Genetic and ‘cultural’ similarity in wild chimpanzees

The question of whether animals possess ‘cultures’ or ‘traditions’ continues to generate widespread theoretical and empirical interest. Studies of wild chimpanzees have featured prominently in this discussion, as the dominant approach used to identify culture in wild animals was first applied to them. This procedure, the ‘method of exclusion,’ begins by documenting behavioural differences between groups and then infers the existence of culture by eliminating ecological explanations for their occurrence. The validity of this approach has been questioned because genetic differences between groups have not explicitly been ruled out as a factor contributing to between-group differences in behaviour. Here we investigate this issue directly by analysing genetic and behavioural data from nine groups of wild chimpanzees. We find that the overall levels of genetic and behavioural dissimilarity between groups are highly and statistically significantly correlated. Additional analyses show that only a very small number of behaviours vary between genetically similar groups, and that there is no obvious pattern as to which classes of behaviours (e.g. tool-use versus communicative) have a distribution that matches patterns of between-group genetic dissimilarity. These results indicate that genetic dissimilarity cannot be eliminated as playing a major role in generating group differences in chimpanzee behaviour.     

Are kubo hunters ‘show offs’?

The ‘show off’ hypothesis proposed by K. Hawkes, and tested using data on Ache foragers, makes important connections between food resource choice, reproductive strategies, and food sharing by human foragers. We test predictions derived from that hypothesis concerning contexts of meat acquisition, association between individuals, mobility, and reproductive success among Kubo hunter-horticulturalists of the interior lowlands of Papua New Guinea. Application of the hypothesis to both the Kubo and Ache cases is questioned. Differences between Kubo males in means and variances of returns from hunting arise as a consequence of differential target specialization; they do not map onto variation in reproductive success.     

Assessing hunters’ ability to identify shot geese: implications for hunting bag accuracy

Reliable hunting bag statistics are a prerequisite for sustainable harvest management. Recently, Internet-based hunting bag reporting systems have been introduced in some European countries, e.g. Denmark, which may enable faster and more detailed reporting. However, reporting of waterfowl bags on a species-specific level may be biased from the individual hunters’ ability to correctly identify species, particularly because juvenile birds can only be identified from subtle differences. We assessed hunters’ ability to identify the five goose species huntable in Denmark. Identifications were made from a line-up of ten full-bodied geese including adults and juveniles. From a total of 2160 identifications made by active hunters, 85.5% were correct while 14.5% were assigned to a wrong species. Active hunters had on average an identification accuracy of 76.0%, highest for Canada goose (99.1%) and lowest for white-fronted goose (74.6%) and bean goose (73.7%). Identification accuracy was significantly lower for juvenile than for adult individuals of white-fronted and bean geese. Correcting the official Danish Bag Record (2013/2014) for identification accuracy, the bags of white-fronted and bean geese increase by 56.5 and 104.4%, respectively, while the bags of greylag and pink-footed geese decrease by 6.7 and 9.0%; the bag for Canada goose remains unchanged. Although identification accuracy is probably higher under field conditions, the study documents that inaccurate species identification is a source of bias in national bag statistics. Hence, improving identification skills by hunters is important to improve bag data accuracy when based on Internet reporting.     

Changes in bacterial communities during two agricultural solid wastes’ co-composting processes

Microbes perform an important role in the solid-state fermentation (SSF) process, and bacterial communities are more or less abundant depending on the starting materials and the composting procedure. In this study, high-throughput sequencing was used to investigate the changes in bacterial communities in different composting piles containing spent pig litter and distiller grains in five dry weight ratios, i.e., 100% distiller grains (treatment 1), 75% distillers grains/25% spent pig litter (treatment 2), 50% distillers grains/50% spent pig litter (treatment 3), 25% distillers grains/75% spent pig litter (treatment 4), and 100% spent pig litter (treatment 5). The results showed that the fermentation time of the thermophilic stage was prolonged with an appropriate content of distiller grains. The alpha-diversity analysis showed that the variation in bacterial richness and diversity in the various treatments (except treatment 5) was greater in the high-temperature stage than in the inception stage and then was slightly lower in the stabilization stage than in the thermophilic stage. The relative abundance of the predominant bacterial communities differed during different composting stages except in treatment 5. The abundant bacterial communities were similar among the treatments with different proportions of distiller grains (treatments 2, 3, and 4) during the high-temperature stage but differed during the stabilization stage, as increasing proportions of distiller grains increased the relative abundance of the phyla Proteobacteria and Firmicutes, and decreased that of Actinobacteria. Additionally, principal coordinate analysis (PCoA) showed that the bacterial communities in treatments 1, 2, 3, and 4 during the initial stage (day 0) were different from those observed during two other stages (day 10 and day 53), while treatment 5 showed only slight variations in the bacterial community structure in response to changes in the composting process. The results indicated that spent pig litter is not suitable for single-material composting and the addition of an appropriate amount of distiller grains can improve the fermentation process. The understanding of the microbial community diversity at molecular level provided a theoretical basis for the optimization of spent pig litter and/or distiller grain fermentation.     

Neural ‘bubble’ dynamics in two dimensions: foundations

An extension to two dimensions of recent results in continuum neural field theory (CNFT) in one dimension is presented here. Focus is placed on the treatment of receptive fields and of learning on afferent synapses to obtain topographic maps. Received: 26 March 1997 / Accepted in revised form: 16 December 1998     

Stability of within-host–parasite communities in a wild mammal system

Simultaneous infection by multiple parasite species is ubiquitous in nature. Interactions among co-infecting parasites may have important consequences for disease severity, transmission and community-level responses to perturbations. However, our current view of parasite interactions in nature comes primarily from observational studies, which may be unreliable at detecting interactions. We performed a perturbation experiment in wild mice, by using an anthelminthic to suppress nematodes, and monitored the consequences for other parasite species. Overall, these parasite communities were remarkably stable to perturbation. Only one non-target parasite species responded to deworming, and this response was temporary: we found strong, but short-lived, increases in the abundance of Eimeria protozoa, which share an infection site with the dominant nematode species, suggesting local, dynamic competition. These results, providing a rare and clear experimental demonstration of interactions between helminths and co-infecting parasites in wild vertebrates, constitute an important step towards understanding the wider consequences of similar drug treatments in humans and animals.     

Social preferences for partners carrying ‘good genes’ in wild house mice

Female wild strain house mice (Mus musculus) can use olfactory cues to discriminate males carrying lethal t-alleles (+/t) from those that do not carry such alleles (+/+). When tested in an arena, female mice tend to avoid +/t males and preferentially direct approaches to +/+ males. The magnitude of a female's avoidance of +/t males is related to the female's own genotype. Females who are themselves +/t show greater avoidance than +/+ females. Male mice tend to be more aggressive toward females carrying t-alleles and are less likely to attempt copulations with such females than with +/+ females. I suggest that these social preferences may be related to mating preferences, providing an example of mating preference based on genetic quality. Furthermore, avoidance of +/t individuals as mates could account for the lower than expected frequency of t-alleles in natural populations.     

‘Agonistic buffering’ in the wild barbary macaque,Macaca sylvana L.

Barbary apes are known to exhibit male care of babies at various locations, but only in the Middle Atlas mountains of Morocco has it been reported that a baby may be used in male-male interactions, apparently reducing the likelihood of aggression. The present study was made in order to discover if the behavior was characteristic of other groups reproductively isolated from the Atlas population. Male-male interactions involving a baby were observed in two groups and are described in detail; their friendly nature supports the hypothesis that the presence of a baby reduces the likelihood of aggression. We did not, however, see the active use of babies in this context which has been described for the Atlas population.     

Are behavioral differences among wild chimpanzee communities genetic or cultural? An assessment using tool‐use data and phylogenetic methods

Over the last 30 years it has become increasingly apparent that there are many behavioral differences among wild communities of Pan troglodytes. Some researchers argue these differences are a consequence of the behaviors being socially learned, and thus may be considered cultural. Others contend that the available evidence is too weak to discount the alternative possibility that the behaviors are genetically determined. Previous phylogenetic analyses of chimpanzee behavior have not supported the predictions of the genetic hypothesis. However, the results of these studies are potentially problematic because the behavioral sample employed did not include communities from central Africa. Here, we present the results of a study designed to address this shortcoming. We carried out cladistic analyses of presence/absence data pertaining to 19 tool‐use behaviors in 10 different P. troglodytes communities plus an outgroup (P. paniscus). Genetic data indicate that chimpanzee communities in West Africa are well differentiated from those in eastern and central Africa, while the latter are not reciprocally monophyletic. Thus, we predicted that if the genetic hypothesis is correct, the tool‐use data should mirror the genetic data in terms of structure. The three measures of phylogenetic structure we employed (the Retention Index, the bootstrap, and the Permutation Tail Probability Test) did not support the genetic hypothesis. They were all lower when all 10 communities were included than when the three western African communities are excluded. Hence, our study refutes the genetic hypothesis and provides further evidence that patterns of behavior in chimpanzees are the product of social learning and therefore meet the main condition for culture. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.     

Impacts of abiotic factors on the fungal communities of ‘Honeycrisp’ apples in Canada

The maintenance of the beneficial plant microbiome to control plant pathogens is an emerging concept of disease management, and necessitates a clear understanding of these microbial communities and the environmental factors that affect their diversity and compositional structure. As such, studies investigating the microbiome of economically significant cultivars within each growing region are necessary to develop adequate disease management strategies. Here, we assessed the relative impacts of growing season, management strategy, and geographical location on the fungal microbiome of ‘Honeycrisp’ apples from seven different orchard locations in the Atlantic Maritime Ecozone for two consecutive growing years. Though apple fruit tissue was dominated by relatively few fungal genera, significant changes in their fungal communities were observed as a result of environmental factors, including shifts in genera with plant-associated lifestyles (symbionts and pathogens), such as Aureobasidium, Alternaria, Penicillium, Diplodia, and Mycosphaerella. Variation in fungal composition between different tissues of fruit was also observed. We demonstrate that growing season is the most significant factor affecting fungal community structure and diversity of apple fruit, suggesting that future microbiome studies should take place for multiple growing seasons to better represent the host–microbiome of perennial crops under different environmental conditions.     

‘Harem’ and ‘non-harem’ type mating systems in two species of subsocial spider mites (Acari,Tetranychidae)

The mating system of a subsocial spider mite, Schizotetranychus miscanthi Saitō, which is closely related to Schizotetranychus longus Saitō (the long seta form of Schizotetranychus celarius (Banks) is a synonym of the latter) was studied in comparison with that of S. longus. Comparisons between nesting patterns of the two related species, S. miscanthi and S. longus revealed a difference in distribution of males among nests. Although more than one male sometimes occurred in the large nests of S. miscanthi, most nests were occupied only by a single male. On the other hand, many nests of S. longus included several males. Behavioral experiments revealed that the male and females of S. miscanthi which cohabited in a nest defended their offspring from phytoseiid predators. Observations and a census of the nesting pattern in a wild population indicate that this is the second example of biparental defense and of a subsocial life-pattern in spider mites. Differences in mating systems were experimentally demonstrated in the two species. Only a single male of S. miscanthi survived in a nest, as a result of highly aggressive male-male combat, while two males of S. longus cohabited in a nest. The mating system of the former species is thus considered as harem polygyny, while that of the latter as scramble type polygyny. Furthermore, observations by video recording and scanning electron microscopy showed that the winning male in the male-male combat in S. miscanthi often preyed on the loser, suggesting cannibalism among them.     

Habitat quality influences relative antler size and hunters’ selectivity in roe deer

Understanding factors affecting antler size, and the extent to which harvesting is selective for these traits, is important in order to address management strategies aimed to minimize the risk of negative evolutionary consequences. In an Alpine study area, we compared the phenotypic quality and the antler size of 2,725 male roe deer hunted in two regions differing for winter harshness and habitat quality, and evaluated whether the selective behaviour of recreational hunters was influenced by phenotypic quality and antler size. Antler length and antler circumference relative to both body mass and jaw length were larger in the region with more favourable climate and habitat conditions, indicating that here roe deer were able to allocate more resources to antler growth. The analysis of the temporal trends of harvest bags suggested that hunters did not select roe deer for their body mass or size, but instead for antler size. This resulted also in a preference for sub-adult and adult age classes, while yearlings were culled reluctantly, especially in the region where antlers were smaller. Our results indicate that environmental heterogeneity may influence the relative investment in antler growth. In this way, it may interact with the hunters’ preferences increasing the risk that recreational hunting of roe deer, which is a widespread practice in many European countries, might result in alteration of male age structure and possibly in directional artificial selection.     

‘Classical’ and ‘non-classical’ reproductive steroids in fish

Summary The nature of the steroids secreted by gonads of fish differs significantly from those of the mammals. The classical teleost steroids, oestradiol, testosterone, 11-ketotestosterone and 17,20P, have been measured in a wide variety of teleosts but do not always reflect biological activities. There is increasing evidence that teleost gonads may produce a number of non-classical steroids which may play an important role in their reproductive biology. Such products include metabolites reduced at C5 to 5 or 5, at C3 to 3 or 3, or hydroxylated at 6-, 7-, or 21. Conjugation, as either glucuronides or sulphates, may contribute either to localization of action within the gonad or to production of pheromones during the immediate pre-spawning period. Although it is often possible only to measure the steroids for which assays are readily available, it is important to recognize that there may be production of steroids that are not detected by such assays, but which nevertheless play a major role in reproductive activity. In evolutionary terms, the teleost hydroxylases probably originated in the very early fishes and show parallels with their analogues in amphibians and mammals. Gene sequencing may reveal a possible common ancestor for all vertebrate 6, 7 and 11-hydroxylases.     

Return to sender? A comparative analysis of immigrant communities in ‘attrition through enforcement’ destinations

Drawing on surveys from two Mexican immigrant sending communities, this paper comparatively examines the link between subnational policy structures in US destinations and immigrants' settlement and residency behaviour. It focuses in particular on attrition through enforcement policy at the local and state level that is formed to trigger the voluntary exit of undesirable immigrants. With a twofold comparison of immigrants in three cities and two states, the analysis indicates that immigrants do not alter the duration of time they spend in receiving locales or change their state of residence due to restrictive subnational policies. Rather, economic and social factors more prominently shape immigrants' settlement and residency patterns. The implications of this analysis are discussed with particular attention to the incorporation process for immigrants who remain in destinations with attrition through enforcement policy.     

Plant and animal communities in brackish supra-littoral pools (‘dobben’) in the northern part of the Netherlands

Fifty brackish supra-littoral pools bordering the Waddenzee were studied. The structure of plant communities (Potamogeton pectinatus L., Ranunculus baudotii Godr. and Zannichellia pedunculata Rchb.) is discussed in relation to water level fluctuations, chlorinity and water transparency. Chlorinity tolerances of the macrophytes (7 species) are discussed. The macrofauna was studied semi-quantitatively. The aquatic Coleoptera had the greatest diversity (24 species). A distinct relationship between the number of Coleoptera species and the percentage of macrophyte coverage was found. The distribution patterns of the most frequent species with respect to chlorinity categories are shown in histograms. The number of aquatic Heteroptera species is also discussed in relation to chlorinity and vegetation coverage. Less important macrofaunal groups (the Crustacea, Mollusca and Odonata) occurred in low species numbers.     

Changes in lipid composition, water relations and gas exchange in leaves of two young ‘Chemlali’ and ‘Chetoui’ olive trees in response to water stress

The comparative responses of two young olive trees (Olea europaea L. ‘Chemlali’ and ‘Chetoui’) to drought stress were investigated during 1 month. Three-month-old own-rooted plants were subjected to two irrigation treatments: WW (well watered plants that were irrigated with fresh water to maintain a soil water content close to field capacity), and WS (water stressed plants by withholding water). Leaf water potential, gas exchange and leaf lipid composition were studied. ‘Chemlali’ was able to maintain higher leaf CO₂ assimilation rate and leaf stomatal conductance throughout the drought cycle compared to ‘Chetoui’. Water stress induced a larger decrease in the total lipid content in ‘Chetoui’ than in ‘Chemlali’. Interestingly, the constitution of different lipid classes was highly altered in ‘Chetoui’. Lipid changes in Chemlali, a drought tolerant cultivar, revealed more stability of its cellular membranes to drought stress as compared to the drought susceptible olive cultivar, Chétoui. Furthermore, in comparison to the controls, drought stressed plants showed an increase in the degree of unsaturation of leaf lipids in the two olive cultivars. Moreover, the results observed in Chemlali showed that besides changes in lipids composition this cultivar may have an efficient defence strategy which can be related on antioxidative production against oxidative stress.     

Genetic and biochemical studies on perchloroethylene ‘in vitro’ and ‘in vivo’

Perchloroethylene (PCE) was tested in a diploid strain (D7) of the yeast Saccharomyces cerevisiae in suspension tests with and without a mammalian microsomal activation system (S9) and ‘in vivo’ by the intrasanguineous host-mediated assay. In addition, enzyme alteration studies were performed in mice non-pretreated or pretreated with phenobarbital + β-naphthoflavone. PCE did not induce any genetic effect either ‘in vitro’ or ‘in vivo’. In the suspension test, PCE was more toxic without metabolic activation and less toxic with mammalian microsomal activation. The enzymatic determinations showed an increase of the aminopyrine demethylase activity and of the level of cytochrome P-450.