Habitat selection of three cryptic Plecotus bat species in the European Alps reveals contrasting implications for conservation

Assessing the ecological requirements of species coexisting within a community is an essential requisite for developing sound conservation action. A particularly interesting question is what mechanisms govern the stable coexistence of cryptic species within a community, i.e. species that are almost impossible to distinguish. Resource partitioning theory predicts that cryptic species, like other sympatric taxa, will occupy distinct ecological niches. This prediction is widely inferred from eco-morphological studies. A new cryptic long-eared bat species, Plecotus macrobullaris, has been recently discovered in the complex of two other species present in the European Alps, with even evidence for a few mixed colonies. This discovery poses challenges to bat ecologists concerned with planning conservation measures beyond roost protection. We therefore tested whether foraging habitat segregation occurred among the three cryptic Plecotus bat species in Switzerland by radiotracking 24 breeding female bats (8 of each species). We compared habitat features at locations visited by a bat versus random locations within individual home ranges, applying mixed effects logistic regression. Distinct, species-specific habitat preferences were revealed. P. auritus foraged mostly within traditional orchards in roost vicinity, with a marked preference for habitat heterogeneity. P. austriacus foraged up to 4.7 km from the roost, selecting mostly fruit tree plantations, hedges and tree lines. P. macrobullaris preferred patchy deciduous and mixed forests with high vertical heterogeneity in a grassland dominated-matrix. These species-specific habitat preferences should inform future conservation programmes. They highlight the possible need of distinct conservation measures for species that look very much alike.

Wild pollinators enhance fruit set of crops regardless of honey bee abundance.

The diversity and abundance of wild insect pollinators have declined in many agricultural landscapes. Whether such declines reduce crop yields, or are mitigated by managed pollinators such as honey bees, is unclear. We found universally positive associations of fruit set with flower visitation by wild insects in 41 crop systems worldwide. In contrast, fruit set increased significantly with flower visitation by honey bees in only 14% of the systems surveyed. Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation. Visitation by wild insects and honey bees promoted fruit set independently, so pollination by managed honey bees supplemented, rather than substituted for, pollination by wild insects. Our results suggest that new practices for integrated management of both honey bees and diverse wild insect assemblages will enhance global crop yields.

Commentary on "Exploring the Association Between Household Food Insecurity, Parental Self-Efficacy and Fruit and Vegetable Parenting Practices Among Parents of 5- to 8-Year-Old Overweight Children"

Invited commentary of an article that discusses the association between parental factors and food insecurity by Angela Hilmers, Karen Cullen, Carolyn Moore and Teresia O’Connor.

Exploring the Association Between Household Food Insecurity, Parental Self-Efficacy, and Fruit and Vegetable Parenting Practices Among Parents of 5- to 8-Year-Old Overweight Children

Background: Food insecurity may negatively impact children’s nutritional status by affecting parenting quality. Because parents have a strong influence on their children’s eating and food choices, examining the effects of food insecurity on parenting may provide important insights into obesity prevention efforts. Objectives: This study explored whether food insecurity was associated with parental self-efficacy and parenting practices related to fruit and vegetable consumption. Methods: Secondary analysis was performed using baseline data from 31 mothers of 5-8 year old overweight or obese children who had participated in a pilot obesity treatment program. Household food security status, fruit and vegetable parental self-efficacy (modeling/socialization, planning/encouraging and availability/accessibility) and fruit and vegetable parenting practices (structure, responsiveness, non-directive control, and external control) were assessed using validated measures. Students' t-test investigated differences in subscales by food security status. Results: There were no significant differences in fruit and vegetable parenting practices and parental self-efficacy between food secure and insecure groups. There was a trend towards a decrease in parental self-efficacy for making fruit and vegetables available in the home among food insecure parents (p=.06). Conclusions: In this small sample no significant associations were found between food insecurity and fruit and vegetable parenting practices and parental self-efficacy. However, the trend observed in this exploratory analysis supports further hypothesis-driven research with a larger sample size able to detect more subtle differences.

Fruit production in three masting tree species does not rely on stored carbon reserves

Fruiting is typically considered to massively burden the seasonal carbon budget of trees. The cost of reproduction has therefore been suggested as a proximate factor explaining observed mast-fruiting patterns. Here, we used a large-scale, continuous 13C labeling of mature, deciduous trees in a temperate Swiss forest to investigate to what extent fruit formation in three species with masting reproduction behavior (Carpinus betulus, Fagus sylvatica, Quercus petraea) relies on the import of stored carbon reserves. Using a free-air CO2 enrichment system, we exposed trees to 13C-depleted CO2 during 8 consecutive years. By the end of this experiment, carbon reserve pools had significantly lower δ13C values compared to control trees. δ13C analysis of new biomass during the first season after termination of the CO2 enrichment allowed us to distinguish the sources of built-in carbon (old carbon reserves vs. current assimilates). Flowers and expanding leaves carried a significant 13C label from old carbon stores. In contrast, fruits and vegetative infructescence tissues were exclusively produced from current, unlabeled photoassimilates in all three species, including F. sylvatica, which had a strong masting season. Analyses of δ13C in purified starch from xylem of fruit-bearing shoots revealed a complete turn-over of starch during the season, likely due to its usage for bud break. This study is the first to directly demonstrate that fruiting is independent from old carbon reserves in masting trees, with significant implications for mechanistic models that explain mast seeding.

From «Pflantz-Gart» to «Stammregister». On the history of knowledge of fruit cultivation in the canton of Bern

Among the efforts for the improvement of agricultural productivity, the cultivation of useful plants is particularly at the center of the Economic Enlightenment. In contrast to fodder and textile plants, cereals and potatoes, fruit trees are not included among its favoured subjects. This may be considered as astonishing in view of the significance that fruit has acquired in the contemporary diet. Be that as it may, efforts to improve fruit cultivation go back to even before the classical period of the Economic Enlightenment. The example of Bern in particular is suited to such an analysis over the Longue durée that covers the time from Daniel Rhagor’s «Pflantz-Gart» (1639) to the «Register of varieties of excellent species of pome fruits for the canton of Bern» (Stammregister, 1865). From the perspective of the history of knowledge, the connections between scholarly knowledge and local experience on the one hand and the changing actors in these knowledge systems on the other hand are of special interest here

Social and cognitive predictors of fruit and vegetable intake among adolescents: The context of changes in body weight

Two studies investigated differences in the relationships between adolescents' fruit and vegetable intake (FVI) and the predictors specified in the Health Action Process Approach and Social-Cognitive Theory. Retrospective (Study 1; N = 502) and prospective (Study 2; N = 668) designs were applied. Among adolescents with overweight/obesity, intention was cross-sectionally associated with FVI (Study 1); no social or cognitive predictors explained FVI at 14-month follow-up (Study 2). The planning - FVI and self-efficacy - FVI relationships were stronger among adolescents who reduced their body weight to normal, compared to effects observed among those who maintained their body weight (Studies 1 and 2).

A Normative Theory of Forgetting: Lessons from the Fruit Fly

Recent experiments revealed that the fruit fly Drosophila melanogaster has a dedicated mechanism for forgetting: blocking the G-protein Rac leads to slower and activating Rac to faster forgetting. This active form of forgetting lacks a satisfactory functional explanation. We investigated optimal decision making for an agent adapting to a stochastic environment where a stimulus may switch between being indicative of reward or punishment. Like Drosophila, an optimal agent shows forgetting with a rate that is linked to the time scale of changes in the environment. Moreover, to reduce the odds of missing future reward, an optimal agent may trade the risk of immediate pain for information gain and thus forget faster after aversive conditioning. A simple neuronal network reproduces these features. Our theory shows that forgetting in Drosophila appears as an optimal adaptive behavior in a changing environment. This is in line with the view that forgetting is adaptive rather than a consequence of limitations of the memory system.