Showing papers by "Jean Clobert published in 2012"

Costs of dispersal

Abstract: Dispersal costs can be classified into energetic, time, risk and opportunity costs and may be levied directly or deferred during departure, transfer and settlement. They may equally be incurred during life stages before the actual dispersal event through investments in special morphologies. Because costs will eventually determine the performance of dispersing individuals and the evolution of dispersal, we here provide an extensive review on the different cost types that occur during dispersal in a wide array of organisms, ranging from micro-organisms to plants, invertebrates and vertebrates. In general, costs of transfer have been more widely documented in actively dispersing organisms, in contrast to a greater focus on costs during departure and settlement in plants and animals with a passive transfer phase. Costs related to the development of specific dispersal attributes appear to be much more prominent than previously accepted. Because costs induce trade-offs, they give rise to covariation between dispersal and other life-history traits at different scales of organismal organisation. The consequences of (i) the presence and magnitude of different costs during different phases of the dispersal process, and (ii) their internal organisation through covariation with other life-history traits, are synthesised with respect to potential consequences for species conservation and the need for development of a new generation of spatial simulation models.

Dispersal Ecology and Evolution

Abstract: PART 1. THE MULTIPLE CAUSES OF THE DISPERSAL PROCESS PART 2. THE GENETICS OF DISPERSAL PART 3. THE ASSOCIATION OF DISPERSAL WITH OTHER LIFE HISTORY TRAITS PART 5. DISTRIBUTION OF DISPERSAL DISTANCES: DISPERSAL KERNELS PART 5. DISPERSAL AND POPULATION SPATIAL DYNAMICS PART 6. DISPERSAL AND CLIMATE CHANGE PART 7. DISPERSAL AND HABITAT FRAGMENTATION CONCLUSION

Modelling dispersal: an eco-evolutionary framework incorporating emigration, movement, settlement behaviour and the multiple costs involved

Abstract: 1. Understanding the causes and consequences of dispersal remains a central topic in ecology and evolution. However, a mismatch exists between our empirical understanding of the complexity of dispersal and our representation of dispersal in models. While the empirical literature is replete with examples of condition dependence at the emigration, movement and settlement phases, models rarely incorporate realism or complexity to this degree. Nor do models often include the different costs associated with dispersal, which can themselves be linked to one or more of the three key phases. 2. Here, we propose that by explicitly accounting for emigration, movement and settlement (and the multiple costs associated with each) we can substantially improve our understanding of both the dispersal process itself and how dispersal traits trade off against other life-history characteristics. We explore some of these issues conceptually, before presenting illustrative results gained from a flexible individual-based model which incorporates considerable dispersal complexity. 3. These results emphasise the nonlinear interplay between the different dispersal stages. For example, we find that investment in movement ability (at a cost to fecundity) depends upon the propensity to emigrate (and vice versa). However, owing to selection acting at the metapopulation level as well as at the individual level, the relationship between the two is not straightforward. Importantly, the shape of the trade-off between movement ability and reproductive potential can strongly influence the joint evolution of dispersal parameters controlling the degree of investment in safer movement, the probability of emigration and the straightness of movement. 4. Our results highlight that the joint evolution of dispersal characteristics can have major implications for spatial population dynamics and we argue that, in addition to increasing our fundamental biological understanding, a new generation of dispersal modelling, which exploits recent empirical advances, can substantially improve our ability to predict and manage the response of species to environmental change.

How is dispersal integrated in life histories: a quantitative analysis using butterflies

Abstract: As dispersal plays a key role in gene flow among populations, its evolutionary dynamics under environmental changes is particularly important. The inter-dependency of dispersal with other life history traits may constrain dispersal evolution, and lead to the indirect selection of other traits as a by-product of this inter-dependency. Identifying the dispersalOs relationships to other life-history traits will help to better understand the evolutionary dynamics of dispersal, and the consequences for species persistence and ecosystem functioning under global changes. Dispersal may be linked to other life-history traits as their respective evolutionary dynamics may be interdependent, or, because they are mechanistically related to each other. We identify traits that are predicted to co-vary with dispersal, and investigated the correlations that may constrain dispersal using published information on butterflies. Our quantitative analysis revealed that (1) dispersal directly correlated with demographic traits, mostly fecundity, whereas phylogenetic relationships among species had a negligible influence on this pattern, (2) gene flow and individual movements are correlated with ecological specialisation and body size, respectively and (3) routine movements only affected short-distance dispersal. Together, these results provide important insights into evolutionary dynamics under global environmental changes, and are directly applicable to biodiversity conservation.

Hormonally mediated maternal effects, individual strategy and global change

Abstract: A challenge to ecologists and evolutionary biologists is predicting organismal responses to the anticipated changes to global ecosystems through climate change. Most evidence suggests that short-term global change may involve increasing occurrences of extreme events, therefore the immediate response of individuals will be determined by physiological capacities and life-history adaptations to cope with extreme environmental conditions. Here, we consider the role of hormones and maternal effects in determining the persistence of species in altered environments. Hormones, specifically steroids, are critical for patterning the behaviour and morphology of parents and their offspring. Hence, steroids have a pervasive influence on multiple aspects of the offspring phenotype over its lifespan. Stress hormones, e.g. glucocorticoids, modulate and perturb phenotypes both early in development and later into adulthood. Females exposed to abiotic stressors during reproduction may alter the phenotypes by manipulation of hormones to the embryos. Thus, hormone-mediated maternal effects, which generate phenotypic plasticity, may be one avenue for coping with global change. Variation in exposure to hormones during development influences both the propensity to disperse, which alters metapopulation dynamics, and population dynamics, by affecting either recruitment to the population or subsequent life-history characteristics of the offspring. We suggest that hormones may be an informative index to the potential for populations to adapt to changing environments.

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 October 2011 - 30 November 2011: PERMANENT GENETIC RESOURCES NOTEM

Abstract: This article documents the addition of 139 microsatellite marker loci and 90 pairs of single‐nucleotide polymorphism sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Aglaoctenus lagotis, Costus pulverulentus, Costus scaber, Culex pipiens, Dascyllus marginatus, Lupinus nanus Benth, Phloeomyzus passerini, Podarcis muralis, Rhododendron rubropilosum Hayata var. taiwanalpinum and Zoarces viviparus. These loci were cross‐tested on the following species: Culex quinquefasciatus, Rhododendron pseudochrysanthum Hay. ssp. morii (Hay.) Yamazaki and R. pseudochrysanthum Hayata. This article also documents the addition of 48 sequencing primer pairs and 90 allele‐specific primers for Engraulis encrasicolus.

The Metatron: an experimental system to study dispersal and metaecosystems for terrestrial organisms

Abstract: Dispersal of organisms generates gene flow between populations. Identifying factors that influence dispersal will help predict how species will cope with rapid environmental change. We developed an innovative infrastructure, the Metatron, composed of 48 interconnected patches, designed for the study of terrestrial organism movement as a model for dispersal. Corridors between patches can be flexibly open or closed. Temperature, humidity and illuminance can be independently controlled within each patch. The modularity and adaptability of the Metatron provide the opportunity for robust experimental design for the study of 'meta-systems'. We describe a pilot experiment on populations of the butterfly Pieris brassicae and the lizard Zootoca vivipara in the Metatron. Both species survived and showed both disperser and resident phenotypes. The Metatron offers the opportunity to test theoretical models in spatial ecology.

The effect of coloration and temperature on sprint performance in male and female wall lizards

Abstract: Phenotypic coloration in animals is often expected to have a signalling function, but it may also evolve as a correlated trait that reflects life-history strategy, social strategy, or ecological divergence. Wall lizards (Podarcis muralis) exhibit substantial colour variation, with both males and females being red, white, yellow, or a mixture of these colours. However, the biological significance of these colour morphs remains unknown. Here we investigate the relationship between coloration and temperature-dependent locomotor performance in an attempt to identify the adaptive significance of colour variation in this species. We investigate the maximum sprint speed of males and females of each of these colour morphs across seven different temperatures, using general additive mixed models (GAMMs). We predicted that the different sexes and colour phenotypes would exhibit differences in sprint speed performance, potentially indicating a correlation between coloration and adaptation into different ecological niches. We found no difference in performance of the discrete colour morphs, but amongst individuals that exhibited red coloration, those with a greater percentage of red were slower than those with less red coloration. This suggests a trade-off between red coloration and high sprint performance in this species. Furthermore, larger animals performed better, independent of colour and sex. Finally, we found no relative or absolute difference between males and females in their sprint performance. Taken together, our results suggest that there is no sex-specific or colour morph-specific differentiation in the use of microhabitats in this species. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 107, 573–582.

When not to copy: female fruit flies use sophisticated public information to avoid mated males.

Abstract: When not to copy: female fruit flies use sophisticated public information to avoid mated males

Incestuous sisters: mate preference for brothers over unrelated males in Drosophila melanogaster.

Abstract: The literature is full of examples of inbreeding avoidance, while recent mathematical models predict that inbreeding tolerance or even inbreeding preference should be expected under several realistic conditions like eg polygyny We investigated male and female mate preferences with respect to relatedness in the fruit fly D melanogaster Experiments offered the choice between a first order relative (full-sibling or parent) and an unrelated individual with the same age and mating history We found that females significantly preferred mating with their brothers, thus supporting inbreeding preference Moreover, females did not avoid mating with their fathers, and males did not avoid mating with their sisters, thus supporting inbreeding tolerance Our experiments therefore add empirical evidence for inbreeding preference, which strengthens the prediction that inbreeding tolerance and preference can evolve under specific circumstances through the positive effects on inclusive fitness

Litter quality and inflammatory response are dependent on mating strategy in a reptile.

Abstract: Maintenance of health and the production of offspring are competing processes that can result in trade-offs. As vertebrates invest substantial resources in their immune system, it is crucial to understand the interactions between immunity and reproductive strategies. In the lizard Zootoca vivipara, females have condition- and context-dependent mating strategies. We predicted that, if the risk of infection is higher for polyandrous females, then polyandrous females should invest more in immune system while monandrous females should invest more in reproduction. In order to test our prediction, we captured 62 gravid females of known age in a natural population; we kept them until parturition to access to their offspring. Then, using microsatellite marker-based paternity analyses within litters, we determine the mating strategy of females (monandrous or polyandrous). Females were also challenged with PHA to estimate their inflammatory response. Our results show that polyandrous females have a higher PHA response than the monandrous females, and that monandrous females produce more males and more juveniles of better body condition than polyandrous females. The relationship between mating behaviour and immune function may have consequences for females and may shape the evolution of mating systems.

The importance of a good neighborhood: dispersal decisions in juvenile common lizards are based on social environment

Abstract: Within a population, dispersers are likely to differ in their motivation and adaptations to disperse; yet individual heterogeneity in dispersal decisions is still poorly documented. In the common lizard, females can be classified into 3 types of ventral color (yellow, orange, and mixed) that signal alternative strategies in reproduction and behavior. The reproductive success of these alternative strategies depends on the frequency of each color type in their local environment. Therefore, we predicted that adaptive emigration and settlement decisions should differ between color types and respond to the social composition of the environment. To test this prediction, we analyzed juvenile local dispersal decisions in response to an experimental manipulation of the local color type frequencies. Offspring from orange or mixed females showed decreased dispersal rate in populations where the frequency of yellow females was increased, and those who dispersed chose to settle in environments with lower female density but higher frequency of yellow females. Our results demonstrate that the composition of the social environment is used as a direct cue for dispersal decisions that provides information on resource competition and environment quality. The frequency of female color types is thus a key parameter of the social environment that influences habitat choice decisions. However, the pattern of spatial autocorrelation of adult females was not consistent with these color-related dispersal patterns, which suggest that other processes also participate in shaping the distribution of individuals at the population scale. Key words: color polymorphism, frequency dependence, ideal free distribution, natal dispersal, public information, spatial niche partitioning. [Behav Ecol]

The importance of habitat resistance for movement decisions in the common lizard, Lacerta vivipara

Abstract: Background Movement behaviour can be influenced by a multitude of biotic and abiotic factors. Here, we investigate the speed of movement in relation to environmental and individual phenotypic properties in subadult common lizards (Lacerta vivipara). We aim to disentangle the importance of substrate, cover, humidity, basking opportunity and individual phenotype on moving tendencies in 12 treatment combinations, at which each lizard was tested.

'Nature Conservation': a new dimension in Open Access publishing bridging science and application

Abstract: This Editorial presents the focus, scope and policies of the inaugural issue of Nature Conservation, a new open access, peer-reviewed journal bridging natural sciences, social sciences and hands-on applications in conservation management. The journal covers all aspects of nature conservation and aims particularly at facilitating better interaction between scientists and practitioners. The journal will impose no restrictions on manuscript size or the use of colour. We will use an XML-based editorial workflow and several cutting-edge innovations in publishing and information dissemination. These include semantic mark-up of, and enhancements to published text, data, and extensive cross-linking within the journal and to external sources. We believe the journal will make an important contribution to better linking science and practice, offers rapid, peer-reviewed and flexible publication for authors and unrestricted access to content.