Urogonimus macrostomus (Digenea: Leucochloridiidae) from the rustic bunting, Emberiza rustica, in Japan

Some trematodes were found in the cloaca of a rustic bunting (Emberiza rustica) captured in Tsushima Islands, Japan. From their morphological characters and distribution, the flukes were identified as Urogonimus macrostomus. The phylogenetic relationship between this fluke and related species was inferred from the 28S rRNA gene sequences, and the gene sequence of the fluke was found to differ at only 4 nucleotide positions from that of U. macrostomus reported from Ukraine. This is the first report of this species in Japan.     

Known and predicted African winter distributions and habitat use of the endangered Basra reed warbler ( Acrocephalus griseldis) and the near-threatened cinereous bunting ( Emberiza cineracea)

The Basra reed warbler (Acrocephalus griseldis) and the cinereous bunting (Emberiza cineracea) are the only two Western Palearctic passerine bird species that overwinter in East Africa and are classified by BirdLife International as endangered and near-threatened, respectively. To refine the African wintering ranges of these two species, we made an effort to collect as much distributional data as possible. We then used the available point-locality data to predict the wintering distributions using a Geographic Information Systems (GIS) based inductive modelling technique called BIOCLIM. For this purpose, we developed four environmental GIS layers that are presumed to reflect the environmental preferences of migrant birds. Our data showed that the known winter distribution of the Basra reed warbler was concentrated in Kenya, Tanzania, Malawi and Mozambique, where it was usually found in dense vegetation growing in coastal scrub, woodland thickets, swamps, marshes, flooded pools and grasslands, and along ditches and edges of rivers, ponds, lagoons and lakes. The predicted winter distribution of this species includes most of East Africa but, given the habitat preferences of this species, is probably limited to low-lying areas near the coastline. The known winter distribution of the cinereous bunting is so far limited to Eritrea, where the species has been observed in October, November, February and March, in sparsely vegetated, sandy or rocky habitats on coastal plains and deserts. The predicted winter distribution of this species includes the plains and hills along the Red Sea coasts in southern Egypt, Sudan, Eritrea, Ethiopia and Sudan, as well as a few inland areas in Sudan, Ethiopia and Kenya.Communicated by F. Bairlein     

Cuckoldry and recapture probability of adult males are not related in the socially monogamous coal tit ( Parus ater)

Despite substantial research effort, the benefits of female extra-pair matings in socially monogamous bird species remain elusive. The good genes hypothesis assumes that females engage in extra-pair copulations with males of superior genetic quality compared to their respective social mate. Therefore, a negative association between the degree of cuckoldry and male survival is predicted, if genetic quality is phenotypically reflected by high viability. Furthermore, genetic sires of extra-pair offspring (EPO) should survive better than the social fathers they cuckolded. We tested these predictions in a nestbox population of the coal tit (Parus ater), a socially monogamous passerine with low breeding dispersal and high rates of extra-pair paternity (EPP). Based on 257 genotyped first broods of two consecutive years, we found no relationship between the incidence of EPP or the proportion of EPO within a given brood and male or female recapture probabilities. Furthermore, recapture rates did not differ between social and genetic fathers of EPO or males that did or did not appear as extra-pair sires in other broods. Our results were not affected by differential (short-range) breeding dispersal with respect to EPP or by other potentially confounding variables. Hence, they are not in accordance with the good genes as viability genes hypothesis.Communicated by F. Bairlein     

Extrapair paternity and offspring immunocompetence in the reed bunting, Emberiza schoeniclus

Female promiscuity is widespread in birds, as well as in other taxa. It is often assumed that in bird species with a socially monogamous mating system, females engage in extrapair copulations to obtain indirect (genetic) benefits. ‘Good genes’ and ‘compatible genes’ models predict that extrapair young (EPY) should be of higher quality than within-pair young (WPY), but the empirical evidence for this effect is limited. A recent study, however, indicated an enhanced cellular immunity in EPY in a passerine bird, the bluethroat, Luscinia svecica. To assess the generality of that finding, we replicated the study using the reed bunting, a passerine with an extrapair mating system similar to that of the bluethroat. Using the same immune assay protocol, we found no indication of enhanced cellular immunity in EPY compared with WPY. Female reed buntings thus do not seem to engage in extrapair copulations to achieve the same type of genetic benefit as in bluethroats. Furthermore, EPY in mixed-paternity broods did not grow faster and were not in better body condition close to fledging than WPY. We conclude that our results do not support the hypotheses assuming indirect benefits to female extrapair copulations. It appears that the adaptive value for females of pursuing extrapair fertilizations varies, even between species with similar extrapair mating systems.     

Analysis of genetic parentage in the tawny owl ( Strix aluco ) reveals extra-pair paternity is low

We have investigated genetic parentage in a Swiss population of tawny owls (Strix aluco). To this end, we performed genetic analysis for six polymorphic loci of 49 avian microsatellite loci tested for cross-species amplification. We found one extra-pair young out of 137 (0.7%) nestlings in 37 families (2.7%). There was no intra-specific brood parasitism. Our results are in accordance with previous findings for other raptors and owls that genetic monogamy is the rule. Female tawny owls cannot raise offspring without a substantial contribution by their mates. Hence one favoured hypothesis is that high paternal investment in reproduction selects for behaviour that prevents cuckoldry. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

No evidence for increased offspring heterozygosity from extrapair mating in the reed bunting (Emberiza schoeniclus)

It has been hypothesized that females mate multiply to increasethe heterozygosity of their progeny because heterozygous individualsare assumed to have a fitness advantage. Females can maximizeheterozygosity of their offspring by mating with geneticallyunrelated and/or heterozygous males. We tested these predictionsin a socially monogamous passerine, the reed bunting (Emberizaschoeniclus), where extrapair paternity occurs frequently. Theresults based on genotypes at nine microsatellite loci revealedthat females were no less genetically related to the extrapairmale(s) (EPMs) than to their pair male (i.e., breeding partner)and that EPMs were no more heterozygous than the males theycuckolded. In addition, a direct comparison of maternal half-siblingsnaturally raised in the same brood showed that extrapair youngwere no more heterozygous than within-pair young. Thus, femalereed buntings do not seem to mate with EPMs to increase offspringheterozygosity. It is not yet known whether extrapair matinginvolves any benefits at all to females in this species.     

Testosterone and testes size in mallards ( Anas platyrhynchos )

The steroid hormone testosterone (T) mediates the expression of many secondary sexual characters, including behaviors which influence male reproductive success. Testes are one of the major sources of androgens, in particular of T. Although a positive relationship between testes size and T levels could be hypothesized, it has rarely been tested intraspecifically. We investigated this link in mallards (Anas platyrhynchos) using a double-antibody radioimmuno-assay to measure hormone levels and X-rays to determine testes size. Here, we report a positive correlation between both traits in a group of 13 drakes during the reproductive season.     

Song dialects in the yellowhammer Emberiza citrinella : bioacoustic variation between and within dialects

The yellowhammer Emberiza citrinella is a common European bird that sings in dialects that for decades have been distinguished by the existence of one single element (called a “specific”). In this study we looked into other possibilities for dialect discrimination, measuring 24 different variables. For the first time, multivariate statistics were used to discriminate dialect in yellowhammer song. Two similar dialects (XlB and XsB) that are not clearly defined in the literature were studied. Statistics incorporated (1) all variables, (2) no variables of “specific” elements, and (3) no variables under the influence of these “specific” variables. Multivariate statistics support dialect discrimination by ear and confirmed that only one element in yellowhammer song characterises dialect. In addition, we looked for local differences within two dialects and found that one local observation area showed a higher separation than the other sites (Meck1). However, as yet there is insufficient evidence for the existence of a new subdialect. The experiments comply with the current laws of the study area.     

Low frequency of extrapair paternity in the common redstart ( Phoenicurus phoenicurus )

Social monogamy is common among passerines whereas genetic monogamy is regarded as rare. Here we report the first study of paternity in the genus Phoenicurus (Aves, Muscicapidae). In the socially monogamous common redstart (Phoenicurus phoenicurus) 2.0% (5/253) of offspring in 10.5% (4/38) of the broods examined were sired by extrapair males. The observed pattern of extrapair paternity was consistent among two geographically separate nest-box populations sampled over two years. Our findings reveal low rates of extrapair paternity compared with other passerine birds, suggesting only a minor role of sperm competition in this sexually dichromatic species.     

Multiple paternity in free-living root voles (Microtus oeconomus)

We used 10 microsatellite loci to determine the mating system and male reproductive success in a natural population of the root vole (Microtus oeconomus). By genotyping 21 females and their 111 offspring (5.28 ± 0.27 S.E. pups per female), we found evidence for multiple paternity in 38% of the litters sired by two or three males. Paternity was not significantly skewed away from the null expectation of equal proportions of offspring sired in any of the multiple-sired litters, and the most successful male fathered between 40% and 60% of the pups in a litter. The results indicate that promiscuity is a common mode of reproduction, consistent with the previous classification of the mating system based on the spatial structure of the root vole population.     

Multiple paternity and kinship in the gray fox (Urocyon cinereoargenteus)

Despite mounting evidence that extra-pair copulations (EPCs) are common in the Canidae, no studies have examined the most basal member of this family, the gray fox (Urocyon cinereoargenteus). In this study we explored the possibility that gray foxes may be socially, but not genetically, monogamous. Multiple paternity was confirmed in one litter and suspected in three others (n=7), thus 14.3–57.1% of all litters had more than one father. In this high-density population, multiple paternity may be one strategy to reduce inbreeding, although only one pair was significantly related to each other (r=0.36). Mother–daughter pairs were more common than father–son pairs. These results coupled with a previous study showing a female-biased sex ratio suggest male-biased dispersal and the potential for helper females.     

A spatially explicit model for integrating species assessments into landscape planning as exemplified by the Corn Bunting (Emberiza calandra)

The integration of spatial information concerning animal species into static, rule-based spatially explicit non-probabilistic models for decision-making regarding the planning of landscapes and regions provides generalised habitat-described landscape-structural parameters. As a basis for an individually developed model, a discussion is first of all presented which involves general data and parametric requirements, necessary for the development of a species-referenced, spatially explicit model for analysis and evaluation. The parameters necessary for an assessment of habitat characteristics of birds in Central Europe will be discussed on the basis of landscape and structural information, using the Corn Bunting (Emberiza calandra) as an example. A spatial analysis and assessment procedure supported by geographical information system (GIS) for this species has been developed for the definition of regulations and assessment categories and subsequently applied to the example of an open agricultural landscape in Saxony-Anhalt. Within the area of examination of approximately 42.4 km², 56 songbird perches were located (density of 1.34 territories/km²). A comparison with the 45 mapped territories from the year 2004 indicated a good correlation with the model assumptions. Indeed, 16 of these 45 territories were only briefly occupied and the establishment of breeding pairs was ascertained in only 17 territories. The analysis and assessment model as presented yielded reality-based results after the utilisation of relatively little landscape-structural entry data, and is well suited for support of the decision-making process for spatial planning. The model framework presented in this paper can be modified and transferred to other species.     

Female lesser kestrel ( falco naumanni ) also accepts extra-pair copulation

The lesser kestrel (Falco naumanni) is considered a socially monogamous species in which extra-pair copulation occurs at a low rate. A wide study of extra-pair mating behaviour carried out on this species found that mated females do not solicit extra-pair copulation and reject all copulation attempts elicited by extra-pair males. In fact, the infrequent instances of extra-pair fertilization found were attributed either to re-mating after divorce, or polygyny. Here I describe an observation indicating that females also promote and accept promiscuous mating, attaining and consummating extra-pair copulation. I suggest the possibility that promiscuous behaviour could vary among different populations in this species, as it has not yet been reported, in spite of the extensive work performed in this respect.     

Reedbed structure and habitat preference of reed passerines during the post-breeding period

Post-breeding habitats of nine passerine species were studied in the permanently flooded reed beds of ponds near the village Pusté úlany (SW Slovakia) in 2002. Structural features of reed beds and the abundance of all birds studied were sampled at two sites and eight study plots. The reed bed structure and abundance of four passerines differed considerably between the individual study plots. The variations in vegetation structure were also caused by winter reed burning in the SE part of study area. Stems in burnt reed beds were smaller and thinner than unburnt. Abundance of the reed warbler and to a lesser extent sedge warbler was higher in tall reed beds, while the bearded tit preferred thick reed stems. Position of reed beds along the shore — open water gradient was an important factor in terms of abundance at the study plots in the case of the reed bunting. This species showed a strong preference for the reed bed edge with open water. Horizontal distribution of other species seems to be random, however, the birds with the exception of Savi’s warbler preferred the upper stratum of reed bed in vertical distribution. Our field data corroborate with those found in experimental studies concerning with ecomorphological characteristics of birds. Some inconsistencies, however, could also be caused by other factors (e.g. foraging preferences). Comparison of breeding and post-breeding habitat requirements of the studied bird species confirmed a more or less random distribution of the majority of species in the post-breeding period. Some variation was found in the cases of only the reed warbler and bearded tit.     

Great reed warbler Acrocephalus arundinaceus and reed warbler Acrocephalus scirpaceus respond differently to cuckoo dummy at the nest

A cuckoo Cuculus canorus dummy was exposed at 24 nests of great reed warbler Acrocephalus arundinaceus (GRW) and 34 nests of reed warbler Acrocephalus scirpaceus (RW) during the egg-laying stage. The eight GRW pairs attacked the cuckoo directly, striking the dummy, but such a behaviour was not recorded in RWs. Also, other behavioural measures (closest distance from the model, duration of distress calls and number of excitement calls) indicated a lower level of defence by RWs compared to GRWs. In the study area, the parasitism rate was much lower in GRWs (1.7% of nests) than in RWs (11.3%). We suggest that one of the reasons for the lower level of cuckoo parasitism on GRWs is its stronger nest defence and hence higher risk of injury or even death for the cuckoo during egg dumping.     

Fitness consequences of hybridization between house sparrows (Passer domesticus) and tree sparrows (P. montanus)

Gene transfer may occur following hybridization between closely related species if hybrids are viable and able to breed with individuals of one or both of the parental species. House (Passer domesticus) and tree sparrows (P. montanus) occasionally hybridize and produce viable offspring. Previously, we concluded that male tree × house sparrow hybrids are most probably fertile based on the observation of a male F1 hybrid feeding the nestlings with a female house sparrow in two consecutive clutches. However, recent DNA analyses based on blood samples revealed that all nestlings (4) in the first clutch were sired by a neighbouring house sparrow male, whereas nestlings in the second clutch (2) were not blood sampled and most probably died before fledging. This indicates that extensive extra-pair fertilization confounded our previous conclusion, and indicates that social partnership and attending behaviour can be imprecise measures of paternity.     

车桑子小孢子发生与雄配子体发育

为了解干热河谷区车桑子(Dodonaea viscosa)胚胎学特征及其结籽率低的原因,采用常规石蜡切片法和电镜扫描技术对车桑子小孢子发生、雄配子体发育和花粉的形态特征进行了观察。结果表明,车桑子花药具有4个花粉囊。完整的花药壁从外到内依次为表皮、药室内壁、2～3层中层细胞和绒毡层;绒毡层类型是腺质绒毡层。花药成熟期,中层、绒毡层均退化消失。小孢子母细胞进行同时型胞质分裂;四分体为四面体型结构。成熟的花粉为二细胞型。花粉近球形,外壁密布颗粒状纹饰,具有3条不构成合沟的萌发沟。雄性生殖发育过程出现的异常现象可能是干热河谷地区车桑子结籽率低的原因之一。     

鹅毛竹大小孢子及雌雄配子体发育

利用扫描电镜、透射电镜、石蜡切片,对鹅毛竹的花芽分化、大、小孢子及雌、雄配子体的发育进行了详细观察.结果发现:鹅毛竹花药具4个药室,花药壁由表皮、药室内壁、中层、绒毡层4层结构组成,花药壁发育为单子叶型,绒毡层为腺质型,小孢子母细胞减数分裂中的胞质分裂为连续型,产生左右对称型小孢子.鹅毛竹成熟花粉大多2细胞型,都具1个萌发孔.鹅毛竹子房为单子房,子房1室,侧膜胎座,一个倒生胚珠,双珠被,薄珠心.大孢子母细胞由一个雌性孢原细胞直接发育而成,大孢子四分体呈线型,合点端一个大孢子分化为功能大孢子,由功能大孢子经过3次有丝分裂形成8核胚囊,发育类型为蓼型,位于核点端的3个细胞核进行多次分裂形成多个反足细胞.至此,成熟胚囊形成.并就鹅毛竹不结实的原因进行了探讨.     

日龄及性别对橘小实蝇实验种群飞行能力的影响

利用飞行磨系统对实验种群橘小实蝇的1、6、11、16、21、26、31日龄的7个雌雄个体分别进行22h连续吊飞试验,测定其累计飞行距离、累计飞行时间、平均飞行速度。橘小实蝇原始种群采自湖南长沙,经室内连续饲养约30代,成为试验种群。试验环境条件为连续光照条件,温度25℃,RH 60%—80%,光照强度为990 lx。整个吊飞过程不补充食物和水份。共得到179组吊飞数据,其中雌虫86组,雄虫93组,每个日龄处理不少于9头。结果显示随着日龄的增加,橘小实蝇雌蝇和雄蝇的飞行能力均逐渐增加,到达16日龄后雌蝇飞行能力迅速下降,表现为单峰型;雄蝇的飞行能力在16—31日龄一般维持较高水平,但在26日龄有一定波动。16日龄雌蝇和雄蝇的累计飞行距离分别是(2485.6±2287.2)m和(2152.3±1773.3)m。其中1头21日龄雄性个体的累计飞行距离最大,完成了8795.80 m的飞行。雌蝇累计飞行距离最远的发生在16日龄,为8116.6 m。日龄对橘小实蝇的累计飞行距离和平均飞行速度的影响都达到了显著水平(前者,F=2.88,P0.05;后者,F=4.98,P0.01)。雌蝇和雄蝇的平均飞行速度的差异达到了显著水平(F=4.10,P0.05)。日龄和性别的互作对平均飞行速度的影响也达到了显著水平(F=2.74,P0.05)。尽管实验种群不能完全代表野生种群,研究结果对研究橘小实蝇扩散规律及综合防治,特别是改进橘小实蝇雄性不育技术仍有重要的参考价值。