Stable Social Hierarchies Research Articles

Effects of Personality and Behavioral Syndromes on Competition for Social Hierarchical Status in Anemonefish Amphiprion clarkii.

In this study, the behavioral ethogram of Amphiprion clarkii during the growth phase prior to sexual differentiation was summarized based on behavioral observations in three social environments. These behaviors can be classified into four categories: in addition to normal behaviors, the other three categories of behaviors-threatening, agonistic, and appeasing behaviors-represent different intentions in interactions with other individuals. Subsequently, the personalities of each individual were assessed by testing their reactions to intruders. These individuals mainly exhibited two distinct personality types: bold-aggressive and shy-submissive. In pairing experiments, the interactive behaviors of the anemonefish were observed in pairing combinations of different body sizes and personalities. The impact of personality on the establishment of a stable social hierarchy was confirmed by significant differences in the success rates of different pairing combinations, with the frequency of appeasing behaviors being the main factor influencing the success rate. Our results suggested that in natural waters, when juvenile individuals migrate among host anemones, shy-submissive individuals are more likely to be accepted due to their appeasing behaviors towards larger individuals, thus avoiding the risk of being attacked and bitten, and benefiting the survival of the individual. Conversely, bold-aggressive individuals are more likely to be driven away to another host anemone due to their unwillingness to settle for a lower-ranked status, thereby contributing to population dispersal and increasing opportunities for gene exchange between populations.

Inferior social hierarchy is vulnerable to anxiety-like behavior in chronic pain mice: Potential role of gut microbiota and metabolites

Social dominance is a universal phenomenon among grouped animals that profoundly affects survival, health, and reproductive success by determining access to resources, and exerting a powerful influence on subsequent behavior. However, the understanding of pain and anxiety comorbidities in dominant or subordinate animals suffering from chronic pain is not well-defined. Here, we provide evidence that subordinate mice are more susceptible to pain-induced anxiety compared to dominant mice. We propose that the gut microbiota may play a mediating role in this mechanism. Our findings demonstrate that transplantation of fecal microbiota from subordinate mice with chronic inflammatory pain, but not dominant mice, into antibiotics-treated pseudo-germ-free mice significantly amplifies anxiety-like phenotypes, highlighting the critical involvement of gut microbiota in this behavioral response. Using chronic inflammatory pain model, we carried out 16S rRNA sequencing and untargeted metabolomic analyses to explore the relationship between microbiota and metabolites in a stable social hierarchy of mice. Interestingly, anxiety-like behaviors were directly associated with some microbial genera and metabolites, especially bile acid metabolism. Overall, we have demonstrated a close relationship between social status and anxiety susceptibility, highlighting the contributions of gut microbiota and the associated metabolites in the high-anxiety state of subordinate mice with chronic inflammatory pain.

Social behaviour and personality profiles of breeding does housed part-time in group.

Housing breeding female rabbits in multi-litter instead of single-litter cages allows for more natural behaviour and social contact with conspecifics. Hierarchy fights among does, however, inhibit uptake on farms. Past focus on high reproductive performances in single-litter cages may have yielded rabbit breeds that are less suited to living in groups. For (part-time) multi-litter systems, it may prove beneficial to identify does with personality traits that are desirable for group-living and that promote the rapid formation and maintenance of a stable social hierarchy without grave injuries and prolonged stress. In this trial, we aimed to profile the personality of does by investigating the consistency of their social behavioural strategy when mixed in different groups. We further tested if strategy and personality of does were linked with skin injuries in the groups and if skin injuries could serve as a proxy to identify doe strategies and profiles. During three consecutive reproduction cycles, three or four does and their 22-day-old kits were housed in multi-litter cages for a period of 13 days (N = 51 does in total). Doe agonistic behaviour was recorded during the first 24 h (cycle 1 and 2) and the first 8 h (cycle 3) after grouping. Cluster analysis revealed two social behavioural strategies does adopted when a new group was formed: ‘offensive’ (36.8%) versus ‘submissive/avoider’ (63.2%). From all does that participated in the study for all three reproduction cycles (N = 32), 46.9% changed strategy at least once between cycles and were identified as an ‘all-rounder’ personality profile. Two other profiles were identified for does that did not change between cycles: ‘consistently submissive’ (40.6%) and ‘consistently offensive’ (12.5%). The presence of both ‘stable’ and ‘unstable’ does suggests that some does adjust their behaviour in response to their social environment. No significant correlations were found between injuries at both individual and group level and doe strategy or profile. Likewise, results could not confirm if skin injuries were a good proxy to identify doe strategy or profile. Future investigations could explore alternatives to identify ‘sociable’ does without relying on intensive behavioural studies (e.g. ano-genital distance of female kits at birth). Additionally, it needs to be ascertained whether removing offensive behaving does would indeed lead to reduced aggression and stress in group housing systems. ImplicationsBreeding female rabbits may benefit from group housing but aggressive behaviour compromises animal welfare and commercial uptake. To gain knowledge on the social dynamics between does, we investigated whether problematic agonistic behaviour could be a stable personality trait. This could facilitate selection towards ‘sociable’ on-farm doe groups. Results showed that social behaviour strategies (offensive or submissive/avoider) were stable across three successive production rounds in half of the does. Other does showed more flexibility, possibly depending on group composition. Links between doe behaviour and skin injuries (including those of group mates), however, are missing which makes identification and practical uptake challenging.

The interaction between social hierarchy and depression/anxiety: Involvement of glutamatergic pyramidal neurons in the medial prefrontal cortex (mPFC)

Social hierarchy greatly impacts physical and mental health, but the relationship between social hierarchy and depression/anxiety and the underlying neural mechanism remain unclear. The present study used the tube test to determine the social hierarchy status of mice and then performed several behavioral tests to evaluate depression-like and anxiety-like behaviors. Electrophysiological techniques were used to record the firing activities of glutamatergic pyramidal neurons and local field potentials in the medial prefrontal cortex (mPFC). The results suggested that the mice in each cage (4 per cage) established a stable social hierarchy after 2 weeks. Subordinate mice displayed significantly fewer pushing and advancing behaviors, and more retreat behaviors compared with dominant mice. Furthermore, subordinate mice had significantly more immobility durations in the TST, but significantly fewer distances, entries, and time into the center in the OFT, as well as significantly less percent of distances, entries, and time into the open arms in the EPMT, compared with dominant mice, which indicated that subordinate mice displayed depression- and anxiety-like behaviors. In addition, chronic restraint stress (CRS) significantly induced depression- and anxiety-like behaviors in mice and altered social dominance behaviors in the tube test. CRS mice displayed significantly fewer pushing and advancing behaviors, and more retreat behaviors compared with control mice. Furthermore, low social rank and CRS significantly decreased the firing of pyramidal neurons and γ-oscillation activity in the mPFC. Taken together, the present study revealed an inverse relationship between social hierarchy and depression/anxiety, and the neural basis underlying this association might be the excitability of pyramidal neurons and γ oscillation in the mPFC. These findings established an important foundation for a depression/anxiety model based on social hierarchy and provided a new avenue for the development of therapies for stress-related mood disorders.

Transcriptomes of testis and pituitary from male Nile tilapia (O. niloticus L.) in the context of social status

African cichlids are well established models for studying social hierarchies in teleosts and elucidating the effects social dominance has on gene expression. Ascension in the social hierarchy has been found to increase plasma levels of steroid hormones, follicle stimulating hormone (Fsh) and luteinizing hormone (Lh) as well as gonadosomatic index (GSI). Furthermore, the expression of genes related to gonadotropins and steroidogenesis and signaling along the brain-pituitary-gonad axis (BPG-axis) is affected by changes of an animal’s social status. In this study, we use RNA-sequencing to obtain an in-depth look at the transcriptomes of testes and pituitaries from dominant and subordinate male Nile tilapia living in long-term stable social hierarchies. This allows us to draw conclusions about factors along the brain-pituitary-gonad axis that are involved in maintaining dominance over weeks or even months. We identify a number of genes that are differentially regulated between dominant and subordinate males and show that in high-ranking fish this subset of genes is generally upregulated. Genes differentially expressed between the two social groups comprise growth factors, related binding proteins and receptors, components of Wnt-, Tgfβ- and retinoic acid-signaling pathway, gonadotropin signaling and steroidogenesis pathways. The latter is backed up by elevated levels of 11-ketotestosterone, testosterone and estradiol in dominant males. Luteinizing hormone (Lh) is found in higher concentration in the plasma of long-term dominant males than in subordinate animals. Our results both strengthen the existing models and propose new candidates for functional studies to expand our understanding of social phenomena in teleost fish.

Plumage colour saturation predicts long-term, cross-seasonal social dominance in a mutually ornamented bird

Dominance hierarchies are known to reduce agonistic interactions between individuals and may be influenced by differences in phenotypes such as body size, personality or cognition. Colour ornamentation, especially with melanin-based colours, can also be a badge of status signalling social dominance, but status signalling with carotenoid-based colours is little understood. Here we studied whether different phenotypes, including individual differences in carotenoid-based colour ornamentation, body size, personality-, cognition- and stress-related traits, predict social dominance in the highly social and mutually ornamented common waxbill, Estrilda astrild . We monitored aggressive interactions of waxbills living in seminatural conditions, in a large mesocosm, using data from a radiofrequency identification system in the nonbreeding and breeding seasons over 2 consecutive years. We found the position of individual waxbills in the dominance hierarchy repeatable across seasons and years. Furthermore, the steepness of the dominance hierarchy was greater in the breeding seasons, perhaps because of increased competition over mates or breeding resources. Contrary to previous work with waxbills in birdcages, here body size did not predict social dominance, perhaps because in our more natural setting aggressive encounters were mostly airborne, where large body size may not confer a fighting advantage and may even reduce manoeuvrability. Sex, reactive-to-proactive personality differences and traits related to cognition or stress did not predict social dominance either. Finally, red colour saturation, but not the size of the red patch, strongly predicted social dominance and may thus act as a badge of status. This is one of the few studies testing whether size or saturation of carotenoid-based plumage coloration indicates social dominance and suggests that saturation may more often signal dominance. • Waxbills have mildly steep but stable social hierarchies across years and seasons. • Saturation of carotenoid-based red plumage colour indicates social dominance. • Size of red plumage areas does not correlate with social dominance. • Sex, personality, cognition and size were not related to social dominance.

Development of Tribal Marketing and Application Possibilities in Postmodern Society

Development of Tribal Marketing and Application Possibilities in Postmodern Society

Song of my people: dialect differences among sympatric social groups of short-finned pilot whales in Hawai’i

In many social species, acoustic dialects are used to differentiate among social groups within a local population. These acoustic dialects and their corresponding social groups are often related to distinct foraging behaviors or spatial movement patterns, and it is possible that vocal repertoire variability is one of the proximate mechanisms driving or maintaining genetic and ecological diversity at a subspecies level in social species. Short-finned pilot whales (Globicephala macrorynchus) inhabiting Hawaiian waters have a stable hierarchical social structure, with familial social units associating in larger social clusters within island-associated communities. In this study, we test the hypothesis that sympatric social groups of short-finned pilot whales have acoustically differentiated dialects, which may be used to maintain the social structure. We first examined call composition of social calls collected from photographically identified social clusters of short-finned pilot whales around the Main Hawaiian Islands, using a catalog of manually classified calls, and found that call composition differed among clusters. We then conducted ANOVA and support vector machine (SVM) learning analyses of the acoustic features of social calls. Social clusters were significantly differentiated in their acoustic features, and the SVM classification accuracy was 60%. These results indicate that vocal repertoire reflects social segregation in short-finned pilot whales and may be a driving mechanism of differentiation, potentially contributing to genetic diversity within populations. This suggests divergent acoustic population structure; however, the small sample size in this study decreases the ability to detect acoustic differences among groups. Additional sampling will improve our power to detect acoustic differences among social clusters of Hawaiian pilot whales and improve classification accuracy. The pattern described here highlights the importance of increasing the spatial and temporal resolution of conservation and management plans for this species, in order to conserve subpopulation genetic and social structure. In some species, vocal repertoires differ among social groups or populations of a species that use the same habitat. These differences, called dialects, are thought to be important to maintaining segregation among groups of animals with overlapping distributions, and in some cases may increase intra-specific ecological or genetic variability. This study is the first to provide evidence that sympatric social clusters of short-finned pilot whales have different vocal repertoires, and that vocal repertoire within groups may change with behavioral context. In terrestrial (e.g., elephants) and marine (e.g., killer whales, sperm whales) species with similarly stable social hierarchies, where acoustic dialects, genetic diversity, and/or ecological variability are linked with social structure, anthropogenic stressors have precipitated rapid declines in abundance with slow or nonexistent recovery. Given the myriad threats faced by short-finned pilot whales in the Hawaiian Islands, including fisheries bycatch, military and commercial anthropogenic noise, and vessel strikes, understanding intra-population social structure and its links with genetic structure and ecological variability is imperative to the proper conservation and management of this species.

Longevity of Willow Tits (Poecile montanus): the significance of flock membership, social rank and body size

The Willow Tit Poecile montanus is highly sedentary and breeding pairs remain in their exclusive areas throughout the year. During the winter, these areas are defended by small, non-kin flocks, formed as the roaming yearlings become sedentary and join adults during late summer and autumn. Once established, stable social hierarchies are maintained in these flocks during the winter. The winter flocks consist normally of the socially dominant adult mated pair and two mated juvenile pairs, one higher-ranked and one lower-ranked. Individually colour-ringed juvenile Willow Tits were followed over years in subalpine forest in Norway from ringing in the autumn till they disappeared. None of the lower ranked birds survived their first winter, whereas only 4 of 71 higher-ranked juvenile pairs disappeared during this time. Half of the 71 pairs survived their first winter, about 25 % survived two winters, 8.5% survived three winters, and 5.6% survived four winters. Survival was similar for males and females. Alpha pairs remained mated and defended their common territory across years. Maximum age as revealed by ringing showed one female became six years old and two males ringed as adults were at least nine years old when last observed. The main factor associated with survival was early flock establishment that led to a high rank position among the juvenile flock members. Body size seemed insignificant. Birds that survived their first winter either succeeded to establish as territory owners or they were forced into the role as floaters and probably perished.

An economic theory of altruism based on rankings in a stable social hierarchy

In order to fully understand the interaction between selfish and non-selfish actors, social scientists need rigorous formal models of other-regarding preferences. While the current models clearly present progress relative to the self-interest approach, the evidence also makes it clear that further theoretical progress is warranted. There is ample opportunity for improving our understanding of other-regarding behavior. This paper develops a theory of economic altruism entirely compatible with self-interest utility maximization by rational individuals. Sympathy arises when someone is interested in improving somebody else’s condition, and this will also enhance the utility of the one who acts. Construed in that way, sympathetic behavior is essentially self-interested behavior. A question addressed in this paper is whether a sympathetic population of individuals will exert their income-producing labor differently than a population of egoistic individuals. Two parameters suffice to characterize the altruistic conduct of an individual: a parameter governing the individual’s ranking in a social hierarchy and a parameter determining the sensitivity of an individual’s sympathy for others at different social ranks. The main testable implication of the theory is that in a large population, where each individual has a concave utility function embodying sympathy, the altruistic behavior of any specific individual is determined by his rank in the social hierarchy. A second implication is that in a horizontal social hierarchy, the most altruistic people in the population are those in the middle of it.

Major urinary protein levels are associated with social status and context in mouse social hierarchies.

We have previously shown that male mice living in groups of 12 males establish and maintain stable linear social hierarchies with each individual having a defined social rank. However, it is not clear which social cues mice use to signal and recognize their relative social status within their hierarchy. In this study, we investigate how individual social status both in pairs and in groups affects the levels of major urinary proteins (MUPs) and specifically MUP20 in urine. We housed groups of adult outbred CD1 male mice in a complex social environment for three weeks and collected urine samples from all individuals repeatedly. We found that dominant males produce more MUPs than subordinates when housed in pairs and that the production of MUPs and MUP20 is significantly higher in alpha males compared with all other individuals in a social hierarchy. Furthermore, we found that hepatic mRNA expression of Mup3 and Mup20 is significantly higher in alpha males than in subordinate males. We also show that alpha males have lower urinary creatinine levels consistent with these males urinating more than others living in hierarchies. These differences emerged within one week of animals being housed together in social hierarchies. This study demonstrates that as males transition to become alpha males, they undergo physiological changes that contribute to communication of their social status that may have implications for the energetic demands of maintaining dominance.

The Roles of Dopamine D2 Receptor in the Social Hierarchy of Rodents and Primates

Dopamine (DA) plays significant roles in regulation of social behavior. In social groups of humans and other animals, social hierarchy exists, which is determined by several behavioral characteristics such as aggression and impulsivity as well as social affiliations. In this study, we investigated the effects of pharmacological blockade of DA D2 receptor on social hierarchy of Japanese macaque and mouse social groups. We found acute administration of the D2 antagonist, sulpiride, in socially housed Japanese macaques attenuated social dominance when the drug was given to high social class macaques. A similar attenuation of social dominance was observed in high social class mice with D2 antagonist administration. In contrast, D2 antagonist administration in low social class macaque resulted in more stable social hierarchy of the group, whereas such effect was not observed in mouse social group. These results suggest that D2 receptor signaling may play important roles in establishment and maintenance of social hierarchy in social groups of several species of animals.

Fighting over burrows: the emergence of dominance hierarchies in the Norway lobster (Nephrops norvegicus).

Animals fight over resources such as mating partners, territory, food or shelter and repeated contests lead to stable social hierarchies in different phyla. The group dynamics of hierarchy formation are not characterized in the Norway lobster (Nephrops norvegicus). Lobsters spend most of the day in burrows and forage outside of them according to a diel (i.e. 24 h-based) activity rhythm. Here, we use a linear and generalized mixed model approach to analyse, in seven groups of four male lobsters, the formation of dominance hierarchies and rank-related changes in burrowing behaviour. We show that hierarchies emerge within 1-3 days and increase in steepness over a period of 5 days, while rank changes and number of fights gradually decrease over a 5-day period. The rank position determined by open area fights predicts the outcome of fights over burrows, the time spent in burrows, and the locomotor activity levels. Dominant lobsters are more likely to evict subordinate lobsters from their burrows and are more successful in defending their own burrows. They spend more time in burrows and display lower levels of locomotor activity outside the burrow. Lobsters do not change their diel activity rhythms as a result of a change in rank, and all tested individuals showed higher activity at night and dusk compared with dawn and daytime. We discuss how behavioural changes in burrowing behaviour could lead to rank-related benefits such as reduced exposure to predators and energy savings.

Fighting Nemo: Effect of 17α-ethinylestradiol (EE2) on aggressive behavior and social hierarchy of the false clown anemonefish Amphiprion ocellaris

Aggressive behavior is crucial for maintaining social hierarchy in anemonefish. Endocrine disrupting chemicals such as EE2 may affect fish social hierarchy via disrupting their aggression. In this study, we aimed to characterize the effects of 17α-ethinylestradiol (EE2) on aggressive behavior and social hierarchy in the false clown anemonefish (Amphiprion ocellaris). In the laboratory experiment, juvenile anemonefish were randomly distributed to separated tanks to form small colonies of three individuals and were fed with EE2-dosed diet (100ng/g food) or a control diet for 90d. Through the experiment, each tank was videotaped and behavioral indicators of social status, including aggressive behavior, submissive response, and shelter utilization, were quantitatively analyzed from the videos. The EE2 exposure caused a higher frequency of intra-colonial aggressive interactions and a less stable social hierarchy. Our findings demonstrate the importance of examining the effects of endocrine disrupting chemicals on the social behavior of coral reef fish.

Dynamic changes in social dominance and mPOA GnRH expression in male mice following social opportunity

Social competence - the ability of animals to dynamically adjust their social behavior dependent on the current social context – is fundamental to the successful establishment and maintenance of social relationships in group-living species. The social opportunity paradigm, where animals rapidly ascend a social hierarchy following the removal of more dominant individuals, is a well-established approach for studying the neural and neuroendocrine mechanisms underlying socially competent behavior. In the current study, we demonstrate that this paradigm can be successfully adapted for studying socially competent behavior in laboratory mice. Replicating our previous reports, we show that male laboratory mice housed in a semi-natural environment form stable linear social hierarchies. Novel to the current study, we find that subdominant male mice immediately respond to the removal of the alpha male from a hierarchy by initiating a dramatic increase in aggressive behavior towards more subordinate individuals. Consequently, subdominants assume the role of the alpha male. Analysis of brain gene expression in individuals 1h following social ascent indicates elevated gonadotropin-releasing hormone (GnRH) mRNA levels in the medial preoptic area (mPOA) of the hypothalamus compared to individuals that do not experience a social opportunity. Moreover, hormonal analyses indicate that subdominant individuals have increased circulating plasma testosterone levels compared to subordinate individuals. Our findings demonstrate that male mice are able to dynamically and rapidly adjust both behavior and neuroendocrine function in response to changes in social context. Further, we establish the social opportunity paradigm as an ethologically relevant approach for studying social competence and behavioral plasticity in mammals.

Social behaviour of cattle in tropical silvopastoral and monoculture systems

Silvopastoral systems can be a good alternative for sustainable livestock production because they can provide ecosystem services and improve animal welfare. Most farm animals live in groups and the social organization and interactions between individuals have an impact on their welfare. Therefore, the objective of this study was to describe and compare the social behaviour of cattle (Bos indicus×Bos taurus) in a silvopastoral system based on a high density of leucaena (Leucaena leucocephala) combined with guinea grass (Megathyrsus maximus), star grass (Cynodon nlemfuensis) and some trees; with a monoculture system with C. nlemfuensis, in the region of Merida, Yucatán. Eight heifers in each system were observed from 0730 to 1530 h each day for 12 consecutive days during the dry season and 12 consecutive days during the rainy season. The animals followed a rotation between three paddocks, remaining 4 days in each paddock. The vegetation was characterized in the paddocks of the silvopastoral system to estimate the average percentage of shade provided. To make a comparison between systems, we used a t test with group dispersion, and Mann–Whitney tests with the frequency of affiliative and agonistic behaviours. We assessed differences in linearity and stability of dominance hierarchies using Landau’s index and Dietz R-test, respectively. The distance of cows with respect to the centroid of the group was shorter, and non-agonistic behaviours were 62% more frequent in the intensive silvopastoral system than in the monoculture one. Heifers in the silvopastoral system had a more linear and non-random dominance hierarchy in both seasons (dry season: h’=0.964; rainy season: h’=0.988), than heifers in the monoculture system (dry season: h’=0.571, rainy season: h’=0.536). The dominance hierarchy in the silvopastoral system was more stable between seasons (R-test=0.779) than in the monoculture system (R-test=0.224). Our results provide the first evidence that heifers in the silvopastoral system maintain more stable social hierarchies and express more sociopositive behaviours, suggesting that animal welfare was enhanced.

The Daily Pattern of Main Activities in the Gelada Baboon (Theropithecus gelada)

The aim of this work was to observe and analyse the main daily activities in the group of geladas kept in the ZlĂ­n Zoo. The experimental group was formed by three males (one of them was a dominant alfa male) and four females who were in the reproductive cycle at the observation period. The behavioural study included five recurrent observations which took place in March 2014. The observations revealed that geladas spent most of the time feeding (44.1%) and performing comfort behaviour (24.6%). About 7.7-10.4% of the total time the geladas spent moving, resting and observing the neighbourhoods. The settled and stable social hierarchy within the group prevented greater incidence (0.7%) of aggressive behaviour. Occurrence of other types of activities was low - play (1.7%), climbing the trees (0.5%) and sexual behaviour (2.3%). The work also studied how the incidence of a particular type of behaviour changed over time within the day. A certain pattern in behavioural activities was apparent because their incidence tended to be similar on all observation days. Foraging activities were the greatest (44.80 ± 3.64 observations) between 15.00 and 16.00, resting (8.00-9.80 observations) between 12.00 and 14.00 and comfort behaviour (23.20 ± 2.82 observations) in the morning.

GENETIC FEATURES of DEVELOPMENTAL PATTERNS OF AGONISTIC BEHAVIOR IN LABORATORY MALE MICE UNDER SOCIAL HIERARCHY CONDITIONS

Background. Agonistic behavior is necessary for formation of dominant-subordinate relationship and for maintenance of social hierarchy in animal communities. However? there are few reports about the genetic features of agonistic behavior development in animals living in stable social groups. The aim of the present study was to investigate the ontogeny of agonistic behavior in male mice of different genotype and social status under stable social hierarchy conditions. Materials and methods. We studied the age dynamics of offensive attacks, the vertical defensive postures and the “runaway” behavior in male mice of inbred strains PT and CBA/Lac housed in genetically heterogeneous pairs during puberty (from 38 to 70 days of life). Results. Dominant-subordinate relationships were stable in 80 % of pairs during the experiment. During the period of stable social hierarchy we observed a transient increase in the number of offensive attacks at the end of puberty in dominants of the strain CBA/Lac but not in PT. Conclusion. In conclusion, the study revealed a significant influence of social rank and genotype on the development of patterns of social behavior in laboratory male mice during puberty.

DEVELOPMENTAL PATTERNS OF SNIFFING BEHAVIOR IN male laboratory MICE in conditions of SOCIAL COMPETITION

Sniffing behavior plays a significant role for communication and maintenance of the ethological structure of population. We studied the number of nose-nasal and nose-anogenital sniffing in male mice of inbred strains PT and CBA/Lac housed in genetically heterogeneous pairs during puberty and later (from 41 to 70 days of life). Male mice of the CBA/Lac strain show a higher number of nose-anogenital and nose-nasal sniffing in comparison with males of the PT strain. Throughout the period of stable social hierarchy we observed a transient increase in the number of sniffing behaviors in dominants and subordinates of the CBA/Lac strain but not in PT. In conclusion, the study revealed a significant influence of genotype and social rank on developmental patterns of sniffing behaviour in laboratory male mice

Quantified Analyses of Aggression Pattern in a Captive Population of Musk Deer (Moschus Sifanicus)

Quantified Analyses of Aggression Pattern in a Captive Population of Musk Deer (Moschus Sifanicus)Alpine musk deer (Moschus sifanicus) are endangered as a result of habitat degradation and loss and centuries of widespread poaching. Consequently, musk deer farming was introduced as a measure to not only protect musk deer but also to provide a means for sustainable musk supply. An increased understanding of the social structure of captive populations is essential for both successful farming and improved welfare of individuals. This study recorded agonistic interactions between captive individuals at Xinglongshan Musk Deer Farm (XMDF), northwest China. The relationship between aggressive interactions and the individual's age and gender and opponent health was analysed. From our observations we found that stable social hierarchies developed within both captive male and gender-mixed musk deer groups. There was no significant correlation found between only age of individual and their status in the social hierarchy, and it was thus concluded, as social rank was not determined singularly by age, that a combination of other factors, such as experience and origin of the individual, better explain rank orders. Three forms of aggressive behaviour were expressed between males, in which threatening (56.38%±7.28%) was significantly more frequent than attacking (17.86%±5.94%) and displacing behaviours (25.78%±3.66%). There was no attacking behaviour observed in interactions initiated by males towards females, however displacing (70.85%±4.15%) was more common than threatening (29.15%±4.15%). Conflict-initiating male deer demonstrated more attacking and threatening behaviour towards male opponents than to female ones, however the differences were statistically insignificant. These results can be implemented into musk deer farming management practices through 1) rotating individuals within an enclosure on a frequent basis; 2) removing males from female enclosures after successful mating and 3) enclosing males in single sex enclosures. Furthermore, in order to improve musk deer farming and captive musk deer welfare, management systems should be kept relatively consistent in order to assist in establishing the stable social hierarchy patterns in captive populations.