Mate fidelity and intra-lineage polygyny in greater horseshoe bats

Mating strategies that lead to increased kinship within socially cooperative groups may offer inclusive fitness benefits to individuals, but can also result in higher levels of inbreeding. Here we show in a sexually segregated bat species that females avoid this conflict through two mating behaviours. First, most females revisit and breed with specific, individual males across years, so that their single offspring born in different years are full siblings. Second, relatives in the maternal line, including mothers and daughters, share breeding partners (intra-lineage polygyny) more often than expected by chance. Although these behaviours increased levels of co-ancestry among colony members, there was no concomitant rise in inbreeding. We suggest that when females engage in mate fidelity and intra-lineage polygyny, kin ties among female roost mates will be strengthened, thereby potentially contributing to social group cohesiveness. Our findings reveal the hidden complexity that can underlie polygynous breeding, and highlight a new potential route by which female mate choice could influence social evolution.     

Patterns of magpie nest utilization by a nesting raptor community in a secondary forest

For a total of 9 years, we examined the patterns of a nesting raptor community that utilized European Magpie (Pica pica) nests in the Zuojia Natural Reserve, northeast China. Eight raptor species and two other bird species were recorded nesting in magpie nests. The reuse rate of abandoned magpie nests was 51.6%, and the number of reused nests was positively correlated with their availability. Raptors utilized 83.3% of the reused abandoned magpie nests. Nests followed for more than 1 year were reused by raptors an average of 1.13 times. Interspecific nest usurpation was common, with 17.3% of new magpie nests being usurped by raptors, and four cases of usurpation occurred among different raptor species. At the community level, 8 of 11 raptor species took over magpie nests to breed in the study area, and 91.9% of their nests came from magpie nests. European Magpies represent the core species in the nest web of the local raptor community that utilizes magpie nests. At the forest stand level, closer proximity to forest edges and greater distances from occupied raptor nests were the best predictors of nest reuse. At the nest-site level, arbor density and canopy coverage were the best predictors of nest reuse.     

Cooperation and conflict in quorum-sensing bacterial populations

It has been suggested that bacterial cells communicate by releasing and sensing small diffusible signal molecules in a process commonly known as quorum sensing (QS). It is generally assumed that QS is used to coordinate cooperative behaviours at the population level. However, evolutionary theory predicts that individuals who communicate and cooperate can be exploited. Here we examine the social evolution of QS experimentally in the opportunistic pathogen Pseudomonas aeruginosa, and show that although QS can provide a benefit at the group level, exploitative individuals can avoid the cost of producing the QS signal or of performing the cooperative behaviour that is coordinated by QS, and can therefore spread. We also show that a solution to the problem of exploitation is kin selection, if interacting bacterial cells tend to be close relatives. These results show that the problem of exploitation, which has been the focus of considerable attention in animal communication, also arises in bacteria.     

Fine-scale genetic structuring on Manacus manacus leks

Leks have traditionally been considered as arenas where males compete to attract females and secure matings. Thus, direct fitness benefits mediated through competition between males to fertilize females have been considered to be the primary force driving the evolution of lekking behaviour. Inclusive fitness benefits mediated through kin selection may also be involved in lek formation and evolution, but to date this theory has been largely ignored. According to kin-selection theory, both reproducing and non-reproducing males may gain indirect inclusive fitness benefits. If females are attracted to larger leks, non-reproducing males add attractiveness to a lek, and therefore, in a genetically structured population, boost the reproductive success of kin. Theory predicts that the attractiveness of leks is plastic, and that males establish themselves on a lek in which the top male, in terms of reproductive success, is a close relative. Here we show that in white-bearded manakins (Manacus manacus), for which larger leks are more attractive to females and so secure the maximum number of matings, there is extraordinary fine-scale genetic structure, with leks being composed of clusters of related kin. We propose that males establish themselves where they find relatives to such an extent that they form groups within leks, and that such behaviour is consistent with kin-selection theory to maximize reproductive success of the group.     

Variation in egg size and nestling growth rate in relation to clutch size and laying sequence in great tits Parus major

The objectives of this study were to examine (1) optimal clutch size in great tits (Parus major) nesting in nest boxes; (2) variation in egg morphology and nestling growth rate with position in the laying sequence; and (3) hatching asynchrony and nestling survival as determined by infrared nest cameras. We collected data from 73 clutches in artificial nest boxes in the Zuojia Natural Preserve area in Jilin Province, China, in 2005 and 2006, using infrared cameras to match laying order to hatching order for four nests. Egg morphology and growth rate were significantly affected by clutch size and position in the laying order. Overall, egg size and growth rate increased with position in the laying order. In general, it was difficult to detect asynchronous hatching from observations alone, but data from our infrared cameras showed that early-laid eggs tended to hatch before later-laid eggs, leading to hatching asynchrony. However, females invested more into last-laid eggs and nestlings, reducing size asynchrony among the chicks and leading to higher survival rates of nestlings. Our results, therefore, provide support for the"brood survival"hypothesis rather than for the"brood reduction"hypothesis.     

Mate choice on fallow deer leks

Leks, on which males defend small clustered mating territories, may have evolved because of the unusual opportunities they provide for female choice of mating partners, and several studies of lek-breeding animals have demonstrated correlations between the mating success of males and their phenotype or behaviour. However, these could arise because (1) females select mates on the basis of male phenotypic traits; (2) males interfere with each other's mating attempts; or (3) females show preferences for particular mating territories, and larger or stronger males are more likely to win access to these territories. Here we report that when fallow bucks on a traditional lek were experimentally induced to change their territories, differences in the mating success of bucks persisted, whereas differences in the position of their territories relative to the centre of the lek did not. The observation that bucks rarely interfered with their neighbours' harems and females moved freely between bucks suggests that females choose their mates on the basis of male phenotype rather than territory type or location. In this population, the immediate factor affecting the movements of females between males was the size of a buck's harem.     

Speciation by host switch in brood parasitic indigobirds

A growing body of empirical and theoretical work supports the plausibility of sympatric speciation, but there remain few examples in which all the essential components of the process are well understood. The African indigobirds Vidua spp. are host-specific brood parasites. Indigobird nestlings are reared along with host young, and mimic the mouth markings of their respective hosts. As adults, male indigobirds mimic host song, whereas females use these songs to choose both their mates and the nests they parasitize. These behavioural mechanisms promote the cohesion of indigobird populations associated with a given host species, and provide a mechanism for reproductive isolation after a new host is colonized. Here we show that all indigobird species are similar genetically, but are significantly differentiated in both mitochondrial haplotype and nuclear allele frequencies. These data support a model of recent sympatric speciation. In contrast to the cuckoo Cuculus canorus, in which only female lineages are faithful to specific hosts, host switches have led to speciation in indigobirds because both males and females imprint on their hosts.     

Two-dimensional nesting system based on hybrid genetic algorithm

According to the cutting stock problem of 2-dimensional shapes, a nesting system (NS) based on hybrid genetic algorithm (HGA) is established. The system optimizes the sequence and angles of polygons with hybrid Genetic Algorithm to accomplish the superior solution. It nests the irregular shape directly without covering irregular shapes with rectangle. It also improves the decoding strategy of 2-dimensional shapes nesting based on classical bottom-left strategy, makes the new strategy be universal to convex polygons, concave polygon and line-circular composted polygons. Foundation item: Supported by the National Key Technology and Equipment Project of the 10th Five-Year Plan (ZZ02-03-03-01)     

Social evolution: kin preference in a social microbe

Kin recognition helps cooperation to evolve in many animals, but it is uncertain whether microorganisms can also use it to focus altruistic behaviour on relatives. Here we show that the social amoeba Dictyostelium purpureum prefers to form groups with its own kin in situations where some individuals die to assist others. By directing altruism towards kin, D. purpureum should generally avoid the costs of chimaerism experienced by the related D. discoideum.     

陕西长青保护区勺鸡种群密度、分布及繁殖

为了了解勺鸡的种群密度、分布及繁殖信息,采用了日常巡护监测数据资料、分布图、样带法、样方法、跟踪调查法.得到勺鸡平均密度为0.2171只/hm2,由此推算勺鸡种群数量为1303只.勺鸡繁殖期选择产卵地点的因子是:巢址海拔区间1430～2220m;在林缘附近,坡度适中,坡向南或者东南、下坡位,巢向向阳;视野开阔、离水源近;有巢材,卵白色、卵数4枚;巢为地面巢,能遮风避雨;巢周围有栖材、沙浴场.勺鸡巢穴处的植被因子乔木、灌木、草本差异不明显,都有一定数量的乔灌草.未发现在乱石堆和无植被覆盖的地方有巢穴.     

Unrelated helpers in a social insect

High-resolution genetic markers have revolutionized our understanding of vertebrate mating systems, but have so far yielded few comparable surprises about kinship in social insects. Here we use microsatellite markers to reveal an unexpected and unique social system in what is probably the best-studied social wasp, Polistes dominulus. Social insect colonies are nearly always composed of close relatives; therefore, non-reproductive helping behaviour can be favoured by kin selection, because the helpers aid reproductives who share their genes. In P. dominulus, however, 35% of foundress nestmates are unrelated and gain no such advantage. The P. dominulus system is unlike all other cases of unrelated social insects, because one individual has nearly complete reproductive dominance over subordinates who could have chosen other reproductive options. The only significant advantage that subordinates obtain is a chance at later reproduction, particularly if the queen dies. Thus, P. dominulus societies are functionally unlike other social insects, but similar to certain vertebrate societies, in which the unrelated helpers gain through inheritance of a territory or a mate.     

Nanotechnology: 'buckypaper' from coaxial nanotubes

Double-walled carbon nanotubes are needed in a pure, highly crystalline form before features such as their electronic properties, thermal transport and mechanical behaviour can be investigated. Here we fabricate a paper-like material that consists of hexagonally packed bundles of clean, coaxial carbon nanotubes whose double walls vary little in diameter; it is prepared in high yields using chemical-vapour deposition with a conditioning catalyst and two-step purification. Our results will enable investigation of the physical properties of double-walled carbon nanotubes, which are predicted to be superior to those of both their single- and multiwalled relatives.     

Forebrain peptides modulate sexually polymorphic vocal circuitry

The peptide arginine-vasopressin (mammals) and its evolutionary precursor arginine-vasotocin (non-mammals) modulate reproductive physiology and numerous related social behaviours, as do oxytocin (mammals) and its homologues mesotocin and isotocin (fish). The distributions in the brain and/or the behavioural functions of these peptides often differ between the sexes, and between species with divergent social structures. Here we present neurophysiological evidence that males with vocal characteristics typical of females share a pattern of neuropeptide function with females rather than conspecific males. The plainfin midshipman fish (Porichthys notatus) has two male morphs with different reproductive tactics and vocalizations (a key species-typical behaviour which varies in its physical attributes and contextual usage, depending on the morph's social strategy). Forebrain-evoked, rhythmic vocal-motor activity that precisely mimics natural vocalizations was modulated by arginine-vasotocin, isotocin and their antagonists delivered to the preoptic area-anterior hypothalamus, a primary site for behavioural integration in all vertebrates. Peptides had different effects in males that acoustically court females (arginine-vasotocin-sensitive) than in females and sneak-spawning males (isotocin-sensitive), showing that the neuromodulatory mechanisms that establish reproduction-related behaviour can be dissociated from gonadal sex.     

工程建设监理投标文件编制系统开发研究

在对监理投标文件分析的基础上 ,对工程建设监理投标文件编制系统软件的开展基础、系统结构和内容进行了研究 ,并在此基础上为投标文件编制工作开发了软件工具     

白腰文鸟（Lonchura striata）繁殖行为的观察和雏鸟食性的分析

2005年3—5月，在四川省南充市高校校园内及附近区域对白腰文鸟繁殖期的求偶、选巢址、筑巢、产卵、孵卵、育雏行为进行较为详细的观察．通过繁殖期的行为观察，初步对野外的雌雄鸟作了判别．观察了易卵、易雏时亲鸟的行为变化．将15日龄雏鸟移出巢外，观察了亲鸟的喂雏方式和系列动作．采用扎颈法观察分析雏鸟的食性．     

Escalation of a coevolutionary arms race through host rejection of brood parasitic young

Cuckoo nestlings that evict all other young from the nest soon after hatching impose a high reproductive cost on their hosts. In defence, hosts have coevolved strategies to prevent brood parasitism. Puzzlingly, they do not extend beyond the egg stage. Thus, hosts adept at recognizing foreign eggs remain vulnerable to exploitation by cuckoo nestlings. Here we show that the breach of host egg defences by cuckoos creates a new stage in the coevolutionary cycle. We found that defences used during the egg-laying period by host superb fairy-wrens (Malurus cyaneus) are easily evaded by the Horsfield's bronze-cuckoo (Chrysococcyx basalis), a specialist fairy-wren brood parasite. However, although hosts never deserted their own broods, they later abandoned 40% of nests containing a lone Horsfield's bronze-cuckoo nestling, and 100% of nests with a lone shining bronze-cuckoo nestling (Chrysococcyx lucidus), an occasional fairy-wren brood parasite. Our experiments demonstrate that host discrimination against evictor-cuckoo nestlings is possible, and suggest that it has selected for the evolution of nestling mimicry in bronze-cuckoos.     

Ecology: Darwin's naturalization hypothesis challenged

Naturalized plants can have a significant ecological and economic impact, yet they comprise only a fraction ot the plant species introduced by humans. Darwin proposed that introduced plant species will be less likely to establish a self-sustaining wild population in places with congeneric native species because the introduced plants have to compete with their close relatives, or are more likely to be attacked by native herbivores or pathogens, a theory known as Darwin's naturalization hypothesis. Here we analyze a complete list of seed-plant species that have been introduced to New Zealand and find that those with congeneric relatives are significantly more, not less, likely to naturalize--perhaps because they share with their native relatives traits that pre-adapt them to their new environment.     

Female mimicry in garter snakes

In many diverse taxa, males of the same species often exhibit multiple mating strategies. One well-documented alternative male reproductive pattern is 'female mimicry', whereby males assume a female-like morphology or mimic female behaviour patterns. In some species males mimic both female morphology and behaviour. We report here female mimicry in a reptile, the red-sided garter snake (Thamnophis sirtalis parietalis). This form of mimicry is unique in that it is expressed as a physiological feminization. Courting male red-sided garter snakes detect a female-specific pheromone and normally avoid courting other males. However, a small proportion of males release a pheromone that attracts other males, as though they were females. In the field, mating aggregations of 5-17 males were observed formed around these individual attractive males, which we have termed 'she-males'. In competitive mating trails, she-males mated with females significantly more often than did normal males, demonstrating not only reproductive competence but also a possible selective advantage to males with this female-like pheromone.     

扎龙自然保护区水资源状况对重要水禽的影响

为了研究扎龙自然保护区水资源状况的变化对湿地重要水禽的影响,2003年春季,对保护区范围内的水禽进行了调查,重点对丹顶鹤和白枕鹤的营巢状况进行了研究,结合以往的调查数据,分析了重要水禽的变化情况及原因.结果表明:扎龙湿地实施补水后,重要水禽的数量逐年增多;丹顶鹤的迁徙期主要集中在4月中上旬,最大迁徙种群个体数为152只;白枕鹤迁徙期集中在4月中下旬,最大种群个体数为48只.补水后,重要水禽的数量明显高于补水前(1996年)的种群数量.说明湿地水资源的恢复有效改善了水禽的生境质量.     

Learned kin recognition cues in a social bird

In many cooperatively breeding birds, kin selection has an important role in the evolution and maintenance of social behaviour, and 'helpers' can maximize indirect fitness gains by preferentially allocating care to close relatives. Although there is evidence for kin-biased helping behaviour in several species, the mechanism of kin recognition underlying this behaviour is poorly understood. Vocalizations are the most commonly used cues in avian recognition systems, but the effectiveness of vocal signals as reliable recognition cues must depend on how they are acquired. However, there have been no experimental studies of the development of vocal recognition cues in cooperative birds; indeed, the ontogeny of all bird vocalizations other than song is poorly known in any species. Here, we show that cooperatively breeding long-tailed tits (Aegithalos caudatus) can discriminate between kin and non-kin according to the individual-specific characteristics of contact calls, and show experimentally that individuals learn these calls from provisioning adults during the nestling period. Finally, we show that the pattern of cooperative behaviour in this species is consistent with the use of recognition cues learned through association.