A Note on the Diet of the Tasmanian Aborigines

Many nonhuman primate diets are dominated by plant foods, yet plant tissues are often poor sources of sodium-a necessary mineral for metabolism and health. Among primates, chimpanzees (Pan troglodytes), which are ripe fruit specialists, consume diverse animal, and plant resources. Insects have been proposed as a source of dietary sodium for chimpanzees, yet published data on sodium values for specific foods are limited. We assayed plants and insects commonly eaten by chimpanzees to assess their relative value as sodium sources. We used atomic absorption spectroscopy to determine sodium content of key plant foods and insects consumed by chimpanzees of Gombe National Park, Tanzania. Dietary contributions of plant and insect foods were calculated using feeding observational data. On a dry matter basis, mean sodium value of plant foods (n = 83 samples; mean = 86 ppm, SD = 92 ppm) was significantly lower than insects (n = 12; mean = 1549 ppm, SD = 807 ppm) (Wilcoxon rank sum test: W = 975, p < 0.001). All plant values were below the suggested sodium requirement (2000 ppm) for captive primates. While values of assayed insects were variable, sodium content of two commonly consumed insect prey for Gombe chimpanzees (Macrotermes soldiers and Dorylus ants) were four to five times greater than the highest plant values and likely meet requirements. We conclude that plant foods available to Gombe chimpanzees are generally poor sources of sodium while insects are important, perhaps critical, sources of sodium for this population.

Arable field margins managed for biodiversity conservation: A review of food resource provision for farmland birds

The eucalyptus forests of Tasmania, Australia are some of the most productive and carbon dense in the world. Of the eucalypt species that are native to Tasmania, messmate stringybark (Eucalyptus obliqua, Euob) dominates 20% of the forested landscape. Moreover, Euob is distributed across both dry and wet forests that exhibit vastly different microclimates and subdominant vegetation communities. However, warming temperatures and increasingly stochastic precipitation events threaten their fate. Here, we reconstruct historical growth and physiology to characterize the sensitivity and timing of Euob tree responses to climate in two contrasting forest types (i.e. wet versus dry). We then combine these data with stand-level surveys and total carbon inventories to scale our findings within their respective geographical footprints. Finally, we develop a novel modeling framework to contextualize differences in the growth potential of trees in each environment under current and future projected environmental conditions. We found Euob tree growth in dry forests is highly sensitive to climate in the late spring, while growth in wet forests is more complacent and driven to a greater extent by mean climate over the course of a growing season. Moreover, intrinsic water use efficiency, the ratio of net photosynthesis to stomatal conductance to water, remains constant across a range of soil moisture in wet Euob forests, but declines with increasing water availability in dry forests. Our data suggest Euob growth, and subsequently carbon uptake and allocation to stem wood, is energy-limited in wet forests and water-limited in dry forests. Growth modeling revealed that, even under ideal conditions (i.e. maximum realized growth potential), stand-level carbon stocks in dry Euob forests achieve only 90% of those currently observed in wet forests. Our results suggest Euob trees in energy-limited wet forests could benefit under future climate, as Tasmania is expected to become warmer in most regions, while dry forests may be particularly vulnerable.&amp;#160;

Global plant trait studies have revealed fundamental trade-offs in plant resource economics. We evaluated such trait trade-offs during secondary succession in two species-rich tropical ecosystems that contrast in precipitation: dry deciduous and wet evergreen forests of Mexico. Species turnover with succession in dry forest largely relates to increasing water availability and in wet forest to decreasing light availability. We hypothesized that while functional trait trade-offs are similar in the two forest systems, the successful plant strategies in these communities will be different, as contrasting filters affect species turnover. Research was carried out in 15 dry secondary forest sites (5-63 years after abandonment) and in 17 wet secondary forest sites (<1-25 years after abandonment). We used 11 functional traits measured on 132 species to make species-trait PCA biplots for dry and wet forest and compare trait trade-offs. We evaluated whether multivariate plant strategies changed during succession, by calculating a ‘Community-Weighted Mean’ plant strategy, based on species scores on the first two PCA-axes. Trait spectra reflected two main trade-off axes that were similar for dry and wet forest species: acquisitive versus conservative species, and drought avoiding species versus evergreen species with large animal-dispersed seeds. These trait associations were consistent when accounting for evolutionary history. Successional changes in the most successful plant strategies reflected different functional trait spectra depending on the forest type. In dry forest the community changed from having drought avoiding strategies early in succession to increased abundance of evergreen strategies with larger seeds late in succession. In wet forest the community changed from species having mainly acquisitive strategies to those with more conservative strategies during succession. These strategy changes were explained by increasing water availability during dry forest succession and increasing light scarcity during wet forest succession. Although similar trait spectra were observed among dry and wet secondary forest species, the consequences for succession were different resulting from contrasting environmental filters.

Does hollow occurrence vary with forest type? A case study in wet and dry Eucalyptus obliqua forest

Disturbance regimes are changing worldwide, and the consequences for ecosystem function and resilience are largely unknown. Functional diversity (FD) provides a surrogate measure of ecosystem function by capturing the range, abundance and distribution of trait values in a community. Enhanced understanding of the responses of FD to measures of vegetation structure at landscape scales is needed to guide conservation management. To address this knowledge gap, we used a whole-of-landscape sampling approach to examine relationships between bird FD, vegetation diversity and time since fire. We surveyed birds and measured vegetation at 36 landscape sampling units in dry and wet forest in southeast Australia during 2010 and 2011. Four uncorrelated indices of bird FD (richness, evenness, divergence and dispersion) were derived from six bird traits, and we investigated responses of these indices and species richness to both vertical and horizontal vegetation diversity using linear mixed models. We also considered the extent to which the mean and diversity of time since fire were related to vegetation diversity. Results showed opposing responses of FD to vegetation diversity in dry and wet forest. In dry forest, where fire is frequent, species richness and two FD indices (richness and dispersion) were positively related to vertical vegetation diversity, consistent with theory relating to environmental variation and coexistence. However, in wet forest subject to infrequent fire, the same three response variables were negatively associated with vertical diversity. We suggest that competitive dominance by species results in lower FD as vegetation diversity increases in wet forest. The responses of functional evenness were opposite to those of species richness, functional richness and dispersion in both forest types, highlighting the value of examining multiple FD metrics at management-relevant scales. The mean and diversity of time since fire were uncorrelated with vegetation diversity in wet forest, but positively correlated with vegetation diversity in dry forest. We therefore suggest that protection of older vegetation is important, but controlled application of low-severity fire in dry forest may sustain ecosystem function by enhancing different elements of FD.

The magnitude of the carbon sink in second-growth forests is expected to vary with successional biomass dynamics resulting from tree growth, recruitment, and mortality, and with the effects of climate on these dynamics. We compare aboveground biomass dynamics of dry and wet Neotropical forests, based on monitoring data gathered over 3–16 years in forests covering the first 25 years of succession. We estimated standing biomass, annual biomass change, and contributions of tree growth, recruitment, and mortality. We also evaluated tree species’ contributions to biomass dynamics. Absolute rates of biomass change were lower in dry forests, 2.3 and 1.9 Mg ha−1 y−1, after 5–15 and 15–25 years after abandonment, respectively, than in wet forests, with 4.7 and 6.1 Mg ha−1 y−1, in the same age classes. Biomass change was largely driven by tree growth, accounting for at least 48% of biomass change across forest types and age classes. Mortality also contributed strongly to biomass change in wet forests of 5–15 years, whereas its contribution became important later in succession in dry forests. Biomass dynamics tended to be dominated by fewer species in early-successional dry than wet forests, but dominance was strong in both forest types. Overall, our results indicate that biomass dynamics during succession are faster in Neotropical wet than dry forests, with high tree mortality earlier in succession in the wet forests. Long-term monitoring of second-growth tropical forest plots is crucial for improving estimates of annual biomass change, and for enhancing understanding of the underlying mechanisms and demographic drivers.

We tested whether and how functional composition changes with succession in dry deciduous and wet evergreen forests of Mexico. We hypothesized that compositional changes during succession in dry forest were mainly determined by increasing water availability leading to community functional changes from conservative to acquisitive strategies, and in wet forest by decreasing light availability leading to changes from acquisitive to conservative strategies. Research was carried out in 15 dry secondary forest plots (5-63 years after abandonment) and 17 wet secondary forest plots (< 1-25 years after abandonment). Community-level functional traits were represented by community-weighted means based on 11 functional traits measured on 132 species. Successional changes in functional composition are more marked in dry forest than in wet forest and largely characterized by different traits. During dry forest succession, conservative traits related to drought tolerance and drought avoidance decreased, as predicted. Unexpectedly acquisitive leaf traits also decreased, whereas seed size and dependence on biotic dispersal increased. In wet forest succession, functional composition changed from acquisitive to conservative leaf traits, suggesting light availability as the main driver of changes. Distinct suites of traits shape functional composition changes in dry and wet forest succession, responding to different environmental filters.

Understanding the diet of threatened wildlife is vital for species-specific conservation and habitat management measures. The Red-crowned Crane (Grus japonensis) is a vulnerable bird distributed in Northeast Asia. Previous dietary studies of this bird focused mainly on its plant food composition based on field observations and microhistological identification. Herein, a total of 45 fecal samples were collected in November, December and January (15 fecal samples each month) from wintering cranes, and then subjected to a high throughput sequencing meta-barcoding approach to determine the primary plant (rbcL) and animal (COI) food items in their diet. A total of 230 operational taxonomic units (OTUs) of plant foods and 371 OTUs of animal foods were obtained. The main plant foods in the wintering period were Miscanthus, Zea, and Hordeum genera, which were similar to those in the breeding and the migration periods. Both agricultural and natural plants were detected, indicating a relatively broad dietary niche for this crane species. However, the main animal foods were representatives of Theridiidae, Megascolecidae, and Agelenidae, in sharp contrast to previous studies. The higher number of small terrestrial arthropods in animal foods might be due to the indirect intake of plants. The composition of both plant and animal foods in the diet showed the highest diversity in December, while it was homogeneous in January. The plant of Zea genus became the main source of nutrition in late winter, as supplementary feeding was performed in the reserve, which could help Red-crowned Cranes to get through the cold season. The results obtained in this work would contribute to the development of effective conservation strategies for the Red-crowned Crane.

Associations between microalbuminuria and animal foods, plant foods, and dietary patterns in the Multiethnic Study of Atherosclerosis

In field study, already published, it was found that the rural Grey Starling chicks (Sturnus cineraceus) were fed primarily with mole-crickets and no vegetable matter mixed, while the city chicks were given variety of animal and vegetable foods, of which the cherries were predominant item. The growth rate of chicks under this different food supply by the parents was generally uniformly good in rural broods and somewhat more variable in those of the city zone, among which an exceptional case of inferior chick growth was included.This was suspected to be the result of over or exclusive feeding of cherries by the parents, since their cherry preference was variable as shown by the number of vomitted cherry stones (by chicks) left it the nest boxes.The present study was aimed to compare the growth rate of chicks artificially raised with animal food and cherries. As animal food, the mole-cricket was not available in sufficient number, so the basket-worms which were found abundantly enough in the garden were substituted.Two chicks, A (male) and B (female), of the fifth day of age were used, and during 7-10th days A was fed with basket-worms and B with cherries. As the result, the growth of B delayed and it was weakened. So, during the next four days, the foods were reversed (though A was fed first two days with artificial pasted food, the following two days with the cherries) and on the first two days the mole-crickets were given as supplemental food equally to A and B (This caused their equall acceleration of growth).This reverse feeding resulted in the reversal of body weights of A and B, this time B becoming heavier than A. Later they were equally fed with pasted food and nine days after A, the male, again became heavier than B, the female (thus the influence of the cherry ceased) and on the 24th day of age, the growth of the birds stopped, reaching maturity as young birds.These data were supported by the very low protein and nitrogen content in the cherries used in the experiment as compared with the basket-worms (Also, known nutrient analyses of edible cherries and silk-worm are cited (Table 6 and 7)).The body length, keel length and parts of limbs were also measured, but the influence of food change upon these was not disctinct as in the body weight and they were not reversed when food was reversed. However, longer bones seemed to be more affected than shorter bones, and the maturity (or stop) of growth was delayed in longer than shorter bones. The growth of wing quills was not affected by the subsequent change of food (after 10 days old) but the effect of initial food difference (before 10 days old) might have continued until their full growth.

1. Endemic herbivory can influence forest ecosystem function, but how annual productivity consumption relates to seasonal resource utilisation by folivore guilds remains poorly understood. 2. Monthly changes in leaf damage and foliage traits were monitored in ‘dry’ and ‘wet’ Nothofagus pumilio (Fagales: Nothofagaceae) deciduous forests in northern Patagonia, Argentina. Herbivore‐induced leaf abscission was assessed and foliar productivity consumption was measured in the canopy and in litterfall harvests. 3. Seasonal damage ranged from 8% to 32% in dry forest, but remained below 5% in wet forest although foliar quality was higher in the latter. In dry forest, dominant guilds were temporally separated; leaf miners consumed younger foliage in spring to early summer, whereas leaf tiers prevailed in late summer to autumn. In wet forest, damage created by external chewers was concentrated in early summer. 4. Insect damage induced premature leaf abscission, especially in dry forest. Although foliar production in wet forest doubled that in dry forest, the percentage of productivity lost to folivores was higher in dry (14–20%) than in wet (1.2–1.8%) forest. 5. The overall greater impact of herbivory in dry forest canopies countered the expectation that consumption would increase with plant productivity and nutritional quality. Lower temperatures and a shorter growing season are likely to constrain folivory in wet forest stands.

Summary Conspecific density may contribute to patterns of species assembly through negative density dependence (NDD) as predicted by the Janzen‐Connell hypothesis, or through facilitation (positive density dependence; PDD). Conspecific density effects are expected to be more negative in darker and wetter environments due to higher pathogen abundance and more positive in stressful, especially dry, environments (stress‐gradient hypothesis). For NDD to contribute to maintaining diversity, it should be apparent at the community‐wide scale as a negative correlation between seedling recruitment, growth or survival and conspecific adult abundance (community compensatory trend; CCT). We examined seedling survival in relation to con‐ and heterospecific adults within 10 m and con‐ and heterospecific seedlings within 1 m for 13 species within two 4‐ha permanent plots located in dry and wet forests in Hawaii. We also examined interactions between conspecific density and light and species’ commonness. For all species pooled, adult conspecific effects were positive (PDD) in both dry and wet forests, though they were stronger in the dry forest. In contrast, seedling conspecific effects were negative (NDD), though only significantly so in the wet forest. The strength and direction of density effects varied with understorey light such that seedlings had the highest survival where both adult conspecific density and light were high but the lowest survival where seedling conspecific density and light were high. In the wet forest, the most common species showed positive effects of adult conspecifics, but the less common species showed negative adult conspecific effects. We found mixed evidence for a CCT: seedling survival was positively correlated with basal area, but negatively correlated with tree density (stems ha−1). Thus, it remains unclear whether NDD is a diversity‐maintaining mechanism in these forests. Synthesis. Overall, we found that positive conspecific effects influenced seedling mortality patterns more than negative interactions did, even in tropical wet forest where NDD is predicted to drive species’ abundances. Additionally, the strength and direction of density effects varied with forest type, PAR, and species’ abundance, underscoring the need to consider abiotic factors and species’ life‐history traits in tests of density dependence hypotheses.

Field surveys of species in the family Muridae and their food resources were conducted in Cat Tien National Park, Vietnam in March 2011 and March and September 2012. Species were identified by DNA barcoding using polymorphic mitochondrial DNA sequences (COI, Cyt b, and D-loop) and external morphology. A total of four species, Maxomys surifer, Niviventer fulvescens, N. bukit, and Rattus sp. were identified. In order to identify which food resources were utilized by these species in the study area, total DNA was extracted from the gastric contents of the collected individuals. Sequence fragments of the chloroplast rbcL and the mitochondrial COI genes were amplified by PCR from the gastric contents and used to identify plant and animal food resources, respectively. We detected 34 plant families and seven animal orders by the homology search using the BLAST algorithm.

In temperate regions of the world, food resources are seasonally limited, which causes some wildlife species to seek out nutrient‐rich resources to better meet their caloric needs. Animals that utilize high‐quality resources may reap fitness benefits as they prepare for mating, migration, or hibernation. American black bears (Ursus americanus) are omnivores that consume both plant and animal food resources to meet macronutrient needs. Black bears capitalize on high‐quality food resources, such as soft mast in summer and hard mast during autumn, but we know less about the importance of resource quality during spring. Therefore, we sought to understand the relationship between the spatiotemporal variation in the availability of food and resource selection of black bears during spring. We also aimed to infer potential changes in foraging tactics, from opportunistic foraging to more active selection. Although black bears are described as opportunistic omnivores, we hypothesized they select areas with high‐quality forage when available. We instrumented 7 black bears with GPS collars in 2017 and 2018 and estimated fine‐scale resource selection with integrated step‐selection functions. We found evidence that black bear movements were influenced by forage quality of vegetative food resources. However, we failed to find evidence that black bears actively alter their movements to take advantage of seasonal neonate elk. Although black bears represent a substantial cause of mortality for neonate elk, we found that black bears likely feed on neonates encountered opportunistically while traveling between patches of high‐quality forage. Few studies have shown evidence of an omnivorous species capitalizing on spatiotemporal variation in forage quality, yet our data suggest this may be an important strategy for species with diverse diets, particularly where resources are seasonally limited.