Relationships between personality traits and the physiological stress response in a wild mammal

Glucocorticoids(GCs)are involved in the regulation of an animal's energetic state.Under stressful situations,they are part of the neuroendocrine response to cope with environmental challenges.Animals react to aversive stimuli also through behavioral responses,defined as coping styles.Both in captive and wild populations,individuals differ in their behavior along a proactive-reactive continuum.Proactive animals exhibit a bold,active explorative and social personality,whereas reactive ones areshy,less active-explorative and less social.Here,we test the hypothesis that personality traits and physiological responses to stressors covary,with more proactive individuals having a less pronounced GC stress response.In wild populations of invasive gray squirrels Sciurus carolinensis,we measuredfecal glucocorticoid metabolites(FGMs),an integrated measure of circulating GCs,and 3 personality traits(activity,sociability,and exploration)derived from open field test(OFT)and mirror image stimulation(MIS)test.Gray squirrels had higher FGMs in Autumn than in Winter and males with scrotal testes had higher FGMs than nonbreeding males.Personality varied with body mass and population density.Squirrels expressed more activity exploration at higher than at lower density and heavier squirrels had higher scores for activity exploration than animals that weighed less.Variation in FGM concentrations was not correlated with the expression of the 3 personality traits.Hence,our results do not support a strong association between the behavioral and physiological stress responses but show that in wild populations,where animals experience varying environmental conditions,the GC endocrine response and the expression of personality are uncorrelated traits among individuals.     

An experimental study on the self-reference effect

Self-reference at encoding increases the probability of recollective experience in recognition memory. Self-reference effect (SRE) in memory is observed when the degree of self-reference of to-be-remembered materials is varied. Usually items encoded in terms of self-reference are associated with significantly higher recall performance relative to items encoded in other ways, including semantic encoding. In our three experiments, four orientating tasks formed four levels in a between-subjects design. The conditions were rating personality traits with reference to self, mother, Lu Xun (a famous Chinese writer) or rating the traits on a negative-positive dimension. In a recognition test, subjects first identified old items and then indicated which of these were accompanied by recollective experience ('remember' responses) and which were recognized on some other basis ('know' responses). Our results showed that both the self-reference condition and mother condition were associated with the same highest propo     

Individual variation in dispersal associated behavioral traits of the invasive Chinese mitten crab （Eriocheir sinensis,H. Milne Edwards, 1854） during initial invasion of Lake V~inern,Sweden

Understanding and predicting species range-expansions and biological invasions is an important challenge in modem ecology because of rapidly changing environments. Recent studies have revealed that consistent within-species variation in behavior （i.e. animal personality） can be imperative for dispersal success, a key stage in the invasion process. Here we investigate the composition and correlation of two important personality traits associated with invasion success, activity and boldness, and how they are connected to sex and individual size in a newly colonised population of the Chinese mitten crab Eriocheir sinensis in Lake Vanem, Sweden. We found no effect of sex or size on behavioral expressions orE. sinensis but a clear positive correlation between boldness and activity. In addition, this study generates important baseline data for monitoring behavioral develop ment, and thereby changing ecological impact, of an invading population over time. This has implications for predicting ecological effects of invasive species as well as for managing ecological invasions.     

Plant-herbivorous insect networks: who is eating what revealed by long barcodes using high-throughput sequencing and Trinity assembly

Interactions between plants and insects are among the most important life functions for all organism at a particular natural community.Usually a large number of samples are required to identify insect diets in food web studies.Previously,Sanger sequencing and next generation sequencing(NGS)with short DNA barcodes were used,resulting in low species-level identification;meanwhile the costs of Sanger sequencing are expensive for metabarcoding together with more samples.Here,we present a fast and effective sequencing strategy to identify larvae of Lepidoptera and their diets at the same time without increasing the cost on Illumina platform in a single HiSeq run,with long-multiplexmetabarcoding(COI for insects,rbcL,matK,ITS and trnL for plants)obtained by Trinity assembly(SHMMT).Meanwhile,Sanger sequencing(for single individuals)and NGS(for polyphagous)were used to verify the reliability of the SHMMT approach.Furthermore,we show that SHMMT approach is fast and reliable,with most high-quality sequences of five DNA barcodes of 63 larvae individuals(54 species)recovered(full length of 100%of the COI gene and 98.3%of plant DNA barcodes)using Trinity assembly(up-sized to 1015 bp).For larvae diets identification,95%are reliable;the other 5%failed because their guts were empty.The diets identified by SHMMT approach are 100%consistent with the host plants that the larvae were feeding on during our collection.Our study demonstrates that SHMMT approach is reliable and cost-effective for insect-plants network studies.This will facilitate insect-host plant studies that generally contain a huge number of samples.     

Behaviors that predict personality components in adult free-ranging Tibetan macaques Macaca thibetana

To further the potential for applied personality studies, we present a methodology for assessing personality in nonhu man animals without a priori assumptions, using behavioral measures to discriminate personality survey results. Our study group consisted of 12 freeranging, provisioned, adult Tibetan macaques Macaca thibetana at the Valley of the Wild Monkeys, China. We asked familiar Chinese park guards and scientists to rate each of the 12 macaques using 27item personality surveys. We also recorded behavioral observations （〉 100 hrs） from AugustSeptember, 2012. The personality surveys showed reliability in 22 of the items that were then utilized in a principal component analysis that revealed five components： Insecurity, Reactivity, Boldness, Sociability, and Leadership. Prior personality research on Macaca show comparable components. In order to determine which behaviors would best predict those five personality components, we conducted discriminant analyses using behavioral measures as predictors. We found that behavioral measures of avoidance, lunging, feargrinning, selfdirected behaviors, touching, proximity and chasing could significantly predict personality component scores in certain situations. Finally, we analyzed the effects of situation （provisioning and tourists） and found situation influenced proximity and rates of avoidance and selfdirected behaviors. Wider implementation of this methodology may permit longterm analysis of personality using behavioral proxies for established personality traits, in particular on research investigating the effects of tourism and provisioning on personality .     

Animal personalities and their implications for complex signaling

Animal personalities have been a major focus of behavioral ecology over the past decade. Consistent individual dif ferences in behavior have been found across taxa, and have been shown to influence a range of ecological processes. The role of personalities in sexual selection has been considered, and examples exist that show selection for personality traits with both assortative and disassortative mating patterns between personality types. One overlooked aspect of the personality and sexual se lection literature is the potential for personalitysignaling interactions, specifically with complex signaling. Complex signaling is a diverse topic in itself, and in short, consists of multiple signals within one or more modalities that interact to elicit a receiver response. Research into complex signaling has been thorough, although at times studies discover complex signaling systems that fail to fit into one of the existing hypotheses in the literature. Here, we argue that personalities may interact with complex signal ing, which should be considered by researchers of both personality and sexual selection and communication. We describe several ways in which personalitycomplex signaling interactions could affect both the signaler and receiver, and the way in which they may drive personalityspecific signals as well as receiver preferences. Finally, we discuss how considering personality in com plex signaling studies may inform theory as well as improve the ability of researchers to accurately describe its function.     

Age and ovarian development are related to worker personality and task allocation in the ant Leptothorax acervorum

In social insects, workers of different morphological castes and age are known to act differently. Yet, it is unclear how body size and ovarian development influence worker personalities （i.e. consistent behavioral variation） and task allocation in similar aged ant workers of monomorphic species. Behavioral variation is thought to be a key element of division of labor, but few studies have linked worker personality to task allocation. We investigated individual behavior in Leptothorax acervorum ant workers at two time points during the first three months of their life and in two different settings. We observed worker behavior in the nest （i.e. task allocation） and in standardized aggression, exploration and brood care experiments （i.e. personality） and found behavioral repeatability in foraging and exploration. Further, workers acted consistently across settings： workers with a more ag gressive and exploratory personality type were more active in the nest. Moreover, ovarian development was associated with worker personality and task allocation： older workers with welldeveloped ovaries foraged less, but were more aggressive and exploratory. In accordance with the typical agepolyethism of social insects, workers became more active and foraged more as they grew older. Consequently, our study suggests that task allocation in Leptothorax acervorum is not only influenced by ovari an development and age, but moreover by the personalities of its workers .     

Personality traits covary with individual differences in inhibitory abilities in 2 species of fish

In a number of animal species,individuals differ in their ability to solve cognitive tasks.However,the mechanisms underlying this variability remain unclear.It has been proposed that individual differences in cognition may be related to individual differences in behavior(i.e.,personality);a hypothesis that has received mixed support.In this study,we investigated whether personality correlates with the cognitive ability that allows inhibiting behavior in 2 teleost fish species,the zebrafish Danio rerio and the guppy Poecilia reticulata.In both species,individuals that were bolder in a standard personality assay,the open-field test,showed greater inhibitory abilities in the tube task,which required them to inhibit foraging behavior toward live prey sealed into a transparent tube.This finding reveals a relationship between boldness and inhibitory abilities in fish and lends support to the hypothesis of a link between personality and cognition.Moreover,this study suggests that species separated by a relatively large phylogenetic distance may show the same link between personality and cognition,when tested on the same tasks.     

Asymmetry in genitalia is in sync with lateralized mating behavior but not with the lateralization of other behaviors

Asymmetries in bilateral organisms attract a lot of curiosity given that they are conspicuous departures from the norm.They allow the investigation of the integration at different levels of biological organization.Here we study whether and how behavioral and asymmetrical anatomical traits coevolved and work together.We ask if asymmetry is determined locally for each trait or at a whole individual level in a species bearing conspicuous asymmetrical genitalia.Asymmetric genitalia evolved in many species;however,in most cases the direction of asymmetry is fixed.Therefore,it has been rarely determined if there is an association between the direction of asymmetry in genitalia and other traits.In onesided livebearer fish of the genus Jenynsia(Cyprinodontiformes,Anablepidae),the anal fin of males is modified into a gonopodium,an intromittent organ that serves to inseminate females.The gonopodium shows a conspicuous asymmetry,with its tip bending either to the left or the right.By surveying 13 natural populations of Jenynsia lineata,we found that both genital morphs are equally common in wild populations.In a series of experiments in a laboratory population,we discovered asymmetry and lateralization for multiple other traits;yet,the degree of integration varied highly among them.Lateralization in exploratory behavior in response to different stimuli was not associated with genital morphology.Interestingly,the direction of genital asymmetry was positively correlated with sidedness of mating preference and the number of neuromasts in the lateral line.This suggests integration of functionally linked asymmetric traits;however,there is no evidence that asymmetry is determined at the whole individual level in our study species.     

Epistatic effect between ACACA and FABP2 gene on abdominal fat traits in broilers

Epistasis is generally defined as the interaction between two or more genes or their mRNA or protein products to influence a single trait. Experimental evidence suggested that epistasis could be important in the determination of the genetic architecture of complex traits in domestic animals. Acetyl-coenzyme A carboxylase alpha (ACACA) and fatty acid binding protein 2 (FABP2) are both key factors of lipogenesis and transport. They may play a crucial role in the weight variability of abdominal adipose tissue in the growing chicken. In this study, the polymorphisms of c.2292GA in ACACA and c.-561AC in FABP2 were detected among individuals from two broiler lines which were divergently selected for abdominal fat content. Epistasis between the two SNPs on abdominal fat weight (AFW) and abdominal fat percentage (AFP) was analyzed. The additive × additive epistatic components between these two SNPs were found significant or suggestively significant on both AFW and AFP in lean lines of the 9th and 10th generation; whereas, it was not significantly associated with either AFW or AFP in fat lines. At the same time, there were not any other significant epistatic components found in both generations or in both lines. Significant epistatic effects between these two SNPs found only in the lean lines could partly be due to the fact that the abdominal fat traits in these two experimental lines have been greatly modified by strong artificial selection. The results suggested that the epistasis mode may be different between the lean and fat chicken lines. Our results could be helpful in further understanding the genetic interaction between candidate genes contributing to phenotypic variation of abdominal fat content in broilers.     

Individual differences in boldness positively correlate with heart rate in orb-weaving spiders of genus Larinioides

Recent years have seen a dramatic increase in the number of studies devoted to consistent individual differences in behavior, termed ＂behavioral syndromes＂ or animal ＂personality＂. In particular, ecologists and evolutionary biologists alike seek to explore the functional consequences of individuals＇ personalities and explanations for their general maintenance. Understand ing the mechanistic underpinnings to personality is arguably key to a deeper understanding of their functional consequences and maintenance. In particular, consistent individual differences in metabolic rate have been proposed as a general explanation for the maintenance of consistent individual differences in boldness, aggressiveness, and activity level. In this paper we explore whether consistent individual differences in boldness are associated with heat rate, a proxy for metabolic rate, in two species of orbweaving spider： Larinioides cornutus and L. patagiatus. We first documented consistent individual differences in boldness in L. cornutus but not L. patagiatus, as estimated by individuals＇ latency to resume movement following an aversive stimulus. We also measured individuals＇ heart rate twice in a separate situation. We then tested for an association between individuals＇ boldness and their heart rate during these two events. We found that increased boldness was associated with increased heart. Thus, indi viduals that resumed movement quickly following an aversive stimulus also exhibited faster heart rates. Our studies provide fur ther evidence that consistent individual differences in key physiological attributes, like metabolic rate, might be a general mecha nism underlying consistent individual differences in behavior .     

Assessing the Suitability of Various Physiological Traits to Screen Wheat Genotypes for Salt Tolerance

Success of improving the salt tolerance of genotypes requires effective and reliable screening traits in breeding programs.The objective was to assess the suitability of various physiological traits to screen wheat genotypes for salt tolerance.Thirteen wheat genotypes from Egypt,Germany,Australia and India were grown in soil with two salinity levels(control and150mmol/L NaCl)in a greenhouse.The physiological traits(ion contents in leaves and stems,i.e.Na~ ,Cl~-,K~ ,Ca~(2 )),theratios of K~ /Na~ and Ca~ /Na~ in the leaves and stems,net photosynthesis rate,stomatal conductance,transpiration rate,chlorophyll content(SPAD value),and leaf water relations,were measured at different growth stages.The physiologicaltraits except for Na~ and Cl~-in stems and the leaf transpiration rate at 150 mmol/L NaCI showed a significant genotypicvariation,indicating that the traits that have a significant genotypic variation may be possibly used as screening criteria.According to the analysis of linear regression of the scores of the physiological traits against those of grain yield,however,the physiological traits of Ca~(2 )and Ca~(2 )/Na~ at 45 d and final harvest with the greatest genotypic variation were ranked atthe top.From a practical and economic point of view,SPAD value should be considered to be used as screening criteriaand/or there is a need to develop a quick and practical approach to determine Ca~(2 )in plant tissues.     

Genetic dissection of root morphological traits as related to potassium use efficiency in rapeseed under two contrasting potassium levels by hydroponics

To reveal the genetic basis of potassium use efficiency(KUE) in rapeseed, root morphology(RM), biomass and KUE-related traits were measured in a recombinant inbred line population with 175 F7 lines that were subjected to high-potassium(HK) and low-potassium(LK) treatments by hydroponics. A total of 109 significant QTLs were identified to be associated with the examined traits. Sixty-one of these QTLs were integrated into nine stable QTLs. The higher heritability for RM and biomass traits and lower heritability for KUE-related traits, as well as nine stable QTLs for RM traits and only two for KUE-related traits,suggested that regulating RM traits would be more effective than selecting KUE traits directly to improve KUE by markerassisted selection. Furthermore, the integration of stable QTLs identified in the HK, LK, high-nitrogen(HN) and low-nitrogen(LN) conditions gave 10 QTL clusters. Seven of these clusters were classified into major QTLs that explained 7.4%–23.7% of the total phenotypic variation. Five of the major QTL clusters were detected under all of the treated conditions, and four clusters were specifically detected under the LK and LN conditions. These common and specific QTL clusters may be useful for the simultaneous improvement of multiple traits by marker-assisted selection.     

Nonlinear maternal effects on personality in a rodent species with fluctuating densities

Consistent among individual variation in behavior,or animal personality,is present in a wide variety of species.This behavioral variation is maintained by both genetic and environmental factors.Parental effects are a special case of environmental variation and are expected to evolve in populations experiencing large fluctuations in their environment.They represent a non-genetic pathway by which parents can transmit information to their offspring,by modulating their personality.While it is expected that parental effects contribute to the observed personality variation,this has rarely been studied in wild populations.We used the multimammate mouse Mastomys natalensis as a model system to investigate the potential effects of maternal personality on offspring behavior.We did this by repeatedly recording the behavior of individually housed juveniles which were born and raised in the lab from wild caught females.A linear correlation,between mother and offspring in behavior,would be expected when the personality is only affected by additive genetic variation,while a more complex relationship would suggests the presence of maternal effects.We found that the personality of the mother predicted the behavior of their offspring in a non-linear pattern.Exploration behavior of mother and offspring was positively correlated,but only for slow and average exploring mothers,while this correlation became negative for fast exploring mothers.This may suggests that early maternal effects could affect personality in juvenile M.natalensis,potentially due to density-dependent and negative frequency-dependent mechanisms,and therefore contribute to the maintenance of personality variation.     

Translocation of Otostegia bucharica,a highly threatened narrowly distributed relict shrub

Translocation is a recognized means of rescuing imperiled species but the evidence for the long-term success of translocations is limited. We report the successful translocation of reproductive individuals of a critically endangered shrub Otostegia bucharica from a site facing imminent habitat destruction into a nearby natural population of the species. The relocated plants were visited the year after planting and 13 years later to assess short-and long-term plant survival. Significant percentage of plants that survived transplanting shock and very dry spring following transplanting(around 36%), and further decrease of this number in the next 12 years by only 14%, indicated that O. bucharica is amenable to translocation using reproductive plants. Based on results of species distribution modeling, and failed attempts of ex situ cultivation, we propose introduction of this species into areas with suitable climatic and soil conditions.However, because there is currently no nature reserve in Uzbekistan having suitable conditions for the species under the present climate and that expected in the near future, and because all known habitats of O. bucharica are exposed to the very strong anthropogenic pressure, establishment of a new protected area, awareness building and involvement of local community in conservation activities are required to prevent extinction of this extremely rare species.     

Female indris determine the rhythmic structure of the song and sustain a higher cost when the chorus size increases

Among the behavioral traits shared by some nonhuman primate species and humans there is singing. Unfortunately, our understanding of animals' rhythmic abilities is still in its infancy. Indris are the only lemurs who sing and live in monogamous pairs, usually forming a group with their offspri ng. All adult members of a group usually participate in choruses that are emitted regularly and play a role in advertising territorial occupa ncy and in tergroup spaci ng. Males and females emit phrases that have similar frequency ranges but may differ in their temporal structure. We examined whether the individuals' contribution to the song may change according to chorus size, the total duration of the song or the duration of the individual con tribution using the in ter-on set intervals within a phrase and between phrases. We found that the rhythmic structure of indri's songs depends on factors that are different for males and females. We showed that females have sigrdficantly higher variation in the rhythm of their contribution to the song and that, changes according to chorus size. Our findings indicate that female indris sustain a higher cost of singing than males whe n the nu mber of singers in creases. These results suggest that cross-species investigatio ns will be crucial to un derstanding the evoluti on ary frame in which such sexually dimorphic traits occurred.     

Insights from the study of complex systems for the ecology and evolution of animal populations

Populations of animals comprise many individuals,interacting in multiple contexts,and displaying heterogeneous behaviors.The interactions among individuals can often create population dynamics that are fundamentally deterministic yet display unpredictable dynamics.Animal populations can,therefore,be thought of as complex systems.Complex systems display properties such as nonlinearity and uncertainty and show emergent properties that cannot be explained by a simple sum of the interacting components.Any system where entities compete,cooperate,or interfere with one another may possess such qualities,making animal populations similar on many levels to complex systems.Some fields are already embracing elements of complexity to help understand the dynamics of animal populations,but a wider application of complexity science in ecology and evolution has not occurred.We review here how approaches from complexity science could be applied to the study of the interactions and behavior of individuals within animal populations and highlight how this way of thinking can enhance our understanding of population dynamics in animals.We focus on 8 key characteristics of complex systems:hierarchy,heterogeneity,selforganization,openness,adaptation,memory,nonlinearity,and uncertainty.For each topic we discuss how concepts from complexity theory are applicable in animal populations and emphasize the unique insights they provide.We finish by outlining outstanding questions or predictions to be evaluated using behavioral and ecological data.Our goal throughout this article is to familiarize animal ecologists with the basics of each of these concepts and highlight the new perspectives that they could bring to variety of subfields.     

Index selection on seed traits under direct, cytoplasmic and maternal effects in multiple environments

Crop seeds are important sources of protein, oil, and carbohydrates for food, animal feeds, and industrial products. Recently, much attention has been paid to quality and functional properties of crop seeds. However, seed traits possess some distinct genetic characteristics in comparison with plant traits, which increase the difficulty of genetically improving these traits. In this study, diallel analysis for seed models with genotype by environment interaction （GE） effect was applied to estimate the variance-covariance components of seed traits. Mixed linear model approaches were used to estimate the genetic covariances between pair-wise seed and plant traits. The breeding values （BV） were divided into two categories for the seed models. The first category of BV was defined as the combination of direct additive, cytoplasmic, and maternal additive effects, which should be utilized for selecting stable cultivars over multi-environments. The three genetic effects, together with their GE interaction, were included in the second category of BV for selecting special lines to be grown in specific ecosystems. Accordingly, two types of selection indices for seed traits, i.e., general selection index and interaction selection index, were developed and constructed on the first and the second category BV, respectively. These proposed selection indices can be applied to solve the difficult task of simultaneously improving multiple seed traits in various environments. Data of crop seeds with regard to four seed traits and four yield traits based on the modified diallel crosses in Upland cotton （Gossypium hirsutum L.） were used as an example for demonstrating the proposed methodology.     

Human-induced environmental changes influence habitat use by an ungulate over the long term

Habitat use and preferences may be subject to spatial and temporal changes. However, long-term studies of species-habitat relationships are the exception. In the prese nt research, I on g-term trends in habitat use by an alpine ungulate, the Tatra chamois Rupicapra rupicapra tatrica, were analyzed. We exami ned how envir on mental changes attributable to climate cha nge, removal of sheep, and habituation to hikers, which took place over the last half-century have changed the spatial distribution of animals. Data on the localities of groups sighted between 1957 and 2013 during autumnal population surveys were used to evaluate habitat associations: these were correlated with year, group size, population size, and climatic conditions. The results indicate that the Tatra chamois is tending, over the long term, to lower its altitude of occurrenee, reduce its average distance to hiking trails, and stay less often on slopes with a southerly aspect. These trends are in dependent of group size, population size, and the weather conditions prevailing during observations, though not for altitude, where increases in air temperature are related to finding chamois at higher elevations. The proportion of alpine meadows and slope in the places used by chamois is correlated with population size, while the proportion of areas with trees and/or shrubs is correlated with group size and air temperature, though long-term changes were not evident for these variables. To the best of our knowledge, this work is the first to document Iong-term trends in habitat use by ungulates. It shows that a species' ecology is influe need by huma n-in duced cha nges: abandonment of pasturage, high-mountain tourism, and climate changes, which constitute the most probable reasons for this aspect of behavioral evolution in the Tatra chamois.     

Behavioral differences within and among populations of an African cichlid found in divergent and extreme environments

Animals are increasingly faced with human?induced stressors that vary in space and time, thus we can expect populati on-level diverge nee in behaviors that help animals to cope with en vironme ntal change. However, empirical evidenee of behavioral trait divergence across environmental extremes is lacking. We tested for variation in behavioral traits among 2 populations of an African cichlid fish (Pseudocrenilabrus multicolor victoriae Seegers, 1990) that experience extremes of dissolved oxygen (DO) and turbidity and are known to vary in a number of physiological and life history traits associated with these stressors. Using a comm on garden reari ng experime nt, F1 progeny from wild-caught parents originating from a swamp (low DO, clear) and a river (high DO, turbid) were reared in high DO, clear water. Predator simulation assays were conducted to test for (1) variation in boldness, general activity, and foraging activity between populations,(2) differences in correlations betwee n behaviors with in and across populati ons, and (3) repeatability of behaviors. There was strong evide nee for diverge nee betwee n populati ons, with swamp fish being more bold (i.e.z leaving refuge sooner after a simulated predator attack) and active (i.e., spent more time out of refuge) than river fish. Across populations there were positive correlations between foraging activity and both boldness and general activity;however, within populations, there was only a strong positive relationship between foraging activity and boldness in the river population. Here, we have demonstrated that populations that originate from drastically different environments can produce proge ny that exhibit measurable differences in behaviors and their correlated relati on ships eve n whe n reared un der comm on conditions.