共查询到20条相似文献,搜索用时 15 毫秒
1.
Jan A. C. von Rnn Martin U. Grüebler Thord Fransson Ulrich Kppen Frnzi Korner‐Nievergelt 《Ecology and evolution》2020,10(4):2225-2237
Ecosystems around the world are connected by seasonal migration. The migrant animals themselves are influenced by migratory connectivity through effects on the individual and the population level. Measuring migratory connectivity is notoriously difficult due to the simple requirement of data conveying information about the nonbreeding distribution of many individuals from several breeding populations. Explicit integration of data derived from different methods increases the precision and the reliability of parameter estimates. We combine ring‐reencounter, stable isotope, and blood parasite data of Barn Swallows Hirundo rustica in a single integrated model to estimate migratory connectivity for three large scale breeding populations across a latitudinal gradient from Central Europe to Scandinavia. To this end, we integrated a non‐Markovian multistate mark‐recovery model for the ring‐reencounter data with normal and binomial mixture models for the stable isotope and parasite data. The integration of different data sources within a mark‐recapture modeling framework enables the most precise quantification of migratory connectivity on the given broad spatial scale. The results show that northern‐breeding populations and Southern Africa as well as southern‐breeding populations and Western–Central Africa are more strongly connected through Barn Swallow migration than central European breeding populations with any of the African wintering areas. The nonbreeding distribution of Barn Swallows from central European breeding populations seems to be a mixture of those populations breeding further north and south, indicating a migratory divide. 相似文献
2.
Sexual selection results in the evolution of exaggerated secondary sexual characters that can entail a viability cost. However, in species where sexual ornaments honestly reflect individual quality, the viability cost of secondary sexual characters may be overwhelmed by variation in individual quality, leading to expect that individuals with the largest secondary sexual characters show higher, rather than lower viability. Here, we used meta‐analyses to test whether such expected positive relationship between sexual ornamentation and viability exists in the barn swallow Hirundo rustica, which is one of the most studied model species of sexual selection under field conditions. We found a mean positive effect size of viability in relation to the expression of secondary sexual characters of 0.181 (CI: 0.084–0.278), indicating that in this species the more ornamented individuals are more viable, and therefore of high quality. Analyses of moderator variables showed similar effects in males and females, the H. r. rustica subspecies rather than others and tail length rather than other secondary sexual characters. Future research emphasis on other subspecies than the European one and secondary sexual characters than tail length may help identify the sources of heterogeneity in effect sizes. 相似文献
3.
E. L. Behrman S. S. Watson K. R. O'Brien M. S. Heschel P. S. Schmidt 《Journal of evolutionary biology》2015,28(9):1691-1704
Seasonal environmental heterogeneity is cyclic, persistent and geographically widespread. In species that reproduce multiple times annually, environmental changes across seasonal time may create different selection regimes that may shape the population ecology and life history adaptation in these species. Here, we investigate how two closely related species of Drosophila in a temperate orchard respond to environmental changes across seasonal time. Natural populations of Drosophila melanogaster and Drosophila simulans were sampled at four timepoints from June through November to assess seasonal change in fundamental aspects of population dynamics as well as life history traits. D. melanogaster exhibit pronounced change across seasonal time: early in the season, the population is inferred to be uniformly young and potentially represents the early generation following overwintering survivorship. D. melanogaster isofemale lines derived from the early population and reared in a common garden are characterized by high tolerance to a variety of stressors as well as a fast rate of development in the laboratory environment that declines across seasonal time. In contrast, wild D. simulans populations were inferred to be consistently heterogeneous in age distribution across seasonal collections; only starvation tolerance changed predictably over seasonal time in a parallel manner as in D. melanogaster. These results suggest fundamental differences in population and evolutionary dynamics between these two taxa associated with seasonal heterogeneity in environmental parameters and associated selection pressures. 相似文献
4.
Pter L. Pap Attila Fülp Marie Adamkova Jaroslav Cepak Romana Michalkova Rebecca J. Safran Alexandru N. Stermin Oldrich Tomasek Csongor I. Vgsi Orsolya Vincze Matthew R. Wilkins Tomas Albrecht 《Ecology and evolution》2019,9(19):11277-11287
Variation in intensity and targets of sexual selection on multiple traits has been suggested to play a major role in promoting phenotypic differentiation between populations, although the divergence in selection may depend on year, local conditions or age. In this study, we quantified sexual selection for two putative sexual signals across two Central and East European barn swallow (Hirundo rustica rustica) populations from Czech Republic and Romania over multiple years. We then related these differences in selection to variation in sexual characters among barn swallow populations. Our results show that tail length and ventral coloration vary between populations, sexes, and age classes (first‐time breeders vs. experienced birds). We found that selection on tail length was stronger in first‐time breeders than in experienced birds and in males than in females in the Romanian population, while these differences between age groups and sexes were weak in Czech birds. We suggest that the populational difference in selection on tail length might be related to the differences in breeding conditions. Our results show that ventral coloration is darker (i.e., has lower brightness) in the Romanian than in the Czech population, and in experienced birds and males compared with first‐time breeders and females, respectively. The sexual difference in ventral coloration may suggest sexual selection on this trait, which is supported by the significant directional selection of ventral coloration in first‐time breeding males on laying date. However, after controlling for the confounding effect of wing length and tarsus length, the partial directional selection gradient on this trait turned nonsignificant, suggesting that the advantage of dark ventral coloration in early breeding birds is determined by the correlated traits of body size. These findings show that ventral coloration may be advantageous over the breeding season, but the underlying mechanism of this relationship is not clarified. 相似文献
5.
Richard Condit Joanne Reiter Patricia A. Morris Ryan Berger Sarah G. Allen Burney J. Le Boeuf 《Marine Mammal Science》2014,30(1):122-138
The aim of this study was to extend 40 yr of prior demographic work on northern elephant seals (Mirounga angustirostris) at Año Nuevo, California, by including the oldest animals. We used a Bayesian mark‐recapture analysis to estimate lifelong survival and lifespan of a cohort of 372 weaned pups branded in 1985–1987 and resighted until 2008. Annual survival probability of females averaged 86.3%/yr at ages 5–16, then declined until age 21, the age of the oldest female. Male survival was lower, averaging 67.7%/yr from age 1 to age 15, the age of the oldest male. Northern elephant seal females in the expanding population at Año Nuevo live longer than southern elephant seal females (M. leonina) at colonies whose populations are declining. This comparison suggests that high survival of females is a key factor in population growth. 相似文献
6.
Evan P. Tanner Jeremy P. Orange Craig A. Davis R. Dwayne Elmore Samuel D. Fuhlendorf 《Ecology and evolution》2019,9(16):9273-9289
Life‐history theory suggests species that typically have a large number of offspring and high adult mortality may make decisions that benefit offspring survival in exchange for increased adult risks. Such behavioral adaptations are essential to understanding how demographic performance is linked to habitat selection during this important life‐history stage. Though studies have illustrated negative fitness consequences to attendant adults or potential fitness benefits to associated offspring because of adaptive habitat selection during brood rearing, equivocal relationships could arise if both aspects of this reproductive trade‐off are not assessed simultaneously. To better understand how adaptive habitat selection during brood rearing influences demographics, we studied the brood survival, attendant parental survival, and space use of two sympatric ground‐nesting bird species, the northern bobwhite (hereafter: “bobwhite”; Colinus virgininanus) and scaled quail (Callipepla squamata). During the 2013–2014 breeding seasons, we estimated habitat suitability across two grains (2 m and 30 m) for both species and determined how adult space use of these areas influenced individual chick survival and parental risk. We found the proportion of a brood's home range containing highly suitable areas significantly increased bobwhite chick survival (β = 0.02, SE = 0.006). Additionally, adult weekly survival for bobwhite was greater for individuals not actively brooding offspring (0.9716, SE = 0.0054) as compared to brooding adults (0.8928, SE = 0.0006). Conversely, brood habitat suitability did not influence scaled quail chick survival during our study, nor did we detect a survival cost for adults that were actively brooding offspring. Our research illustrates the importance of understanding life‐history strategies and how they might influence relationships between adaptive habitat selection and demographic parameters. 相似文献
7.
Tara L. Imlay Belen Garcia‐Perez Keith A. Hobson Sievert Rohwer 《Journal of Field Ornithology》2017,88(4):405-415
Molt is energetically demanding and various molt strategies (i.e., molt series, duration, intensity, timing, and location) have evolved to reduce the negative fitness consequences of this process. As such, molt varies considerably among species. Identifying where and when specific feathers are molted is also crucial to inform species‐specific studies using stable isotope markers to assign individuals to geographical regions where they molt. Using museum specimens, we examined the molt of three species of migratory swallows in the Americas: Bank Swallows (Riparia riparia), Barn Swallows (Hirundo rustica), and Cliff Swallows (Petrochelidon pyrrhonota). All three species have one primary and two secondary molt series. Bank and Cliff swallows had one rectrix molt series, and Barn Swallows molted the outer rectrix (R6) separately from the inner five rectrices (R1‐5). All three species have a relatively long flight feather molt duration (i.e., 140–183 days) and low molt intensity. Barn Swallows initiated flight feather molt in the fall, about 2 months later than Bank and Cliff swallows. Barn Swallows likely delay molt because of constraints associated with double brooding. For all three species, molt started with the primaries and inner secondaries and was closely followed by the rectrices and, finally, the outer secondaries. For those that began and then interrupted molt either in breeding areas or during fall migration, the first feathers molted were predominantly S8 and P1. All three species underwent body molt throughout the year, but most individuals molted their body plumage in wintering areas. We recommend that the most appropriate feathers for stable isotope research examining migratory connectivity and habitat use are either R2‐R4 or S2‐S4. 相似文献
8.
A. Romano M. Romano M. Caprioli A. Costanzo M. Parolini D. Rubolini N. Saino 《Journal of evolutionary biology》2015,28(6):1234-1247
Parents should differentially invest in sons or daughters depending on the sex‐specific fitness returns from male and female offspring. In species with sexually selected heritable male characters, highly ornamented fathers should overproduce sons, which will be more sexually attractive than sons of less ornamented fathers. Because of genetic correlations between the sexes, females that express traits which are under selection in males should also overproduce sons. However, sex allocation strategies may consist in reaction norms leading to spatiotemporal variation in the association between offspring sex ratio (SR) and parental phenotype. We analysed offspring SR in barn swallows (Hirundo rustica) over 8 years in relation to two sexually dimorphic traits: tail length and melanin‐based ventral plumage coloration. The proportion of sons increased with maternal plumage darkness and paternal tail length, consistently with sexual dimorphism in these traits. The size of the effect of these parental traits on SR was large compared to other studies of offspring SR in birds. Barn swallows thus manipulate offspring SR to overproduce ‘sexy sons’ and potentially to mitigate the costs of intralocus sexually antagonistic selection. Interannual variation in the relationships between offspring SR and parental traits was observed which may suggest phenotypic plasticity in sex allocation and provides a proximate explanation for inconsistent results of studies of sex allocation in relation to sexual ornamentation in birds. 相似文献
9.
Laboratory experiments showed that the mussel Mytilus edulis aggregated more intensely around living organisms (the bivalve Hiatella arctica and the solitary ascidian Styela rustica, which commonly co‐occur with mussels in fouling communities) than around inanimate objects. When exposed to an inanimate object, mussels attached their byssal threads primarily to the substrate, close to the object, but when exposed to a living organism, they attached their byssal threads directly to the organism. The ascidian was more intensely covered with byssal threads than was the bivalve. Mussel attachment to the ascidians was apparently determined by the physical characteristics of the tunic and to a lesser extent by the excretion‐secretion products released by S. rustica. This study indicates that mussels can use byssus threads as a means of entrapment of potential competitors for space. It remains unclear why mussels preferentially attached to ascidians compared to the bivalve. This can be explained either by competitive interactions, or by attractiveness of the ascidian tunic as an attachment substratum. 相似文献
10.
Survival records of longevity experiments are a key component in research on aging. However, surprisingly there have been very few cross‐study analyses, besides comparisons of median lifespans or similar summary information. Here, we use a large set of full survival data from various studies to address questions in aging, which are beyond the scope of individual studies. We characterize survival differences between female and male flies of different genetic Drosophila strains, showing significant differences between strains. We further analyse the variation in survival of control cohorts recorded under highly similar conditions within different Drosophila strains. We found that overall transgenic constructs of the UAS/GAL4 expression system which should have no effect (e.g. a GAL4 construct alone) extend lifespan significantly in the w1118 strain. Using a large data set comprised of various studies, we found no evidence for larger lifespan extensions being associated with shorter lifespans of the control in Drosophila. This demonstrates that lifespan extending treatments are not purely rescuing weak backgrounds. 相似文献
11.
Climate variation and trends affect species distribution and abundance across large spatial extents. However, most studies that predict species response to climate are implemented at small spatial scales or are based on occurrence‐environment relationships that lack mechanistic detail. Here, we develop an integrated population model (IPM) for multi‐site count and capture‐recapture data for a declining migratory songbird, Wilson's warbler (Cardellina pusilla), in three genetically distinct breeding populations in western North America. We include climate covariates of vital rates, including spring temperatures on the breeding grounds, drought on the wintering range in northwest Mexico, and wind conditions during spring migration. Spring temperatures were positively related to productivity in Sierra Nevada and Pacific Northwest genetic groups, and annual changes in productivity were important predictors of changes in growth rate in these populations. Drought condition on the wintering grounds was a strong predictor of adult survival for coastal California and Sierra Nevada populations; however, adult survival played a relatively minor role in explaining annual variation in population change. A latent parameter representing a mixture of first‐year survival and immigration was the largest contributor to variation in population change; however, this parameter was estimated imprecisely, and its importance likely reflects, in part, differences in spatio‐temporal distribution of samples between count and capture‐recapture data sets. Our modeling approach represents a novel and flexible framework for linking broad‐scale multi‐site monitoring data sets. Our results highlight both the potential of the approach for extension to additional species and systems, as well as needs for additional data and/or model development. 相似文献
12.
S. Kecko A. Mihailova K. Kangassalo D. Elferts T. Krama R. Krams S. Luoto M. J. Rantala I. A. Krams 《Journal of evolutionary biology》2017,30(10):1910-1918
Deficiency of food resources in ontogeny is known to prolong an organism's developmental time and affect body size in adulthood. Yet life‐history traits are plastic: an organism can increase its growth rate to compensate for a period of slow growth, a phenomenon known as ‘compensatory growth’. We tested whether larvae of the greater wax moth Galleria mellonella can accelerate their growth after a fast of 12, 24 or 72 h. We found that a subgroup of female larvae showed compensatory growth when starved for 12 h. Food deficiency lasting more than 12 h resulted in longer development and lower mass gain. Strength of encapsulation reactions against a foreign body inserted in haemocoel was the weakest in females that showed compensatory growth, whereas the strongest encapsulation was recorded in the males and females that fasted for 24 and 72 h. More specifically, we found sex‐biased immune reactions so that females had stronger encapsulation rates than males in one group that fasted for 72 h. Overall, rapidly growing females had a short larval development period and the shortest adult lifespan. These results suggest that highly dynamic trade‐offs between the environment, life‐history traits and sex lead to plasticity in developmental strategies/growth rates in the greater wax moth. 相似文献
13.
Chloe Heys Anne Lizé Frances Blow Lewis White Alistair Darby Zenobia J. Lewis 《Ecology and evolution》2018,8(8):4150-4161
In recent years, there has been a surge in interest in the effects of the microbiota on the host. Increasingly, we are coming to understand the importance of the gut microbiota in modulating host physiology, ecology, behavior, and evolution. One method utilized to evaluate the effect of the microbiota is to suppress or eliminate it, and compare the effect on the host with that of untreated individuals. In this study, we evaluate some of these commonly used methods in the model organism, Drosophila melanogaster. We test the efficacy of a low‐dose streptomycin diet, egg dechorionation, and an axenic or sterile diet, in the removal of gut bacteria within this species in a fully factorial design. We further determine potential side effects of these methods on host physiology by performing a series of standard physiological assays. Our results showed that individuals from all treatments took significantly longer to develop, and weighed less, compared to normal flies. Males and females that had undergone egg dechorionation weighed significantly less than streptomycin reared individuals. Similarly, axenic female flies, but not males, were much less active when analyzed in a locomotion assay. All methods decreased the egg to adult survival, with egg dechorionation inducing significantly higher mortality. We conclude that low‐dose streptomycin added to the dietary media is more effective at removing the gut bacteria than egg dechorionation and has somewhat less detrimental effects to host physiology. More importantly, this method is the most practical and reliable for use in behavioral research. Our study raises the important issue that the efficacy of and impacts on the host of these methods require investigation in a case‐by‐case manner, rather than assuming homogeneity across species and laboratories. 相似文献
14.
Jonathan B. Cohen Sidney B. Maddock Melissa K. Bimbi W. Walker Golder Olivia E. Ledee Francesca J. Cuthbert Daniel H. Catlin James D. Fraser Cheri L. Gratto‐Trevor 《Ibis》2018,160(2):342-354
Conservation of beach‐nesting medium‐distance migrants has focused on breeding areas because protection of nests is more tractable than protection of non‐breeding habitat. As breeding ground management has encountered diminishing returns, interest in understanding threats in non‐breeding areas has increased. However, robust estimates of non‐breeding demographic rates and abundance are generally lacking, hindering the study of limiting factors. Estimating such rates is made more difficult by complex population dynamics at non‐breeding sites. In South Carolina, endangered Piping Plovers Charadrius melodus start arriving in July and some depart prior to December (the autumn‐only population) while others remain through at least March (the wintering population). State uncertainty capture‐mark‐recapture models provide a means for estimating vital rates for such co‐occurring populations. We estimated the proportion of the population entering the study area per survey (entry probability) and proportion remaining per survey (persistence rate) for both populations during autumn, and abundance of the wintering population, at four sites in South Carolina in 2006/7 and 2007/8, taking advantage of birds previously colour‐ringed on the breeding grounds. We made fairly precise estimates of entry and persistence rates with small sample sizes. Cumulative entry probability was ~50% by the end of July and reached 95% for both populations by October. Estimated stopover duration for birds in the autumn‐only population was 35 days in year 1 and 42 days in year 2. We estimated a wintering super‐population size of 71 ± 16 se birds in the first year and 75 ± 16 in the second. If ringing programmes on the breeding grounds continue, standardized resighting surveys in the non‐breeding period and mark‐recapture models can provide robust estimates of entry and persistence rates and abundance. Habitat protection intended to benefit non‐breeding Piping Plovers at our coastal sites should be in effect by late summer, as many birds are resident from July to the end of winter. 相似文献
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Experimental manipulation of tail ornament size affects the hematocrit of male barn swallows (Hirundo rustica) 总被引:2,自引:0,他引:2
Nicola Saino José Javier Cuervo Marco Krivacek Florentino de Lope Anders Pape Møller 《Oecologia》1997,110(2):186-190
Ornamental tail feathers of male barn swallows (Hirundo rustica) confer an advantage in sexual selection because long-tailed males are preferred by females. However, the size of tail ornaments exceeds the natural selection optimum and males are predicted to pay an energetic cost for flying, directly related to tail length. An increase in hematocrit is an adaptive response to enhance oxygen uptake, for example during periods of intense locomotory activity. In this study, we analyzed the effect of experimental manipulation of tail length on the hematocrit of male barn swallows from an Italian and a Spanish population. We predicted that the natural decrease in hematocrit during the breeding season would be reduced by experimental elongation and enhanced by experimental shortening of tail ornaments. The results showed that the decrease in hematocrit was significantly different among tail treatments, and tail-elongated males had the smallest hematocrit reduction. In Italy, the hematocrit of tail-elongated males did not change after tail manipulation, while that of two control groups and tail-shortened males decreased. A comparatively high hematocrit in males with experimentally enlarged tail ornaments may be a response to increased energetic requirements and, hence, to oxygen demands for flying imposed by their tail morphology. Received: 22 June 1996 / Accepted: 23 October 1996 相似文献
17.
Aggregated recruitment patterns under adult crowns in Photinia glabra,a bird‐dispersed tree species
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To clarify recruitment patterns of Photinia glabra, which is an evergreen, broad‐leaved, bird‐dispersed tree species, we analyzed spatial distribution in P. glabra recruits at each growth stage and demography of current‐year seedlings with respect to distributions of adults in a warm‐temperate secondary forest, western Japan. Although individuals ≥ 5 cm diameter at breast height (DBH) that had nearly produced fruits showed a random distribution, seedlings (≥ 1 year old, < 10‐cm stem length [SL]), small saplings (10 ≤ SL < 30 cm) and large saplings (≥ 30‐cm SL, < 5‐cm DBH) were clumped and associated with reproductive adults at approximately 2–3‐m scales, nearly equal to their average crown radius. Based on monitoring the demography of current‐year seedlings, emerged seedling density profoundly decreased, and no seedlings survived at longer than an adult's crown scales, with distance‐dependent mortality as a result of disease and herbivory not greatly affecting the current‐year seedling mortality. Thus, aggregated seed dispersal under the crown of adult P. glabra would directly influence the distribution of recruits for P. glabra in this forest. Of the bird‐dispersed tree species in this forest, P. glabra produced the highest amount of fruits during large crop years, and their fruits ripened during the late seasonal period (early January), suggesting that birds might be strongly attracted to these species, in turn leading to seeds being deposited mostly under the tree crowns. We propose that dispersal limitation would occur, even in a bird‐dispersed tree species such as P. glabra, owing to plant–bird interactions in the forest. 相似文献
18.
Mathieu Douhard Jean‐Paul Crampe Anne Loison Christophe Bonenfant 《Ecology and evolution》2020,10(6):2793-2802
While all models of sexual selection assume that the development and expression of enlarged secondary sexual traits are costly, males with larger ornaments or weapons generally show greater survival or longevity. These studies have mostly been performed in species with high sexual size dimorphism, subject to intense sexual selection. Here, we examined the relationships between horn growth and several survival metrics in the weakly dimorphic Pyrenean chamois (Rupicapra pyrenaica). In this unhunted population living at high density, males and females were able to grow long horns without any apparent costs in terms of longevity. However, we found a negative relationship between horn growth and survival during prime age in males. This association reduces the potential evolutionary consequences of trophy hunting in male chamois. We also found that females with long horns tended to have lower survival at old ages. Our results illustrate the contrasting conclusions that may be drawn when different survival metrics are used in analyses. The ability to detect trade‐off between the expression of male secondary sexual traits and survival may depend more on environmental conditions experienced by the population than on the strength of sexual selection. 相似文献
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Fiona S. A. Bracken A. Rus Hoelzel John B. Hume Martyn C. Lucas 《Molecular ecology》2015,24(6):1188-1204
The tendency of many species to abandon migration remains a poorly understood aspect of evolutionary biology that may play an important role in promoting species radiation by both allopatric and sympatric mechanisms. Anadromy inherently offers an opportunity for the colonization of freshwater environments, and the shift from an anadromous to a wholly freshwater life history has occurred in many families of fishes. Freshwater‐resident forms have arisen repeatedly among lampreys (within the Petromyzontidae and Mordaciidae), and there has been much debate as to whether anadromous lampreys, and their derived freshwater‐resident analogues, constitute distinct species or are divergent ecotypes of polymorphic species. Samples of 543 European river lamprey Lampetra fluviatilis (mostly from anadromous populations) and freshwater European brook lamprey Lampetra planeri from across 18 sites, primarily in the British Isles, were investigated for 13 polymorphic microsatellite DNA loci, and 108 samples from six of these sites were sequenced for 829 bp of mitochondrial DNA (mtDNA). We found contrasting patterns of population structure for mtDNA and microsatellite DNA markers, such that low diversity and little structure were seen for all populations for mtDNA (consistent with a recent founder expansion event), while fine‐scale structuring was evident for nuclear markers. Strong differentiation for microsatellite DNA loci was seen among freshwater‐resident L. planeri populations and between L. fluviatilis and L. planeri in most cases, but little structure was evident among anadromous L. fluviatilis populations. We conclude that postglacial colonization founded multiple freshwater‐resident populations with strong habitat fidelity and limited dispersal tendencies that became highly differentiated, a pattern that was likely intensified by anthropogenic barriers. 相似文献