Life history Research Papers - Academia.edu (original) (raw)

Coral mortality has increased in recent decades, making coral recruitment more important than ever in sustaining coral reef ecosystems and contributing to their resilience. This review summarizes existing information on ecological factors... more

Coral mortality has increased in recent decades, making coral recruitment more important than ever in sustaining coral reef ecosystems and contributing to their resilience. This review summarizes existing information on ecological factors affecting scleractinian coral recruitment. Successful recruitment requires the survival of coral offspring through sequential life history stages. Larval availability, successful settlement, and post-settlement survival and growth are all necessary for the addition of new coral individuals to a reef and ultimately maintenance or recovery of coral reef ecosystems. As environmental conditions continue to become more hostile to corals on a global scale, further research on fertilization ecology, connectivity, larval condition, positive and negative cues infl uencing substrate selection, and post-settlement ecology will be critical to our ability to manage these diverse ecosystems for recovery. A better understanding of the ecological factors infl uencing coral recruitment is fundamental to coral reef ecology and management.

Este libro es testimonio del oficio de los hombres de mar de la Región de Magallanes y Antártica Chilena; una pincelada dentro de las miles de historias que componen el pasado, el presente y el devenir de la pesca artesanal en la región... more

Este libro es testimonio del oficio de los hombres de mar de la Región de Magallanes y Antártica Chilena; una pincelada dentro de las miles de historias que componen el pasado, el presente y el devenir de la pesca artesanal en la región más austral del mundo. Busca contribuir al conocimiento de las personas y experiencias que dan vida a la actividad pesquera, tanto en el mar como en el borde costero. Son historias que arrojan luces sobre dimensiones poco tratadas en los estudios marítimo-costeros de la región magallánica.

To enable a relevant interpretation of otolith strontium : calcium (Sr/Ca) variations in terms of habitat shifts of eels, the Sr/Ca-salinity relationship in eel otoliths was validated. Downstream and upstream migrations of young eels were... more

To enable a relevant interpretation of otolith strontium : calcium (Sr/Ca) variations in terms of habitat shifts of eels, the Sr/Ca-salinity relationship in eel otoliths was validated. Downstream and upstream migrations of young eels were reproduced in the laboratory by transferring groups of fish every 2 months between aquaria filled with water coming from the Dordogne river (salinity = 0), the upper Gironde estuary (salinity = 5), the lower Gironde estuary (salinity = 25) and the coast (salinity = 30), which represented the salinity gradient observed in the Gironde-Garonne-Dordogne watershed. Ontogenetic changes in otolith Sr/Ca were assessed in two groups of control fish that were kept in one of either two constant salinities (fresh water or seawater). X-ray electron microprobe (wavelength dispersive spectrometry, WDS) analyses of Sr/Ca ratios in the otoliths showed that the change of aquarium was recorded as a Sr/Ca increase (downstream migration) or a Sr/Ca decrease (upstream migration). No ontogenetic effect was detected in otoliths of control fish outside glass eel marks in either group of fish. The electron microprobe (WDS) analysis of the Sr/Ca life (transected in several otoliths of eels caught in the Gironde-Garonne-Dordogne watershed) showed that some of them were migrant eels that had experienced one major habitat shift during their continental life.

Technology is a concept rife with confusion. Here, I argue that technologies can be distinguished as a combination of type of producer and an idealized artefact life history. Using this definition, a number of technologies are identified.... more

Technology is a concept rife with confusion. Here, I argue that technologies can be distinguished as a combination of type of producer and an idealized artefact life history. Using this definition, a number of technologies are identified. The first technology historically, in the Protostomes, was the production of individual or family dwellings. Next came objects such as spider webs for trapping prey. Stigmergy followed, with the social insects, as a collective endeavour to construct a mega-structure using simple rules of accretion. Some birds and primates began to make tools, or simple technological objects whose function is closely related to their form. Humans are distinguished by their ability to make machines. Traditional technology took place once people voluntarily organised into groups with specialised knowledge to produce more complex objects and structures. Monumental objects like ceremonial pyramids came with the command economies of the early agrarian societies, which also resulted in a new category of artefact, the network. Finally, with modern civilizations came ad hoc accretion, or population-level adding-on, to make truly complex technological systems. Developing a theoretical framework within which artefacts, production processes and ways of interacting with them are identified should help the study of technology to become more scientific.

In an effort to improve knowledge of Cottonmouth (Agkistrodon piscivorus) life history and behavior, we conducted a capture-mark-recapture study in Tuskegee National Forest, Alabama over four years to examine the influence of body size on... more

In an effort to improve knowledge of Cottonmouth (Agkistrodon piscivorus) life history and behavior, we conducted a capture-mark-recapture study in Tuskegee National Forest, Alabama over four years to examine the influence of body size on survival, recapture probabilities, and behavior; as well as monitor change in the population's body-size distribution over time. Our estimate of annual Cottonmouth survival (0.79) is among the highest reported for all snakes. Although we did not detect an effect of body size on survival, the probability of recapturing individuals increased with body size up to a snout-vent-length of 82 cm, after which it remained approximately constant. Relative to large snakes, small snakes were more likely to be found in a resting coil and less likely to move away from researchers, suggesting that our lower probability of recapturing small snakes was not due to behavioral avoidance of researchers but perhaps dispersal patterns or microhabitat use. Furthermore, the observed frequency of snakes ≤ 30 cm in length increased each year, indicative of an increase in recruitment over time. Our findings provide new information about Cottonmouth life history, and we suggest future paths of research that could further enhance knowledge of Cottonmouth demography and population dynamics.

T he present report shows a personal history of a 35-year-old woman, diagnosed of a breast cancer 2 years earlier. It expresses her own way of living her illness and the different processes she had submitted to fight against it. At the... more

T he present report shows a personal history of a 35-year-old woman, diagnosed of a breast cancer 2 years earlier. It expresses her own way of living her illness and the different processes she had submitted to fight against it. At the same time, her wish for life and her continuous positive behaviour not to consider herself as "a sick woman", as well as her developing strategies to face desperate moments in her daily life. The use of life histories as a working technique in the data gathering could help nurse professionals to discover the personal and real meaning of such an illness, to deepen into the roots of different experiences and to articulate nursing strategies and ways addressed to lessen negative feelings in order to get better evolutions within the process of an illness. At the same time, these type of reports help the main character implied-"the protagonist"-to feel very well acquainted with all those other women undertaking the same sort of process.

Recruitment is essential for the maintenance of populations, but far more is typically known about the more easily-observed adult stages than their smaller, often microscopic early life-history counterparts. This discrepancy can be... more

Recruitment is essential for the maintenance of populations, but far more is typically known about the more easily-observed adult stages than their smaller, often microscopic early life-history counterparts. This discrepancy can be particularly problematic for populations of foundation species that create biogenic habitat for a multitude of other taxa, but are themselves prime candidates for exploitation, fragmentation, and loss, and therefore become the focus of restoration eVorts partly or fully dependent on recruitment. The purpose of this study was to improve ecological understanding for early life-history stages of the habitat-forming marine alga Cystoseira barbata (Stackhouse) C. Agardh (Fucales: Sargassaceae), member of a genus that has experienced considerable fragmentation and population decline on European coasts. Using experimental manipulations of water temperature, light intensity, and sediment accumulation, we observed that sediment virtually precluded recruitment of C. barbata, and greatly impacted the survival of recently settled germlings (up to »83% mortality). Stronger intensities of light facilitated the growth of germlings, including the capacity for »50% of them to outgrow detrimental sediment and survive. Temperature (10 vs. 16°C) had no eVect on early recruitment, survival, or growth. This information helps to identify likely causes and locations of recruitment failure, and by extension, the conditions needed (either naturally or through human intervention) to facilitate recruitment and possible habitat restoration. Ultimately, this knowledge can increase our capacity to predict population persistence and the likely success of restoration eVorts. Communicated by S. D. Connell.

We compared three proportional back-calculation methods for scales using data sets for pumpkinseeds Lepomis gibbosus and golden shiners Notemigonus crysoleucas from 10 southern Quebec lakes, and we validated back-calculations by comparing... more

We compared three proportional back-calculation methods for scales using data sets for pumpkinseeds Lepomis gibbosus and golden shiners Notemigonus crysoleucas from 10 southern Quebec lakes, and we validated back-calculations by comparing them with observed lengths at lime of annulus formation. Ordinary least-squares regression (OR) was compared with geometric mean regression (GMR) for describing bodyscale relationships. Although minor differences were detected in body-scale regressions among lakes, pooling data across lakes yielded linear bodyscale relationships with very high r2. Differences between OR and GMR body-scale relationships were negligible in both species. Likewise, all back-calculation methods produced equivalent results. Back-calculated lengths generally corresponded well with observed lengths in all pumpkinseeds age-classes and in golden shiners older than 1 year. Observed lengths were often greater than back-calculated lengths for age-1 golden shiners. Our results, indicating little or no difference among methods, contradict recent reviews claiming substantial disagreement among methods. Tighter body-scale relationships in our data sets than in previous studies appear to explain this contradiction. We suggest that light body-scale relationships are attainable for many species, obviating concern over which proportional back-calculation method is chosen.

The National Longitudinal Study of Adolescent Health data were used to test predictions from life history theory. We hypothesized that (1) in young adulthood an emerging life history strategy would exist as a common factor underlying many... more

The National Longitudinal Study of Adolescent Health data were used to test predictions from life history theory. We hypothesized that (1) in young adulthood an emerging life history strategy would exist as a common factor underlying many life history traits (e.g., health, relationship stability, economic success), (2) both environmental harshness and unpredictability would account for unique variance in expression of adolescent and young adult life history strategies, and (3) adolescent life history traits would predict young adult life history strategy. These predictions were supported. The current findings suggest that the environmental parameters of harshness and unpredictability have concurrent effects on life history development in adolescence, as well as longitudinal effects into young adulthood. In addition, life history traits appear to be stable across developmental time from adolescence into young adulthood.

Learning is ubiquitous in the animal kingdom but has been studied extensively in only a handful of species. Moreover, learning studied under laboratory conditions is typically unrelated to the animal's natural environment or life history.... more

Learning is ubiquitous in the animal kingdom but has been studied extensively in only a handful of species. Moreover, learning studied under laboratory conditions is typically unrelated to the animal's natural environment or life history. Here, we designed a task relevant to the natural behavior of male African cichlid fish (Astatotilapia burtoni), to determine if they could be trained on a spatial task to gain access to females and shelter. We measured both how successfully animals completed this task over time and whether and how immediate early gene and hormone expression profiles were related to success. While training fish in a maze, we measured time to task completion, circulating levels of three key hormones (cortisol, 11-ketotestosterone, and testosterone) and mRNA abundance of seven target genes including three immediate early genes (that served proxies for brain activity) in nine brain regions. Data from our subjects fell naturally into three phenotypes: fish that could be trained (learners), fish that could not be trained (non-learners) and fish that never attempted the task (non-attempters). Learners and nonlearners had lower levels of circulating cortisol compared to fish that never attempted the task. Learners had the highest immediate early gene mRNA levels in the homologue of the hippocampus (dorsolateral telencephalon; Dl), lower cortisol (stress) levels and were more motivated to accomplish the task as measured by behavioral observations. Fish that never attempted the task showed the lowest activity within the Dl, high stress levels and little to no apparent motivation. Data from non-learners fell between these two extremes in behavior, stress, and motivation.

Growth rates and longevities were estimated for five major fishery species of parrotfishes (“uhu”) at Oahu, Hawai’i. All species grew rapidly with von Bertalanffy growth formula k values ≥0.4·year−1. Longevities were found to range... more

Growth rates and longevities were estimated for five major fishery species of parrotfishes (“uhu”) at Oahu, Hawai’i. All species grew rapidly with von Bertalanffy growth formula k values ≥0.4·year−1. Longevities were found to range broadly among the three small species, 4 years in Calotomus carolinus and 6 and 11 years in Scarus psittacus and Chlorurus spilurus, and to 15–20 years in Scarus rubroviolaceus and Chlorurus perspicillatus for the two large species. Age reading and growth curves for the latter two large species were validated using bomb radiocarbon dating. Median ages at sexual maturity as females (AM50) and at sex change (from female to terminal phase male, AΔ50) were estimated using logistic models. Sexual maturation occurred at 1–2 years for the small species and at 3–3.5 years in the large species. AΔ50 estimates ranged from 2 to 4 years in the small species and were about 5 and 7 years in S. rubroviolaceus and C. perspicillatus, respectively. Estimated milestones poo...

The life-history raw data of the Australian sheep blow fly Lucilia cuprina (Wiedemann) were collected in the laboratory conditions and analyzed based on the age-stage, two-sex life table to take into consideration both sexes and the... more

The life-history raw data of the Australian sheep blow fly Lucilia cuprina (Wiedemann) were collected in the laboratory conditions and analyzed based on the age-stage, two-sex life table to take into consideration both sexes and the variable development rates among individuals. The intrinsic rate of increase (r) is 0.236 d-1 , while the finite rate of population increase (λ) is 1.266 d-1. The net reproductive rate (R 0) is 106.1. The mean generation time (T) is 19.8 days. The population parameters suggest that L. cuprina population is r-strategist.

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When the development of gap models began about three decades ago, they became a new category of forest productivity models. Compared with traditional growth and yield models, which aim at deriving empirical relationships that best fit... more

When the development of gap models began about three decades ago, they became a new category of forest productivity models. Compared with traditional growth and yield models, which aim at deriving empirical relationships that best fit data, gap models use semi-theoretical relationships to simulate biotic and abiotic processes in forest stands, including the effects of photosynthetic active radiation interception, site fertility, temperature and soil moisture on tree growth and seedling establishment. While growth and yield models are appropriate to predict short-term stemwood production, gap models may be used to predict the natural course of species replacement for several generations. Because of the poor availability of historical data and knowledge on species-specific allometric relationships, species replacement and death rate, it has seldom been possible to develop and evaluate the most representative algorithms to predict growth and mortality with a high degree of accuracy. For this reason, the developers of gap models focused more on developing simulation tools to improve the understanding of forest succession than predicting growth and yield accurately.

Spring temperatures in temperate regions have increased over the past 20 years and many organisms have responded to this increase by advancing the timing of their growth and reproduction. However, not all populations show an advancement... more

Spring temperatures in temperate regions have increased over the past 20 years and many organisms have responded to this increase by advancing the timing of their growth and reproduction. However, not all populations show an advancement of phenology. Understanding why some populations advance and others do not will give us insight into the possible constraints and selection pressures on the advancement of phenology. By combining two decades of data on 24 populations of tits (Parus sp.) from six European countries, we show that the phenological response to large-scale changes in spring temperature varies across a species' range, even between populations situated close to each other. We show that this variation cannot be fully explained by variation in the temperature change during the pre-and post-laying periods, as recently suggested. Instead, we find evidence for a link between rising temperatures and the frequency of second broods, which results in complex shifts in the laying dates of first clutches. Our results emphasize the need to consider links between different life-history parameters in order to predict the ecological consequences of large-scale climate changes.

This study examined the morphology, growth and life history of dwarf minke whales to identify and confirm any differences from other minke whale species and subspecies. The study was based on biological samples and data obtained from 16... more

This study examined the morphology, growth and life history of dwarf minke whales to identify and confirm any differences from other minke whale species and subspecies. The study was based on biological samples and data obtained from 16 whales (3 males and 13 females) collected through the 1987/88 to 1992/93 austral summer seasons by the Japanese Whale Research Program under Special Permit in the Antarctic (JARPA). The whales were collected between latitudes 58°23′S and 65°04′S in the Antarctic area between 90°E and 180°. Mean body length at physical maturity was estimated to be 7.16 m for females, approximately 1.5 m to 2.0 m smaller than equivalent values of Antarctic minke whales and North Pacific common minke whales. The characteristic feature of a white shoulder/flipper patch was confirmed and some variations in the overall color pattern was found. Skeletal observations confirmed the previously reported characteristic features on the vertex of the skull. In addition, this study found a longer rostrum, deeply curved mandible, and narrower nasal bone in dwarf minke whales in comparison with other minke whales. All pregnant females had conceived in mid-austral winter (middle of June to early August). Females are likely to attain sexual maturation at 6-6.5 m and at around 7-10 years of age. Stomach contents indicated that dwarf minke whales mainly fed on lantern fishes around the Antarctic Convergence in summer. Analyses by ANCOV revealed significant differences in both external body and skull morphology among different species and subspecies. Furthermore, cluster analyses on the skull morphology revealed differentiation between dwarf minke whales and other common minke whales but they are more closely related to North Atlantic common minke whales. These analyses concurred with previous genetic analyses results. The results of this study provided support for the proposed subspecific status of dwarf minke whales.

Copepods (1-10 mm aquatic crustaceans moving at 1-1000 mm s Ϫ1) live at Reynolds numbers that vary over 5 orders of magnitude, from 10 Ϫ2 to 10 3. Hence, they live at the interface between laminar and turbulent regimes and are subject to... more

Copepods (1-10 mm aquatic crustaceans moving at 1-1000 mm s Ϫ1) live at Reynolds numbers that vary over 5 orders of magnitude, from 10 Ϫ2 to 10 3. Hence, they live at the interface between laminar and turbulent regimes and are subject to the physical constraints imposed by both viscous and inertial realms. At large scales, the inertially driven system enforces the dominance of physically derived fluid motion; plankton, advected by currents, adjust their life histories to the changing oceanic environment. At Kolmogorov scales, a careful interplay of evenly matched forces of biology and physics occurs. Copepods conform or deform the local physical environment for their survival, using morphological and behavioral adaptations to shift the balance in their favor. Examples of these balances and transitions are observed when copepods engage in their various survival tasks of feeding, predator avoidance, mating, and signaling. Quantitative analyses of their behavior give measures of such physical properties of their fluid medium as energy dissipation rates, molecular diffusion rates, eddy size, and eddy packaging. Understanding the micromechanics of small-scale biological-physical-chemical interactions gives insight into factors influencing largescale dynamics of copepod distribution, patchiness, and encounter probabilities in the sea.

An understanding of geographic and phylogenetic variation in passerine life histories is hampered by the scarcity of studies from the Southern Hemisphere. We documented the breeding biology of the White-browed Scrubwren (Sericornis... more

An understanding of geographic and phylogenetic variation in passerine life histories is hampered by the scarcity of studies from the Southern Hemisphere. We documented the breeding biology of the White-browed Scrubwren (Sericornis frontalis), an Australia endemic in the Pardalotidae (parvorder Corvida). Like other members of the Pardalotidae, scrubwrens had a long laying interval (two days), a long incubation period (declining from 21 to 17 days through the season), and a long period of postfiedging parental care (6 to 7 weeks). Scrubwrens appeared to be typical of the Australian Corvida in having a small clutch size (three eggs) and a long breeding season (5.4 months), and they also had a long interval between breeding attempts (10 days after a failed attempt, 21 days after a successful attempt). Scrubwrens were multibrooded, often raising two broods successfully and occasionally raising three broods. The breeding biology of scrubwrens adds further support to claims of a distinct life-history strategy for members of the Corvida but also reinforces evidence that some "Corvida" life-history traits more specifically are those of the Pardalotidae.

Estudo transversal em 1.026 trabalhadores em distrito de perfuração de petróleo do Nordeste brasileiro mostrou prevalência global de doença do disco intervertebral lombar de 5%, variando de 1,8% (atividades sem manuseio de carga), 4,5%... more

Estudo transversal em 1.026 trabalhadores em distrito de perfuração de petróleo do Nordeste brasileiro mostrou prevalência global de doença do disco intervertebral lombar de 5%, variando de 1,8% (atividades sem manuseio de carga), 4,5% (manuseio ocasional) até 7,2% (manuseio habitual). Tal prevalência foi de 11,4% em operadores de sonda de perfuração de petróleo com mais de 40 anos de idade e de 10,5% naqueles com mais de 15 anos de empresa. A razão de prevalência (R.P.) à associação entre trabalho em operação de sonda e doença do disco foi 2,3 (I.C. 95%: 1,3, 4,0). Para minimizar o efeito sobrevivência do trabalhador sadio foram usadas informações retrospectivas acerca da exposição. A informação referente à ocupação atual em lugar do histórico ocupacional resultaria em RP subestimada de 1,1 (I.C. 95%: 0,6, 1,9). A regressão logística ratificou os achados da análise tabular. Não houve confundimento nem interação. O incremento da indústria de petróleo no país e as alterações na gestã...

Despite the considerable number of studies of avian mating systems, the reasons for divorce in monogamous birds are still poorly understood. It is now generally believed that divorce is a reproductive strategy by an individual to maximize... more

Despite the considerable number of studies of avian mating systems, the reasons for divorce in monogamous birds are still poorly understood. It is now generally believed that divorce is a reproductive strategy by an individual to maximize its own fitness, and that birds are continuously faced with the decision of whether to stay with the old mate or divorce in favour of a different partner. The key to understanding when divorce will occur lies in determining the costs and benefits of both pair fidelity and divorce. These are likely to be species-specific and related to the varying life histories. Individuals are expected to divorce when the benefits outweigh the costs. Although a number of hypotheses have been proposed to explain why and when individuals may divorce, these are scattered throughout the literature and have not been critically compared and contrasted either theoretically or empirically. Confusion still exists as to the underlying assumptions and predictions of the individual models, mainly because a sound theoretical framework is lacking. Empirical studies to date are few and have been mainly post-hoc interpretations. Further advances in the field require sound mathematical modelling of the hypotheses and more experimental studies that rigorously test a priori predictions. These include removal of mates to create vacancies under controlled situations, manipulating sex ratios to increase intra-sexual competition, reducing or enlarging clutch sizes to alter perceived fitness, and manipulating the availability or quality of territories or mates to determine to what extent this affects divorce rates.

It has been hypothesized that salmonids use olfactory cues to return to their natal rivers and streams. However, the key components of the molecular pathway involved in imprinting and homing are still unknown. If odorants are involved in... more

It has been hypothesized that salmonids use olfactory cues to return to their natal rivers and streams. However, the key components of the molecular pathway involved in imprinting and homing are still unknown. If odorants are involved in salmon homing migration, then olfactory receptors should play a critical role in the dissipation of information from the environment to the fish. Therefore, we examined the expression profiles of a suite of genes encoding olfactory receptors and other olfactory-related genes in the olfactory rosettes of different life stages in two anadromous and one nonanadromous wild Atlantic salmon populations from Newfoundland, Canada. We identified seven differentially expressed OlfC genes in juvenile anadromous salmon compared to returning adults in both populations of anadromous Atlantic salmon. The salmon from the Campbellton River had an additional 10 genes that were differentially expressed in juveniles compared to returning adults. There was no statistically significant difference in gene expression of any of the genes in the non-anadromous population (P < 0.01). The function of the OlfC gene products is not clear, but they are predicted to be amino acid receptors. Other studies have suggested that salmon use amino acids for imprinting and homing. This study, the first to examine the expression of olfactory-related genes in wild North American Atlantic salmon, has identified seven OlfC genes that may be involved in the imprinting and homeward migration of anadromous Atlantic salmon.

Grazing experiments were performed with the zooplankters Daphnia pulex and Daphnia magna feeding on nitrogen-and phosphorus-limited cells of two green algae (Chlamydomonas reinhardtii and Selenastrum cupricornutum). To analyze the role of... more

Grazing experiments were performed with the zooplankters Daphnia pulex and Daphnia magna feeding on nitrogen-and phosphorus-limited cells of two green algae (Chlamydomonas reinhardtii and Selenastrum cupricornutum). To analyze the role of the cell wall structure in digestibility of the algae by Daphnia, the same experiments were carried out with both wild-type C. reinhardtii and a cell wall-deficient mutant.

Conservation of fauna breeding in vernal pools is challenging given their complex life histories. Many species, including the widespread North American Wood Frog (Rana sylvatica), require both aquatic and terrestrial habitat, yet... more

Conservation of fauna breeding in vernal pools is challenging given their complex life histories. Many species, including the widespread North American Wood Frog (Rana sylvatica), require both aquatic and terrestrial habitat, yet insufficient information exists about movements between these environments, nor fine-scale selection patterns within them. To inform conservation planning, we conducted a radio-telemetry study of seasonal patterns of Wood Frog movements and habitat selection in southern Maine. Forty-three frogs were tracked an average of 25.6 days each, April to November 2003. In early spring, Wood Frogs generally selected damp leaf litter retreats on the margins of breeding pools. Following breeding, frogs selected forested wetlands (9.3% of the landscape) over forested uplands (90.7% of the landscape) in 75.3% of radio locations (N 5 544). Postbreeding movements from breeding pools to nearby, closed-canopy, forested wetlands ranged from 102-340 m (median 169m, N 5 8) and included stopovers in upland forest floors ranging from one to 17 days (median two days, N 5 7). Summer refugia were characterized by shady, moist (nonaquatic), and sphagnum-dominated microhabitats. In urbanizing areas, we recommend a shift from a core-habitat conservation model to a spatially explicit approach that considers pool-breeding amphibian habitat as a network of migration-connected habitat elements (e.g., breeding pools, upland forest, nearby forested wetlands). In our study, this approach reduced the amount of land potentially requiring protection by . 2/3 from that of core habitat models. With the rapid dissemination of GIS technology, spatially explicit planning for pool-breeding amphibians is increasingly feasible.

Life-history variation in annuals is known to be caused by size requirements for photoinduction of flowering, but the importance of germination date and injury was overlooked so far even though they may play an important role in disturbed... more

Life-history variation in annuals is known to be caused by size requirements for photoinduction of flowering, but the importance of germination date and injury was overlooked so far even though they may play an important role in disturbed habitats. To test the effect of germination date and timing of injury on life-history variation of an annual plant, we performed a 2-year pot experiment with the root-sprouting herb Rorippa palustris. Plants belonging to six different cohorts, and sown at monthly intervals from April to September, were injured (all stem parts removed) in three ontogenetic stages: vegetative rosettes, flowering plants and fruiting plants. Plants from the April, and partly from the May, cohort behaved as summer annuals: they started to bolt at the same time, resprouted and overwintered poorly. Plants from the June cohort flowered in the first season as well, but they entered the bolting stage a month later than the preceding cohorts, produced the least fruits, but overwintered successfully and flowered again the second year (polycarpic perennials).

This paper explores graduates' views on the relationship between higher education and employment. It draws on a major European study involving graduates five years after graduation and highlights similarities and differences between UK... more

This paper explores graduates' views on the relationship between higher education and employment. It draws on a major European study involving graduates five years after graduation and highlights similarities and differences between UK graduates' experiences and their European counterparts. Specifically we address questions raised in the study about subjects studied and their relevance to entry into the labour market, if the academic level obtained was appropriate, whether graduates, with hindsight of five years, would choose the same subjects or the same institution again, and if they were satisfied with their current job. Such specific questions relate to broader perspectives such as the perceived value of higher education study in relation to initial employment and future life histories. These have to be seen in the context of cultural differences in higher education systems at the time of the research and, perhaps increasing convergences in light of the Bologna agreement.

Conservation Assessments for Five Forest Bat Species in the Eastern United States Monitor Population Trend and Abundance 1. Develop and validate methods to assess abundance of forest bat species during nonhibernating periods. (High... more

Conservation Assessments for Five Forest Bat Species in the Eastern United States Monitor Population Trend and Abundance 1. Develop and validate methods to assess abundance of forest bat species during nonhibernating periods. (High priority.) 2. Develop a long-term population monitoring strategy for nonhibernating periods. (High priority but subsequent to #1 above.) Determine Terrestrial Habitat Relationships 1. Determine summer habitat use relationships (roosting and foraging) for forest bats across multiple spatial and temporal scales within the range of each species, by demographic group. This effort should be coordinated across the range of the species to provide for adequate sample size to evaluate meaningful relationships. (High priority but subsequent to Monitor Population Trend and Abundance section.) 2. Evaluate habitat quality by associating habitat parameters with reproductive success. (Due to the patchy distribution of most forest bat species, design studies using baseline or pre-treatment to post-treatment at the same location.)

The current research analyzed the relationship between methamphetamine use and violence among young adults eighteen to twenty-five years old. Interviews were conducted with a sample of 106 respondents. The research was based primarily on... more

The current research analyzed the relationship between methamphetamine use and violence among young adults eighteen to twenty-five years old. Interviews were conducted with a sample of 106 respondents. The research was based primarily on in-depth, life-history interviews with individuals who used methamphetamine for a minimum of three months and who resided in Los Angeles County.

Capture-mark-recapture methods are used widely for monitoring and diagnosis of bird populations as they permit robust estimates of population abundance and demographic parameters (e.g. survival) to be obtained from incomplete records of... more

Capture-mark-recapture methods are used widely for monitoring and diagnosis of bird populations as they permit robust estimates of population abundance and demographic parameters (e.g. survival) to be obtained from incomplete records of individual life histories. The statistical analysis of these data relies on the important assumption that individuals of the same local populations (i.e. colony) have the same parameters (the homogeneity assumption). We used data from six medium-to long-term monitoring schemes of local Mediterranean populations of the European Storm Petrel Hydrobates pelagicus to empirically show that the level of individual heterogeneity and the consequent bias in the parameter of interest depend on the recapture methodology, which has important consequences for the experimental design. We found that the recapture probability varied over time and among methodologies. The study design had a strong influence on the proportion of transients caught (i.e. individuals not recaptured after marking); however, the survival probability estimate for resident birds was fairly similar across the studies. The differences found in survival seem to depend on the biological variability between sites (e.g. predation pressure), and not on the recapture methods.

This qualitative study uses life course theory along with risk and resilience as a foundation from which to examine the life histories of 14 adolescent mothers recruited from an urban homeless shelter. Semi-structured individual... more

This qualitative study uses life course theory along with risk and resilience as a foundation from which to examine the life histories of 14 adolescent mothers recruited from an urban homeless shelter. Semi-structured individual interviews focused on exploring experiences with violence and adversity, adaptations and coping in response, and sources of support; we analyzed the data using a grounded theory approach involving open, axial, and selective coding. The key storyline that emerged is risk chains over the life course, including lack of family support and a turning point at early adolescence. Participants' adaptations to violence influenced their identity development, and formal support from the shelter staff facilitated critical protective processes as the young women transitioned to adulthood.

This paper introduces a functional-structural plant model based on artificial life concepts and L-systems. This model takes into account realistic physiological rules, the architecture of the plants and their demography. An original... more

This paper introduces a functional-structural plant model based on artificial life concepts and L-systems. This model takes into account realistic physiological rules, the architecture of the plants and their demography. An original benefit of this approach is that it allows the simulation of plant evolution at both functional and life-history levels implementing mutations to the L-systems and a set of genetic parameter values. The conducted experiments focus on the evolutionary emergence of different life history strategies in an environment with heterogeneous resource availability and disturbance frequency. It is found that, depending on the encountered conditions, the plants develop three major strategies classified as competitors, stress-tolerators and ruderals according to Grime's CSR theory. Most of the evolved characteristics comply with theoretical biology or field observations on natural plants. Besides these results, our modelling framework is highly flexible and many refinements can be readily implemented depending on the issues one intends to address. Moreover, the model can readily be used to address many questions at the interface between evolutionary ecology, plant functional and community ecologies and ecosystem ecology.

To assist risk assessors at the Department of Energy’s Savannah River Site (SRS), a Geographic Information System (GIS) application was developed to provide relevant information about specific receptor species of resident wildlife that... more

To assist risk assessors at the Department of Energy’s Savannah River Site (SRS), a Geographic Information System (GIS) application was developed to provide relevant information about specific receptor species of resident wildlife that can be used for ecological risk assessment. Information was obtained from an extensive literature review of publications and reports on vertebrate- and contaminant- related research since 1954

This paper describes the linkage of a three-dimensional hydrodynamic circulation model with descriptive and experimental biological data concerning oyster (Crassostrea virginica) population dynamics in the Apalachicola Estuary (Florida,... more

This paper describes the linkage of a three-dimensional hydrodynamic circulation model with descriptive and experimental biological data concerning oyster (Crassostrea virginica) population dynamics in the Apalachicola Estuary (Florida, U.S.A.). Our intent was to determine the direct and indirect role of Apalachicola River flow in the maintenance of oyster production. Results of a monthly field sampling programme conducted on the oyster reefs in the Apalachicola system during 1985-1986 were used to develop statistical models relating several life-history characteristics of oysters to physical-chemical aspects of water quality. The same life-history characteristics were related statistically to output from a circulation model of Apalachicola Bay. Highest oyster densities and overall bar growth were found in the vicinity of the confluence of high salinity water moving westwards from St George Sound and river-dominated (low salinity) water moving south and eastwards from East Bay. With the exception of models for oyster mortality, the predictive capability of results from the parallel modelling efforts was low. A time-averaged model was developed for oyster mortality during the summer of 1985 by running a regression analysis with averaged predictors derived from the hydrodynamic model and observed (experimental) mortality rates throughout the estuary. A geographic information system was then used to depict the results spatially and to compare the extent of expected mortality in 1985 and 1986. High salinity, relatively low-velocity current patterns, and the proximity of a given oyster bar to entry points of saline Gulf water into the bay were important factors that contribute to increased oyster mortality. Mortality was a major determinant of oyster production in the Apalachicola Estuary with predation as a significant aspect of such mortality. By influencing salinity levels and current patterns throughout the bay, the Apalachicola River was important in controlling such mortality. Oyster production rates in the Apalachicola system depend on a combination of variables that are directly and indirectly associated with freshwater input as modified by wind, tidal factors, and the physiography of the bay. River flow reduction, whether through naturally occurring droughts, through increased upstream anthropogenous (consumptive) water use, or a combination of the two, could have serious adverse consequences for oyster populations. By coupling hydrodynamic modelling with descriptive and experimental biological data, we were able to determine the effects of potential freshwater diversions on oyster production in Apalachicola Bay.

The last two decades have seen a changing profile of young male mental health in Britain, including increased suicidal and parasuicidal behaviours. For mental health professionals to respond effectively and appropriately to meet these... more

The last two decades have seen a changing profile of young male mental health in Britain, including increased suicidal and parasuicidal behaviours. For mental health professionals to respond effectively and appropriately to meet these changing needs there needs to be further theorising and development of knowledge of young men's psychological processes and, in particular, how they make sense of their experiences within the cultural context of their lives. By drawing upon contemporary theories of subjectivities, this paper attempts to begin to address some of these issues. It looks in detail at two young men's accounts of their experiences of mental health problems. By using narrative, thematic and discourse analyses, the authors consider the cultural concepts the young men draw upon, and the language they use to voice their distress. The paper focuses on how gender and traditional masculinities constrain and influence the young men's narratives within the context of their individual life-histories and how these may become problematic for their mental health. The analyses provide a contemporary language-sensitive and culturally-sensitive reading of the young men's accounts of mental distress. It highlights how young men may talk about their distress in ways that are not immediately recognisable and extends the knowledge of the contemporary discourses used by young men in British society today. The implications for male subjectivities and mental health and therapeutic engagement are discussed.

Fire plays an important role in the evolution of life-history characteristics of organisms living in fire-prone regions. Although there are many reports of plants exhibiting adaptations to reduce the harmful or lethal effects of fire,... more

Fire plays an important role in the evolution of life-history characteristics of organisms living in fire-prone regions. Although there are many reports of plants exhibiting adaptations to reduce the harmful or lethal effects of fire, little is known about fire-resistance mechanisms among animals, other than fleeing responses. Here, we report observations that may represent a type of fire adaptation in a bird species: bowers in one population of the Great Bowerbird Chlamydera nuchalis remained unburned after fire. If a bower is destroyed by fire or other mechanisms during courtship and breeding season, the male may lose the opportunity to mate with females, thereby reducing his apparent fitness. Therefore, traits that minimise the damage to bowers from fires may be beneficial. By measuring the unburned areas surrounding bowers after fires, we showed that the survival of bowers after fires is unlikely to be solely related to chance. Our observations are consistent with the hypothesis that bower resistance to fire is an adaptation of the Great Bowerbird. However, it is also possible that unburned bowers are by-products of sexual selection.

Geonoma orbignyana is a common understory palm, whose leaves are used as foliage in Colombia. This palm has been used for more than 30 years; but there is no information about its life history or conservation status. Our objective was to... more

Geonoma orbignyana is a common understory palm, whose leaves are used as foliage in Colombia. This palm has been used for more than 30 years; but there is no information about its life history or conservation status. Our objective was to characterize the life history of this palm and population dynamics of a natural population as a first step to assess the effect of leaf harvesting. More than 1600 palms were monitored from June 1999 to March 2000; we measured growth, mortality, and reproductive success. Population dynamics were evaluated using a Lefkovitch matrix model, and elasticity analysis. Results indicate that G. orbignyana grows at a rate of 1.98 ± 0.047 leaves/year, the palm has a long lifespan, and growth and reproduction are related to light conditions in the forest. The density of this palm is high (108–311 palms/100 m2), which is explained in part by its capacity to continue growing after damage, and to respond to the frequent gap formation in the forest. The population is growing (λ = 1.074, CI = [1.046–1.099]). Survival transitions account for 77% of population growth, a value that is higher compared to other understory plants. Because of the high density, the recovery capacity of these palms, and the correlations found between individual and population performances with forest dynamics, we hypothesize that G. orbignyana behaves as an opportunistic species taking advantage of forest gaps. This palm is a promising non-timber forest product (NTFP) with a high profile for further exploitation, although we recommend that harvesting regimens should consider time of recovery and forest dynamics. Without these considerations mortality could increase in all classes, which will compromise population persistence. Further studies should accurately estimate the recovery time after defoliation as well as to characterize forest dynamics identifying its most important features for population growth.

The debate over the role of stochasticity is central in evolutionary biology, often summarised by whether or not evolution is predictable or repeatable. Here we distinguish three types of stochasticity: stochasticity of mutation and... more

The debate over the role of stochasticity is central in evolutionary biology, often summarised by whether or not evolution is predictable or repeatable. Here we distinguish three types of stochasticity: stochasticity of mutation and variation, of individual life histories and of environmental change. We then explain when stochasticity matters in evolution, distinguishing four broad situations: stochasticity contributes to maladaptation or limits adaptation; it drives evolution on flat fitness landscapes (evolutionary freedom); it might promote jumps from one fitness peak to another (evolutionary revolutions); and it might shape the selection pressures themselves. We show that stochasticity, by directly steering evolution, has become an essential ingredient of evolutionary theory beyond the classical Wright-Fisher or neutralist-selectionist debates.

A review of research on the effects of hurricanes on coral reefs suggests that the intermediate disturbance hypothesis may be applicable to shallow reef zones dominated by branching or foliaceous coral species that are especially... more

A review of research on the effects of hurricanes on coral reefs suggests that the intermediate disturbance hypothesis may be applicable to shallow reef zones dominated by branching or foliaceous coral species that are especially susceptible to mechanical damage from storms. Diversity (H') increases because of an increase in evenness following destruction or removal of the species that was monopolizing the space. The intermediate disturbance hypothesis as presented by Connell focuses on changes in number of species, but should be expanded to include diversity (H') and evenness. It should also be modified to incorporate changes in living cover and the time elapsed since disturbances of varying intensities. This hypothesis predicts that when cover is high, diversity will be low. However, research on coral reefs does not consistently demonstrate an inverse correlation of coral diversity and coral cover. An increase in cover and decrease in diversity with depth would also be expected because deeper reef zones generally experience less disturbance. However, higher diversity (both H' and species richness) is often associated with deeper zones. The effects of hurricanes on coral reefs will depend on the temporal and spatial scales under consideration, the life history characteristics and morphology of the dominant species, the depth of the reef zone, the ecological history of the site, and the influence of any additional natural or human stresses.

Previous studies indicated that a tropical freshwater eel Anguilla bicolor bicolor occurs in Africa, India, Sri Lanka, Bangladesh, Myanmar, Indonesia and Australia, but an intensive survey has indicated an extended distribution range for... more

Previous studies indicated that a tropical freshwater eel Anguilla bicolor bicolor occurs in Africa, India, Sri Lanka, Bangladesh, Myanmar, Indonesia and Australia, but an intensive survey has indicated an extended distribution range for the species into Peninsular Malaysia. Thus, A. b. bicolor is a native subspecies of Malaysia.

Everybody is born into a family. Each has its own history, therefore, 'our history' is not made by us, but by previous generations. The rise of International migration and the crumbling of family structures, however, only make it harder... more

Everybody is born into a family. Each has its own history, therefore, 'our history' is not made by us, but by previous generations. The rise of International migration and the crumbling of family structures, however, only make it harder for descendants to learn about their family history. Inhibited by language and geographical barriers as well as lost connections to the bearers of knowledge, many offspring of migrant families year for answers to questions such as 'Where do I come from?' or 'How did I get here?' Answering these requires re-establishing lost connections and meeting family one previously did not know. This paper illustrates how the juxtaposition of two generations of Chinese Australian migrants' narrative (a 'pioneer migrant' and an 'overseas born Chinese' are vital to piecing together a segment of family history.

Species distribution models (SDMs) to evaluate trees' potential responses to climate change are essential for developing appropriate forest management strategies. However, there is a great need to better understand these models'... more

Species distribution models (SDMs) to evaluate trees' potential responses to climate change are essential for developing appropriate forest management strategies. However, there is a great need to better understand these models' limitations and evaluate their uncertainties. We have previously developed statistical models of suitable habitat, based on both species' range and abundance, to better understand potential changes of 134 tree species habitats in the eastern United States (http://www.nrs.fs.fed.us/ atlas). Our focus here is to build on these results via a more robust assessment framework called modification factors (ModFacs) that is made up of five components. ModFac 1 addresses nine biological characteristics (e.g., shade tolerance and seedling establishment) that quantify the influence of species life-history traits. ModFac 2 considers 12 disturbance characteristics (e.g., insect pests, drought, and fire topkill) which address the capacity of a species to tolerate and respond to climate-induced changes in habitat. ModFac 3-5 distill the tree SDM results and facilitate communication of model uncertainty; we quantified the variability in projected change for General Circulation Models (GCM) and emissions scenarios (ModFac 3), the extent to which each species' habitat intersects novel climate conditions (Mod-Fac4), and accounted for long-distance extrapolations beyond a species' current range (ModFac5). The life-history components of ModFacs 1 and 2 demonstrate the marked variability among species in terms of biological and disturbance characteristics, suggesting diverse abilities to adapt to climate change. ModFacs 3-5 show that the information from the SDMs can be enhanced by quantifying the variability associated with specific GCM/emission scenarios, the emergence of novel climates for particular tree species, and the distances of species habitat shifts with climate change. The ModFacs framework has high interpretive value when considered in conjunction with the outputs of species habitat models for this century. Importantly, the intention of this assessment was not to create a static scoring system, but to broadly assess species characteristics that likely will play an important role in adaptation to climate change. We believe these scores based on biological, disturbance, and model synthesis factors provide an important expansion of interpretive and practical value to habitat model projections.

... The Operations Team, with NMFS, must develop research to identify shark nurseryareas and to recommend management measures involving area closures. As knowledge about shark habitats, nursery areas, and pupping ...

Blubber biopsy samples were obtained for contaminant analysis from two discrete populations of killer whales (Orcinus orca) which frequent the coastal waters of British Columbia, Canada. Detailed life history information for the... more

Blubber biopsy samples were obtained for contaminant analysis from two discrete populations of killer whales (Orcinus orca) which frequent the coastal waters of British Columbia, Canada. Detailed life history information for the ®sh-eating`resident' population, comprising two distinct communities, and the marine mammal-eating transient' killer whale population, provided an invaluable reference for the interpretation of contaminant concentrations. Total PCB concentrations (sum of 136 congeners detected) were surprisingly high in all three communities, but transient killer whales were particularly contaminated. PCB concentrations increased with age in males, but were greatly reduced in reproductively active females. The absence of age, sex and inter-community dierences in concentrations of polychlorinated-dibenzo-p-dioxins (PCDDs) and-dibenzofurans (PCDFs) may have partly re¯ected low dietary levels, but more importantly, metabolic removal of dioxin-like compounds in killer whales. While information on toxic thresholds does not exist for PCBs in cetaceans, total 2,3,7,8-TCDD Toxic Equivalents (TEQ) in most killer whales sampled easily surpassed adverse eects levels established for harbour seals, suggesting that the majority of free-ranging killer whales in this region are at risk for toxic eects. The southern resident and transient killer whales of British Columbia can now be considered among the most contaminated cetaceans in the world.

This article presents the consequences caused by the war in Afghanistan (1979-1989) upon the participants from Republic of Moldova. A number of evidence are offered through biographies, interviews etc.. They highlight the impact that this... more

This article presents the consequences caused by the war in Afghanistan (1979-1989) upon the participants from Republic of Moldova. A number of evidence are offered through biographies, interviews etc.. They highlight the impact that this event had both economic, and social as well, upon the active participants in this war