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Birds’ behavioral response to brood parasitism can be influenced not only by evolution but also by context and individual experience. This could include nest sanitation, in which birds remove debris from their nests. Ultimately, nest sanitation behavior might be an evolutionary precursor to the rejection of parasitic eggs. Proximately, the context or experience of performing nest sanitation behavior might increase the detection or prime the removal of parasitic eggs, but evidence to date is limited. We tested incubation-stage nests of herring gulls Larus argentatus to ask whether nest sanitation increased parasitic egg rejection. In an initial set of 160 single-object experiments, small, red, blocky objects were usually rejected (18 of 20 nests), whereas life-sized, 3D-printed herring gull eggs were not rejected whether red (0 of 20) or the olive-tan base color of herring gull eggs (0 of 20). Next, we simultaneously presented a red, 3D-printed gull egg and a small, red block. These nests exhibited frequent nest sanitation (small, red block removed at 40 of 48 nests), but egg rejection remained uncommon (5 of those 40) and not significantly different from control nests (5 of 49) which received the parasitic egg but not the priming object. Thus, performance of nest sanitation did not shape individuals’ responses to parasitism. Interestingly, parents were more likely to reject the parasitic egg when they were present as we approached the nest to add the experimental objects. Depending on the underlying mechanism, this could also be a case of experience creating variation in responses to parasitism. 相似文献
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Esa Koskela Pinja Juutistenaho Tapio Mappes Tuula A. Oksanen 《Evolutionary ecology》2000,14(2):99-109
According to parental investment theory, nest defence activity should be related to the reproductive value of the offspring. Alternative hypotheses suggest that defence activity may, for example, depend upon the conspicuousness of the young. Studies concerning this topic have been carried out almost exclusively on birds and experimental data on the diversity of organisms is lacking. Bank voles Clethrionomys glareolus were used to study the effects of the number and age of offspring upon the pup defence activity of mothers. Male bank voles are infanticidal and thus an adult male was used as a predator. Defence trials were conducted in the laboratory and filmed for subsequent analysis. Litter sizes were divided into three treatment groups: reduced (−2 pups), control (±0 pups) and enlarged (+2 pups). In order to study the effect of offspring age upon maternal defence activity the trials were conducted twice: when the pups were 3 and 8 days old. Defence activity increased with the number of offspring and enlarged litters were most actively defended. This result supports parental investment theory and conclusions drawn by earlier studies of birds. However, in contrast to the conclusions of earlier studies, older offspring were defended less than the younger ones. Whilst new-born pups are totally defenceless against predators their vulnerability decreases as they age. Therefore, we suggest that maternal aggression in female bank voles is related to the value as well as to the vulnerability of the offspring. The validity of this explanation and the determinants of parental investment decisions in small mammals in general deserve further study. This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Breeding success is a key element of animal population dynamics. In many taxa including birds, nest success, or the proportion of laid clutches that actually hatch, is mainly determined by predation. Previous research gives an inconsistent picture of the prevalence of density-dependent nest predation and one reason for this is the general lack of well-designed replicated experiments. Using simulated Mallard Anas platyrhynchos nests and a crossover design for 20 lakes in the nemoral and boreal biotic zones, we tested the predictions that nest survival is negatively density-dependent and that nest predation is higher in agricultural than in forested landscapes. Study day and daily abundance of waterfowl, other waterbirds, as well as avian predators were included as covariates in the analysis. Model fitting in program mark revealed a general negative effect of nest density on nest survival. In addition, nest survival rate was higher at forest lakes than at lakes in agricultural landscapes, irrespective of nest density. The only covariate producing model improvement was study day; older nests had higher survival rates than recently initiated ones. This is the first replicated lake-level experimental study showing that nest predation is density-dependent in waterfowl. The pattern was consistent between landscape types, implying that density-dependent nest predation may affect habitat choice and population dynamics over large parts of the Mallard's range. 相似文献
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Bird nestlings may be at risk not only from starvation but alsofrom predators attracted to the nest by parental feeding visits.Hence, parents could trade reduced visitation rates for a lowerpredation risk. Here, through field data and an experiment,we show plasticity in daily patterns of nest visitation in theSiberian jay, Perisoreus infaustus, in response to predatoractivity. In high-risk territories, jay parents avoided goingto the nest at certain times of the day and compensated by allocatingmore feeding effort to periods when predators were less active.Such modifications in provisioning routines allowed parentsin high-risk habitat to significantly lower the risk of providingvisitation cues to visually oriented corvid nest predators.These results indicate that some birds modify their daily nestvisitation patterns as a fourth mechanism to reduce predator-attractingnest visits in addition to the clutch size reduction, maximizationof food load-sizes, and prevention of allofeeding suggestedby Skutch. 相似文献
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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. 相似文献
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Differential investment in offspring by parental and progeny gender has been discussed and periodically analyzed for the past 80 years as an evolutionary adaptive strategy. Parental investment theory suggests that parents in poor condition have offspring in poor condition. Conversely, parents in good condition give rise to offspring in good condition. As formalized in the Trivers-Willard hypothesis (TWH), investment in daughters will be greater under poor conditions while sons receive greater parental investment under good conditions. Condition is ultimately equated to offspring reproductive fitness, with parents apparently using a strategy to maximize their genetic contribution to future generations. Analyses of sex ratio have been used to support parental investment theory and in many instances, though not all, results provide support for TWH. In the present investigation, economic strategies were analyzed in the context of offspring sex ratio and survival to reproductive age in a Zapotec-speaking community in the Valley of Oaxaca, southern Mexico. Growth status of children, adult stature, and agricultural resources were analyzed as proxies for parental and progeny condition in present and prior generations. Traditional marriage practice in Mesoamerican peasant communities is patrilocal postnuptial residence with investments largely favoring sons. The alternative, practiced by ～25% of parents, is matrilocal postnuptial residence which is an investment favoring daughters. Results indicated that sex ratio of offspring survival to reproductive age was related to economic strategy and differed significantly between the patrilocal and matrilocal strategies. Variance in sex ratio was affected by condition of parents and significant differences in survival to reproductive age were strongly associated with economic strategy. While the results strongly support TWH, further studies in traditional anthropological populations are needed. 相似文献
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2009—2011年4—7月在陕西红碱淖对同域分布的遗鸥和棕头鸥巢参数特征、巢群空间分布和巢址生境选择进行了对比分析。结果表明:巢外径、巢深、巢高等参数均存在显著差异,这主要是与营巢生境和巢址空间分布上有关;从巢群空间分布上来看,两者均选择于湖心岛上营巢繁殖,巢群呈斑块状分布,但彼此没有混巢现象,有时甚至通过压缩种间巢间距来达到共存,由于遗鸥繁殖群体数量占优势,遗鸥总是占据最佳的巢域,棕头鸥巢群通常被排挤至湖心岛边缘部分;在巢址生境选择上,植被类型、植被高度、植被盖度、巢离水面高度和巢距最近水边距离均存在显著差异。这表明两者巢址生境选择上具有特异性,这种特异性使得巢址生境选择上存在生态位差异,促成了遗鸥和棕头鸥能在同一湖心岛上营巢繁殖因素之一。 相似文献
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José Ragusa-Netto 《Studies on Neotropical Fauna and Environment》2013,48(3):219-226
A nuclear or leader species is the one around which foraging activity is organized. In the campo-cerrado (Brazilian savannah) up to four bird species (Saltator atricollis, Cypsnagra hirundinacea, Mimus saturninus, and Neothraupis fasciata) may function as nuclear or leader species in mixed species flocks. The aim of this study was to assess the features shown by these nuclear species. I quantified parameters of sociality, communication and alertness of nuclear bird species in mixed flocks with different composition. Parameters related to sociality (mean intraspecific group size) and communication (frequency of contact calls) were not correlated with the leadership. On the other hand, the most alert species was in the front of a given mixed flock most of the time. The leader species spent more time in vigilance and gave most alarm calls due to approaching raptors earlier. The results of this study strongly suggest that the alertness of a species is the major character of nuclear bird species in mixed flocks of the campo-cerrado. 相似文献
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Brian D. Uher‐Koch Joshua C. Koch Kenneth G. Wright Joel A. Schmutz 《Journal of avian biology》2018,49(7)
Identifying factors influencing nest survival among sympatric species is important for understanding and managing sources of variation in population dynamics of individual species. Three species of loons nest sympatrically in northern Alaska and differ in body size, life history characteristics, and population trends. We tested the effects of competition, nest site selection, and water level variations on nest survival of Pacific Gavia pacifica, yellow‐billed G. adamsii, and red‐throated loons G. stellata on the Arctic Coastal Plain in Alaska. Although overall nest survival rates did not differ between species, the factors influencing nest survival varied. Nest site selection influenced nest survival for Pacific and yellow‐billed loons, with both species having high nest survival when nesting on islands and peninsulas, likely due to a reduction in access by terrestrial predators. However, on mainland shorelines, Pacific loons had lower nest survival than yellow‐billed loons, and used a higher proportion of vegetation mats for nest sites suggesting that their smaller body size makes them less adept at nest defense. Nest site selection did not influence nest survival of red‐throated loons corresponding to our result of no nest site preferences by this species. Initiation date had a strong influence on nest survival for Pacific and yellow‐billed loons with nests laid earlier having higher survival. Pacific and yellow‐billed loon nests were susceptible to flooding due to precipitation, which contrasted with red‐throated loons that nest on smaller lakes with lower water level variations. Competition did not affect nest survival for any of the species likely due to most territorial encounters occurring prior to incubation. The only influence we found on red‐throated loon nest survival was differences among years. Our results indicate that loons chose nest sites based on predation risk and that factors influencing breeding success of closely related species may differ under similar breeding conditions. 相似文献
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Many avian studies, aimed at collecting samples for genetic analysis, rely upon invasive procedures involving the capture and handling of parents and their offspring. Our goal was to develop a nondestructive method for sampling maternal DNA that would not require blood collection from the mother. Herein, we describe a method for isolating genomic DNA from eggshell powder, obtained by filing the outer shell of an avian egg. Comparison of microsatellite profiles, obtained from genomic DNA found within eggshell matrices and their corresponding parents, verified the presence of maternal DNA in the eggshell matrix in 100% of the herring gull nests assessed (n= 11). In addition, the microsatellite profiles of eggshell DNA were identical among eggs from the same clutch. The ability to rapidly obtain a DNA sample from an avian eggshell in a noninvasive manner could aid in a wide range of genetic sampling studies, and in this study, we provide one potential application of this finding: assessing the fertilization status of nonviable herring gull (Larus argentatus) eggs from the Laurentian Great Lakes. Detection of fertilization was successful as the microsatellite profiles of eggshell powder (maternal only) and the fertilized embryonic contents of those eggs did not match. Ideally, the application of such an approach will help to discriminate unfertilized eggs from embryos aborted early in development and provide insights into avian reproductive health. 相似文献
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旅游快速发展对野生动物的繁衍和种群发展造成的影响不容忽视。鸡形目鸟类大多为地面营巢,易受人为活动的影响。为揭示旅游对鸡形目鸟类巢成功率的影响,于2018年3—5月在河南董寨国家级自然保护区采用地面人工巢进行了两轮模拟试验,分析了试验轮次、巢密度、代表旅游活动强度的客流量和车流量,及植被类型、海拔等栖息地影响因子对人工巢成功率的影响。结果显示:客流量和海拔在繁殖成功巢和失败巢之间均存在不同程度的差异,繁殖成功巢的客流量较大、海拔较小,且在客流量较大、海拔较小的区域中人工巢的表观存活率明显较高。其中客流量是影响巢成功率的主导因素。此外,第二轮试验人工巢表观存活率显著低于第一轮试验,捕食者组成在不同试验轮次上也存在明显的差异,第一轮试验主要是鸟类,第二轮试验则是哺乳动物。白颈鸦、貉和野猪在本研究中是对巢威胁最大的捕食者。结果表明旅游活动可能会影响鸡形目鸟类的繁殖。因此建议在开展旅游活动时应综合考虑该区域所分布的野生动物及优先保护政策,注意控制旅游活动强度,以免对野生动物造成不良影响,并加强栖息地的保护。 相似文献
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Rebecca Mcguire Christopher Latty Stephen Brown Shiloh Schulte Sarah Hoepfner Samuel Vassallo Paul Smith 《Ibis》2022,164(1):329-335
Cameras are important tools used to determine nest fate, identify predators and evaluate behaviour; however, they may impact the parameters they are used to measure, thereby biasing results. We evaluated the impact of cameras ? 10 m from the nest on shorebird nest survival at the Canning River Delta, Alaska, 2017–2018 (ncontrol = 122, ncamera = 109) using a much larger sample size than in previous studies conducted in the Arctic and random assignments at nest discovery. We found no effect of camera presence at the nest on daily nest survival (model-averaged daily survival rate (DSR) 85% confidence interval (CI); control: 0.971–0.983, camera: 0.969–0.982). We suggest that nest survival studies of tundra-nesting birds should consider the use of cameras to minimize researcher disturbance, increase the accuracy of fate assignments, and broaden the ecological data collected (e.g. incubation behaviour, predator identification and non-anthropogenic non-predation disruption such as by caribou). 相似文献
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研究活动(如查巢和视频拍摄)对鸟类巢存活率的影响一直受到关注。近年来的研究虽然已表明这种影响较小, 但以往研究多以开放巢或洞巢鸟类为研究对象, 对营球形巢的鸟类研究较少。为探究研究活动对营球形巢鸟类巢存活率的影响, 本文以营球形巢的红头长尾山雀(Aegithalos concinnus)为研究对象, 利用2011-2018年在河南董寨国家级自然保护区采集的监测数据, 分析了研究者的查巢及视频拍摄活动对其卵期(产卵期及孵卵期)和育雏期的巢日存活率的影响。结果显示, 无论是在卵期(n = 215巢)还是在育雏期(n = 200巢), 红头长尾山雀巢的日存活率与查巢或视频拍摄活动均无显著相关性, 亦不随巢高或巢日龄显著变化。但是, 红头长尾山雀卵期的巢日存活率与产卵日期呈显著的负相关关系, 即产卵日期越晚, 日存活率越低。与此相似, 其育雏期的巢日存活率与雏鸟出壳日期也呈显著的负相关关系, 即出壳日期越晚, 巢的日存活率越低。本研究结果表明, 研究活动不会显著影响营球形巢的红头长尾山雀的巢存活率。尽管如此, 本文仍建议科研人员应注意研究活动可能对研究对象造成的潜在影响, 并尽可能地避免或降低这种影响。 相似文献
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Using contemporary population data from Taiwan, we examine the relationships between parental age difference, educationally assortative mating, income and offspring count. Controlling for women's reproductive value (measured by age at first birth), we find that an older husband is associated with fewer offspring, whereas a husband with similar or higher education is associated with more offspring. Concerning resources, we find that women's income is negatively associated with fertility and husband's income is positively associated with fertility among highly educated women. These results are consistent with the view that women compensate for trade-offs between education, income generation and childbearing by seeking mates with a higher status. 相似文献
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Alain Blanc Nicolas Ogier Angélique Roux Sébastien Denizeau Nicolas Mathevon 《Comptes rendus biologies》2010,333(9):688-693
Communication behaviours are now considered from a signallers–receivers network perspective. This concept seems well suited to the study of interactions between parents and offspring in birds, so far mainly treated as a dyadic signalling system involving the brood or a single chick as a signaller and the parent as a receiver. Family conflicts over resource allocation drive parent–offspring and sib–sib communication. In the Black-headed Gull Larus ridibundus, parents respond to the whole-brood begging intensity and siblings often synchronize their begging signalling thus limiting individual effort. By monitoring five nests of two-chick broods during the whole rearing period in the nest, we show how an intra-brood simultaneity of begging emerges from successive phases of solitary begging of junior and senior nestlings. Although this result remains preliminary due to the sample size, it underlines a dynamical aspect of chicks’ behaviour. Because they always favour coordinated begging and because they elevate their response threshold across the rearing period, parents may play a major role in the plasticity of begging behaviour. 相似文献