Aspects Of Life History Research Articles

Eat on the beach: diet composition of an endemic miniature frog from sandy coastal environments of southeastern Brazil

ABSTRACT Diet is one of the most important dimensions of the ecological niche. Pseudopaludicola genus comprises 25 species of which four have their diet studied. In this study, we quantify the diet of the recently described Pseudopaludicola restinga, which is found in sandy coastal environments of southeastern Brazil. We obtained a sample of 137 individuals from Parque Nacional da Restinga de Jurubatiba from which 97 were used in analyses of diet composition. We registered 136 prey items distributed in 10 prey categories. Only arthropods were consumed. Insects were the most common food items. Hymenoptera was the most important item in terms of prey frequency, number, and index of relative importance. The variety of prey categories suggests that P. restinga is an opportunistic predator. In comparison with dietary information available for other four Pseudopaludicola species, P. restinga has intermediate values of the number of prey items, niche breadth, and importance index. This study is the first to document aspects of the natural history of P. restinga and to compare it with data available for congeners. Data brought here provide a better understanding of life history aspects of P. restinga. These information hence could guide development of effective conservation strategies for this poorly known species.

Parental status is related to homing motivation in males of the glassfrog Centrolene savagei

The interaction between homing and parental care offers insights about the motivational aspects underlying movement patterns in animals. For species that care for offspring at fixed locations, offspring mortality in the absence of care might impact a parent’s motivation to home after being displaced from young. We tested whether homing motivation is related to parental care in the glassfrog Centrolene savagei (Centrolenidae), a species with extended male care and territoriality. Specifically, we evaluated how parental status (i.e. caring for eggs vs unmated yet territorial males) and translocation distance impacts homing motivation. Along a stream located in the Central Andes of Colombia, we translocated 23 male C. savagei between 5 and 80 m away from their reproductive territories. We found that both parental status and translocation distance impacts homing motivation, as caring males were more likely to return to their initial territories after translocation. Seven of the 16 caring males and one of the seven unmated males returned to the initial capture site. While unmated males might be motivated to home if reproductive territories are a limited resource, our results support that caring males exhibited much higher motivation to home. It is possible that the fitness benefits accrued from caring for vulnerable offspring alters the cost-to-benefits of homing, and thus accounts for a greater frequency of homing among caring males. This study contributes to understanding how aspects of life history (e.g. parental care) relate to homing motivation in vertebrates.

Identifying the paths of climate effects on population dynamics: dynamic and multilevel structural equation model around the annual cycle

How environmental factors influence population dynamics in long-distance migrants is complicated by the spatiotemporal diversity of the environment the individuals experience during the annual cycle. The effects of weather on several different aspects of life history have been well studied, but a better understanding is needed on how weather affects population dynamics through the different associated traits. We utilise 77 years of data from pied flycatcher (Ficedula hypoleuca), to identify the most relevant climate signals associated with population growth rate. The strongest signals on population growth were observed from climate during periods when the birds were not present in the focal location. The population decline was associated with increasing precipitation in the African non-breeding quarters in the autumn (near the arrival of migrants) and with increasing winter temperature along the migration route (before migration). The number of fledglings was associated positively with increasing winter temperature in non-breeding area and negatively with increasing winter temperature in Europe. These possible carry-over effects did not arise via timing of breeding or clutch size but the exact mechanism remains to be revealed in future studies. High population density and low fledgling production were the intrinsic factors reducing the breeding population. We conclude that weather during all seasons has the potential to affect the reproductive success or population growth rate of this species. Our results show how weather can influence the population dynamics of a migratory species through multiple pathways, even at times of the annual cycle when the birds are in a different location than the climate signal.

Działania prawne składające się na budowanie wizerunku Białegostoku z marką Esperanto

The article presents the legal activities of the city of Bialystok related to building its image using the brand Esperanto over the past years. The text deals with the complicated side of building the image of the city which is legal actions using the asset of the city which the case of Bialystok is the brand Esperanto. These actions were taken both by the executive body of the municipality – the Mayor – and the legislative body – the City Council. The following activities were discussed: the activity of the Bialystok City Council, the activity connected with the celebration of the 100th anniversary of Ludwik Zamenhof’s death, the organisation of the Esperanto Congress in 2009 and the significance of the so-called participatory budget for the discussed issue. In the analysis of the topic, only those activities undertaken in Bialystok and related to Ludwik Zamenhof, his successors and the Esperanto language were chosen, which are not only based on but have their source in legal acts and are of direct or indirect legal character. The article also briefly discusses the aspect of life history of Ludwik Krzysztof Zaleski Zamenhof in connection with granting him the Honorary Citizenship of the City of Bialystok. The article discusses the legal activities of the city of Bialystok connected with building its image with the use of the Esperanto brand in the perspective of the last years, touching upon an interesting matter which is the promotion of the Municipality on the basis of the only universal language in the world. The legal actions described in the article reflect the perspective of young Ludwik Zamenhoff, which led to the creation of Esperanto language. The text combines two matters, the creation of a supranational language, with legal actions that are used to promote the small homeland of its creator.

Diet-based strategies, informed by genetics, to improve healthspan

Diet is one of the most variable aspects of life history, as most individuals have a large diversity of choices, varying in the type and amount that they ingest. In the short-term, diet can affect metabolism and energy levels. However, in the long run, the net deficiency or excess of calories from diet can influence the progression and severity of age-related diseases. An old and yet still debated question is: how do specific dietary choices impact health- and lifespan? It is clear that genetics can play a critical role - perhaps just as important as diet choices. For example, poor diet in combination with genetic susceptibility can lead to metabolic disorders, such as obesity and type 2 diabetes. We have identified the existence of diet-gene pairs, where the consequence of mutating a specific gene is only realized on specific diets. Although only a handful of these diet-gene pairs have been characterized, there are potentially thousands of such interactions, which may explain the variability in the rates of aging in humans and the incidence and severity of age-related diseases.

Becoming alive within science education (research): thinking with life history(ies), bodies and stickiness

In life history methodologies, ‘human’ lives appear to take primacy over other lives. Within science education literature, life history methods often are approached as reflective tools to make meaning out of teachers’ pedagogical practices and commitments. In the present research, we tinker with life history research, to follow its performative work in (re-)producing what counts as life, nature, science and science education. Thinking with life history(ies), bodies and stickiness, we analyze a college instructor’s (Nurul) life with others. Nurul is committed to a science pedagogical approach (‘STEPWISE’) centered on STSE education for social and environmental justice. This paper relays what was (re-)produced when Nurul’s life narrative, and our own encounters with life history methodologies were plugged into one another. Analytically, we discuss stickiness of humanist and meaning-making practices in life history methodologies and how this might have enabled/complicated our analyses of Nurul’s life history. We invite further analyses into productive aspects of life history(ies) and how they might gesture to pedagogical possibilities for being/living differently within nature, science and science education.

Seasonal Activity Patterns of Golden Mantellas (Mantella aurantiaca)

The Golden Mantella (Mantella aurantiaca) is a highly threatened frog species found in east-central Madagascar. They are seasonally active and difficult to observe outside the summer breeding season. We used a captive population maintained within the native range of the species to examine two aspects of life history that otherwise would be impracticable to observe in the field: sheltering behavior and nearest neighbor distance (NND). We made weekly observations on seven groups of frogs for 1 yr, recording NND of each individual and how many individuals were sheltering under cover. We also recorded whether eggs were present in terraria to better define the breeding season and determine how time of year relates to NND and sheltering behavior. Frogs were closer together and more often took shelter during cool winter months. This corresponds to the time of year when fewer egg clutches were recorded. There was no difference between NND and sheltering behavior in wild-caught vs. captive-bred frogs, and there was no significant difference between NND of males and females. Golden Mantellas may be at increased risk from infectious diseases because behavior that increases contact between infected individuals can facilitate disease transmission.

Ectoparasite‐induced increase in Drosophila host metabolic rate

AbstractParasites exert numerous effects upon their hosts, including physiological and metabolic changes that can in turn influence various aspects of host life history. Using flow‐through respirometry, we investigated how infection intensity of an ectoparasitic mite (Macrocheles subbadius) affects the respiratory rate (CO2 production) of its host Drosophila nigrospiracula. Mean fly respiratory rate increased with infection intensity with the strongest effect, a 40% increase relative to uninfected controls, occurring with three mites attached. We also verified the causal relationship between elevated respiration rate and mite attachment by examining changes in host respiration before and after mite exposure. We found that the rate of CO2 production increased by 11% for individual flies following parasite attachment. Fly locomotor activity was not significantly different between infected and uninfected individuals. Metabolic rate of hosts increased as a result of infection in an intensity dependent manner and was not simply due to changes in host activity. These results demonstrate that parasites can have a significant influence on the energy requirements of their host, which may account for the parasite‐mediated loss in host fitness.

Reproductive cycle, sexual maturity and longevity of Odontophrynus americanus (Anura: Odontophrynidae) in South Brazil

AbstractStudies on the reproductive biology and age of amphibians provide primary information about the life history and population demographic parameters of species. Here, we describe the reproductive cycle, size–fecundity relationships, reproductive effort, sexual dimorphism and sexual maturity of Odontophrynus americanus, the flood frog, from South Brazil. A total of 96 individuals were analysed. The reproductive cycles of males and females were described through morphoanatomical analysis of testis and ovary. Age at onset of sexual maturity and estimated longevity were determined by skeletochronology. Individuals of O. americanus presented a potentially continuous reproductive cycle with a peak of reproductive activity in the warmer months. Females presented a higher reproductive investment than males. Sexual maturity was reached at around one year of age for both sexes while longevity differed between the sexes, with females living up to six years and males up to ten years. No evidence of sexual size dimorphism was found. This study is among the few that have assessed age at sexual maturity and longevity in a Neotropical anuran. Basic aspects of life history are of paramount importance because they allow comparisons and test of hypotheses to be made, which can help to build generalizations about the evolutionary meaning of ecological strategies.

Life history aspects of the buthid scorpion Tityus forcipula (Gervais, 1843) with remarks on its thermal limits

Observations on the entire life history of scorpion species are uncommon, and these studies primarily focus on postembryonic development. So far, little is known on how changes in temperature or humidity could affect communities of scorpions. Here, we present data on the embryonic and postembryonic development of Tityus forcipula (Gervais, 1843), a scorpion living in the Colombian Central Cordillera that was subjected to different climate regimes. For a comparative approach, one group was raised under lower conditions (23–24°C) and another group was raised under higher temperatures (25–27°C, meaning a 2–3°C increase). Our results clearly demonstrate that T. forcipule reared under laboratory conditions is not able to thrive under constant higher temperatures. A minority of the latter group (< 10%) reached adulthood, but never reproduced. Of the 43 specimens kept under lower temperatures (with a mild diapause), 21 females and 19 males reached maturity in the 5th instar; only one female and two males required an extra molt to mature. Tityus forcipula specimens reached maturity after 463 days of postembryonic development. The average for embryonic development was 208 days, with an average of 12 neonates per litter. Twenty-four different morphometric measurements were taken from all specimens for each exuvium of the juveniles and the adult stage. The results indicated a relationship, albeit partly poorly developed, between the sexes, in several measured structures and the instars.

Criteria for acceptable studies of animal personality and behavioural syndromes

Criteria for acceptable studies of animal personality and behavioural syndromes

Vulnerability and Decision-Making in Multispecies Fisheries: A Risk Assessment of Bacalao (Mycteroperca olfax) and Related Species in the Galapagos’ Handline Fishery

Marine fish populations can be vulnerable to overfishing, as a response of their life history, ecology, and socio-economic aspects. Vulnerability assessments, in this regard, can be used to support fisheries decision-making by aiding species prioritization. Assessments like Productivity–Susceptibility Analyses are well suited for multispecies fisheries, with low gear selectivity and insufficient fishery-independent and dependent data. Using this method, we assessed local vulnerability of the Galapagos grouper (‘bacalao’; Mycteroperca olfax) and compared it with other phylogenetically-related species caught in the Galapagos’ handline-fishery. Bacalao is an overfished regionally endemic fish species, characterized by low resilience, high market and cultural value and high spatial overlap with the fishery. Our results suggested that bacalao is a species of high management priority, requiring urgent measures to prevent fisheries’ collapse. In addition, if current fishing pressure persists, other related species may become threatened in the near future. We also evaluated different management scenarios using this approach. Results suggested that the inclusion of additional no-take zones in the marine reserve, comprising key nursery habitats (such as mangroves) and spawning aggregation sites, would be necessary to reduce species vulnerability and to benefit other related species. Improving enforcement and fishers’ compliance are essential to guarantee the effectiveness of these measures.

High-resolution stable isotope profiles of modern elephant (Loxodonta africana) tusk dentin and tail hair from Kenya: Implications for identifying seasonal variability in climate, ecology, and diet in ancient proboscideans

Stable isotope ratios in tissues of large mammalian herbivores record diet and climate information integrated over large spatial areas and can be used to study modern and fossil ecosystems. Sound interpretation of data requires that tissue growth rates be determined accurately and that ecological and behavioral variables that influence stable isotope ratios of tissues be measured and related to experienced environmental conditions assessed through field observations, remote sensing data, and meteorological records. If well-understood in modern herbivores, stable isotopes from closely-related extinct taxa have tremendous potential for resolving paleodiet, paleoenvironment, and paleoclimate of terrestrial ecosystems. We present multiyear, high-resolution (i.e., weekly) stable isotope records from bioapatite in tusk dentin (δ13Cdentin and δ18Odentin) and tail hair (δ13Chair and δ15Nhair) of an African elephant (Loxodonta africana) from Kenya that was fitted with a GPS collar intermittently over a five year period and observed for nearly a decade. GPS and observational data provide behavioral, life history, and location information. Normalized Difference Vegetation Index (NDVI), precipitation, and isotopic data from plants and water provide further constraints for interpreting isotope profiles. We determine tusk and hair growth rates using a combination of histological and geochemical approaches, including bomb-curve radiocarbon, that confirm approximately weekly resolution in the stable isotope profiles. Tusk dentin isotope profiles spanning the periods 1982 to 1987 and 2000 to 2006 record weekly variability in δ13Cdentin, where increases of up to 4.5‰ from baseline values due to diet switches from predominantly C3 browsing to mixed C3 browsing and C4 grazing occur during the twice-yearly (biannual) rainy seasons. The δ13Chair values show a similar trend. The δ13C profiles served as a proxy for seasonal changes in rainfall, vegetation, and diet. The δ18O of tusk bioapatite varied approximately biannually up to 5‰, likely reflecting increases in the proportion of plant water ingested during the wet season. Using a least squares inverse filter, we show that NDVI can be used to predict δ13C of dentin and vice versa, offering the possibility to reconstruct seasonal changes in vegetation and rainfall in the geologic past. Our results demonstrate that high-resolution tusk isotope profiles serve as a proxy for seasonality of diet and precipitation, and thus can be used to reconstruct aspects of elephant life history, vegetation, and climate at unprecedented resolution from modern and fossil proboscidean samples.

Establishment of time-resolved fluoroimmunoassays for detection of growth hormone and insulin-like growth factor I in rainbow trout plasma

The GH/IGF-I axis influences many aspects of salmonid life history and is involved in a variety of physiological processes that are related to somatic growth (e.g., reproduction, smoltification, and the response to fasting and stress). As such, fisheries studies utilize GH/IGF-I axis components as indicators of growth and metabolic status. This study established time-resolved fluoroimmunoassays (TR-FIAs) for rainbow trout plasma GH and IGF-I using commercially available reagents. For the GH TR-FIA, the ED80 and ED20 were 0.6 and 28.1 ng/mL, the minimum detection limit was 0.2 ng/mL, and the intra- and inter-assay coefficients of variation (%CV) were 4.1% and 13.4%, respectively. Ethanol remaining from acid-ethanol cryoprecipitation (AEC) of plasma samples to remove IGF binding proteins reduced binding and increased variability in the IGF-I TR-FIA. Drying down and reconstituting extracted samples restored binding and reduced variability. The extraction efficiency of IGF-I standards through AEC, drying down, and reconstitution did not vary over the working range of the assay. For the IGF-I TR-FIA, the ED80 and ED20 were 0.2 and 6.5 ng/mL, the minimum detection limit was 0.03 ng/mL, and the intra- and inter-assay %CV were 3.0% and 6.5%, respectively. Biological validation was provided by GH injection and fasting studies in rainbow trout. Intraperitoneal injection with bovine GH increased plasma IGF-I levels. Four weeks of fasting decreased body weight, increased plasma GH levels, and decreased plasma IGF-I levels. The GH and IGF-I TR-FIAs established herein provide a cost-comparable, non-radioisotopic method for quantifying salmonid plasma GH and IGF-I using commercially available reagents.

Influence of Anthropic Impacts on the Functional Structure of Aquatic Invertebrates in Subtropical Wetlands

Changes in land cover are the main threats to integrity and biodiversity of wetlands. Here, we evaluated the effects of agriculture and urbanization on the functional traits (FT) of aquatic invertebrate. We evaluated 30 wetlands distributed among agricultural, urban and natural landscapes on the south of Brazil. We selected eight FT that encompassed aspects of life history, morphology and behavioral strategies to functionally characterize invertebrate fauna and 10 environmental variables of wetlands. We collected 3868 organisms distributed among 138 taxa (Crustacea, Mollusca, Hexapoda. The RLQ analysis (environmental, R; species-abundances, L; species-traits, Q) showed that there was a relationship between environmental conditions and the functional composition of the invertebrates. The FT that were more sensitive to environmental changes were scrapers feeding habit, reproduction mode, resistance form, adult aquatic stage, flat body shape, and dispersal mode. Our results suggest that land use acted as environmental filters, as they promote the selection and convergence of specific characteristics that give organisms more resilience and/or resistance to cope with the effects of anthropogenic disturbances. Also this results showed that (i) human disturbance can influence directly on the dynamic of the wetlands ecosystems functioning and (ii) the efficiency of the use FT in the environmental monitoring.

Applying the zoo model to conservation of threatened exceptional plant species.

Maintaining a living plant collection is the most common method of ex situ conservation for plant species that cannot be seed banked (i.e., exceptional species). Viability of living collections, and their value for future conservation efforts, can be limited without coordinated efforts to track and manage individuals across institutions. Using a pedigree‐focused approach, the zoological community has established an inter‐institutional infrastructure to support long‐term viability of captive animal populations. We assessed the ability of this coordinated metacollection infrastructure to support the conservation of 4 plant species curated in living collections at multiple botanic gardens around the world. Limitations in current practices include the inability to compile, share, and analyze plant collections data at the individual level, as well as difficulty in tracking original provenance of ex situ material. The coordinated metacollection framework used by zoos can be adopted by the botanical community to improve conservation outcomes by minimizing the loss of genetic diversity in collections. We suggest actions to improve ex situ conservation of exceptional plant species, including developing a central database to aggregate data and track unique individuals of priority threatened species among institutions and adapting a pedigree‐based population management tool that incorporates life‐history aspects unique to plants. If approached collaboratively across regional, national, and global scales, these actions could transform ex situ conservation of threatened plant species.

Reciprocal-transplantation between shallow and mesophotic stony corals

Most studies to date on the various life-history aspects of scleractinian corals (e.g. reproduction, connectivity, and physiology) have focused on their innate habitats. However, comprehensive data on the ability of both shallow and mesophotic corals to contend in the coming decades with the different environmental conditions they may encounter due to new habitats or environmental changes (e.g. eutrophication), are scarce. Long-term cross-transplantation experiments assessing the potential responses and acclimatization ability of corals are thus needed in order to expand our knowledge. Here we examined the survivorship and changes in the photobiological acclimatization of corals following their cross-transplantation between two different depths (5–10 m and 45 m) and two sites characterized by different abiotic conditions (i.e. light, nutrient, and sedimentation regime). This year-long in-situ experiment was performed on five depth-generalist coral species. Depth of origin and the species’ particular morphology were found to be the strongest predictors of survivorship. Physiological responses occurred mainly among those corals that had been translocated from deep-to-shallow water, and were expressed in a significant reduction in chlorophyll-a concentration and algal density, as well as changes in photosynthetic parameters (e.g. minimal/maximal saturating points, Ek and Em, and rETRmax). Our study contributes to a better assessment of the physiological and ecological consequences of corals under acute and long-term environmental perturbations and their endurance abilities. Furthermore, it contributes to the information necessary for effective management intervention aimed at supporting the possible acclimation or rehabilitation of coral species

Influence of plants on soil mites (Acari, Oribatida) in gardens

Influence of plants on soil mites (Acari, Oribatida) in gardens

No Sperm Morphometric Differences between Two Populations of Diamond-backed Watersnakes (Nerodia rhombifer) with Varying Resource Availability

Vast differences in available resources between habitats can have profound influences on aspects of an organism's life history, such as reproductive investment. Our study investigated how differences in nutrient availability affect sperm size in Diamond-backed Watersnakes (Nerodia rhombifer). We compared body size and sperm morphometrics between two populations with differing nutrient availability: a naturally occurring lake and a commercial fish farm. We hypothesized that prey availability affects sperm morphometrics. Our null hypothesis was that there would be no significant difference in sperm morphometrics between populations, whereas our alternative hypothesis was that the snakes from the fish farm would have significantly longer sperm. We measured total sperm length, sperm head length, sperm tail length, and snout–vent length (SVL). We then used two-tailed t-tests and AIC model selection to test our hypotheses. SVL was not correlated with sperm size. Furthermore, none of the sperm morphometrics were significantly different between the two populations. Finally, a nearly 1:1 correlation between sperm tail length and total sperm length was found. AIC model selection corroborated these results by choosing only sperm head length and sperm tail length as significant predictors of total sperm length. This is the first published study to explicitly compare sperm morphometrics between two populations of the same snake species. Additional studies of this nature are required to corroborate whether lack of significant differences in sperm morphometrics among snake populations are common.

Trade-off Between Thermal Quality and Predation Risk at Timber Rattlesnake Gestation Sites

Trade-offs can cause conservation measures designed to improve habitat for one aspect of a species life history to inadvertently decrease its suitability in other ways. We explored the potential trade-off between thermal characteristics and risk of predation in important habitat for Timber Rattlesnakes (Crotalus horridus). Although typically a woodland species, pregnant C. horridus congregate in sunny, rocky clearings known as gestation sites that provide improved thermal habitat for embryonic development. Gestation sites can become overgrown with vegetation and, thus, sites may vary in canopy openness. We hypothesized that gestation sites with more canopy openness will be warmer but leave the snakes more exposed to predators. We used hemispherical photography to calculate canopy openness and operative temperature models to quantify thermal quality. Rattlesnake foam models and time-lapse cameras were deployed to quantify the relative predator richness and risk of predation. We found that more-open gestation sites were warmer than enclosed sites. We found that potential for predator encounters was similarly common regardless of gestation site canopy openness. However, we did find that predator species richness increased with canopy openness, with the most dangerous predators (raptors, mustelids, and felids) being only present at the most-open gestation sites. These results suggest that conservation actions for C. horridus that involve opening up the canopy at existing gestation sites may have unintended fitness consequences, as more dangerous predators appear to visit these more-open sites.