Large grazers modify effects of aboveground–belowground interactions on small-scale plant community composition

Aboveground and belowground organisms influence plant community composition by local interactions, and their scale of impact may vary from millimeters belowground to kilometers aboveground. However, it still poorly understood how large grazers that select their forage on large spatial scales interact with small-scale aboveground–belowground interactions on plant community heterogeneity. Here, we investigate how cattle (Bos taurus) modify the effects of interactions between yellow meadow ants (Lasius flavus) and European brown hares (Lepus europaeus) on the formation of small-scale heterogeneity in vegetation composition. In the absence of cattle, hares selectively foraged on ant mounds, while under combined grazing by hares and cattle, vertebrate grazing pressure was similar on and off mounds. Ant mounds that were grazed by only hares had a different plant community composition compared to their surroundings: the cover of the grazing-intolerant grass Elytrigia atherica was reduced on ant mounds, whereas the relative cover of the more grazing-tolerant and palatable grass Festuca rubra was enhanced. Combined grazing by hares and cattle, resulted in homogenization of plant community composition on and off ant mounds, with high overall cover of F. rubra. We conclude that hares can respond to local ant–soil–vegetation interactions, because they are small, selective herbivores that make their foraging decisions on a local scale. This results in small-scale plant patches on mounds of yellow meadow ants. In the presence of cattle, which are less selective aboveground herbivores, local plant community patterns triggered by small-scale aboveground–belowground interactions can disappear. Therefore, cattle modify the consequences of aboveground–belowground interactions for small-scale plant community composition

Strategies for the Use of Fallback Foods in Apes

Researchers have suggested that fallback foods (FBFs) shape primate food processing adaptations, whereas preferred foods drive harvesting adaptations, and that the dietary importance of FBFs is central in determining the expression of a variety of traits. We examine these hypotheses in extant apes. First, we compare the nature and dietary importance of FBFs used by each taxon. FBF importance appears greatest in gorillas, followed by chimpanzees and siamangs, and least in orangutans and gibbons (bonobos are difficult to place). Next, we compare 20 traits among taxa to assess whether the relative expression of traits expected for consumption of FBFs matches their observed dietary importance. Trait manifestation generally conforms to predictions based on dietary importance of FBFs. However, some departures from predictions exist, particularly for orang-utans, which express relatively more food harvesting and processing traits predicted for consuming large amounts of FBFs than expected based on observed dietary importance. This is probably due to the chemical, mechanical, and phenological properties of the apes’ main FBFs, in particular high importance of figs for chimpanzees and hylobatids, compared to use of bark and leaves—plus figs in at least some Sumatran populations—by orang-utans. This may have permitted more specialized harvesting adaptations in chimpanzees and hylobatids, and required enhanced processing adaptations in orang-utans. Possible intercontinental differences in the availability and quality of preferred and FBFs may also be important. Our analysis supports previous hypotheses suggesting a critical influence of the dietary importance and quality of FBFs on ape ecology and, consequently, evolution

The global economic crisis, household income and pre-adolescent overweight and underweight: a nationwide birth cohort study in Japan

BACKGROUND: We hypothesized that children from lower income households and in households experiencing a negative income change in connection to the global economic crisis in 2008 would be at increased risk of adverse weight status during the subsequent years of economic downturn. METHODS: Data were obtained from a nationwide longitudinal survey comprising all children born during 2 weeks of 2001. For 16,403 boys and 15,206 girls, information about anthropometric measurements and household characteristics was collected from 2001 to 2011 on multiple occasions. Interactions between the crisis onset (September 2008) and household income group, as well as the crisis onset and a >30% negative income change in connection to the crisis, were assessed with respect to risk of childhood over- and underweight. RESULTS: Adjusted for household and parental characteristics, boys and girls in the lower household income quartiles had a larger increase in risk of overweight after the crisis onset relative to their peers in the highest income group. (Odds ratio (95% confidence interval) for interaction term in boys=1.23 (1.02–1.24); girls=1.35 (1.23–1.49) comparing the lowest with the highest income group.) Among girls, an interaction between the crisis onset and a >30% negative change in household income with respect to risk of overweight was observed (odds ratio for interaction term=1.23 (1.09–1.38)). Girls from the highest income group had an increased risk of underweight after the crisis onset compared with girls from the lowest income group. CONCLUSIONS: Boys and girls from lower household income groups and girls from households experiencing a negative income change in connection to the global economic crisis in 2008, may be at increased risk of overweight. Vulnerability to economic uncertainty could increase risk of overweight in preadolescence