Sharing the burden : on the division of parental care and vocalizations during incubation

In species with biparental care, individuals only have to pay the costs for their own parental investment, whereas the contribution of their partner comes for free. Each parent hence benefits if its partner works harder, creating an evolutionary conflict of interest. How parents resolve this conflict and how they achieve the optimal division of parental tasks often remains elusive. In this study, we investigated whether lesser black-backed gulls (Larus fuscus) divide parental care during incubation equally and whether this correlates with the extent of vocalizations between pair-members during incubation. We then investigated whether pairs showing more evenly distributed incubation behavior had a higher reproductive success. To this end, we recorded incubation behavior and vocalizations for 24-h time periods. Subsequently, we experimentally increased or decreased brood sizes in order to manipulate parental effort, and followed offspring development from hatching till fledging. Although incubation bouts were, on average, slightly longer in females, patterns varied strongly between pairs, ranging from primarily female incubation over equal sex contributions to male-biased incubation. Pairs contributing more equally to incubation vocalized more during nest relief and had a higher reproductive output when brood sizes were experimentally increased. Thus, vocalizations and a more equal division of parental care during incubation may facilitate higher levels of care during the nestling period, as suggested by a greater reproductive success when facing high brood demand, or they indicate pair quality

Bioaugmentation of UASB reactors with immobilized Sulfurospirillum barnesii for simultaneous selenate and nitrate removal

Whole-cell immobilization of selenate-respiring Sulfurospirillum barnesii in polyacrylamide gels was investigated to allow the treatment of selenate contaminated (790¿µg Se¿×¿L-1) synthetic wastewater with a high molar excess of nitrate (1,500 times) and sulfate (200 times). Gel-immobilized S. barnesii cells were used to inoculate a mesophilic (30°C) bioreactor fed with lactate as electron donor at an organic loading rate of 5 g chemical oxygen demand (COD)¿×¿L-1 day-1. Selenate was reduced efficiently (>97%) in the nitrate and sulfate fed bioreactor, and a minimal effluent concentration of 39¿µg Se¿×¿L-1 was obtained. Scanning electron microscopy with energy dispersive X-ray (SEM–EDX) analysis revealed spherical bioprecipitates of =2¿µm diameter mostly on the gel surface, consisting of selenium with a minor contribution of sulfur. To validate the bioaugmentation success under microbial competition, gel cubes with immobilized S. barnesii cells were added to an Upflow Anaerobic Sludge Bed (UASB) reactor, resulting in earlier selenate (24 hydraulic retention times (HRTs)) and sulfate (44 HRTs) removal and higher nitrate/nitrite removal efficiencies compared to a non-bioaugmented control reactor. S. barnesii was efficiently immobilized inside the UASB bioreactors as the selenate-reducing activity was maintained during long-term operation (58 days), and molecular analysis showed that S. barnesii was present in both the sludge bed and the effluent. This demonstrates that gel immobilization of specialized bacterial strains can supersede wash-out and out-competition of newly introduced strains in continuous bioaugmented systems. Eventually, proliferation of a selenium-respiring specialist occurred in the non-bioaugmented control reactor, resulting in simultaneous nitrate and selenate removal during a later phase of operatio

Items of interest from recent ornithological literature: Perspectives from long-term ornithological research in the Taita Hills

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Rabbits (<i>Oryctolagus cuniculus</i> L.) in coastal dune grasslands

We describe a field experiment for examining the impact of wild rabbits (Oryctolagus cuniculus L.) on the vegetation in two Flemish coastal dune grasslands. When numerous, rabbits had a major impact on the vegetation. This impact can be considered positive in the case of the studied grasslands, as evidenced by a decreasing abundance by dominant grass species and a declining species richness. The decrease of the number of rabbits, due to VHS, may hence negatively affect dune grassland species richness. Introducing large herbivores can be part of the solution for preserving the dune grasslands, and this introduction may even have positive effects on rabbit populations through feeding facilitation

Personal and contextual antecedents of achievement goals: Their direct and indirect relations to students' learning strategies

Cataloged from PDF version of article.In this correlational research, we investigated to what extent achievement goals, in conjunction with need for achievement and fear of failure as well as perceived classroom goal structures, are related to learning strategies among upper elementary school students. After taking into account students' tendency to respond in a socially desirable way, we found, through path analysis, that mastery-approach goals partially mediated the relation of need for achievement and perceived mastery goal structures to learning strategies. These findings are discussed within the hierarchical model framework proposed by Elliot (1999). They suggest that the simultaneous examination of personal and contextual antecedents of achievement goals can enhance our understanding of the processes underlying achievement motivation and its outcomes

Perceived structure and achievement goals as predictors of student' self-regulated learning and affect and the mediating role of competence need satisfaction

Cataloged from PDF version of article.We investigated the extent to which perceived structure and personal achievement goals could explain students' effective learning strategies and affect-related experiences in a sample of Greek adolescent students (N=606; 45.4% males; mean age: M=15.05, SD=1.43). Having controlled for students' social desirability responses, we used multilevel analyses, and found that between-student (i.e., within class) differences in perceived structure related positively to learning strategies and positive affect and negatively to negative affect, with the relations being partially mediated by competence need satisfaction. In addition, we found between-student differences in the relations of mastery-approach, performance-approach, and performanceavoidance goals to the learning-strategy and affect outcomes. Moreover, at the between-class level, perceived structure related positively to learning strategies and positive affect, and negatively to depressive feelings. Finally, an interesting cross-level interaction between perceived structure and performance-avoidance goals for negative affect revealed that well-structured classrooms attenuated the positive, harmful relation between performance-avoidance goals and negative affect. These findings indicate the key role of structure and the endorsement of mastery-approach goals in the classroom

Germination success of temperate grassland species after passage through ungulate and rabbit guts

Dispersal of endozoochorous seed involves uptake by a herbivore and exposure to different kinds of digestive fluids during passage through the gastrointestinal tract. Assessment of the ecological significance of endozoochory therefore requires examination of the survival rate of seeds during this phase. A feeding experiment was conducted with seeds of 19 plant species that are important constituents of temperate semi-natural grasslands and five animal species (two ruminants, two colon fermenters and a caecum fermenter). Mean retention time of germinable seeds was determined and seed characteristics that might affect germination success were examined. Gut-passed seeds had a much lower germination success (0-26%) than non-gut-passed seeds either sown directly on dung (2-79%) or bare soil (7-89%). Relative germination success differed considerably between both plant and animal species. This may result from complex, herbivore-specific interactions between animal behaviour (chewing, digestion) and seed characteristics. Germination success was positively related to seed longevity and, remarkably, also to seed mass and seed shape. Retention time of germinable seeds varied from c. 12 hours (rabbit) to 72 hours (ungulates), potentially allowing long-distance seed dispersal. This study highlights both the complex interaction between animal species and seed characteristics and the considerable differences in germination success of gut-passed seeds, which exist between plant species. The loss of seed germinability after gut passage calls into question the ecological significance of endozoochory, although the costs of other dispersal mechanisms remain to be tested

A stochastic movement simulator improves estimates of landscape connectivity

Acknowledgments This publication issued from the project TenLamas funded by the French Ministère de l'Energie, de l'Ecologie, du Développement Durable et de la Mer through the EU FP6 BiodivERsA Eranet; by the Agence Nationale de la Recherche (ANR) through the open call INDHET and 6th extinction MOBIGEN to V. M. Stevens, M. Baguette, and A. Coulon, and young researcher GEMS (ANR-13-JSV7-0010-01) to V. M. Stevens and M. Baguette; and by a VLIR-VLADOC scholarship awarded to J. Aben. L. Lens, J. Aben, D. Strubbe, and E. Matthysen are grateful to the Research Foundation Flanders (FWO) for financial support of fieldwork and genetic analysis (grant G.0308.13). V. M. Stevens and M. Baguette are members of the “Laboratoire d'Excellence” (LABEX) entitled TULIP (ANR-10-LABX-41). J. M. J. Travis and S. C. F. Palmer also acknowledge the support of NERC. A. Coulon and J. Aben contributed equally to the work.Peer reviewedPublisher PD

Within-person configurations and temporal relations of personal and perceived parent-promoted life goals to school correlates among adolescents

Cataloged from PDF version of article.Grounded in self-determination theory, this longitudinal study examined the academic correlates of middle and high school students' (N = 923; 33.4% male) intrinsic and extrinsic aspirations (i.e., life goals) and the type of aspirations that they perceive their parents to promote to them. Person-centered analysis revealed 3 meaningful groups: a relatively high intrinsic aspiration group, a relatively moderate intrinsic aspiration group, and a relatively high-intrinsic and high-extrinsic aspiration group. Tukey post hoc comparisons indicated that students in the high intrinsic aspiration group scored higher on mastery-approach goals, effort regulation, and grades than students in the other 2 groups and lower on performance-approach goals and test anxiety than students in the high-high aspiration group. A match between learners' own aspiration profile and the perceived parent-promoted aspiration profile did not alter these between-group differences. Further, intrapersonal fluctuations of intrinsic aspirations covaried with mastery-approach goals over a 1-year time interval, while extrinsic aspirations covaried with performance-approach goals and test anxiety in the same period; none of these within-person associations were consistently moderated by between-student differences in perceived parental aspiration promotion. Instead, perceived parent-promoted intrinsic and extrinsic aspirations were, respectively, positive and negative predictors of between-student differences in positive school functioning. The present results highlight the importance of endorsing and promoting intrinsic aspirations for school adjustment. © 2013 American Psychological Association

Age of first breeding interacts with pre- and post-recruitment experience in shaping breeding phenology in a long-lived gull

Individual variation in timing of breeding is a key factor affecting adaptation to environmental change, yet our basic understanding of the causes of such individual variation is incomplete. This study tests several hypotheses for age-related variation in the breeding timing of Lesser Black-backed Gulls, based on a 13 year longitudinal data set that allows to decouple effects of age, previous prospecting behavior, and years of breeding experience on arrival timing at the colony. At the population level, age of first breeding was significantly associated with timing of arrival and survival, i.e. individuals tended to arrive later if they postponed their recruitment, and individuals recruiting at the age of 4 years survived best. However, up to 81% of the temporal variation in arrival dates was explained by within-individual effects. When excluding the pre-recruitment period, the effect of increasing age on advanced arrival was estimated at 11 days, with prior breeding experience accounting for a 7 days advance and postponed breeding for a 4 days delay. Overall, results of this study show that delayed age of first breeding can serve to advance arrival date (days after December 1st) in successive breeding seasons throughout an individual’s lifetime, in large part due to the benefits of learning or experience gained during prospecting. However, prospecting and the associated delay in breeding also bear a survival cost, possibly because prospectors have been forced to delay through competition with breeders. More generally, results of this study set the stage for exploring integrated temporal shifts in phenology, resource allocation and reproductive strategies during individual lifecycles of long-lived migratory species