Lifetime Fitness Research Articles

Grin and Barre It: Building Healthy Students in Physical Education

Barre fitness classes are ballet-inspired challenges that incorporate ballet barre and ballet positions. This non-traditional lifetime fitness activity is appropriate for a vast array of student learners. Non-traditional units can be defined as new or different from established norms and methods. Physical educators should consistently integrate a variety of units to offer student choice regarding their physical activity options. This article will support professionals with the implementation of a lifetime wellness, non-traditional Barre unit in Physical Education.

Pollination Services to Impatiens capensis (Balsaminaceae) Are Maintained across an Urbanization Gradient

Premise of research. Urbanization is associated with the fragmentation of natural habitats, a reduction in agricultural pesticides, and high numbers of introduced species. Urbanization has also been connected to declines in native biodiversity, including of important ecosystem service providers such as pollinators. We expected that reported patterns of lower pollinator diversity and abundance in highly built-up urban areas should translate into higher pollen limitation of plant reproduction.Methodology. We set up arrays of 20 pots containing the native plant Impatiens capensis in 15 community gardens around the city of Ottawa, Ontario, Canada, that were selected to span a gradient of urbanization (defined as the percentage of surface area in a 100-m radius that was covered by pavement, buildings, or other impermeable surfaces). We collected data on the pollen limitation, lifetime fitness, and investment in selfed versus outcrossed reproduction over the course of each plant’s life span.Pivotal results. The plants in our study were pollen limited on average, but there was no association between the extent of pollen limitation and site urbanization. This result was robust to the landscape scale at which urbanization was calculated. In fact, the pollen limitation of our plants was similar to what has been reported in studies of I. capensis in the wild. Plant investment in selfing was not associated with urbanization; however, hand-pollinated plants in our study tended to invest more in outcrossed reproduction than open-pollinated plants, highlighting the mating system plasticity of this species.Conclusions. Our findings indicate that, for a plant that is native to this area, pollen limitation was not consistently higher in heavily built-up urban areas. We frame our findings in terms of new studies reporting the complexity of the impacts of urbanization on pollinators and their ecosystem services.

Timing and Intensity of Weather Events Shape Nestling Development Strategies in Three Alpine Breeding Songbirds

Across taxa, offspring size traits are linked to survival and life-time fitness. Inclement weather can be a major constraint on offspring growth and parental care. Despite the adaptive benefits of larger offspring, we have a limited understanding of the effects of severe environmental conditions across developmental stages and how coping strategies differ among species. We assessed the influence of inclement weather on offspring size and mass traits within populations of three alpine breeding songbirds in British Columbia: 1) horned lark (Eremophila alpestris), 2) dark-eyed junco (Junco hyemalis), and 3) savannah sparrow (Passerculus sandwichensis). Specifically, we investigated at which stages during early-life development offspring are most vulnerable to inclement weather and whether thresholds exist in the developmental response to severe weather events. Across species, we identified two critical periods that best predicted offspring size: 1) clutch initiation, and 2) the nestling stage. Colder temperatures experienced by the female during clutch initiation were associated with larger, heavier offspring in horned larks but smaller offspring for savannah sparrows, indicating the potential for maternal effects, albeit acting through different mechanisms. Additionally, horned lark offspring were resilient to colder average temperatures during the nestling stage but were vulnerable to extreme cold events and multi-day storms. In contrast, dark-eyed junco nestlings were robust to storms, but smaller size and mass traits were associated with lower daily maximum temperatures (i.e., more mild temperature challenges). We suggest species differences may be linked to life-history traits, such as: 1) the thermoregulatory benefits of larger body mass in horned larks, 2) the benefits of greater nest cover to buffer dark-eyed junco against precipitation events, and 3) delayed clutch initiation for savannah sparrows to limit exposure to cold storms. We provide evidence for stage-specific impacts of inclement weather on offspring development with implications for reproductive success. These results advance our understanding of early-life resilience to stochastic environments, as we may be able to predict differences in the vulnerability of alpine species to increasingly variable and severe weather conditions.

Electron irradiation induced molecular changes in PMMA: A positron spectroscopy study

To examine the positron annihilation parameters with regard to microstructural changes, the positron annihilation lifetime spectroscopy and measurements of the Doppler broadening of annihilation radiation (DBAR) of electron‐irradiated poly(methyl methacrylate) were carried out at room temperature. Trapping rate equations were applied in terms of the positron bulk lifetime as well as the positron lifetime fitting results to investigate the molecular changes due to electron irradiation effects. It was found that the mean positron lifetime shows the same trend as the o‐Ps intensity. In disordered regions, the positronium trapping rate suggests that trapping of o‐Ps increases with increasing electron irradiation fluence until electron fluence reached 5.9 × 1013 electrons/cm2, after which it begins to decrease. The line shape S‐parameter was found to have similar behavior as the o‐Ps intensity, and suggests that poly(methyl methacrylate) undergoes chain scission, followed by cross‐linking, and eventually degradation, due to the electron radiation effects. The results of positron annihilation spectroscopy were verified by X‐ray results, mechanical, and electrical measurements.

Seed germination of gynodioecious species: theoretical considerations and a comparison of females and hermaphrodites.

Better seed germination of females than of hermaphrodites is not a major contributor to the greater geometric lifetime fitness that females require to be maintained in a gynodioecious population. Gynodioecy is a sexually dimorphic breeding system in which females (F, male sterile) and hermaphrodites (H) coexist in the same population. For plants with nuclear (biparental) inheritance of male sterility, theory predicts that except when the product of selfing rate (s) and inbreeding depression (δ) in H is high (sδ > 0.50), F must compensate (female advantage) for the loss of gene transmission via pollen production by producing more or higher-quality offspring than H to be maintained in the population. For species with cytoplasmic (maternal) inheritance of male sterility, the female requires only a small compensation in seed production or some other offspring fitness trait to persist. Reallocation to seeds of resources saved by loss of pollen production is expected to increase the quantity (number) and/or quality (mass, germinability) of seeds produced by F, thus compensating for the lack of pollen production. The primary aim of our study was to compare seed germination of F and H via a literature review. Based on theoretical considerations, we hypothesized that seeds of F should germinate better or equally as well as those of H. We found that of 235 case studies for 47 species Fgerm > Hgerm in 48.1%, Fgerm = Hgerm in 38.3% and Fgerm < Hgerm in 13.6%. Our results are very similar to those of a previously published meta-analysis that included germination of F and H for 12 species. For 162 cases on seed size, F > H in 29.0%, F = H in 63.6% and F < H in 7.4%. Since [(Fgerm > Hgerm) < (Fgerm ≤ Hgerm)] and [(Fseedsize > Hseedsize) < (Fseedsize ≤ Hseedsize)], these results suggest that seed quality is not a major fitness component of female advantage.

Nutrient enrichment and neopolyploidy interact to increase lifetime fitness of Arabidopsis thaliana

Nascent polyploids, or neopolyploids, frequently arise within diploid plant lineages and are expected to experience increased requirements for growth-limiting nutrients because of building a larger genome. Because this may have important consequences for the ecology of neopolyploids, we need studies that track the lifetime fitness effects of whole genome duplication. Here we investigated how multiple origins of neopolyploidy and nutrient supply rate affected fitness-related traits of Arabidopsis thaliana. We investigated the interaction between cytotype, independent neopolyploid origins, and soil fertility by conducting a greenhouse experiment with five nutrient treatments that varied nitrogen and phosphorus supply. We compared biomass, flowering phenology, fecundity, average mass per seed, and offspring germination rates of diploids and their descendent neotetraploids from four independent origins. The results supported the hypothesis that neopolyploidy increases nutrient limitation. Diploids outpaced their neotetraploid descendants in growth and composite fitness in all nutrient treatments except with high supply of nitrogen and phosphorus, where neotetraploid growth and composite fitness exceeded diploids. In contrast, we did not detect an interaction between cytotype and nutrient treatment for flowering phenology, but neotetraploids flowered later, and low nutrient supply caused earlier flowering. We additionally found that the trait responses of neotetraploids were strongly contingent on their independent, maternal origin. Polyploidy has myriad effects on plant physiology, but few studies have tested how neopolyploid-induced physiological changes can affect plant environmental interactions. By showing that neopolyploid fitness is more constrained by nutrient supply, we conclude that neotetraploidy increases nutrient limitation in A. thaliana.

Why did sauropod dinosaurs grow so big? – A possible answer from the life history theory

Dinosaurs are known for their large body size. Sauropod dinosaurs (Sauropodomorpha) had an especially large body size; some species reached 30 m long and 50 tons. Many hypotheses have been proposed to explain this phenomenon. In this study we examined this question using the life history theory. We constructed a simple model of life history with the following assumptions: the body size of immature individuals increases following a logistic equation. A higher quality and availability of food plants make the initial growth rate faster and the final saturating size larger. The increase in body size stops once reproduction starts. Fertility increases with adult body size and food-plant quality. Mortality due to predation is mitigated by a larger body size. We calculated the optimal body size at maturity that would maximize the lifetime reproductive success or fitness. The analysis showed that adult body size increased with food-plant quality and availability but decreased with higher mortality due to predators and other factors. This conclusion is consistent with geological studies that suggest a high quality and availability of food plants in the Mesozoic era, efficient air-sac breathing, and the lightweight bones of sauropod dinosaurs, allowing rapid growth of small individuals.

Risk of predation on offspring reduces parental provisioning, but not flight performance or survival across early life stages

Abstract Developmental responses can help young animals reduce predation risk but can also yield costs to performance and survival in subsequent life stages with major implications for lifetime fitness. Compensatory mechanisms may evolve to offset such costs, but evidence from natural systems is largely lacking. In songbirds, increased nest predation risk should favour reduced provisioning, but also young that fledge (leave their nest) at an earlier age. Both responses can result in fledglings with shorter wings, reduced mobility and decreased survival. Young may compensate for shorter wings developmentally by reallocating resources towards feather development or behaviourally by adjusting flight kinematics or habitat use. However, underfed young may lack the capacity to express these phenotypes due to insufficient resources or an inability to adjust allocation of resources. Using predation risk experiments and 29 years of observational field data, we test whether increased nest predation risk reduces flight performance and survival during the fledgling stage and explore potential mechanisms that might underlie these effects. We show that young from high‐risk nests did not leave the nest earlier on average, but wing growth was slower likely due to observed reductions in parental feeding rates. Wings were shorter in high‐risk nests when fledglings left the nest early. Yet, fledglings from high‐risk nests showed improved flight performance for a given wing length such that flight performance at fledging did not differ between young from high‐risk and low‐risk nests. Young from high‐risk nests may have offset the costs of shorter wings on flight performance by accelerating the emergence of flight feathers from their sheaths to reduce wing porosity, though evidence for this mechanism was mixed. Fledglings from high‐risk nests also selected habitat with denser woody vegetation compared with young from low‐risk nests. Together, these developmental and behavioural responses seem to mitigate the expected effects of increased nest predation risk on fledgling survival. Ultimately, our results show that offspring predation risk can affect parental provisioning and offspring morphology without major implications for performance and survival in subsequent life stages. A free Plain Language Summary can be found within the Supporting Information of this article.

Diminished fitness of red cotton bug Dysdercus koenigii Fabricius induced by the volatiles in the hexane extract of Catharanthus roseus

Survival, longevity, growth index and development of fifth instar nymphs of Dysdercus koenigii (Heteroptera: Pyrrhocoriedae) as influenced by the Catharanthus roseus was assessed in the present investigation. The fifth instar nymphs were exposed to the volatiles present in the extract for 24 h. Different concentrations of the extract ranging from 0.00625% to 10% were used for the treatment. The results indicate that the survival of treated nymphs was not affected significantly. However, the volatiles present in the extract influenced the growth and development of the treated fifth instar nymphs. The nymphs exhibited decreased growth as reflected by the decrease in growth index. The extract induced different types of developmental anomalies notably incomplete moulting, supernumerary instars, adultoids and adults with deformed wing. In some cases, exuviae did not detach from the body of the adults and create obstacle in the feeding, walking and mating. The effects of the extract on nymphal development were also dose-dependent. No normal adults could develop in the treatments with the concentration 5% or more; various morphological and developmental abnormalities were reported in the nymphs treated with 2.5% to 0.1% of the extract. GC-MS analysis of the hexane leaf extract of C. roseus showed the presence of sesquiterpenes including geranylgerniol and many toxic chemicals. These phytoconstituents of the C. roseus extract besides having cidal effects also showed juvenile hormone mimic activities which impair lifetime fitness of D. koenigii. Therefore, botanical from the C. roseus can potentially be used as an alternative approach in pest management.

Sex- and context-specific associations between personality and a measure of fitness but no link with life history traits

The pace-of-life syndrome hypothesis posits that personality traits (i.e. consistent individual differences in behaviour) are linked to life history and fitness. Specifically, fast-paced individuals are predicted to be proactive (i.e. active and aggressive) with an earlier age at first reproduction, a shorter life span and higher fecundity than slow-paced individuals. Environmental conditions and sex differences may be important in maintaining behavioural and life history variation in populations and may influence the covariance of personality with life history or lifetime fitness. However, these effects are rarely tested together. We investigated whether the occurrence of a resource pulse (called a mast year) during adulthood altered the associations between personality and life history traits or lifetime offspring production in adult North American red squirrels, Tamiasciurus hudsonicus. Despite accounting for environmental context during adulthood, we found no evidence of an overall pace-of-life syndrome in this population as personality was not associated with age at first reproduction or longevity in either sex. Males and females had similar activity levels, but females were more aggressive, potentially due to the fitness benefits of protecting their offspring from predation. In all females, regardless of mast experience, there was no association between activity and lifetime pup production, but there was a positive association between aggression and lifetime pup production. In males that experienced a mast, there was a positive association between lifetime pup production and both activity and aggression. In males that did not experience a mast, there was no association between activity and lifetime pup production, but there was a negative association between aggression and lifetime pup production. Lifetime recruit production (number of adult offspring recruited into the breeding population) in either sex was not influenced by activity or aggression regardless of mast experience. Overall, our results suggest that the infrequent occurrence of mast years may contribute to maintaining variation in personality traits in red squirrels.

Early-life relationships matter: Social position during early life predicts fitness among female spotted hyenas.

How social development in early-life affects fitness remains poorly understood. Though there is growing evidence that early-life relationships can affect fitness, little research has investigated how social positions develop or whether there are particularly important periods for social position development in an animal's life history. In long-lived species in particular, understanding the lasting consequences of early-life social environments requires detailed, long-term datasets. Here we used a 25-year dataset to test whether social positions held during early development predicted adult fitness. Specifically, we quantified social position using three social network metrics: degree, strength and betweenness. We determined the social position of each individual in three types of networks during each of three stages of ontogeny to test whether they predict annual reproductive success (ARS) or longevity among adult female spotted hyenas Crocuta crocuta. The social positions occupied by juvenile hyenas did predict their fitness, but the effects of social position on fitness measures differed between stages of early development. Network metrics when individuals were young adults better predicted ARS, but network metrics for younger animals, particularly when youngsters were confined to the communal den, better predicted longevity than did metrics assessed during other stages of development. Our study shows how multiple types of social bonds formed during multiple stages of social development predict lifetime fitness outcomes. We suggest that social bonds formed during specific phases of development may be more important than others when considering fitness outcomes.

Mate fidelity improves survival and breeding propensity of a long-lived bird.

Evolutionary and behavioural ecologists have long been interested in factors shaping the variation in mating behaviour observed in nature. Although much of the research on this topic has focused on the consequences of mate choice and mate change on annual reproductive success, studies of a potential positive link between mate fidelity and adult demographic rates have been comparatively rare. This is particularly true for long-lived birds with multi-year, socially monogamous pair bonds. We used a 26-year capture-mark-recapture dataset of 3,330 black brent Branta bernicla nigricans to test whether breeding with a familiar mate improved future breeding propensity and survival. We predicted that experienced breeders nesting with a new partner would have rates of survival similar to familiar pairs because long-lived species avoid jeopardizing survival since their lifetime fitness is sensitive to this vital rate. In contrast, we expected that any costs of breeding with a new partner would be paid through skipping the subsequent breeding attempt. We found that unfamiliar pairs had lower subsequent breeding propensity than faithful partners. However, contrary to our expectations, individuals breeding with a new mate also suffered reduced survival. These results add to a small number of studies indicating that a positive relationship between mate retention and adult demographic rates may exist in a diverse array of avian species. Given these results, researchers should consider costs of mate change that extend beyond within-season reproductive success to fully understand the potential adaptive basis for perennial social monogamy. We caution that if mate retention enhances survival prospects, improvements in annual reproductive success with pair-bond length could be a secondary factor favouring perennial social monogamy, particularly in species with slower life-history strategies. Furthermore, some cases where annual reproductive success does not improve with pair-bond duration, yet multi-year pair bonds are common, could be explained by benefits afforded by mate fidelity to adult vital rates.

Rapid adaptation to invasive predators overwhelms natural gradients of intraspecific variation

Invasive predators can exert strong selection on native populations. If selection is strong enough, populations could lose the phenotypic variation caused by adaptation to heterogeneous environments. We compare frog tadpoles prior to and 14 years following invasion by crayfish. Prior to the invasion, populations differed in their intrinsic developmental rate, with tadpoles from cold areas reaching metamorphosis sooner than those from warm areas. Following the invasion, tadpoles from invaded populations develop faster than those from non-invaded populations. This ontogenetic shift overwhelmed the intraspecific variation between populations in a few generations, to the point where invaded populations develop at a similar rate regardless of climate. Rapid development can have costs, as fast-developing froglets have a smaller body size and poorer jumping performance, but compensatory growth counteracts some costs of development acceleration. Strong selection by invasive species can disrupt local adaptations by dampening intraspecific phenotypic variation, with complex consequences on lifetime fitness.

Full lifetime perspectives on the costs and benefits of lay-date variation in tree swallows.

Animals must balance various costs and benefits when deciding when to breed. The costs and benefits of breeding at different times have received much attention, but most studies have been limited to investigating short-term season-to-season fitness effects. However, breeding early, versus late, in a season may influence lifetime fitness over many years, trading off in complex ways across the breeder's lifespan. In this study, we examined the complete life histories of 867 female tree swallows (Tachycineta bicolor) breeding in Ithaca, New York, between 2002 and 2016. Earlier breeders outperformed later breeders in short-term measures of reproductive output and offspring quality. Though there were weak indications that females paid long-term future survival costs for breeding early, lifetime fledgling output was markedly higher overall in early-breeding birds. Importantly, older females breeding later in the season did not experience compensating life history advantages that suggested an alternative equal-fitness breeding strategy. Rather, most or all of the swallows appear to be breeding as early as they can, and differences in lay dates appear to be determined primarily by differences in individual quality or condition. Lay date had a significant repeatability across breeding attempts by the same female, and the first lay date of females fledged in our population was strongly influenced by the first lay date of their mothers, indicating the potential for ongoing selection on lay date. By examining performance over the entire lifespan of a large number of individuals, we were able to clarify the relationship between timing of breeding and fitness and gain new insight into the sources of variability in this important life history trait.

Fitness Estimation for Ecological Studies: An Evaluation in Columbian Ground Squirrels

The topics of evolution by natural selection and ecological interactions are closely intertwined. Thus, measurements of evolutionary fitness are ubiquitous in the ecological literature. As an empirical problem, the components of fitness, reproduction and survival, may be analyzed to produce fitness estimates in several ways. These can be divided into annual estimates that are most appropriate for short-term (e.g., annual) and experimental studies, and lifetime fitness estimates that are most appropriate for evaluating functional organismal traits. The latter are appropriate for comparative studies of natural selection in species with lifetimes that extend over several years. These estimates may also be particularly useful for estimating the direct and indirect components of inclusive fitness, an important topic for the evolution of cooperation. We reviewed examples of some of these alternatives from our research on Columbian ground squirrels (Urocitellus columbianus). Using empirical data, we also test the degree of correspondence of annual fitness, lifetime reproductive success, and individual fitness measures that are based on matrix methods. We conclude that correspondence of different methods is not strong, though each method appears most appropriate for different types of traits and research questions about fitness differences among trait forms.

Mitochondria as central characters in a complex narrative: Linking genomics, energetics, pace-of-life, and aging in natural populations of garter snakes.

As a pacesetter for physiological processes, variation in metabolic rate can determine the shape of energetic trade-offs and thereby drive variation in life-history traits. In turn, such variation in metabolic performance and life-histories can have profound consequences for lifespan and lifetime fitness. Thus, the extent to which metabolic rate variation is due to phenotypic plasticity or fixed genetic differences among individuals or populations is likely to be shaped by natural selection. Here, we first present a generalized framework describing the central role of mitochondria in processes linking environmental, genomic, physiological, and aging variation. We then present a test of these relationships in an exemplary system: populations of garter snakes (Thamnophis elegans) exhibiting contrasting life-history strategies - fast-growing, early-reproducing, and fast-aging (FA) versus slow-growing, late-reproducing, and slow-aging (SA). Previous work has characterized divergences in mitochondrial function, reactive oxygen species processing, and whole-organism metabolic rate between these contrasting life-history ecotypes. Here, we report new data on cellular respiration and mitochondrial genomics and synthesize these results with previous work. We test hypotheses about the causes and implications of mitochondrial genome variation within this generalized framework. First, we demonstrate that snakes of the FA ecotype increase cellular metabolic rate across their lifespan, while the opposite pattern holds for SA snakes, implying that reduced energetic throughput is associated with a longer life. Second, we show that variants in mitochondrial genomes are segregating across the landscape in a manner suggesting selection on the physiological consequences of this variation in habitats varying in temperature, food availability, and rates of predation. Third, we demonstrate functional variation in whole-organism metabolic rate related to these mitochondrial genome sequence variants. With this synthesis of numerous datasets, we are able to further characterize how variation across levels of biological organization interact within this generalized framework and how this has resulted in the emergence of distinct life-history ecotypes that vary in their rates of aging and lifespan.

Opposing fitness consequences of habitat use in a harvested moose population.

Landscape changes are happening at an unprecedented pace, and together with high levels of wildlife harvesting humans have a large effect on wildlife populations. A thorough knowledge of their combined influence on individual fitness is important to understand factors affecting population dynamics. The goal of the study was to assess the individual consistency in the use of risky habitat types, and how habitat use was related to fitness components and life-history strategies. Using data from a closely monitored and harvested population of moose Alces alces, we examined how individual variation in offspring size, reproduction and survival was related to the use of open grasslands; a habitat type that offers high-quality forage during summer, but at the cost of being more exposed to hunters in autumn. The use of this habitat type may therefore involve a trade-off between high mortality risk and forage maximization. There was a high repeatability in habitat use, which suggests consistent behaviour within individuals. Offspring number and weight were positively related to the mothers' use of open grasslands, whereas the probability of surviving the subsequent harvest season was negatively related to the use of the same habitat type. As a consequence, we found a nonsignificant relationship between habitat use and lifetime fitness. The study suggests that harvesting, even if intended to be nonselective with regard to phenotypes, may be selective towards animals with specific behaviour and life-history strategies. As a consequence, harvesting can alter the life-history composition of the population and target life-history strategies that would be beneficial for individual fitness and population growth in the absence of hunting.

Genotype-environment interaction and the maintenance of genetic variation: an empirical study of Lobelia inflata (Campanulaceae).

High levels of genetic variation are often observed in natural populations, suggesting the action of processes such as frequency-dependent selection, heterozygote advantage and variable selection. However, the maintenance of genetic variation in fitness-related traits remains incompletely explained. The extent of genetic variation in obligately self-fertilizing populations of Lobelia inflata (Campanulaceae L.) strongly implies balancing selection. Lobelia inflata thus offers an exceptional opportunity for an empirical test of genotype-environment interaction (G × E) as a variance-maintaining mechanism under fluctuating selection: L. inflata is monocarpic and reproduces only by seed, facilitating assessment of lifetime fitness; genome-wide homozygosity precludes some mechanisms of balancing selection, and microsatellites are, in effect, genotypic lineage markers. Here, we find support for the temporal G × E hypothesis using a manipulated space-for-time approach across four environments: a field environment, an outdoor experimental plot and two differing growth-chamber environments. High genetic variance was confirmed: 83 field-collected individuals consisted of 45 distinct microsatellite lineages with, on average, 4.5 alleles per locus. Rank-order fitness, measured as lifetime fruit production in 16 replicated multilocus genotypes, changed significantly across environments. Phenotypic differences among microsatellite lineages were detected. Results thus support the G × E hypothesis in principle. However, the evaluation of the effect size of this mechanism and fitness effects of life-history traits will require a long-term study of fluctuating selection on labelled genotypes in the field.

Investigating social and environmental predictors of natal dispersal in a cooperative breeding bird

AbstractNatal dispersal is a crucial life-history trait that affects both individual fitness and population structure, yet drivers of variation in dispersal probability and distance are difficult to study in wild populations. In cooperatively breeding species, individuals typically delay dispersal beyond their first breeding season and remain on the natal territory as nonbreeders, which prolongs social dynamics that can affect dispersal decisions. Using a 35-year data set covering almost 600 dispersal events in the cooperatively breeding Florida scrub-jay (Aphelocoma coerulescens), we examined the environmental and social parameters that predict dispersal probability over time and distance. In both sexes, dispersal probability increased with age, which, in turn, was negatively correlated with dispersal distance. In males, individuals occupying low-quality natal territories and living with a stepfather had an increased probability of dispersal. Older and more dominant males were more likely to inherit their natal territory. In females, which generally disperse earlier and farther than males, socially subordinate jays dispersed farther than dominant ones. Overall, jays that delayed dispersal the longest were more likely to attain breeding status near their natal territory, which was previously found to be associated with increased survival and lifetime fitness. Our results suggest that social dynamics and environmental factors on the natal territory affect delayed dispersal patterns differently for the two sexes in this cooperative breeder.

Sex, personality and conspecific density influence natal dispersal with lifetime fitness consequences in urban and rural burrowing owls.

There is a growing need to understand how species respond to habitat changes and the potential key role played by natal dispersal in population dynamics, structure and gene flow. However, few studies have explored differences in this process between conspecifics living in natural habitats and those inhabiting landscapes highly transformed by humans, such as cities. Here, we investigate how individual traits and social characteristics can influence the natal dispersal decisions of burrowing owls (Athene cunicularia) living in urban and rural areas, as well as the consequences in terms of reproductive success and apparent survival. We found short dispersal movements among individuals, with differences between urban and rural birds (i.e., the former covering shorter distances than the latter), maybe because of the higher conspecific density of urban compared to rural areas. Moreover, we found that urban and rural females as well as bold individuals (i.e., individuals with shorter flight initiation distance) exhibited longer dispersal distances than their counterparts. These dispersal decisions have effects on individual fitness. Individuals traveling longer distances increased their reproductive prospects (productivity during the first breeding attempt, and long term productivity). However, the apparent survival of females decreased when they dispersed farther from their natal territory. Although further research is needed to properly understand the ecological and evolutionary consequences of dispersal patterns in transformed habitats, our results provide information about the drivers and the consequences of the restricted natal movements of this species, which may explain its population structuring through restricted gene flow between and within urban and rural areas.