions among rival sperm. Few studies have addressed the potential for sperm competition in species exhibiting prolonged sperm storage. We used microsatellite markers to examine offspring paternity in field-collected clutches of the Ocoee salamander (Desmognathus ocoee), a species in which female organisms store sperm for up to 9 months prior to fertilization. We found that 96% of clutches were sired by multiple males, but that the majority of females used sperm from only two or three males to fertilize their eggs. The high rate of multiple mating by females suggests that sperm competition is an important aspect of this mating system. Comparison of our data with those of other parentage studies in salamanders and newts reveals that multiple mating may be common in urodele amphibians. Nevertheless, the number of males siring offspring per clutch in D. ocoee did not differ appreciably from that in other species of urodeles with shorter storage periods.     

微卫星DNA在吉戎兔亲子鉴定中的应用研究

选用Sat2、Sat3、Sat4、Sat5、Sat7、Sat8、Sat12、Sat13、Sat16、Sol08、Sol28、Sol30、Sol03 等13个微卫星位点PCR扩增30只吉戎兔的基因组DNA,然后在8%聚丙烯酰胺凝胶上电泳分型,检测结果为平均等位基因数为3.46个,平均杂合度（H）为0.578,平均多态信息含量（PIC）为0.531,双亲资料未知时13个位点的累计非父排除率（PE1）为0.935226,置信度低于80%,一亲本资料已知时13个位点的累计非父排除率（PE2）为0.999329,置信度为95%。由于所鉴定兔群的母本资料已知,因此基因型的分型结果能有效确认18只仔兔子的真父。     

Parentage test in broad-snouted caimans (Caiman latirostris, Crocodylidae) using microsatellite DNA

In this study, microsatellite markers, developed for Alligator mississipiensis and Caiman latirostris, were used to assess parentage among individuals from the captive colony of Caiman latirostris at the University of São Paulo, in Piracicaba, São Paulo, Brazil. Many of the females in the colony were full siblings, which made maternal identification difficult due to genotypic similarity. Even so, the most likely mother could be identified unambiguously among offspring in most of the clutches studied. Two non-parental females displayed maternal behavior which would have misled managers in assigning maternity based on behavior alone. This set of variable loci demonstrates the utility of parentage testing in captive propagation programs.     

Microsatellite DNA markers for the study of Atlantic salmon (Salmo salar) kinship,population structure,and mixed‐fishery analyses

Eleven microsatellite DNA loci were identified and characterized for Atlantic salmon (Salmo salar) collected from the Penobscot River, Maine, USA and the River Nith, Scotland, UK. The markers revealed high levels of genetic diversity (seven to 48 alleles per locus), heterozygosity (to 100%), and allelic heterogeneity (all comparisons). Considerable differentiation was observed as the genetic distance (chord) between the two collections was 0.680 and the pairwise F_ST, 0.12, was highly significant. These findings are consistent with patterns of continental‐level differentiation observed previously using an alternate suite of microsatellite loci. Locus‐by‐locus analyses of molecular variance suggested that most markers were suitable for delineating kinships and population genetic structure.     

Spatial relatedness and brood parasitism in a female-philopatric bird population

The spatial structure of relatedness between individuals ina population can be crucial for social selection and evolution.Here we analyze a female alternative reproductive tactic, conspecificbrood parasitism, in relation to spatial relatedness among femalesin a Baltic Sea population of the common eider Somateria mollissima.The role of relatedness in brood parasitism is debated: somemodels predict parasite avoidance of related hosts, others predicthost–parasite relatedness. We estimate pairwise relatednessfrom protein fingerprinting of egg albumen in 156 nests, withpairwise nest distances ranging from 1 to 6 km. Relatednessincreases significantly from the longest distances to an averageof r 0.09 below 20 m. Brood parasitism is common, and averagepairwise relatedness between host and parasite is estimatedat 0.18–0.21. Parasites thus do not avoid relatives, andcombined with the findings of a similar study in another eiderpopulation, the results show that mean host–parasite relatednessis higher than that among close neighbors. High host–parasiterelatedness is therefore not an effect of natal philopatry alone;some other form of kin bias is also involved. Recognition andassociation between birth nest mates is a candidate mechanismfor further study.     

Kinship and social structure of bobcats (Lynx rufus) inferred from microsatellite and radio-telemetry data

Kinship analysis using 12 microsatellites was compared with radio-telemetry data to examine the social structure of bobcats Lynx rufus in southern Texas. Genetically identified kinship relationships combined with capture data were used to reconstruct pedigrees. Three family groups were constructed from parent/offspring pairs identified from shared alleles. All parents identified by genetic analysis had established home ranges. Individuals with no distinct home ranges were not genetically observed to have offspring among the bobcats sampled. This suggests that establishing a home range is necessary for bobcats to breed. Of three identified male offspring and three identified female offspring, two female offspring were philopatric. These females became a part of the breeding population in their natal area. Among sibling pairs that included nine female and four male individuals, four females and one male were residents suggesting male-biased dispersal.     

A new interpretation of the social organization and mating system of the Callitrichidae

Tamarins and marmosets are usually described as monogamous, or as living in extended family groups. Field research on a variety of callitrichid species shows, however, that immigration and emigration by adults are common and that groups are likely to be composed largely of unrelated adults of both sexes. Despite the number of adult females present in a group, only a single female is usually reproductively active. This female may mate with more than one male. Care for the young is provided by all group members but principally by adult males. This generally is referred to as a “communal breeding system. ” However, a vertebrate social system in which more than two reproductively active adults participate in infant care is rare and has otherwise been reported only in a small number of avian and canid species. Wild callitrichid groups virtually always include helpers, but the number of adults of each sex is highly variable. We propose that the Callitrichidae tend to live in small multimalemultifemale groups, communally rear the young of one female, and exhibit a mating pattern characterized by female promiscuity but a breeding system that is functionally polyandrous. There is a significant correlation between the number of males and a group and the total number of surviving young. The possible adaptive advantages of this social organization are discussed. An erratum to this article is available at .     

On minimizing assignment errors and the trade‐off between false positives and negatives in parentage analysis

Genetic parentage analyses provide a practical means with which to identify parent–offspring relationships in the wild. In Harrison et al.'s study (2013a), we compare three methods of parentage analysis and showed that the number and diversity of microsatellite loci were the most important factors defining the accuracy of assignments. Our simulations revealed that an exclusion‐Bayes theorem method was more susceptible to false‐positive and false‐negative assignments than other methods tested. Here, we analyse and discuss the trade‐off between type I and type II errors in parentage analyses. We show that controlling for false‐positive assignments, without reporting type II errors, can be misleading. Our findings illustrate the need to estimate and report both the rate of false‐positive and false‐negative assignments in parentage analyses.     

Association studies in QTL regions linked to bovine trypanotolerance in a West African crossbred population

African animal trypanosomosis is a parasitic blood disease transmitted by tsetse flies and is widespread in sub-Saharan Africa. West African taurine breeds have the ability, known as trypanotolerance, to limit parasitaemia and anaemia and remain productive in enzootic areas. Several quantitative trait loci (QTL) underlying traits related to trypanotolerance have been identified in an experimentally infected F(2) population resulting from a cross between taurine and zebu cattle. Although this information is highly valuable, the QTL remain to be confirmed in populations subjected to natural conditions of infection, and the corresponding regions need to be refined. In our study, 360 West African cattle were phenotyped for the packed cell volume control under natural conditions of infection in south-western Burkina Faso. Phenotypes were assessed by analysing data from previous cattle monitored over 2 years in an area enzootic for trypanosomosis. We further genotyped for 64 microsatellite markers mapping within four previously reported QTL on BTA02, BTA04, BTA07 and BTA13. These data enabled us to estimate the heritability of the phenotype using the kinship matrix between individuals computed from genotyping data. Thus, depending on the estimators considered and the method used, the heritability of anaemia control ranged from 0.09 to 0.22. Finally, an analysis of association identified an allele of the MNB42 marker on BTA04 as being strongly associated with anaemia control, and a candidate gene, INHBA, as being close to that marker.     

Genetic population structure of the Greater Bilby Macrotis lagotis, a marsupial in decline

The Greater Bilby has shown a rapid decline in range during this century and now occupies only a small isolated area in south-western Queensland (QLD) and a larger, but mostly low-density area in the north-western deserts of the Northern Territory (NT) and Western Australia (WA). We have examined variation in the control region of mitochondrial DNA (mtDNA) and at nine microsatellite loci in order to investigate the extent of current and historical subdivision across the species range, and to provide a preliminary assessment of genetic structuring and mating system on a finer scale within the QLD population. Both mtDNA and microsatellite loci had substantial variation within and among populations, with mtDNA divergence being greater between QLD and NT than between NT and WA. The QLD population had two unique and divergent mtDNA lineages, but there was no evidence for strong phylogeographical structure across the range. The available evidence suggests that the bilby should be considered as a single Evolutionarily Significant Unit consisting of multiple Management Units. Augmentation of the remnant QLD population from the NT does not appear necessary at this stage, at least not on genetic grounds. Finer-scale analysis of microsatellite variation for two QLD colonies revealed a deficiency of heterozygotes and significantly greater relatedness within than between colonies. However, structuring was observed only for males; relatedness values for females did not depart from those expected under panmixia. Parentage exclusion analysis for one colony allowed the construction of a partial pedigree which indicated strong polygyny, with one male fathering all but one of the eight offspring assigned. The extent to which fine-scale genetic structuring and differences between sexes is due to sex-biased dispersal vs. effects of mating system remain to be determined.     

Significant population of Egyptian Vulture Neophron percnopterus found in Morocco

The Egyptian Vulture Neophron percnopterus population in Morocco has undergone a marked decline since the 1980s to the point of nearing local extinction in the twenty-first century. A field study of some possible sites for Egyptian Vultures was carried out over six days during June 2014 in the Middle Atlas Mountains, Morocco. We counted a total of 48 Egyptian Vultures at three different localities: two occupied breeding sites and one communal roost that hosted 40 vultures of different ages. A (probable) singe adult bird at the breeding site was located and a previously occupied site was also visited. A preliminary survey amongst local people indicated that threats faced by this species are predator poisoning in some areas, and the use of vulture parts for traditional medicine. Given that the species is considered globally Endangered and populations continue to decline in many areas, the discovered population reported here, although relatively small, is of national and regional (North-west Africa) importance. We expect this new situation will revive the hopes for studying and conserving this and other vulture species in Morocco and North-west Africa in general.     

The frequency and fitness consequences of communal breeding in a natural population of burying beetles: a test of reproductive skew

Abstract.  1. Reproductive cooperation occurs in diverse taxa and a defining characteristic of these social systems is how reproduction is shared. Both male and female burying beetles ( Nicrophorus spp.) facultatively form associations to bury a carcass and rear a single brood, making burying beetles a model system for testing skew theory.
2. In this study, 50% of 40–45 g carcasses and 75% of 55–60 g ones were buried by more than one male and/or female Nicrophorus tomentosus .
3. Females were significantly more likely to cooperate on 55–60 g carcasses than on 40–45 g ones.
4. Analysis of parentage of 13 broods using microsatellite loci as genetic markers showed that maternity analysis of only 2% of the young excluded all females captured leaving the brood chamber after burial. Males previously mated with resident females or displaced by resident males fathered 7% of the young.
5. The male and female remaining the longest were usually the parents of the most offspring, and reproductively dominant individuals also tended to be the largest.
6. Although all but two or three individuals that helped to bury the carcass produced some offspring, reproduction was often not shared equitably. Reproduction of females was significantly skewed on six of nine 40–45 g carcasses but shared fairly equitably on all three 55–60 g ones. Reproduction was skewed among males on 7 of 10 broods.
7. Both males and females relinquished a greater proportion of the brood as the days of assistance from all consexuals increased.