Comparative Life History Study Research Articles

Length-weight relationships for eight Chondrichthyes from the north-eastern Atlantic Ocean

Length-weight relationships (LWRs) are pivotal for comparative life-history studies, conservation strategies and ecosystem modelling among regions. They provide essential information on the growth, fitness and wellbeing of a population in an ecosystem. Length and weight relationships and descriptive statistics for eight Chondrichthyes, caught off the Madeira archipelago between 2004 and 2019 from depths ranging from 350 to 2500 m, are herein reported. A total of 767 specimens was studied and it was observed that the parameter b (relative growth rate) oscillated between 2.558 for males of Centrophorus squamosus and 3.494 for females of Etmopterus princeps. This study is the first to include the LWRs for these 8 Chondrichthyes species in Madeira waters.

Contested Practice: Political Activism in Nursing and Implications for Nursing Education.

Canadian nurses have a social mandate to address health inequities for the populations they serve, as well as to speak out on professional and broader social issues. Although Canadian nursing education supports the role of nurses as advocates for social justice and leadership for health care reform, little is known about how nurse educators understand activism and how this translates in the classroom. A comparative life history study using purposeful sampling and a critical feminist lens was undertaken to explore political activism in nursing and how nurse educators foster political practice among their students. Findings from interviews and focus groups with 26 Ontario nurse educators and nursing students suggested that neoliberal dynamics in both the practice setting and in higher education have constrained nurses' activist practice and favour a technical rational approach to nursing education. Implications and strategies to inspire political action in nursing education are discussed.

How Activism Features in the Career Lives of Four Generations of Canadian Nurses.

Recent nursing research using a critical feminist lens challenges the prevailing view of political inertia in nursing. This comparative life history study using a critical feminist lens explores the relevance of activism with four generations of Canadian nurses. Purposeful sampling of Ontario nurses resulted in 40 participants who were diverse in terms of generation, practice setting, and activist practice. Interviews and focus groups were completed with the sample of Ontario registered nurses or undergraduate and graduate nursing students: 8 Generation X, 9 Generation Y (Millennials), 20 Boomers, and 3 Overboomers. Factors such as professional norms and personal and organizational supports shaped contradictory nursing activist identities, practices, and impacts. Gendered norms, organizational dynamics, and the political landscape influenced the meanings nurses attributed to critical incidents and influences that prompted activism inside and outside the workplace, shaping the transformative potential of nursing. Despite its limitations, the study has implications for creating professional and organizational supports for consideration of health politics and policy, and spaces for dialogue to support practice and research aligned with social justice goals.

The logic of comparative life history studies for estimating key parameters, with a focus on natural mortality rate

There are a number of key parameters in population dynamics that are difficult to estimate, such as natural mortality rate, intrinsic rate of population growth, and stock-recruitment relationships. Often, these parameters of a stock are, or can be, estimated indirectly on the basis of comparative life history studies. That is, the relationship between a difficult to estimate parameter and life history correlates is examined over a wide variety of species in order to develop predictive equations. The form of these equations may be derived from life history theory or simply be suggested by exploratory data analysis. Similarly, population characteristics such as potential yield can be estimated by making use of a relationship between the population parameter and bio-chemico-physical characteristics of the ecosystem. Surprisingly, little work has been done to evaluate how well these indirect estimators work and, in fact, there is little guidance on how to conduct comparative life history studies and how to evaluate them. We consider five issues arising in such studies: (i) the parameters of interest may be ill-defined idealizations of the real world, (ii) true values of the parameters are not known for any species, (iii) selecting data based on the quality of the estimates can introduce a host of problems, (iv) the estimates that are available for comparison constitute a non-random sample of species from an ill-defined population of species of interest, and (v) the hierarchical nature of the data (e.g. stocks within species within genera within families, etc., with multiple observations at each level) warrants consideration. We discuss how these issues can be handled and how they shape the kinds of questions that can be asked of a database of life history studies.

Evaluating the predictive performance of empirical estimators of natural mortality rate using information on over 200 fish species

AbstractMany methods have been developed in the last 70 years to predict the natural mortality rate, M, of a stock based on empirical evidence from comparative life history studies. These indirect or empirical methods are used in most stock assessments to (i) obtain estimates of M in the absence of direct information, (ii) check on the reasonableness of a direct estimate of M, (iii) examine the range of plausible M estimates for the stock under consideration, and (iv) define prior distributions for Bayesian analyses. The two most cited empirical methods have appeared in the literature over 2500 times to date. Despite the importance of these methods, there is no consensus in the literature on how well these methods work in terms of prediction error or how their performance may be ranked. We evaluate estimators based on various combinations of maximum age (tmax), growth parameters, and water temperature by seeing how well they reproduce >200 independent, direct estimates of M. We use tenfold cross-validation to estimate the prediction error of the estimators and to rank their performance. With updated and carefully reviewed data, we conclude that a tmax-based estimator performs the best among all estimators evaluated. The tmax-based estimators in turn perform better than the Alverson–Carney method based on tmax and the von Bertalanffy K coefficient, Pauly’s method based on growth parameters and water temperature and methods based just on K. It is possible to combine two independent methods by computing a weighted mean but the improvement over the tmax-based methods is slight. Based on cross-validation prediction error, model residual patterns, model parsimony, and biological considerations, we recommend the use of a tmax-based estimator (M=4.899tmax−0.916, prediction error = 0.32) when possible and a growth-based method (M=4.118K0.73L∞−0.33 , prediction error = 0.6, length in cm) otherwise.

A comparative life history study of two mirid bugs preying on Tuta absoluta and Ephestia kuehniella eggs on tomato crops: implications for biological control

The omnivorous predators Nesidiocoris tenuis (Reuter) and Macrolophus pygmaeus Rambur (Hemiptera: Miridae) are indigenous natural enemies that commonly inhabit tomato crops in the Mediterranean basin. Both predators are mass-reared and primarily released to control whiteflies, although recently they have also contributed to the control of the invasive tomato pest Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). The life history traits of these two predators have been studied in the laboratory under the conditions of being fed exclusively the eggs of T. absoluta or the eggs of the factitious prey Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae). Immature stages of both predator species successfully developed while preying on eggs of T. absoluta. However, the mature M. pygmaeus females produced significantly lower numbers of offspring in comparison to the offspring produced when preying on E. kuehniella eggs. This resulted in higher than expected demographic indexes for N. tenuis when compared to M. pygmaeus (e.g., the intrinsic rates of increase were 0.127 and 0.005, respectively). Our results support previous studies on the potential of N. tenuis has as biological control agent of T. absoluta, and indicate that the role of M. pygmaeus in controlling T. absoluta in the absence of other food sources is possibly limited.

A PRIMER ON SUMMARIZING MOLT DATA FOR FLIGHT FEATHERS

Abstract Once established with reliability, the rules of flight feather replacement become an important component of comparative life-history studies. Here I illustrate the form of tables that should be used to describe the pattern and intensity of flight feather molt. Using a subset of original data summarizing primary, secondary, and rectrix molt in Western Kingbirds (Tyrannus verticalis), I show how to assign scores indicating direction of replacement and points where waves of molt started or will stop. Combining these scores across birds yields a molt summary table, the starting point for determining the rules of feather replacement. This raw summary table is then iterated to show breaks between molt series and how summary scores around these breaks are reassigned to acknowledge series breaks. Molt summary tables also give sample sizes, because the rules of flight feather replacement cannot reliably be inferred unless birds in active molt are available for all the feathers being considered.

Comparative life history study of two species of Nemouridae (Plecoptera) from an intermittent-perennial stream continuum from the central Kentucky karst region, U.S.A.

(2005). Comparative life history study of two species of Nemouridae (Plecoptera) from an intermittent-perennial stream continuum from the central Kentucky karst region, U.S.A. SIL Proceedings, 1922-2010: Vol. 29, No. 2, pp. 912-916.

Comparative life-history study on sympatric hyperiid amphipods (Themisto pacifica and T. japonica) in the Oyashio region, western North Pacific

Life-history features of the sympatric amphipods Themisto pacifica and T. japonica in the western North Pacific were analyzed based on seasonal field samples collected from July 1996 through July 1998, and data from laboratory rearing experiments. T. pacfica occurred throughout the year, with populations peaking from spring to summer. In contrast, T. japonica were rare from autumn to early winter, but became abundant in late winter to spring. Mature T. pacifica females and juveniles occurred together throughout the year, indicating year-round reproduction. Mature T. japonica females were observed only in spring, and juveniles occurred irregularly in small numbers, suggesting limited, early-spring reproduction in this study area. Size composition analysis of T. pacifica identified a total of eight cohorts over the 2 years of the study. Due to the smaller sample size and rarity of mature females (>9.6 mm) and males (>7.1 mm), cohort analyses of T. japonica were not comparable. Laboratory rearing of specimens at 2°C, 5°C, 8°C and 12°C revealed that a linear equation best expressed body length growth by T. pacifica, while a logistic equation best expressed body length growth by T. japoncia. Combining these laboratory-derived growth patterns with maturity sizes of wild specimens, the minimum and maximum generation times of females at a temperature range of 2–12°C were computed as 32 days (12°C) and 224 days (2°C), respectively, for T. pacifica, and 66 days (12°C) and 358 days (2°C), respectively, for T. japonica. The numbers of eggs or juveniles in females’ marsupia increased with female body length and ranged from 23 to 64 for T. pacifica and from 152 to 601 for T. japonica. Taking into account the number of mature female instars, lifetime fecundities were estimated as 342 eggs for T. pacifica and 1195 eggs for T. japonica. Possible mechanisms for the coexistence of these two amphipods in the Oyashio region are also discussed.

Male sterility thermal thresholds in Drosophila: D. simulans appears more cold-adapted than its sibling D. melanogaster.

Numerous different criteria may be used for analysing species thermal adaptation. We compared male sterility thresholds in the two most investigated cosmopolitan siblings, D. melanogaster and D. simulans. A survey of various populations from Europe and North Africa evidenced consistent differences between the two species, and a detailed analysis was made on flies from Marrakech. Sharp sterility thresholds were observed in both species but at different temperatures: D. simulans appeared more tolerant to cold than its sibling (difference 1 degrees C) but more sensitive to heat (difference 1.5 degrees C). When transferred to an optimum temperature of 21 degrees C, D. simulans males, sterilized by a low temperature, recovered more rapidly than males of D. melanogaster; the reverse was true on the high temperature side. The analysis of progeny number also revealed the better tolerance of D. simulans males to cold but a lesser tolerance to heat. From these observations, we might expect that D. simulans should be more successful in cold temperate countries than its sibling, while ecological observations point to the contrary. Our data clearly show the difficulty of comparing ecophysiological data to field observations, and also the need of extensive comparative life history studies in closely related species.

Fifteen years of Phormia - on the value of an insect for the study of aging.

The blowfly Phormia is currently used for studying various aspects of aging. In the context of comparative life history studies this fly can be characterized as an example of an 'r' selected type with a short life span and explosive reproduction. This is in contrast to the mecopteran fly Panorpa which shows senescence even under free living conditions and represents the 'K' selected type. A sudden drop of flight performance, low levels of enzyme activities at the end of life and specific kinetic adaptations of single enzymes are part of the 'aging syndrome' of Phormia. In the context of general aging investigations Phormia proved to be a suitable model system. This is shown in several examples covering the age variation of oscillating glycolysis, the influence of the cell redox state on purified enzymes, and treatment with geriatrics.

Comparative life history studies of Frankliniella occidentalis and Thrips tabaci (Thysanoptera: Thripidae) on cucumber

AbstractShortly after its invasion into Europe, the western flower thrips, Frankliniella occidentalis (Pergande), became a more severe pest of greenhouse crops than the onion thrips, Thrips tabaci Lindeman. To test whether this differential pest status was due to a larger capacity of population increase, a comparative life history study was carried out on cucumber (Cucumis sativus cv. Corona). Experiments at 25°C showed that the egg-to-egg period of F. occidentalis was shorter, but its peak ovipositional rate was lower and its offspring sex ratio more male biased. These differences resulted in a slightly lower intrinsic rate of population increase (rm) for F. occidentalis than for T. tabaci (0.166 vs. 0.176/day). It was shown experimentally that between 15 and 28°C, developmental rate of F. occidentalis is linearly related to temperature, with a theoretical threshold temperature similar to the value reported for T. tabaci (10.9 vs. 11.5°C). It is argued that the rm-value of F. occidentalis will not be higher than that of T. tabaci for any temperature within this range. Alternative explanations for the difference in pest status between the two thrips species are discussed.

Model-Based Estimates of Annual Survival Rate Are Preferable to Observed Maximum Lifespan Statistics for Use in Comparative Life-History Studies

Estimates of longevity are available for many animals, and are commonly used in comparative life-history analyses. We suggest that annual survival rate is a more appropriate life history parameter for most comparative life history analyses. Observed maximum lifespans estimate complicated functions of survival and sampling probabilities. Annual survival rate estimates derived from modern band-recovery statistical procedures are becoming available for a variety of organisms. We compiled annual survival rate estimates and observed maximum longevities derived from band recovery data for North American waterfowl. Observed maximum longevities were not correlated with the annual survival rate estimates and appear to be unstable over time. We recommend that observed maximum lifespans not be used in life history analyses.

Regulation of Reproduction in Eusocial Hymenoptera

Eusocial insects are those that display all three of the following traits: coopera­ tion among colony members in caring for the young; reproductiv.e division of labor, with more or less sterile individuals working on behalf of others engaged in reproduction; and overlap of at least two generations of life stages capable of contributing to colony labor (177). Important evolutionary questions about eusociality are the following: (a) How did it originate in the Hymenoptera (which, by the above definition, is synonymous with the question, how did a sterile worker caste evolve)? and (b) How is the eusocial condition maintained? Answers to these questions are sought through comparative life history studies in order to discern possible routes to eusociality, and also through studies involving genetic modeling. Research into the regulation of reproduction lies at the heart of these activities because it is the basis upon which the relevant hypotheses and theories are constructed and tested. An evolutionary framework focuses attention on the social factors that regulate reproduction, but to avoid separating them artificially from their ecological context, factors extrinsic to a colony must occasionally enter the discussion. Analysis of social mechanisms has generally begun, as is proper, at the behavioral level, but an understanding of the physiological causes and consequences of the behavior is somewhat laggard. The literature is neverthe­ less extensive, necessitating the omission of much material relevant to this review.

Biosystematics of three taxa in theAmblyseius finlandicusgroup from south africa, with comparative life history studies (Acari: Phytoseiidae)

Abstract Hybridization tests indicated that 2 morphologically distinct populations of Amblyseius in the finlandicus species group on citrus trees from Addo and Citrusdal, South Africa, were both A. addoensis van der Merwe and Ryke. These are designated as subspecies addoensis stat. nov. and rubicolus comb. nov., respectively. A third population, from Rustenberg, was not reproductively compatible with the other 2, and was determined as A. citri van der Merwe and Ryke. Morphological data and a tabular key are included. Biological studies indicated that pollen of Malephora crocea Jacq. was a more favorable food for development and reproduction than eggs and larvae of Tetranychus pacificus McGregor. The eggs of A. citri survived at lower R. H.'s than those of the 2 subspecies of rubicolus.

A Comparative Life-history Study of Four Species of Woodpeckers, by Louise de Kiriline Lawrence [Review

A Comparative Life-history Study of Four Species of Woodpeckers, by Louise de Kiriline Lawrence [Review

A Comparative Life-History Study of Four Species of Woodpeckers

A Comparative Life-History Study of Four Species of Woodpeckers

A Comparative Life-History Study of Four Species of Woodpeckers

A Comparative Life-History Study of Four Species of Woodpeckers

Observations on the Life Histories of Turtles (Genus Pseudemys and Graptemys) in Lake Texoma, Oklahoma

Aspects of the life histories of Pseudemys scripta elegans and Graptemys pseudogeographica ouachitensis (Reptilia: Testudines) were studied in Lake Texoma, Oklahoma. Variation in the color patterns of the two species is considered. Males of Pseudemys are sexually mature at a plastron length of 9.0 to 10.0 cm; females at 17.4 to 19.3 The realized annual reproductive capacity of a female Pseudemys is estimated to be 26.4 eggs (3 clutches; 8.8 eggs per clutch). Some males become sexually mature in their third year; females in their fourth. Males of Graptemys are sexually mature at a plastron length of 7.0 cm; females at 15.0 cm. Each Graptemys female lays approximately 19.5 eggs per year (3 clutches; 6.5 eggs per clutch). The elongation of the tail and third claw of the forelimb are secondary sexual characters in males of both species. Growth in both species progresses rapidly prior to maturity, however, Graptemys females seemingly grow more slowly than Pseudemys during this period. Rapid fluctuation of the water level may result in a slowing of growth in Pseudemys, but the evidence is only suggestive, not conclusive. Alternation of habitats along the shoreline due to the changing water level is believed to be responsible for the nomadic behavior of Pseudemys as well as in determining the quality and quantity of food available. The abundance of the red-eared turtle, Pseudemys scripta elegans Wied, and the Ouachita map turtle, Graptemys pseudogeographica ouachitensis Cagle, in Lake Texoma, made possible a comparative life history study at the University of Oklahoma Biological Station, Marshall County, 2 miles east of Willis. Acknowledgments.-I am grateful to Dr. Carl D. Riggs, Director of the Biological Station for permission to utilize facilities in his care. I am indebted further to Dr. Harley P. Brown of the University of Oklahoma Department of Zoology for the analysis of the animal material in the contents of digestive tracts of selected turtles, and to Dr. George J. Goodman of the University of Oklahoma Department of Botany for selected botanical determinations. Finally, thanks are extended to Drs. Fred R. Cagle and Henry S. Fitch for constructive criticism of the manuscript.

Colladonus geminatusandC. montanus: Life histories on virus-infected and on healthy plants

Comparative life-history studies of these two species (selected for study because they experience no nymph mortality on either healthy or diseased celery plants) show no significant differences in the duration of nymphal stages between specimens reared on healthy celery and those reared on diseased celery. In Colladonus montanus the total duration of nymphal stages is shorter for the males than for the females. In both species, males were smaller than females. C. geminatus and C. montanus do not interbreed.