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Summary: Little is known about the life‐history traits exhibited by burbot (Lota lota) throughout their circumpolar range. Monitoring burbot movements between lentic and lotic habits and collection of demographic data (length, age, sex, and maturity) were used to answer the following questions in the Torrey Creek drainage of west‐central Wyoming, USA: (a) is there plasticity in the life‐history traits of the burbot population, (b) do Trail Lake origin and Torrey Creek origin burbot interchange during the spawning period, and (c) is there a difference in growth and age at sexual maturity between burbot captured in Trail Lake and Torrey Creek? Results indicated that burbot in Trail Lake and Torrey Creek exhibit plasticity in their life history traits. Directional movement of PIT‐tagged burbot in Trail Lake and Torrey Creek was monitored nearly continuously by tandem stream‐width antennas. Thirty‐five percent of lentic‐origin burbot migrated upstream into Torrey Creek, and 11% of lotic‐origin burbot migrated downstream of the antennas near the Torrey Creek inlet to Trail Lake. Migratory activity of burbot was highest during the late winter and early spring at a time that coincided with spawning. Additionally, Torrey Creek‐origin burbot were smaller and younger than Trail Lake‐origin burbot. In addition to documenting migration, the sampling of small, sexually mature burbot in Torrey Creek suggests that stream‐resident burbot reach maturity earlier than adfluvial and lacustrine burbot in Trail Lake. Furthermore, high catch rates of age‐0 burbot indicate that Torrey Creek upstream from Trail Lake provides nursery habitat to the burbot population. Life history trait plasticity and spawning and nursery habitats documented in this study should be considered when selecting conservation actions for this unique burbot population. [ABSTRACT FROM AUTHOR]

Trade-offs between reproductive effort and subsequent growth in males are not well explored, despite their relevance in questions of individual energy allocation. Regarding the growth of sexual secondary characters in polygynous breeding male mammals, indeed, no conclusive studies exist. We investigated in male Alpine ibex (Capra ibex) the relationship between their behavioral reproductive effort, current horn size, and subsequent horn growth. While controlling for age, no evidence was found for male behavioral reproductive effort during the rut being affected by their horn size. On the other hand, reproductive effort significantly decreased age-specific horn growth during the following summer. Our study provides evidence that growth of secondary sexual characters is traded against behavioral investments in reproduction in a male mammal. It bears important implications for the understanding of energy allocation between various life-history components and the evolutionary ecology of secondary sexual characters. [ABSTRACT FROM AUTHOR]

Life histories can influence the degree of parasite infestations on a host. Pressures exerted on hosts based on age and sex convey varying degrees of parasite prevalence due to differences in host lifestyles, but it is not known how interactions between different host traits affect tick numbers. The objective of this study was to determine if host characteristics (e.g., age, sex, weight, and their interactions) affect the mean number of ticks found on small mammals regardless of host species or habitat. Sherman live traps were placed in forest and grass/forb habitats representative of the southeastern United States. After capture, host characteristics were recorded, and hosts were then searched for ticks. A total of 281 small mammals (148 Peromyscus leucopus, 34 P. maniculatus, 76 Sigmodon hispidus, 16 Microtus pinetorum, and 7 Ochrotomys nuttalli) and 610 ticks (488 Dermacentor variabilis, 114 Ixodes scapularis, 1 Amblyomma americanum, and 7 A. maculatum) were collected in this study. Host's age, sex, and weight affected the number of ticks collected from small mammals and significant interaction effects between host traits occurred (weight by sex, weight by age, and sex by age). For instance, female subadult rodents had significantly more ticks compared to female adults, male subadults had significantly fewer ticks compared to male adults, and the number of ticks on a host increased as host body mass increased. These results support the hypothesis that the number of ticks vary on rodent hosts based on life histories and trait interactions. Therefore, understanding the behavioral mechanisms of a host can aid in the management of parasites in the environment.

Abstract Reproductive mode, ancestry, and climate are hypothesized to determine body size variation in reptiles but their effects have rarely been estimated simultaneously, especially at the intraspecific level. The common lizard (Zootoca vivipara) occupies almost the entire Northern Eurasia and includes viviparous and oviparous lineages, thus representing an excellent model for such studies. Using body length data for >10,000 individuals from 72 geographically distinct populations over the species' range, we analyzed how sex‐specific adult body size and sexual size dimorphism (SSD) is associated with reproductive mode, lineage identity, and several climatic variables. Variation in male size was low and poorly explained by our predictors. In contrast, female size and SSD varied considerably, demonstrating significant effects of reproductive mode and particularly seasonality. Populations of the western oviparous lineage (northern Spain, south‐western France) exhibited a smaller female size and less female‐biased SSD than those of the western viviparous (France to Eastern Europe) and the eastern viviparous (Eastern Europe to Far East) lineages; this pattern persisted even after controlling for climatic effects. The phenotypic response to seasonality was complex: across the lineages, as well as within the eastern viviparous lineage, female size and SSD increase with increasing seasonality, whereas the western viviparous lineage followed the opposing trends. Altogether, viviparous populations seem to follow a saw‐tooth geographic cline, which might reflect the nonmonotonic relationship of body size at maturity in females with the length of activity season. This relationship is predicted to arise in perennial ectotherms as a response to environmental constraints caused by seasonality of growth and reproduction. The SSD allometry followed the converse of Rensch's rule, a rare pattern for amniotes. Our results provide the first evidence of opposing body size—climate relationships in intraspecific units.

Abstract Background In species with complex life cycles, size at metamorphosis is a key life-history trait which reflects the complex interactions between costs and benefits of life in the aquatic and terrestrial environments. Whereas the effects of a deteriorating larval habitat (e.g. pond desiccation) on triggering an early metamorphosis have been extensively investigated in amphibians, the consequences of the resulting reduced size at metamorphosis on fitness in the post-metamorphic terrestrial stage remain poorly understood. We tested the hypothesis that a smaller size at metamorphosis negatively affects performance and survival in the ensuing terrestrial stage. Using as model a tropical amphibian (Ceratophrys stolzmanni) showing a large phenotypic plasticity in metamorphosing traits, we evaluated the effects of size at metamorphosis on fitness-related trophic and locomotor performance traits, as well as on growth and survival rates. Results Our results support the hypothesis that a larger size at metamorphosis is correlated with better survival and performance. The survival rate of large metamorphosing individuals was 95%, compared to 60% for those completing metamorphosis at a small size. Locomotor performance and gape size were positively correlated with body size, larger animals being more mobile and capable to ingest larger prey. However, smaller individuals achieved higher growth rates, thus reducing the size gap. Conclusions Overall, size at metamorphosis affected profoundly the chances of survival in the short term, but smaller surviving individuals partly compensated their initial disadvantages by increasing growth rates.

Abstract As the environment changes, so too must plant communities and populations if they are to persist. Life‐history transitions and their timing are often the traits that are most responsive to changing environmental conditions. To compare the contributions of plasticity and natural selective response to variation in germination and flowering phenology, we performed a quantitative genetic study of phenotypic selection on Chamaecrista fasciculata (Fabaceae) across two consecutive years in a restored tallgrass prairie. The earliest dates of germination and flowering were recorded for two parental cohorts and one progeny cohort in an experimental garden. Environmental differences between years were the largest contributors to phenological variation in this population. In addition, there was substantial heritability for flowering time and statistically significant selection for advancement of flowering. Comparison between a progeny cohort and its preselection parental cohort indicated a change in mean flowering time consistent with the direction of selection. Selection on germination time was weaker than that on flowering time, while environmental effects on germination time were stronger. The response to selection on flowering time was detectable when accounting for the effect of the environment on phenotypic differences, highlighting the importance of controlling for year‐to‐year environmental variation in quantitative genetic studies.

Abstract Atlantic salmon (Salmo salar) is a species with diverse life‐history strategies, to which the timing of maturation contributes considerably. Recently, the genome region including the gene vgll3 has gained attention as a locus with a large effect on Atlantic salmon maturation timing, and recent studies on the vgll3 locus in salmon have indicated that its effect might be mediated through body condition and accumulation of adipose tissue. However, the cellular and physiological pathways leading from vgll3 genotype to phenotype are still unknown. Standard metabolic rate is a potentially important trait for resource acquisition and assimilation and we hypothesized that this trait, being a proxy for the maintenance energy expenditure of an individual, could be an important link in the pathway from vgll3 genotype to maturation timing phenotype. As a first step to studying links between vgll3 and the metabolic phenotype of Atlantic salmon, we measured the standard metabolic rate of 150 first‐year Atlantic salmon juveniles of both sexes, originating from 14 different families with either late‐maturing or early‐maturing vgll3 genotypes. No significant difference in mass‐adjusted standard metabolic rate was detected between individuals with different vgll3 genotypes, indicating that juvenile salmon of different vgll3 genotypes have similar maintenance energy requirements in the experimental conditions used and that the effects of vgll3 on body condition and maturation are not strongly related to maintenance energy expenditure in either sex at this life stage.

Life-history traits have been identified as major indicators of mammals' susceptibility and exposure to viruses due to evolutionary constraints that link life-history speed with species' ecology and immunity. Nonetheless, it is unclear where along the fast-slow continuum of mammalian life-history lies the greatest diversity of host species. Consequently, life-history patterns that govern host-virus associations remain largely unknown. Here we analyse the virome of 1350 wild mammals and detect the characteristics that drive species' compatibility with different groups of viruses. We highlight that mammals with larger body size and either very rapid or very slow life histories are more likely to carry different groups of viruses, particularly zoonotic ones. While some common life-history patterns emerge across carriers, eco-evolutionary characteristics of viral groups appear to determine association with certain carrier species. Our findings underline the importance of incorporating both mammals' life-history information and viruses' ecological diversity into surveillance strategies to identify potential zoonotic carriers in wildlife., Competing Interests: The authors declare no competing interests., (© 2024 The Authors.)

Heterogeneity in the intrinsic quality and nutritional condition of individuals affects reproductive success and consequently fitness. Black brant (Branta bernicla nigricans) are long‐lived, migratory, specialist herbivores. Long migratory pathways and short summer breeding seasons constrain the time and energy available for reproduction, thus magnifying life‐history trade‐offs. These constraints, combined with long lifespans and trade‐offs between current and future reproductive value, provide a model system to examine the role of individual heterogeneity in driving life‐history strategies and individual heterogeneity in fitness. We used hierarchical Bayesian models to examine reproductive trade‐offs, modeling the relationships between within‐year measures of reproductive energy allocation and among‐year demographic rates of individual females breeding on the Yukon‐Kuskokwim Delta, Alaska, using capture–recapture and reproductive data from 1988 to 2014. We generally found that annual survival tended to be buffered against variation in reproductive investment, while breeding probability varied considerably over the range of clutch size‐laying date combinations. We provide evidence for relationships between breeding probability and clutch size, breeding probability and nest initiation date, and an interaction between clutch size and initiation date. Average lifetime clutch size also had a weak positive relationship with apparent survival probability. Our results support the use of demographic buffering strategies for black brant. These results also indirectly suggest associations among environmental conditions during growth, fitness, and energy allocation, highlighting the effects of early growth conditions on individual heterogeneity, and subsequently, lifetime reproductive investment. [ABSTRACT FROM AUTHOR]

Seasonally dry forests (SDFs) are one of the most challenging ecosystems for amphibians, fueling the diversity of this group of vertebrates. An updated inventory of native amphibians present in the Equatorial SDF is provided, which extends along the Pacific coast of Ecuador and northwestern Peru. The study is based on an extensive field sampling (two thirds of the total records) carried out throughout the Equatorial SDF, along with a compilation of the available information on distribution of amphibians in the region from published scientific papers, museum collections and on-line databases. The final dataset included 2,032 occurrence records for 30 amphibian species, belonging to eight anuran families. Additionally, data regarding conservation status, habitat use, spawn deposition site, reproductive mode, and body size, along with an identification key for all encountered species are provided. The results indicate a strong sampling bias with a deficit in the Peruvian part of the study area, and a need for urgent inventories targeted at under-sampled areas, using modern taxonomic methods. The study emphasizes the conservation priorities in the Equatorial SDF, based on the distribution, conservation status and life-history data. This information should be useful for the local authorities and institutions involved in the management and conservation of biodiversity in SDF. [ABSTRACT FROM AUTHOR]

All organisms face resource limitations that will ultimately restrict population growth, but the controlling mechanisms vary across ecosystems, taxa, and reproductive strategies. Using four decades of data, we examine how variation in the environment and population density affect reproductive outcomes in a capital-breeding carnivore, the northern elephant seal (Mirounga angustirostris). This species provides a unique opportunity to examine the relative importance of resource acquisition and density-dependence on breeding success. Capital breeders accrue resources over large temporal and spatial scales for use during an abbreviated reproductive period. This strategy may have evolved, in part, to confer resilience to short-term environmental variability. We observed density-dependent effects on weaning mass, and maternal age (experience) was more important than oceanographic conditions or maternal mass in determining offspring weaning mass. Together these findings show that the mechanisms controlling reproductive output are conserved across terrestrial and marine systems and vary with population dynamics, an important consideration when assessing the effect of extrinsic changes, such as climate change, on a population. [ABSTRACT FROM AUTHOR]

Senescence is often described as an age‐dependent increase in natural mortality (known as actuarial senescence) and an age‐dependent decrease in fecundity (known as reproductive senescence), and its role in nature is still poorly understood. Based on empirical estimates of reproductive and actuarial senescence, we used mathematical simulations to explore how senescence affects the population dynamics of Coregonus albula, a small, schooling salmonid fish. Using an empirically based eco‐evolutionary model, we investigated how the presence or absence of senescence affects the eco‐evolutionary dynamics of a fish population during pristine, intensive harvest, and recovery phases. Our simulation results showed that the presence or absence of senescence affected how the population responded to the selection regime. At an individual level, gillnetting caused a larger decline in asymptotic length when senescence was present, compared to the nonsenescent population, and the opposite occurred when fishing was done by trawling. This change was accompanied by evolution toward younger age at maturity. At the population level, the change in biomass and number of fish in response to different fishery size‐selection patterns depended on the presence or absence of senescence. Since most life‐history and fisheries models ignore senescence, they may be over‐estimating reproductive capacity and under‐estimating natural mortality. Our results highlight the need to understand the combined effects of life‐history characters such as senescence and fisheries selection regime to ensure the successful management of our natural resources. [ABSTRACT FROM AUTHOR]

Questions: In Mediterranean‐type systems, invasive C3 annual grasses appear early in the season and can pre‐empt resources and attain a competitive dominance over native perennial grasses. Here, we investigated whether planting C3 and C4 native grasses (a) combined, so that resources are extracted over a longer period, or (b) at higher density would make planted communities more competitive against invasive species. Location: Para Woodlands Reserve, near Adelaide, South Australia. Methods: In 72 experimental plots, native grasses were planted in combinations of seasonal patterns (three levels; single‐season assemblages with either C3 or C4 and extended season with both C3 and C4) and planting density (two levels; high = 44 plants/m2 and low = 20 plants/m2). Data were collected on native plant survival and biomass, invasive biomass and soil properties. Results: Overall, C3 native grasses were superior competitors against both invasive C3 grasses and native C4 grasses. We found no interaction between the combination of C3 and C4 grasses planted together and density of planting. Assemblages with higher densities were successful at reducing exotic plant biomass; however, there was a trade‐off with reduced individual performance among the native plants. Even though individual plants were larger in the low‐density treatment, total biomass was lower in these plots suggesting that density limits the growth of native communities as a whole. The C3 native plants were planted earlier than the C4 native plants because of differences in phenology and therefore likely pre‐empted resources and gained a size advantage, making them the superior competitor. Conclusion: Native perennial grasses can outcompete exotic plants for resources if planted earlier in the season. This resource pre‐emption appears to be more important than resource use over a longer period with C3 and C4 plants together and could be an effective restoration strategy. [ABSTRACT FROM AUTHOR]

Life‐history and other vital rate information is important for effective species conservation by informing demographic trends and aspects of population viability. However, species‐specific information is lacking for many small‐bodied freshwater fishes, which can make it difficult to relate demographic trends to threats or recovery actions. Silver Shiner (Notropis photogenis), a small‐bodied species listed as Threatened under Canada's Species at Risk Act, lacks well‐informed age and vital rate information. We aged 254 Silver Shiner using opercular and otolith structures and determined that Silver Shiner is short‐lived, with a probable maximum age of 4. Three years of field collections (2017–2019) were used to parameterize growth models and to estimate adult (age 1–3+) mortality rates. Silver Shiner captured in urban reaches exhibited altered growth and higher mortality compared to non‐urban reaches, indicating that urbanization may have demographic impacts on the species. Results highlight the importance of detailed age and vital rate information for assessing threats and informing effective conservation approaches for imperilled fishes. Furthermore, the potential negative impact of urbanization on the growth and survival of this species highlights the urgency of better understanding the influence of urbanization on small‐bodied freshwater fishes in general. [ABSTRACT FROM AUTHOR]

Phenotypic plasticity in heterogeneous environments can provide tight environment‐phenotype matching. However, the prerequisite is a reliable environmental cue(s) that enables organisms to use current environmental information to induce the development of a phenotype with high fitness in a forthcoming environment. Here, we quantify predictability in the timing of precipitation and temperature change to examine how this is associated with seasonal polyphenism in tropical Mycalesina butterflies. Seasonal precipitation in the tropics typically results in distinct selective environments, the wet and dry seasons, and changes in temperature can be a major environmental cue. We sampled communities of Mycalesina butterflies from two seasonal locations and one aseasonal location. Quantifying environmental predictability using wavelet analysis and Colwell's indices confirmed a strong periodicity of precipitation over a 12‐month period at both seasonal locations compared to the aseasonal one. However, temperature seasonality and periodicity differed between the two seasonal locations. We further show that: (a) most females from both seasonal locations synchronize their reproduction with the seasons by breeding in the wet season but arresting reproduction in the dry season. In contrast, all species breed throughout the year in the aseasonal location and (b) species from the seasonal locations, but not those from the aseasonal location, exhibited polyphenism in wing pattern traits (eyespot size). We conclude that seasonal precipitation and its predictability are primary factors shaping the evolution of polyphenism in Mycalesina butterflies, and populations or species secondarily evolve local adaptations for cue use that depend on the local variation in the environment. [ABSTRACT FROM AUTHOR]

The high energetic demands associated with the vertebrate brain are proposed to result in a trade‐off between the pace of life‐history and relative brain size. However, because both life‐history and brain size also have a strong relationship with body size, any associations between the pace of life‐history and relative brain size may be confounded by coevolution with body size. Studies on systems where contrasts in the pace of life‐history occur without concordant contrasts in body size could therefore add to our understanding of the potential coevolution between relative brain size and life‐history. Using one such system – 21 species of killifish – we employed a common garden design across two ontogenetic stages to investigate the association between relative brain size and the pace of life‐history. Contrary to predictions, we found that relative brain size was larger in adult fast‐living killifishes, compared to slow‐living species. Although we found no differences in relative brain size between juvenile killifishes. Our results suggest that fast‐ and slow‐living killifishes do not exhibit the predicted trade‐off between brain size and life‐history. Instead, fast and slow‐living killifishes could differ in the ontogenetic timing of somatic versus neural growth or inhabit environments that differ considerably in cognitive demands. [ABSTRACT FROM AUTHOR]

The present study provides the first wide-ranging elucidation of life-history traits, including length-frequency distribution (LFD), length-weight and length-length relationship (LWR and LLR), form factor (a3.0), best condition factor (allometric, KA; Fulton, KF; relative, KR; and relative weight, WR), length at first maturity (Lm), natural mortality (Mw) and optimum catchable length (Lopt) of Lepidocephalichthyes guntea from the Payra River in southern Bangladesh. A total of 470 fishes were randomly collected seasonally from February 2019 to January 2020, using several traditional fishing gears (cast nets; drag nets; lift nets; and gill nets). The total length (TL), standard length (SL) and total body weight (BW) of each individual fish were measured with a 0.01 cm and 0.01 g precision, respectively. The TL size classes of 6.00-6.99 cm and 7.00-7.99cm TL were the numerically dominant groups among the total fish population. Exponential b values of LWR (TL vs. BW) indicate a positive allometric growth (b = 3.20) pattern in the Payra River. The b value of LLR also indicates the same growth pattern. The estimated a3.0 value was 0.007, indicating the fish has an elongated body profile. Among the four types of condition factors, KF is the best-suited tool for evaluating the well-being of L. guntea in the Payra River. Additionally, WR exhibited very significant divergence from 100 (p < .0001), designating an imbalanced habitat for L. guntea. The calculated Lm, Mw and Lopt values were 6.54 (~6.5 cm) in TL, 1.16/year and 7.46 cm TL for L. guntea in the Payra River, respectively. Thus, the results of the present study could be used in the future for improved management of this species in Payra River, as well as for linking ecosystems. [ABSTRACT FROM AUTHOR]

Life history varies across latitudes, with the 'pace of life' being 'slower' in tropical regions. Because life history is coupled to energy metabolism via allocation tradeoffs and links between performance capacity and energy use, low metabolic intensity is expected in tropical animals. Low metabolism has been reported for lowland tropical birds, but it is unclear if this is due to 'slow' life history or to a warm, stable environment. We measured basal metabolic rates (BMR) of 253 bird species across a 2·6 km altitude gradient in Peru. We predicted higher BMR at high altitude due to lower temperatures leading to elevated thermoregulatory costs. We also tested for BMR differences between widely separated tropical regions (Peru and Panama), and between tropical- and temperate-breeding birds. We found no effect of altitude on BMR in Peruvian species and no difference in BMR between Peruvian and Panamanian birds, suggesting that BMR in Neotropical birds is consistent and independent of environmental temperature. In a data set encompassing more than 500 species, tropical birds had significantly lower BMR than temperate-breeding birds. In contrast to several recent analyses, we found higher BMR in passerine birds than in non-passerines, independent of breeding latitude. Breeding latitude affects BMR, but diversity in avian life history within and between temperate and tropical regions may explain some of the residual variation in BMR after accounting for body mass and breeding latitude. Future studies of links between life history, metabolism and environmental factors might benefit from examining these variables within individual species as well as across broad geographic contrasts.

How can a poem be true? This autoethnographic study uses poetic inquiry to explore the boundaries between fiction and reality within poetic experience. A series of poems composed during, and about, the current COVID-19 pandemic, provides a means of understanding the experience of having one’s everyday reality overturned by crisis. A central theme of the author’s poems and accompanying reflections is how art can be used to explore psychological experiences, such as melancholia and depression, and, in turn how the experience of suffering can be used to facilitate artistic expression. Using poetic inquiry, the author examines the complex interplay between speaker and authorial intention, fiction and truth, text and the performance of writing, reading, and poetic interpretation.

Fragmentation of rivers through anthropogenic modifications poses an imminent threat to the persistence of migratory fish, necessitating direct actions such as trap-and-haul programs to restore and conserve the migratory life-history component in populations of partially migratory species such as bull trout Salvelinus confluentus. We used a PIT-tag system to assess how biological and abiotic factors influence the out-migration dynamics of juvenile bull trout in Graves Creek, Montana, USA. The largest fish within a cohort were more likely to out-migrate at age 1 when compared to smaller fish within the cohort, and this was particularly evident in a high-density year-class (2018), where large bull trout out-migrated an average of 115 days earlier than bull trout in the medium size category, and 181 days earlier than bull trout in the small size category. Relative changes in abiotic factors, including discharge, water temperature, and photoperiod, appeared to act as cues to out-migration, with the direction of change varying by season. These results highlight the complex interplay between individual characteristics, population dynamics, and environmental conditions, which influence out-migration dynamics and can be used to inform management actions to conserve the migratory component in bull trout populations.

Predator-induced plasticity in life-history and antipredator traits during the larval period has been extensively studied in organisms with complex life-histories. However, it is unclear whether different levels of predation could induce warning signals in aposematic organisms. Here, we investigated whether predator-simulated handling affects warning coloration and life-history traits in the aposematic wood tiger moth larva, Arctia plantaginis. As juveniles, a larger orange patch on an otherwise black body signifies a more efficient warning signal against predators but this comes at the costs of conspicuousness and thermoregulation. Given this, one would expect that an increase in predation risk would induce flexible expression of the orange patch. Prior research in this system points to plastic effects being important as a response to environmental changes for life history traits, but we had yet to assess whether this was the case for predation risk, a key driver of this species evolution. Using a full-sib rearing design, in which individuals were reared in the presence and absence of a non-lethal simulated bird attack, we evaluated flexible responses of warning signal size (number of orange segments), growth, molting events, and development time in wood tiger moths. All measured traits except development time showed a significant response to predation. Larvae from the predation treatment developed a more melanized warning signal (smaller orange patch), reached a smaller body size, and molted more often. Our results suggest plasticity is indeed important in aposematic organisms, but in this case may be complicated by the trade-off between costly pigmentation and other life-history traits.

Life‐history theory predicts a negative correlation between reproduction and survival because individuals differ in their investment in early reproduction at the expense of survival. However, life‐history trade‐offs can be masked when individual differences in resource allocation are smaller than those in resource acquisition. In polymorphic species, as distinct morphs exhibit differences in intrinsic physiology, the relative effects of resource acquisition and allocation on life‐history traits will differ between morphs, contributing to morph‐specific life‐history correlations. Here, in the wing‐dimorphic water strider Aquarius paludum, we found that wing morphs differed in within‐morph individual‐level life‐history correlations. Longer‐lived flight‐capable long‐winged females produced fewer eggs per day and matured later, whereas life‐history trade‐offs were not observed in short‐winged flightless females. The survival–reproduction trade‐off observed in long‐winged females may be a result of individual differences in the timing of wing muscle histolysis. Individuals that underwent wing histolysis early would have increased reproduction at the expense of a shorter life, whereas individuals with late wing histolysis would have reduced reproduction but a longer life. Short‐winged females, who never develop wings, effectively have more resources to allocate to both survival and reproduction, masking any life‐history trade‐offs. Thus, we suggest that morph‐specific effects of resource allocation trade‐offs can shape the morph‐specific extent of individual variation in life‐history strategies, which may contribute to the evolution and maintenance of within‐species polymorphism. [ABSTRACT FROM AUTHOR]

Small birds in winter face trade-offs between predation risk and foraging, and alternate life-history strategies may arise from these trade-offs. Animal personality shows similarities with alternative life-history strategies, and using a life-history context to understand personality can provide valuable insights. Golden-crowned sparrows, Zonotrichia atricapilla , a small migratory bird, have a complex winter social system with high site-fidelity, long-term social associations between individuals and competition mediated by badges of status. We asked whether golden-crowned sparrows show personalities during winter, whether these personalities were consistent over 3 years and whether they correlated with social and morphological traits. We found that golden-crowned sparrows had highly repeatable behaviours, as measured in captive behavioural assessments, constituting personalities consistent within one season and over time for up to 3 years, a time span that covers the average life span of the sparrows. While long-term repeatability was present, it varied considerably among different behaviours and time spans, and length of time between measures did not predict the magnitude of repeatability. Two movement-based aspects of sparrow personality were independent of the traits we measured (dominance, badges of status, size and age). However, nonsong vocalizations (a repeatable aspect of personality) correlated with wing length and gold badge size in some years. Because personality did not strongly link to the social traits we measured, sparrow personality could represent a separate axis of variation that might connect with other winter life-history parameters such as foraging, predation response or survival. • We studied whether wintering golden-crowned sparrows show personalities. • Personality was stable both within and across years. • Across-year repeatability showed considerable variability, indicating plasticity. • Personality was independent of dominance, badges of status, size, sex and age. • Personality may represent a separate axis of variation (e.g. survival, foraging). [ABSTRACT FROM AUTHOR]

One enduring priority for ecologists has been to understand the cause(s) of variation in reproductive effort among species and localities. Avian clutch size generally increases with increasing latitude, both within and across species, but the mechanism(s) driving that pattern continue to generate hypotheses and debate. In 1961, a Ph.D. student at Oxford University, N. Philip Ashmole, proposed the influential hypothesis that clutch size varies in direct proportion to the seasonality of resources available to a population. Ashmole's hypothesis has been widely cited and discussed in the ecological literature. However, misinterpretation and confusion has been common regarding the mechanism that underlies Ashmole's hypothesis and the testable predictions it generates. We review the development of well‐known hypotheses to explain clutch size variation with an emphasis on Ashmole's hypothesis. We then discuss and clarify sources of confusion about Ashmole's hypothesis in the literature, summarise existing evidence in support and refutation of the hypothesis, and suggest some under‐utilised and novel approaches to test Ashmole's hypothesis and gain an improved understanding of the mechanisms responsible for variation in avian clutch size and fecundity, and life‐history evolution in general. [ABSTRACT FROM AUTHOR]

[Display omitted] • The response of C. maculatus to P. guineense was influenced by the variety of the stock culture. • Fecundity, hatchability, and survival differed among the exposed varietal populations. • Oviposition and hatchability index of C. maculatus postively correlated with the cowpea varieties. • Varietal difference, and not just exposure to sublethal doses of P. guineense , explained observed response. • Thus, white cowpea seeds predisposed C. maculatus to sublethal effects of P. guineense than colored seeds. Cowpea varieties show a wide range of characteristics in their composition that can determine Callosobruchus maculatus (Fabricius) response and survival. Consequently, this work investigated the influence of sublethal doses of Piper guineense on C. maculatus raised on four cowpea varieties: ART-98–12, Niger White, Oloyin, and Ife Brown. Our results demonstrated that C. maculatus from different varieties, despite being reared under the same conditions, responded differently to sublethal doses of P. guineense. Cowpea beetles from ART-98–12 were the most susceptible while those reared on Ife Brown were the least susceptible. Across varieties, survival and reproductive parameters of C. maculatus differed. Furthermore, the ranking for the percentage reduction in the number of eggs laid by C. maculatus was ART-98–12 > Niger White > Oloyin > Ife Brown. According to the log-rank statistic test, the difference observed in C. maculatus ' survival can be explained by variety (log-rank statistic: χ2 [df = 3, N = 16] = 15, p = 0.004). Conversely, the survivability of the chrysomelid beetles reared on Niger white was significantly lower (p = 0.012) compared to the other varieties. This study highlights the role of cowpea variety in dictating the efficacy of a given botanical against C. maculatus. [ABSTRACT FROM AUTHOR]

We use an Australian freshwater invertebrate species, Daphnia carinata, to assess whether variation in habitat permanence influences life-history traits in subpopulations. Using a life table experiment, we measure the life-history traits of populations from both permanent and temporary pools. We show that these habitat classes are associated with clear differences in important life-history traits and evidence of trade-offs in important traits influencing reproduction, diapause, and growth rate and suggest this is evidence for local adaptation. Here we use Daphnia from Australian populations spanning semi-arid and temperate climates generating results that are in broad agreement with similar studies in the northern hemisphere, and so extend these results to a new continent and its particular climate. Variation in habitat permanence, it appears, is a very general driver of life-history divergence. [ABSTRACT FROM AUTHOR]

A collection of forty populations were used to study the phenotypic adaptation of Drosophila melanogaster larvae to urea-laced food. A long-term goal of this research is to map genes responsible for these phenotypes. This mapping requires large numbers of populations. Thus, we studied fifteen populations subjected to direct selection for urea tolerance and five controls. In addition, we studied another twenty populations which had not been exposed to urea but were subjected to stress or demographic selection. In this study, we describe the differentiation in these population for six phenotypes: (1) larval feeding rates, (2) larval viability in urea-laced food, (3) larval development time in urea-laced food, (4) adult starvation times, (5) adult desiccation times, and (6) larval growth rates. No significant differences were observed for desiccation resistance. The demographically/stress-selected populations had longer times to starvation than urea-selected populations. The urea-adapted populations showed elevated survival and reduced development time in urea-laced food relative to the control and nonadapted populations. The urea-adapted populations also showed reduced larval feeding rates relative to controls. We show that there is a strong linear relationship between feeding rates and growth rates at the same larval ages feeding rates were measured. This suggests that feeding rates are correlated with food intake and growth. This relationship between larval feeding rates, food consumption, and efficiency has been postulated to involve important trade-offs that govern larval evolution in stressful environments. Our results support the idea that energy allocation is a central organizing theme in adaptive evolution. [ABSTRACT FROM AUTHOR]

The life-history of an organism consists of its lifetime pattern of growth, development, storage, age, and reproduction. In this study, some life-history traits of Hyla savignyi were studied in populations from different parts of Iran. The microscopic and macroscopic analysis showed that testicular activity in H. savignyi is potentially continuous, reaching its peak level in April. Metamorphosis was completed in approximately 102 days after egg deposition, and body size at metamorphosis was 10 mm. Significant sexual size dimorphism was present in all populations, and a larger female asymptotic body size was observed (43.07 mm for females vs 41.16 mm for males). The adult survival rate (S) and life expectancy (ESP) were the same for both sexes (S = 0.73 and ESP = 4.2 years). Age and body size were positively correlated with each other for both females and males. Maximum longevity was recorded to be six years in both females and males, and ages of sexual maturity were estimated to be two or three years in breeding individuals. The adult sample age ranged from two to six years (mean age of females: 4.40±0.68 years; males: 3.63±0.13 years). Our data confirm the general patterns of body size variation and mean age in anurans and show that females are larger than males and live longer. [ABSTRACT FROM AUTHOR]

Populations of northern Dolly Varden (Salvelinus malma malma) exhibit partial seaward migration, yet little is known about this phenomenon in Dolly Varden populations. Our study analyzed data from three different Dolly Varden populations in the western Canadian Arctic in order to determine if: (1) differences in size-at-first seaward migration exist between fish that migrate at early and late ages among populations inhabiting different river systems, and (2) annual growth influences anadromous or resident life history choice. Otolith strontium analysis and back-calculation were used to determine age- and size-at-first seaward migration, respectively. Differences in age- and size-at-first seaward migration were determined across river system and migration age. Back-calculated fish lengths were compared using a mixed effect model to determine how early growth influences migratory tactics (early or late aged smolt, or resident). Our results indicate that fish exhibiting faster early growth migrated in earlier years and at smaller sizes than slower growing fish, however size- and age-at first seaward migration varied by river system. Faster growing Dolly Varden tended to become either residents or early smolts, while slower growth was associated with smolting later in life. This is contrary to life history theory where the fastest growing fish in a population should mature as a resident. Our results indicate factors other than growth may be influencing life history 'decisions' in Dolly Varden. Future work on growth efficiencies and metabolic rates is needed to assess how they affect migratory behaviours. [ABSTRACT FROM AUTHOR]

Many animals have evolved associations with symbiotic microbes that benefit the host through increased growth, lifespan, and survival. Some interactions are obligate (essential for survival) while others are facultative (usually beneficial but not essential). Not all individuals host all facultative symbionts in a population, and thus there is probably a trade‐off between the cost of hosting these symbionts and the benefits they confer to the host. Plant‐sucking insects have been one of the most important models to test these costs and benefits experimentally. This research is now moving beyond the description of symbiont effects towards understanding the mechanisms of action, and their role in the wider ecological community. We present a quantitative and systematic analysis of the published evidence exploring this question. We found that whitefly and true bugs experience benefits through increased growth and fecundity, whereas aphids experience costs to their fecundity but benefits through increased resistance to natural enemies. We also report the lack of data in some plant‐sucking groups, and explore variation in effect strengths and directions across aphid host, symbiont and plant species thus highlighting the importance of considering the context dependency of these interactions. [ABSTRACT FROM AUTHOR]

Abstract Background The nematode Caenorhabditis elegans has been extensively used to explore the relationships between complex traits, genotypes, and environments. Complex traits can vary across different genotypes of a species, and the genetic regulators of trait variation can be mapped on the genome using quantitative trait locus (QTL) analysis of recombinant inbred lines (RILs) derived from genetically and phenotypically divergent parents. Most RILs have been derived from crossing two parents from globally distant locations. However, the genetic diversity between local C. elegans populations can be as diverse as between global populations and could thus provide means of identifying genetic variation associated with complex traits relevant on a broader scale. Results To investigate the effect of local genetic variation on heritable traits, we developed a new RIL population derived from 4 parental wild isolates collected from 2 closely located sites in France: Orsay and Santeuil. We crossed these 4 genetically diverse parental isolates to generate a population of 200 multi-parental RILs and used RNA-seq to obtain sequence polymorphisms identifying almost 9000 SNPs variable between the 4 genotypes with an average spacing of 11 kb, doubling the mapping resolution relative to currently available RIL panels for many loci. The SNPs were used to construct a genetic map to facilitate QTL analysis. We measured life history traits such as lifespan, stress resistance, developmental speed, and population growth in different environments, and found substantial variation for most traits. We detected multiple QTLs for most traits, including novel QTLs not found in previous QTL analysis, including those for lifespan and pathogen responses. This shows that recombining genetic variation across C. elegans populations that are in geographical close proximity provides ample variation for QTL mapping. Conclusion Taken together, we show that using more parents than the classical two parental genotypes to construct a RIL population facilitates the detection of QTLs and that the use of wild isolates facilitates the detection of QTLs. The use of multi-parent RIL populations can further enhance our understanding of local adaptation and life history trade-offs.

Abstract Background A proposed mediator of trade-offs between survival and reproduction is oxidative stress resistance. Investments in reproduction are associated with increased oxidative stress that reduces lifespan. We used the bdelloid rotifer Adineta vaga to examine baseline patterns of survival, reproduction, and measures of oxidative stress, as well as how these patterns change in the face of treatments known to induce oxidative stress. Results We discovered that under standard laboratory conditions late-life mortality may be explained by increased levels of oxidative stress induced by reproduction. However, following exposure to the oxidizing agent ionizing radiation, survival was unaffected while reproduction was reduced. Conclusions We suggest that under normal environmental conditions, reduced survival is mediated by endogenously generated oxidative stress induced by reproduction, and thus represents a cost of reproduction. Alternatively, the reduced reproduction evident under exogenously applied oxidative stress represents a cost of somatic maintenance. Biochemical analyses designed to assess levels of oxidative stress, oxidative stress resistance, and oxidative damage under normal and oxidizing conditions suggest that varying investments in enzymatic and non-enzymatic based oxidative stress resistance determine whether a cost of reproduction or a cost of somatic maintenance is observed.

The use of black soldier fly (BSF) larvae to recycle various organic materials while producing biomass for use as feed is well established. Variety selection is important from the perspective of application. In the current study, morphometric and life-history traits of a Wuhan-domesticated BSF colony (Wuhan strain) were compared to those of a ‘selectively inbred’ population (inbred strain, inbred for 10 generations). In terms of morphological characteristics, the results showed that both strains had dichoptic compound eyes, club-shaped antennae, blue halters, and blue-green metallic luster wings with a hexagon discal cell. In both strains, the body and wing length of female adults were slightly larger than those of male adults. The first four larval stages of the BSF occurred rapidly (1–12 days) with transitions across stages resulting in doubling of size for both populations. Selective inbreeding did not alter the life-history traits of the larval exuviate stage in terms of age, size, weight, and feed reduction rate. Overall egg production for the inbred strain was significantly higher (1.5 times greater) than the Wuhan strain. This is explained by increased adult emergence and individual oviposition performance. It was speculated that inbreeding improved the reproductive success of inbred adult female offspring and selection process steadied it. The findings indicate that selective inbreeding could enhance overall oviposition performance and provide a strategy to selectively breed BSF with high egg production for future applications.

Orientation: The study explores three African leaders’ experiences, contextual influences and perspectives on how shared African human values can be incorporated into business leadership practice. Research purpose: The study has twofold purposes: (1) to unravel and describe the experiences and perceptions of three business leaders in Africa, (2) to integrate the leaders’ first-order conceptualisations with scholarly insights to construct a substantive framework for developing business leadership in Africa. Motivation for the study: To explore contextual circumstances, which may enhance the formation of African shared human values in leaders and how these values may be translated into business leadership practice. Research approach/design and method: This is an explorative-descriptive qualitative-constructivist study of three African leaders’ experiences and perceptions regarding the translation of shared African human values into leadership and business practice in the continent. Main findings: The findings reveal that each of the three participants substantially embrace African shared human values in their daily actions and decision-making. Multiple themes covering the person, contextual and societal factors that influence the formation and use of these values are highlighted. Practical/managerial implications: Business leaders, strategists and managers should explore strategies for employing shared African human values as a way of strengthening a values-driven business culture, employee performance, and stakeholder management. Contributions/value-add: The findings suggest that incorporating shared African human values promises a more humane organisational culture and thereby improving businesses’ financial and social performance in the African setting.

We investigated the presence and ecology of Chirocephalus croaticus (Steuer, 1899) during three successive seasons (spring and autumn 2018, spring 2019) at Lake Petelinje (SW Slovenia). Although the presence (duration, abundance) of this fairy shrimp strongly differs among different seasons and both years, we showed that in a season with favourable conditions (spring 2018) its abundance increases rapidly at the end of the season as the shrimps persist in small pools until the water dries out. The species may appear again during the autumn, however, its abundance and persistence seem to be much lower and shorter than during the spring, respectively. Nevertheless, persistence and abundance may also differ strongly among the two successive spring seasons (less shrimps found during the shorter season of 2019 than in 2018). Larvae appear first, and are most abundant at the beginning of the season, and are followed by adult males (protandry) and females, which become most abundant at the end of the season. Also, larvae seem to be more abundant on exposed bottom (gravel path), while adults are much more abundant in the shelter of a submerged meadow. Ovigerous females had 9-37 cysts (fertilized eggs) in their brood pouch, and the position of differently developed eggs changed during the season; the presence of females without eggs during mid- and at the end of season indicates the production of thin-shelled summer, and thick-shelled winter cysts, respectively. In contrast with the water decrease that is in strongly negative association with the abundance of the fairy shrimps (lake size — abundance: r = − 0.56 , P < 0.001), no other environmental parameters were highly associated (r ⩽ | 0.38 |) with species abundance. Although the local population (one of only two currently known) seems to be in good condition, appropriate conservation action should be taken to prevent the decrease of this population in the future. Résumé: Nous avons étudié la présence et l'écologie de Chirocephalus croaticus (Steuer, 1899) au cours de trois saisons successives (printemps et automne 2018, printemps 2019) dans le Lac Petelinje (SO Slovanie). Bien que la présence (durée, abondance) de cette crevette diffère fortement selon les différentes saisons et les deux années, nous avons montré que dans une saison avec des conditions favorables (printemps 2018) son abondance augmente rapidement à la fin de la saison et que les crevettes persistent dans des flaques d'eau jusqu'à l'assèchement. L'espèce peut apparaitre de nouveau en automne, cependant son abondance semble être plus basse et sa persistance plus courte que pendant le printemps. Néanmoins, persistance et abondance peuvent aussi différer entre deux printemps successifs (moins de crevettes trouvées durant la courte saison de 2019 qu'en 2018). Les larves apparaissent en premier et sont plus abondantes en début de saison, elles sont suivies par des males adultes (protandrie) et les femelles qui deviennent plus abondantes en fin de saison. De plus, les larves semblent être plus abondantes sur des fonds ouverts (graviers), tandis que les adultes sont beaucoup plus abondants dans les abris de prairies submergées. Les femelles ovigères avaient 9-37 cystes (œufs fécondés) dans leur poche incubatrice, et la position des œufs à des stades de développement différents change au cours de la saison ; la présence des femelles sans œufs à la mi-saison et en fin de saison indique la production de cystes d'été à fine enveloppe et de cystes d'hiver à enveloppe épaisse. Alors que la baisse de l'eau est fortement associé négativement avec l'abondance des crevettes (taille du lac — abondance : r = − 0 , 56 , P < 0 , 001), aucun autre facteur environnemental n'a été aussi fortement associé (r ⩽ | 0 , 38 |) avec l'abondance de l'espèce. Bien que la population locale (une ou deux connues actuellement) semble être en bonne condition, une action de conservation appropriée devrait être prise pour éviter la diminution de cette population dans le futur. [ABSTRACT FROM AUTHOR]

Elucidating factors that limit the number of offspring produced is fundamental to understanding life‐history evolution. Here, we examine the hypothesis that parental ability to maintain an optimal physical developmental environment for all offspring constrains clutch size via effects on offspring quality.Experimental laboratory studies of birds have shown that a <1°C difference in average incubation temperature has diverse effects on fitness‐related post‐hatching offspring phenotypes. Thus, the inability of parents to maintain optimal incubation temperatures could constrain clutch sizes.A fundamental question that has not been sufficiently addressed is whether larger clutch sizes lead to within nest variation in egg temperature that is large enough to produce offspring with different phenotypes within a brood. This could lead to differential survival among offspring, and could create a trade‐off between offspring number and quality.We manipulated clutch size in nests of free‐living wood ducks and measured incubation temperature among and within clutches using multiple temperature loggers.As clutch size increased, average incubation temperatures were lower and more variable, and eggs took longer to hatch. Notably, the range in average incubation temperature among eggs within nests increased with clutch size and exceeded 1°C in large clutches. Clutch size did not affect hatch success.In conjunction with our companion laboratory studies that used artificial incubation to document the effects of temperature variation on fitness‐related traits in this species, our work suggests that suboptimal incubation temperatures could be a factor that limits clutch size through diminishing returns on post‐hatch offspring quality. A free plain language summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

This study examines Cambodian students' exam cheating practices throughout their schooling. Based on a thorough analysis of interviews with 19 university students, the study found that, although cheating was more prevalent at the secondary level, individual students' cheating experiences varied in frequency and timing (i.e. when they started, stopped, increased, or decreased such practices). Curricula, parents' attitudes, peer behaviour, institutional policies, and – most significantly – relationships with teachers were identified as influencing factors for students' cheating practices. These findings largely echo academic dishonesty literature, but they also indicate the context-specific features of these factors. [ABSTRACT FROM AUTHOR]

The genus, Pupulanella, Adamski and Nishida, n. gen. is proposed, and synapomorphies are given as supportive evidence. All life stages of P. gemma Adamski and Nishida, n. sp. (Lepidoptera: Gelechioidea: Depressariidae) are described, and observations of its natural history are provided. The eggs are saddle-shaped, with several rows of shallow, parallel, and alternating longitudinal ridges and furrows, each contiguous with a transverse crest on opposing polar ends that are steeply sloped. Each egg is laid singly on the underside of leaves along the veins, and occasionally on stems or leaf petioles of the host plant, Rivina humilis L. (Petiveriaceae). The first instar and early second instar live within a weblike silken tunnel on the undersurface of leaves along the leaf veins while later instars construct and live within a partially-rolled shelter along the outer margin the leaf. Pupation occurs within a dried leaf fold in litter on the ground. The pupa is covered with short hairs, is deeply excavated between the labrum and the proximal margins of the maxillae, and possesses a ridgelike structure (= cocoon cutter) on the dorsolateral area of the prothorax. Adult moths exhibit an unusual survival behavior in microlepidoptera, by resting conspicuously on the upper surfaces of leaves exposing a "false head" and eye-spot patterned on the apical part of the forewings, on each side of the posterior end of the insect. Additionally, the terminal portions of the antennae and hindlegs extend well beyond the posterior wing margins contributing to a more realistic headlike mimic. Males and females are crepuscular, exhibiting short distance flights among host plants. Pupulanella brunniceps (Felder and Rogenhofer, 1875), n. comb. is transferred from Filinota.. [ABSTRACT FROM AUTHOR]

Predator‐released kairomones indicating the presence of predatory fish are known to alter the behaviour and life‐history traits of several aquatic herbivores. Culex mosquitoes (Diptera: Culicidae) respond to such cues by altering oviposition habitat selection and larval development time. These responses differ among fish species indicating composition differences among fish‐released cues, but the recognition pattern is not clear. This study tested the dependence of fish recognition to co‐evolution and the level of threat to larvae. We compared Culex responses to three fish, the invasive larvivorous Gambusia affinis (Cyprinodontiformes: Poeciliidae), the native larvivorous Aphanius mento (Cyprinodontiformes: Cyprinodontidae) and the native algivorous Garra rufa (Cypriniformes: Cyprinidae). The effects of cues released by the three fish on Culex oviposition and life‐history shifts were compared in field mesocosms and lab tests. Our results showed that ovipositing females were significantly repelled only by cues originated from G. affinis, while developing larvae response was a more general one. Our results support the idea that fish‐released kairomones differ in composition or quantities among different species. [ABSTRACT FROM AUTHOR]

In mammals, reproduction is influenced by sexual competition, temperature and food availability and these factors might be crucial already during early life. Favorable early life environment and high maternal investment are expected to improve survival and reproduction. For example, in mammals, maternal investment via lactation predicts offspring growth. As body mass is often associated with fitness consequences, females have the potential to influence offspring fitness through their level of investment, which might interact with effects of population density and temperature. Here, we investigate the relationship between house mouse (Mus musculus domesticus) pup body mass at day 13 (used as approximation for weaning mass) and individual reproductive parameters, as well as longevity, under natural variation in population density and temperature (as approximation for season). Further, we assessed the extent to which mothers influence the body mass of their offspring until weaning. To do so, we analyzed life data of 384 house mice from a free-living wild commensal population that was not food limited. The mother’s contribution accounted for 49% of the variance in pup body mass. Further, we found a complex effect of population density, temperature and maternal investment on life-history traits related to fitness: shorter longevity with increasing pup body mass at day 13, delayed first reproduction of heavier pups when raised at warmer temperatures, and increased lifetime reproductive success for heavier pups at high densities. Our study shows that the effects of maternal investment are not independent of the effects of the environment. It thus highlights the importance of considering ecological conditions in combination with maternal effects to unravel the complexity of pup body mass on fitness measures.

The stable isotope ratio 87Sr/86Sr has been shown to have extraordinary potential for documenting the movement and life-histories of humans and other animals, both in history and prehistory. Thirty years of expanding applications has taken the method from a niche (if not fringe) approach to a normal part of archeological and paleobiological enquiry; indeed a “Golden Age.” The technique is inherently interdisciplinary, because in addition to those archeologists and paleobiologists wishing to apply it, most applications require informed input from ecologists, geochemists, and calcified tissue biologists. This perspective explores how such interdisciplinarity is both a strength and an impediment to further advancement.

Arctic marine ecosystems are undergoing a series of major rapid adjustments to the regional amplification of climate change, but there is a paucity of knowledge about how changing environmental conditions might affect reproductive cycles of seafloor organisms. Shifts in species reproductive ecology may influence their entire life-cycle, and, ultimately, determine the persistence and distribution of taxa. Here, we investigate whether the combined effects of warming and ocean acidification based on near-future climate change projections affects the reproductive processes in benthic bivalves (Astarte crenata and Bathyarca glacialis) from the Barents Sea. Both species present large oocytes indicative of lecithotrophic or direct larval development after ∼4 months exposure to ambient [

Climate change is forecasted to generate a range of evolutionary changes and plastic responses. One important aspect of avian responses to climate change is how weather conditions may change nestling growth and development. Early life growth is sensitive to environmental effects and can potentially have long-lasting effects on adult phenotypes and fitness. A detailed understanding of both how and when weather conditions affect the entire growth trajectory of a nestling may help predict population changes in phenotypes and demography under climate change. This review covers three main topics on the impacts of weather variation (air temperature, rainfall, wind speed, solar radiation) on nestling growth. Firstly, we highlight why understanding the effects of weather on nestling growth might be important in understanding adaptation to, and population persistence in, environments altered by climate change. Secondly, we review the documented effects of weather variation on nestling growth curves. We investigate both altricial and precocial species, but we find a limited number of studies on precocial species in the wild. Increasing temperatures and rainfall have mixed effects on nestling growth, while increasing windspeeds tend to have negative impacts on the growth rate of open cup nesting species. Thirdly, we discuss how weather variation might affect the evolution of nestling growth traits and suggest that more estimates of the inheritance of and selection acting on growth traits in natural settings are needed to make evolutionary predictions. We suggest that predictions will be improved by considering concurrently changing selection pressures like urbanization. The importance of adaptive plastic or evolutionary changes in growth may depend on where a species or population is located geographically and the species’ life-history. Detailed characterization of the effects of weather on growth patterns will help answer whether variation in avian growth frequently plays a role in adaption to climate change.

The spiny lobster Palinurus elephas has been intensively harvested across its range and is generally considered overfished, with global landings declining sharply from an average of 820 t in 1960–79 to 385 t in 2000–19. Despite its economic and ecological importance, limited information is available to perform stock assessments and make robust management decisions. In this study, demographics and exploitation levels of P. elephas were determined from coastal areas of the Azores, and the relevance of these data for conservation planning was discussed. Carapace length varied between 39.6 and 174.3 mm, with mean sizes decreasing by depth. Males reached larger sizes and grew faster than females but were less dominant. Lifespan was 43 years for females and 60 years for males. The estimated mean length at first capture was 101.65 mm—around 58% of its asymptotic length. Fishing mortality and exploitation levels were close to the optimal values, indicating an uncertain future for Azorean populations if stock assessment and management initiatives are not focused on this species. Conservation and management strategies may benefit from these results under the ‘precautionary approach’ principle. However, up–to–date and accurate catch and fishing effort data need to be urgently collected.