动物求偶场交配制度及其发生机制

求偶场是动物在繁殖期的集群求偶交配的场所, 是动物求偶与繁殖行为的表达空间。为探索求偶场的发生及其进化机制, 研究者们在短短20 年中提出了近10 种关于求偶场发生与进化机制的假说与模型。在鸟类、哺乳类、两栖爬行类和鱼类中已广泛地展开有关求偶场的研究, 但目前国内却还鲜见相关研究报道。本文介绍了求偶场的特征、类型及其进化假说与模型。结合保护生物学理论, 简单阐述了求偶场研究的保护生物学及行为生态学意义。     

俄罗斯远东地区勺嘴鹬繁殖地夏季水鸟调查

俄罗斯远东地区是全球鸟类重要的繁殖地之一,特别是楚科奇半岛的阿纳德尔地区是全球极危鸟种勺嘴鹬(Calidris pygmeus)已知的重要繁殖地。为了履行中俄候鸟及其栖息地保护双边协定,掌握俄罗斯远东的阿纳德尔地区夏季水鸟的资源状况,2017年6月25日至7月20日,中俄双方对阿纳德尔南部地区进行了夏季水鸟资源调查。调查区域主要包括阿纳德尔、从阿纳德尔至白令戈夫斯基的海域、白令戈夫斯基、梅内皮尔吉诺周边苔原区域以及附近海域四个部分。共记录35种水鸟,隶属于6目10科,其中14种有繁殖活动。分析中俄环志回收数据表明,在我国长江流域和东部沿海地区越冬的雁鸭类和鸻鹬类水鸟,夏季迁徙到俄罗斯的哈巴罗夫斯克、萨哈林岛、勘察加半岛、雅库特、楚科奇等远东地区繁殖。此外,勺嘴鹬的主要繁殖繁殖地梅内皮尔吉诺周边苔原地区存在着巢址被洪水淹没、卵和雏鸟遭天敌捕食等风险;在勺嘴鹬迁徙路线上的重要迁徙停歇地和越冬地的退化、环境污染和人为活动是导致勺嘴鹬种群数量下降的重要因素。研究结果表明,需要进一步加强中俄双方勺嘴鹬保护的合作与交流,共同保护鸟类的栖息地。     

江西吉安彩鹬的繁殖生态学研究

彩鹬Rostratula benghalensis是一类中小型涉禽,主要分布于我国华北东部、西南和沿海地区,是江西吉安地区常见留鸟。为了解当地彩鹬的繁殖生态,我们于2011~2012年对其繁殖进行了调查研究。结果表明,彩鹬3月中旬开始营巢,巢为典型的水面浮巢,平均巢外径为161.62 mm,巢内径为108.61 mm,巢深为39.14 mm;3月下旬至4月中旬产卵,窝卵数为3.46(2~4),平均卵重为11.76 g,卵大小为36.35 mm×25.41 mm。彩鹬雄鸟承担大部分营巢和孵卵工作,孵卵期18~19 d。雏鸟为早成鸟,出壳后不久便能在水中活动,随亲鸟离开巢区。     

笼养冠斑犀鸟繁殖生态的初步观察

2002~2004年通过对笼养冠斑犀鸟的繁殖生态进行观察,结果表明:冠斑犀鸟的发情期为3月中旬至4月初,求偶的追求者为雌鸟,雌鸟占据选巢营巢主导地位,从入巢到破巢的整个营巢期雌鸟始终把自己封闭在巢洞内,雄鸟担负了运送巢料和食物的所有任务直到雌鸟出巢,出巢后幼鸟在未具有觅食能力前,绝大部分的哺育任务仍由雄鸟承担。冠斑犀鸟的繁殖封巢期为89.0±12.99天,首次营巢的时间较长达15天左右,从第二年起营巢时间缩短为3天,孵化期为25.25±3.86天,育雏期为45.75±2.87天,繁殖成功率为100%。繁殖期除了人工投料外,冠斑犀鸟仍可从生态园中获得多种食物,以满足幼鸟的生长需要。     

野化放飞朱出现集群营巢现象

2007年3~7月,我们在陕西省洋县华阳镇对野化放飞朱鹮(Nipponia nippon)个体进行监测的过程中,发现3对朱鹮在同一棵树上集群营巢(communal breeding),并繁殖成功。这是自1981年野生朱鹮种群重新发现以来,首次记录到朱鹮集群营巢的现象。3对朱鹮营巢的地点位于洋县华阳镇中学附近,经纬度为107°54′204E,33°59′670N,海拔1113m。营巢树种为油松,树高25m,胸径82cm,据当地村民说已有近百年树龄。3巢的详细信息见表1。表1朱鹮集群繁殖信息巢编号亲鸟环号雄鸟♂雌鸟♀巢高(m)产卵数(枚)出壳数(只)出飞数(只)1红色09红色10162222红色06无环14222…     

红瘰疣螈的繁殖生态

红瘰疣螈(Tylototriton shanjing)为国家Ⅱ级重点保护野生动物,对其繁殖生态尚无系统的研究。2007～2010年在云南省新平县哀牢山对红瘰疣螈形态、繁殖栖息地、求偶和交配行为、产卵及孵化等繁殖特征进行了研究。结果表明,红瘰疣螈雌雄两性在广泛的形态学度量特征上存在着差异;繁殖栖息地主要为稻田和潮湿的沟渠;参与繁殖的雌雄成体性比随繁殖时间的推移而不断变化,繁殖前期和后期雄性比例高,中期雌性比例高。求偶和交配主要在陆地潮湿的水沟中完成,也可在静水中进行。成体产卵活动从5月初持续至6月下旬,呈现出波浪式的产卵进程,个体完成产卵平均时间为(22.2±2.7)h。繁殖前期雌螈产卵于稻田,中后期产于多杂草的田埂草丛和泥壁,平均产卵数(126±18)枚(n=17)。平均孵化期(17.3±0.1)d(n=225),孵化率59.8%(n=79),孵化时幼体平均体长12.7mm(n=6)。     

不同社群序位布氏田鼠的繁殖行为

在实验室条件下观察了捕自内蒙古草原的不同序位布氏田鼠的繁殖行为特征。结果表明, 雌鼠对雄性配偶存在着激烈的竞争, 高序位雌鼠获得被选择、交尾及产仔的机会最多, 较低序位雌鼠若被选择并且产仔, 则其序位将随之上升; 高序位雄鼠对各个序位雌鼠均可选择, 且在繁殖期间对同性个体表现很强的攻击性, 以获得更多的交配机会。在社群繁殖中高序位雌、雄个体的作用明显高于低序位个体, 这是布氏田鼠种群长期选择进化的生存策略。实验支持了布氏田鼠为混交制、一雄多雌的婚配制度推论。     

基于栖息地斑块尺度的青弋江河源溪流鱼类群落的时空格局

确定鱼类的栖息地利用格局是研究物种与环境关系的基础, 也是鱼类多样性保护和管理的必要前提。目前, 有关溪流鱼类群落的栖息地斑块利用格局尚存在争议。基于2012年9月至2013年8月对青弋江河源溪流的逐月调查数据, 初步研究了鱼类群落的栖息地斑块利用格局, 着重在栖息地斑块尺度上解析了鱼类群落的时空变化规律。主要研究结果显示, 深潭和急滩2类斑块间的底质、流速、水深、溶氧栖息地因子显著差异, 且深潭斑块的环境稳定性高于急滩。研究共采集鱼类15种, 其中鲤科鱼类8种, 占采集物种数50%以上。基于鱼类物种存在与否的不连续变量的分析结果显示, 鱼类物种组成的斑块间和月份间变化均不具显著性。但是, 基于鱼类物种多度的连续变量的分析结果显示, 鱼类群落结构存在有显著的斑块间变化和时间动态; 就斑块间变化而言, 原缨口鳅(Vanmanenia stenosoma)在急滩斑块中的多度更高, 而宽鳍 (Zacco platypus)、光唇鱼(Acrossocheilus fasciatus)和尖头 (Phoxinus oxycephalus)等其他关键物种则在深潭中具有更高多度。深潭斑块的鱼类物种数显著高于急滩, 但2类斑块间的个体数无显著差异。深潭斑块的鱼类物种数较稳定, 而个体数月变化显著, 可能与鱼类繁殖和群体补充以及越冬死亡等有关; 急滩鱼类物种数和个体数的月变化均显著, 除了与鱼类群体补充和越冬死亡有关以外, 还可能受越冬时栖息地斑块选择变化的影响。上述结果表明, 在栖息地斑块空间尺度上, 由于研究区域内大多数物种在栖息地斑块选择上无明显的特化性, 深潭和急滩斑块间鱼类的物种组成分布不符合前人所报道的生境-共位群格局, 但区域内常见种多度的变化可引起鱼类群落结构的斑块间差异和季节动态。       

怒江河谷栗喉蜂虎的繁殖行为观察

2007年3月26日—7月16日,采用典型野外记录法和所有事件取样法对云南省保山市道街怒江河谷栗喉蜂虎繁殖行为进行了观察。结果表明：1）产卵期雄性栗喉蜂虎求偶喂食的食物以蜻蜓目和膜翅目昆虫为主,占83.56%;雌鸟接受喂食的可能性为96.83%,接受喂食后仅有17.49%的雌鸟与雄鸟进行交配。2）在孵卵期昼间,雄鸟每次坐巢的时间为（23.521.6）min,每日坐巢的时间占54.4%;雌鸟每次坐巢的时间为（25.811.5）min,每日坐巢的时间占42.1%,雌雄鸟每次坐巢的时间无明显差异。3）幼雏出壳后亲鸟对幼雏的暖雏时间逐日减少,至第20 d亲鸟不再暖雏。栗喉蜂虎的育雏期为29～33 d,在繁殖过程中帮助喂食的鸟确实能提高被助鸟的繁殖成功率。     

大型年长鱼类对海洋生态系统生物资源养护的作用

随着人口增长和渔业资源需求的上升,人类沿着食物网营养级自上向下捕捞渔业资源的趋势仍在持续,导致海洋生物多样性丧失及其生态功能与服务价值迅速下降。由捕捞活动造成的渔业诱导进化进一步导致鱼类资源小型化已受到国内外学者的广泛关注。从大型年长鱼类这一独特视角出发,综述了大型年长鱼类在种群繁衍过程中的作用,其具备巨大的繁殖能量输出、丰富的亲本繁殖经验以及强大的年龄组繁殖力贡献,更有利于种群的延续;大型年长鱼类对于初次性成熟亲鱼生殖洄游具有一定的引领作用,并在季节性集群繁殖过程中占据主导地位,可通过抑制小个体同类繁殖维护种群结构的稳定;大型年长鱼类在生态系统中更是占据了较高营养级和广阔的生态位宽度,面对生态环境的改变,具有更强的适应调控能力;大型年长鱼类在种群基因交流过程中亦起到十分关键的作用。保护大型年长鱼类更有利于鱼类种群的快速恢复,这为生物资源养护和渔业管理政策制定方面提供了一定的参考。     

Secondary poisoning of stoats (Mustela erminea), feral ferrets (Mustela furo), and feral house cats (Felis catus) by the anticoagulant poison,brodifacoum

Abstract

The extent of darkening of melanin‐based plumages in birds has previously been linked with increasing aggressive encounters between individuals. The North Island robin (Petroica longipes) is a territorial New Zealand endemic passerine that displays delayed plumage maturation (darkening of the plumage with age). Aggressive boundary interactions in the robin are relatively common during the breeding season, when territories are protected and juveniles are dispersing. This study tests the hypothesis of aggression‐mediated plumage darkening in a population of North Island robins by examining if males and older (darker) birds are either (1) involved in a higher number of aggressive interactions, or (2) are more often the aggressor than females and younger birds. When sex and age are accounted for, darker individuals will be either (3) involved in a higher number of interactions or (4) more often the aggressor in encounters with other individuals. Data were collected by scoring the plumage darkness of 32 individuals in the field, and observing (1) interaction behaviours, and (2) age and sex of the birds involved in each interaction. The results show no support for any aggression‐mediated plumage darkness in the robin; males and older birds were not involved in more aggressive interactions, and were not more often the aggressor; and neither the frequency of interactions or the number of aggressive interactions were correlated with a darker plumage. Other more complex mechanisms may explain delayed plumage darkness in the North Island robin.     

Breeding dispersal in a heterogeneous landscape: the influence of habitat and nesting success in greater snow geese

Despite numerous studies on breeding dispersal, it is still unclear how habitat heterogeneity and previous nesting success interact to determine nest-site fidelity at various spatial scales. In this context, we investigated factors affecting breeding dispersal in greater snow geese (Anser caerulescens atlanticus), an Arctic breeding species nesting in two contrasting habitats (wetlands and mesic tundra) with variable pattern of snowmelt at the time of settlement in spring. From 1994 to 2005, we monitored the nesting success and breeding dispersal of individually marked females. We found that snow geese showed a moderate amount of nest-site fidelity and considerable individual variability in dispersal distance over consecutive nesting attempts. This variability can be partly accounted for by the annual timing of snowmelt. Despite this environmental constraint, habitat differences at the colony level consistently affected nesting success and settlement patterns. Females nesting in wetlands had higher nesting success than those nesting in mesic tundra. Moreover, geese responded adaptively to spatial heterogeneity by showing fidelity to their nesting habitat, independently of snowmelt pattern. From year to year, geese were more likely to move from mesic to high-quality wetland habitat, regardless of previous nesting success and without cost on their subsequent nesting performance. The unpredictability of snowmelt and the low cost of changing site apparently favour breeding-site dispersal although habitat quality promotes fidelity at the scale of habitat patches.     

Identification and breeding of yearling Piping Plovers

ABSTRACT Age of first breeding is an important life history trait. Many Piping Plovers (Charadrius melodus) do not breed as yearlings, but little information is available concerning the age of first breeding. From 2000 to 2006, we marked 991 chicks in three areas in Saskatchewan, Canada, and subsequently determined when 102 (49 females and 53 males) first bred. Females bred significantly earlier, on average, than males. More females (68%) bred as yearlings than did males (41%; P= 0.04), with most others first nesting when 2‐yr old (29% of females and 50% of males). As expected from differences between the sexes in age of first breeding, younger females were more likely to pair with older males than were younger males with older females. Chicks that hatched early in the breeding season did not breed at an earlier age than those that hatched late in the year. Unlike older birds, juvenile Piping Plovers do not replace flight feathers during their first winter. As a result, 18 of 27 yearlings (67%) had worn outer primaries, whereas only one of 123 (1%) older birds had worn primaries. In addition, whereas 20 of 24 yearlings (83%) retained a few buff‐tipped median coverts, none of 119 known older birds had such coverts. As a result, we were able to identify all yearlings by their worn primaries, buff‐tipped median wing coverts, or both. Wing lengths of yearling Piping Plovers were 3% shorter than those of older birds, presumably due to wear. Because there is no evidence of differences in adult survival rates between the sexes and breeding habitat is available, we speculate that fewer yearling males than females breed because primary wear may reduce the ability of yearling males to perform aerial breeding displays.     

American Kestrel reproduction: evidence for the selection hypothesis and the role of dispersal

Many hypotheses attempt to explain why younger, less experienced birds have a relatively low reproductive output. We evaluated reproductive patterns of marked American Kestrels Falco sparverius nesting in boxes in southwestern Idaho from 1992 to 2006 to test predictions of these hypotheses. Results were consistent with the selection (differential mortality) hypothesis and did not support the constraint, restraint or recruitment hypotheses. Most known-age Kestrels nested in their first year of life, and there was no apparent short-term or long-term reproductive advantage to delayed breeding. The number of years that Kestrels nested in study area boxes ranged from 1 to 6 years, with most Kestrels nesting in only 1 year. Reproductive rates were higher for birds with at least 1 year of nesting experience than for birds nesting in boxes for the first time. After 2 years of nesting, reproductive rates levelled off; there was no evidence for additional improvement or for senescence. Differences in reproductive output with experience/age were due to variation among and not within individuals. Individuals that nested in more than 1 year had similar reproductive rates in their first and second years. Poor producers either died or dispersed after 1 year of nesting in study area boxes. Successful females that nested early in the season and successful males that had been produced locally had the highest probability of returning to nest in a subsequent year.     

Nest positioning by male Daito White‐eyes Zosterops japonicus daitoensis improves with age to reduce nest predation risk

Age‐related improvement in reproductive success is widely observed in birds, and the mechanisms by which productivity is enhanced have received considerable attention. However, little is known about how parental age affects the loss of eggs or nestlings despite the fact that age effects on nesting success are often reported. We examined parental age effects on reproductive success in relation to the avoidance of nest predation in an island subspecies of the Japanese White‐eye, the Daito White‐eye Zosterops japonicus daitoensis. Clutch size and annual number of breeding attempts did not differ between parental age classes. Reproductive success was affected only by male age through an increase in nesting success. Nest failure was attributed only to predation in this species and nest concealment and nest height were important nest characteristics promoting successful fledging. Older males built their nests in more concealed and higher positions than first‐year birds, regardless of vegetation status around the nest. Analysis of individual birds suggested that by shifting the nest to a safer position, male White‐eyes achieved higher nesting success than in the previous year. Of three hypotheses of age‐related improvement in reproductive success considered, our data favoured the hypothesis that as individuals grow older, their breeding competence improves.     

Nest Defence of Nesting Chinstrap Penguins (Pygoscelis antarctica) against Intruders

We tested some predictions of parental investment theory by studying the aggressive behaviour of colonial nesting chinstrap penguins (Pygoscelis antarctica) against human intruders into their nesting territories. We tested for differences in the aggressive behaviour of penguins according to offspring age (eggs vs. chicks), offspring number, nest location in the colonies (central vs. peripheral) and sex. Offspring age was the main factor influencing nest defence, although nest location and sex were also important. Chicks were defended more strongly than eggs, in accordance with changes in the reproductive value of offspring, and this increase in aggressiveness was not related to revisitation of the same individuals. The level of aggression of penguins breeding in central sites was higher than that of peripheral birds, a difference that could be due to the lower residual reproductive value of central-nesting, probably older, birds. The stronger aggressiveness of males could be due to a combination of factors related to sexual selection and life-history traits. Offspring number did not affect the level of nest defence.     

Extension of ideal free resource use to breeding populations and metapopulations

The concept of an ideal and free use of limiting resources is commonly invoked in behavioural ecology as a null model for predicting the distribution of foraging consumers across heterogeneous habitat. In its original conception, however, its predictions were applied to the longer timescales of habitat selection by breeding birds. Here I present a general model of ideal free resource use, which encompasses classical deterministic models for the dynamics in continuous time of feeding aggregations, breeding populations and metapopulations. I illustrate its key predictions using the consumer functional response given by Holling's disc equation. The predictions are all consistent with classical population dynamics, but at least two of them are not usually recognised as pertaining across all scales. At the fine scale of feeding aggregations, the steady state of an equal intake for all ideal free consumers may be intrinsically unstable, if patches are efficiently exploited by individuals with a non-negligible handling time of resources. At coarser scales, classical models of population and metapopulation dynamics assume exploitation of a homogeneous environment, yet they can yield testable predictions for heterogeneous environments too under the assumption of ideal free resource use.     

Habitat availability,social attraction and nest distribution patterns in longear sunfish (Lepomis megalotis peltastes)

Synopsis Two forces, limited availability of preferred habitat and social attraction between conspecifics were hypothesized to explain nest aggregation in male longear sunfish. In the laboratory, males cluster their nests within a small segment of a much larger uniform area of nesting habitat. In the field, large areas of unused habitat suitable for nesting were found, suggesting that nesting aggregations are not formed as a result of limited preferred habitat. Males appear to be socially attracted during breeding, and social nesting presumably is a successful reproductive strategy for at least a portion of the population.     

Distribution and reproductive success of the Pied Flycatcher Ficedula hypoleuca in relation to forest patch size and vegetation characteristics; the effect of scale

We studied habitat choice, distribution and reproductive success in the Pied Flycatcher Ficedula hypoleuca in relation to the spatial structure of a fragmented forest area. Two hierarchical levels of forest habitat structure were used: (1) forest patch size (macrohabitat) and (2) vegetative structure within forest patches (microhabitat). In spring, both males and females settled preferentially in large and medium-sized forest stands (>1 ha) where breeding density was also higher than in small stands (<1 ha). Stands <5 ha were occupied later, and the proportion of unpaired males was higher there than in large stands (>5 ha). The known age distributions of breeding birds and breeding success were independent of forest patch size. Nest predation rate was not associated with stand size or nest distance from the forest edge. The preference of breeding birds for large forest patches was presumably related to the higher amount of resources (nest sites, mates, food) a large patch can offer for reproduction compared with a small patch. At the microhabitat level, territories of old males were characterized by relatively more deciduous trees that contained more invertebrate food than coniferous tree-dominated territories of yearling males. The reproductive success of old males, as measured by the number of fledged young per male, was higher than that of yearling males. This suggests that the larger body size and blacker plumage of old males possibly contributed to male dominance and that old males excluded younger males from preferred habitats through territorial behaviour. Our results suggest that habitat choice of the Pied Flycatcher was affected by both micro- and macrohabitat. On the basis of settlement pattern, density and reproductive success, the distribution of Pied Flycatchers across forest stands of different sizes followed the ideal-free distribution model, whereas at the microhabitat level, age-related unequal distribution of males followed the ideal-despotic model of Fretwell and Lucas.     

The dilemma of where to nest: influence of spring snow cover,food proximity and predator abundance on reproductive success of an arctic-breeding migratory herbivore is dependent on nesting habitat choice

Pink-footed geese Anser brachyrhynchus nest in two contrasting but commonly found habitats: steep cliffs and open tundra slopes. In Svalbard, we compared nest densities and nesting success in these two environments over ten breeding seasons to assess the impact of spring snow cover, food availability to nesting adults and arctic fox Vulpes lagopus (main terrestrial predator) abundance. In years with extensive spring snow cover, fewer geese at both colonies attempted to breed, possibly because snow cover limited pre-nesting feeding opportunities, leaving adults in poor breeding condition. Nesting success at the steep cliff colony was lower with extensive spring snow cover; such conditions force birds to commit to repeated and prolonged recess periods at far distant feeding areas, leaving nests open to predation. By contrast, nesting success at the open tundra slope was not affected by spring snow cover; even if birds were apparently in poor condition they could feed immediately adjacent to their nests and defend them from predators. Foxes were the main nest predator in the open tundra slopes but avian predators likely had a larger impact at the steep cliffs colony. Thus, the relative inaccessibility of the cliffs habitat may bring protection from foxes but also deprives geese from readily accessing feeding areas, with the best prospects for successful nesting in low spring snow cover years. Our findings indicate that spring snow cover, predator abundance and food proximity did not uniformly influence nesting success of this herbivore, and their effects were dependent on nesting habitat choice.