Hierarchy Rank Research Articles

Wound inflammation post-orchiectomy affects the social dynamic of Nelore bulls

BackgroundConfinement of cattle imposes spatial restrictions and predisposes to aversive social encounters that can lead to contusions, wounds, pain, stress, fright, and reduced productivity. Although endogenous testosterone concentrations are linked to agonistic dominance behaviors in males, it is unknown whether decreased blood testosterone concentrations after castration alter social hierarchy rank in Nelore bulls. Therefore, in this study, we investigated the impact of the surgical would inflammation post-orchiectomy on social dynamics in a group of Nelore bulls (Bos indicus). Fourteen Nelore (Bos indicus) bulls were castrated and assessed pre- and post-surgically. Parameters evaluated were agonistic (mounting, headbutting, and fighting) and affiliative (head-play) behavior, plasma testosterone concentrations, average daily weight gain (ADG), and a score for severity of post-surgical infection. Exploratory statistics included social network analysis (SNA), hierarchy rank delta (Δ), and principal component analysis (PCA). Furthermore, statistical inferences included the Wilcoxon test, multiple logistic regression models, and Spearman's correlation.ResultsThe social dynamic of Nelore bulls was modified after castration based on the findings of the SNA and the PCA. The moderate correlation between the postoperative inflammation level with the Δ, and the significant effect of this level in the logistic model post-castration were partially attributed to effects of pain on social relations.ConclusionsOur findings suggest the severity of post-surgical inflammation, which has an association with pain intensity, was closely associated with changes in the social hierarchy.

Observation of Masturbation After Visual Sexual Stimuli From Conspecifics in a Captive Male Bearded Capuchin (Sapajus libidinosus).

Masturbation is part of the natural behavioral repertoire of primates, with visual sexual stimuli known to trigger this behavior. Here, we report masturbation events triggered by visual sexual stimulus (VSS) in the South American primate Sapajus libidinosus. We observed a multi-male multi-female captive colony of 17 bearded capuchins between January and October 2014. Over this period, we registered 11 copulation events, 68 attempt copulations, and five masturbation events. The same low-ranking male (named Fu) performed all masturbation events. Fu directly looked at other individuals engaged in sexual displays while he masturbated in three events. The masturbation events associated with VSS lasted up to 2min and 40s. Our observations show that VSS can trigger masturbation in capuchin monkeys. The low hierarchy rank of the male, and the consequent lack of mating opportunities in the multi-male multi-female recently formed group in captivity, may have prompted the masturbation events.

PSVI-14 Effect of Morphometric Traits Upon Social Hierarchy of Dorper Rams from Northern Mexico

Abstract Usually, social order is defined by the animal size, live weight, or age. This study aimed to evaluate the association among horn presence (HP), and horn size (HS) on social rank hierarchy. Adult Dorper rams (n=24) with similar live weight (LW), body condition score (BCS), and age (AG) were subjected to a behavioral test to define the success index (SI, ranked form 0 to 1) based on male-to-male interactions, determining three social ranks: low hierarchy rams (LHR; SI = 0-0.33; n=9), medium hierarchy rams (MHR; SI=0.34-0.66; n=10) and high hierarchy rams (HHR; SI= 0.67-1; n=5). Afterward, skull, horn (HP and HS), and body morphometrics were measured. The GLM procedure of SAS (SAS Institute, Cary, NC) was used to analyze LW, AG, BCS, HS and HP with three social ranks and five to ten replicates per group. Rams within social rank were the experimental units. Differences were considered as significant at P < 0.05. Regarding HP, 80% of the HHR rams had horns, while 77.7% of the LHR rams were hornless, with intermediate values for MHR (50%), but no differences were found regarding HS between low, medium and high hierarchy rams (85.1±2.6, 84.3±3.3, and 90.7±4.7, respectively). In conclusion, while presence of horns have an important role for establishing social hierarchy, it is a complex trait influenced by factors other than horn presence or size so, we recommend more research in relation to other factors that could influence the position of rams in the hierarchy rank levels of the herds.

99 Determining dominance hierarchy of horses in an equine assisted services program

An ethogram was constructed as part of an undergraduate research course and used to determine the dominance hierarchy of a small (n = 4) herd of horses in a university-based equine-assisted services program. The herd consisted of one gelding and 3 mares ranging in age from 10 to 27 years. An ethogram of mutually exclusive agonistic behaviors was developed, with behaviors further defined and sub-categorized as either aggressive (approach, arched neck threat, bite, bite threat, boxing, circling, chase, ears pinned, following, grasping, head bowing, head threat, herding, interference, kick, kick threat, mount, neck wrestle, head on body, nip, push, rear stomp, strike, strike threat) or submissive (retreat/avoidance, balk, rump presentation, snapping). Horses had been group housed together during daytime hours for 22 mo before the study in a 23 by 38 m dry lot with ad libitum access to clean water and one round bale of mixed brome, timothy and orchardgrass hay. At approximately 4:30 p.m. daily horses were brought inside where they were maintained overnight in individual 3 by 3 m stalls with pine shavings and fed evening and morning grain meals with access to water and grass and/or alfalfa hay to meet their dietary requirements. When group housed, horses had access to shade in the morning hours, but no covered shelter. Horses were observed in June 2020 where the average temperature was 22°C, and ranged from 10 to 37°C and the average relative humidity was 61%, ranging from 18 to 100%. Horse behaviors were recorded in 1-h intervals between 9 a.m. and 4 p.m. on random days with 4 replicates of each hour for a total of 28 h of observation. All agonistic horse interactions were recorded as event behaviors. At the conclusion of the study, a score of +1 was assigned to all aggressive agonistic behaviors performed by a horse and –1 assigned to all submissive agonistic behaviors performed by a horse. The point value of all behaviors performed by each horse was added together. The hierarchy rank was then determined by the total scores, with more positive scores equaling a higher social ranking in the herd. Scores for horses from most dominant to least dominant were +168, +32, +20 and –52. These scores reflected a clearly dominant mare in the herd, as well as a dominance hierarchy that matched the hypothesized social structure based on informal observations. Awareness of social hierarchy among horses is essential for good herd management as well as human and equine safety, particularly in equine assisted services programs.

Potential female mate choice in a male dominated system: the female capybara, Hydrochoerus hydrochaeris

AbstractCapybaras, Hydrochoerus hydrochaeris (Rodentia: Caviidae: Hydrochoerinae), show a strict social hierarchy among males, wherein the top-ranking male gains preferential access to females. Despite minimal sexual size dimorphism, males have a prominent scent gland on their snouts that is greatly reduced in the females. Top-ranking males have a larger gland and mark more frequently than subordinate males. This species also shows a moderately complex courtship that seems to be modulated by female behavior. In this study, we evaluated several components of courtship, as well as the females’ interactions with males during and outside courtship, in relation to the hierarchy rank of males. We found that subordinate males engaged in longer courtships than top-ranking males. However, there was no difference in the number of mount attempts or the success rate of these mounts as a function of the social status of the male, despite the longer courtship performed by subordinate males in comparison to top-ranking males. Outside courtship, females directed the same number of social interactions to males regardless of status. However, during courtship, females avoided copulation by subordinate males both directly and indirectly by encouraging courtship disruption by higher-ranking males. Females’ avoidance of subordinates may force these males to invest a higher amount of effort in courtships, thus engaging in longer courtships, yet achieving similar mount success as top-ranking males. We show that the original assumption of male hierarchy as the main mechanism of reproductive distribution is incomplete, and female mate choice plays an important role in determining which males reproduce.

Early Social Stress Promotes Inflammation and Disease Risk in Rhesus Monkeys

Early social stress has potent lifelong health effects. We examined the association of early stress in the attachment relationship (low maternal sensitivity, low MS), lower maternal social hierarchy rank, and greater frequency of group-level social conflict, with biomarkers of inflammatory stress response in plasma (IL-8, MCP-1 and CRP collected two hours after temporary separation from mothers and social groups) and risk for developing a common macaques disease outcome (infectious colitis) in 170 socially-housed rhesus monkeys. We controlled for gene-environment correlations by comparing cross-fostered subjects with infants reared by their biological mothers. Low MS predicted higher levels of pro-inflammatory cytokines and proteins at 3–4 months of age (F(3, 162) = 3.508, p = 0.002, partial eta2 = 0.061) and higher lifetime risk for developing colitis for up to twelve years of age (chi square = 5.919, p = 0.026). Lower maternal social rank (F (3, 162) = 3.789, p = 0.012, partial eta2 = 0.06) and higher rates of social conflict (F (3, 162) = 4.264, p = 0.006, partial eta2 = 0.074) each also predicted greater inflammation in infancy, but not lifetime colitis risk (both p > 0.05). The effects of low MS, lower social rank, and higher social conflict were significant in infants reared by biological mothers and cross-fostered infants, suggesting that our results did not arise from gene-environment correlations, but environmental stressors alone. We conclude that several types of early social stress confer risk for inflammation in infancy, but that stress in the mother-infant relationship may confer the longest-term risk for adverse health outcomes.

Agonistic behaviour and feed efficiency in juvenile Nile tilapia Oreochromis niloticus

Given the strong effects of behavioural hierarchies on growth in many cultured species and the key role of feed efficiency in aquaculture economics, understanding the nature of the interaction of these variables is important for the sustainability of aquaculture. The relationship between agonistic behaviour, growth and feed efficiency in Nile tilapia, Oreochromis niloticus, was studied by rearing 120 fish in eight aquaria. Fish were video-recorded to estimate the occurrence of agonistic behaviour during a fasting and a refeeding period. Growth, feed intake and feed conversion efficiency (FCE - calculated as the inverse of feed conversion ratio (FCR)) were subsequently measured individually for each fish. Fish showed 58% less agonistic traits during the fasting period compared to the feeding period, but generally, an aggressive fish during the fasting period was also aggressive during the refeeding period. The nature of agonistic behaviours between individuals was used to assess the presence of hierarchical relationships between fish. There were dominance hierarchies established in each experimental aquarium that despite minor shifts were maintained throughout the experiment. Agonistic behaviours were strongly correlated with each other, the aggression Index (AI) and with hierarchy rank. PCA analysis of the agonistic behaviours summarising the behavioural information showed little or no correlation between agonistic behaviour, fish growth or FCE. FCE was correlated with body weight gain (BWG). These results suggest that agonistic interactions in juvenile Nile tilapia do not have a large impact on growth and feed conversion efficiency.

Bystanders intervene to impede grooming in Western chimpanzees and sooty mangabeys.

Grooming interactions benefit groomers, but may have negative consequences for bystanders. Grooming limits bystanders' grooming access and ensuing alliances could threaten the bystander's hierarchy rank or their previous investment in the groomers. To gain a competitive advantage, bystanders could intervene into a grooming bout to increase their own grooming access or to prevent the negative impact of others' grooming. We tested the impact of dominance rank and social relationships on grooming intervention likelihood and outcome in two sympatric primate species, Western chimpanzees (Pan troglodytes verus) and sooty mangabeys (Cercocebus atys atys). In both species, rather than increasing their own access to preferred partners, bystanders intervened mainly when an alliance between groomers could have a negative impact on them: when the lower-ranking groomer was close to the bystander in rank, when either groomer was an affiliation partner whose services they could lose, or the groomers were not yet strongly affiliated with each other. Thus, bystanders in both species appear to monitor grooming interactions and intervene based on their own dominance rank and social relationships, as well as triadic awareness of the relationship between groomers. While the motivation to intervene did not differ between species, mangabeys appeared to be more constrained by dominance rank than chimpanzees.

Ambient temperature, body condition and sibling rivalry explain feather corticosterone levels in developing black kites

Summary In birds, the steroid hormone corticosterone (CORT) is considered a major mediator in a number of physiological mechanisms and behaviours critical for the regulation of an organism's energy balance. However, the question of whether the way in which circulating plasma CORT is incorporated into feathers actually reflects this regulation, and consequently whether feather CORT (CORT‐F) measures allow to make inferences on past levels of energetic demands (also known as the allostatic load), remains unclear. While previous studies have yielded promising results, the technique still wants further study and validation in a wider range of bird species, across life‐history stages and under different ecological situations. Here, we tested whether CORT‐F levels in a sample of 427 nestling black kites (Milvus migrans) reflected interindividual variation in a number of environmental, social and physiological variables known to elevate allostatic load during development. We found that nestlings exposed to low ambient temperatures exhibited high CORT‐F, suggesting that feathers registered the expected rise in circulating CORT levels inducing thermogenesis in response to cold stress. CORT‐F was also negatively related to body condition, supporting the notion that allostasis becomes less affordable as energy stores become depleted. Finally, CORT‐F also reflected brood hierarchy rank, with subordinate chicks exhibiting the highest levels, followed by first‐hatched (dominant) chicks and lastly singleton nestlings. Moreover, CORT‐F levels in nestlings from multiple‐chick broods (but not in singletons) declined with age, mirroring the dynamics of establishment and stabilization of sibling hierarchies in black kites. Altogether, our results underscore the potential of using CORT‐F to infer allostatic load in wild avian populations and their potential power as indicator tools in conservation biology.

Supplier selection in supply chain using analytical hierarchy process

Supplier selection is an important constituent in supply chain management. Supply chain management emphasises on evaluation and selection of supplier against multiple criteria rather than cost as a single criteria. Multi criterion includes both qualitative and quantitative criteria. In this paper, we have proposed analytical hierarchy process model, to evaluate and rank the potential supplier, supplying copper component (busbar), to a multinational organisation, engaged in designing, manufacturing and delivering a range of products covering various stages of power transmission and distribution system. AHP is a four step decision analysis model which converts the qualitative factor of supplier transferred into the quantitative measure reliability and a decision making method for ranking alternative course of action when multiple criteria must be considered.

Study on performance assessment mode of clinical departments in modern hospital

Objective Construct the reasonably effective performance assessment mode of clinical departments,which is suitable for the continuous development of modern hospital.Method Use of balanced scorecard (BSC) principle,using the analytic hierarchy process (AHP) and Rank sum ratio method (RSR)to establish a performance assessment system. Results Constructed the performance assessment mode of clinical departments,which can be dynamically adjusted based on management objectives strategy.The mode takes the BSC as the baseline,the strategy of hospital development as the guide,performance assessment index system as the key element. Conclusion The performance assessment mode of clinical departments,base on BSC,achieve the strategic performance management,and is conducive to the hospital for continuous improvement of medical care quality,in line with the long-term strategic needs of the hospital. Key words: Clinical departments; performance assessment; Balanced Scorecard

The combination of social and personal contexts affects dominance hierarchy development in shore crabs, Carcinus maenas

Many animals that live in groups maintain competitive relationships, yet avoid continual fighting, by forming dominance hierarchies. We compare predictions of stochastic, individual-based models with empirical experimental evidence using shore crabs to test competing hypotheses regarding hierarchy development. The models test (1) what information individuals use when deciding to fight or retreat, (2) how past experience affects current resource-holding potential, and (3) how individuals deal with changes to the social environment. First, we conclude that crabs assess only their own state and not their opponent’s when deciding to fight or retreat. Second, willingness to enter, and performance in, aggressive contests are influenced by previous contest outcomes. Winning increases the likelihood of both fighting and winning future interactions, while losing has the opposite effect. Third, when groups with established dominance hierarchies dissolve and new groups form, individuals reassess their ranks, showing no memory of previous rank or group affiliation. With every change in group composition, individuals fight for their new ranks. This iterative process carries over as groups dissolve and form, which has important implications for the relationship between ability and hierarchy rank. We conclude that dominance hierarchies emerge through an interaction of individual and social factors, and discuss these findings in terms of an underlying mechanism. Overall, our results are consistent with crabs using a cumulative assessment strategy iterated across changes in group composition, in which aggression is constrained by an absolute threshold in energy spent and damage received while fighting.

The ghost of social environments past: dominance relationships include current interactions and experience carried over from previous groups

Dominance hierarchies pervade animal societies. Within a static social environment, in which group size and composition are unchanged, an individual's hierarchy rank results from intrinsic (e.g. body size) and extrinsic (e.g. previous experiences) factors. Little is known, however, about how dominance relationships are formed and maintained when group size and composition are dynamic. Using a fusion-fission protocol, we fused groups of previously isolated shore crabs (Carcinus maenas) into larger groups, and then restored groups to their original size and composition. Pre-fusion hierarchies formed independently of individuals' sizes, and were maintained within a static group via winner/loser effects. Post-fusion hierarchies differed from pre-fusion ones; losing fights during fusion led to a decline in an individual's rank between pre- and post-fusion conditions, while spending time being aggressive during fusion led to an improvement in rank. In post-fusion tanks, larger individuals achieved better ranks than smaller individuals. In conclusion, dominance hierarchies in crabs represent a complex combination of intrinsic and extrinsic factors, in which experiences from previous groups can carry over to affect current competitive interactions.

Personality traits predict hierarchy rank in male rainbowfish social groups

Personality traits are becoming increasingly important in explaining adaptive individual differences in animal behaviour and probably represent a leading edge of the evolutionary process. Despite the new-found interest in animal personality among behavioural ecologists, few studies have investigated the link between personality traits and fitness measures. We examined this link using male rainbowfish, Melanotaenia duboulayi, as a model species and found that a range of personality traits (aggression, activity and boldness) covaried with a male’s position in a hierarchy, which is directly related to reproductive success in this and many other species. Dominant fish were more aggressive, active, bold and also significantly larger than subordinate fish. Moreover, we found strong correlations between activity levels and boldness suggesting that selection may act on a suite of traits in concert (sensu behavioural syndromes). When taken together with previous research, our results suggest that the activity–boldness syndrome is likely to be domain specific. We suggest that multiple trait correlations may be generated by high levels of competition (e.g. sexual selection) in addition to predation pressure as identified by previous studies.

Correlation of dominance as determined by agonistic interactions with feeding order in cats

To determine whether the direction of dominance as determined by agonistic interactions away from food was different from the direction of dominance as determined by access to a resource in cats. 28 cats. Dyadic relationships and hierarchy formed from observation of agonistic interactions away from food were compared with those formed from interactions at the food bowl. A cat was scored as subordinate to another cat if it lost 3 of 3 interactions or lost > or = 75% of the interactions when > 3 interactions occurred. Cats were observed for 449.4 hours. Hierarchy rank determined by agonistic interactions away from food was significantly correlated with rank determined by interactions at the food bowl. In 27 of 31 dyads, the direction of dominance was the same for food bowl and agonistic relationships, which was significant. In post hoc analyses, when considering the relationship between 2 cats, the heavier cat most likely ranked higher in each hierarchy; however, age was not significantly correlated with either hierarchy. On the basis of dyadic information, the older cat in a dyad was more often dominant in agonistic interactions. Males had a higher mean dominance rank than females; however, sex had no effect on rank determined by interactions at the food bowl. Factors influencing dominant-subordinate relationships are of interest for understanding and treating behavior problems such as aggression and resource control. The outcome of agonistic interactions away from food was related to, but not perfectly correlated with, the outcome of interactions at the food bowl, although winners of those agonistic interactions tended to have control of food.

SELECTED RURAL GROWTH IN ESTONIA 1989–2000 – SUB- OR COUNTERURBANISATION? DIFFERENT ANALYSES – DIFFERENT RESULTS

Introduction There is no common understanding of the essence of suburbanisation and counterurbanisation (Berry 1976, Frey 1987, 1988, Champion 1989, Johnston 2000, Tammaru 2001). Both terms refer to a situation of population outflow from more densely populated towns, but the borderline between suburbanisation and counterurbanisation remains ambiguous. In this paper we will define counterurbanisation as an outflow of population from bigger towns into smaller towns and rural areas (sometimes also called deurbanisation, desurbanisation, or disurbanisation), and suburbanisation as an outflow of population mainly into the nearest hinterland of bigger towns (also called spillover, or seen as continuous growth of towns over their borders). Consequently, the distance of migration from bigger towns is an essential differentiator between suburbanisation and counterurbanisation. Large amounts of literature have been dedicated to the essence and trends of urbanisation and counterurbanisation (Berry & Dahman 1977, Champion 1989, 1992). Although there are some reports about earlier signs of urban reversal of concentration in London and America (Korcelli 1984), the counterurbanisation process became well known and was most visible in the 1970s in USA. Many authors have stressed that the growth rate of rural areas was in favour of more peripheral regions, smaller settlements, or cities of intermediate scale (Champion 1992). After 1970, the process accelerated. According to Hall and Hay (1980; 87), virtually ceased to grow and with continuing losses from the non-metropolitan areas--the rings actually accounted for more than the entire net growth of the population. These generalisations included rather substantial variations among individual countries analysed in the study by Hall and Hay. It was found that counterurbanisation was related to the hierarchy of towns. As the correlation between hierarchy rank and the rate of population growth was negative, the main contributors to counterurbanisation were revealed to be the towns in higher hierarchical order. Korcelli (1984) found that, despite the fact that metropolitan areas were still growing, they were decentralising people from cores into rings, mainly because of stagnation of older metropolitan centres. Using the USA population census data from 1990-2000, Lopez and Hynes (2003) got the same results. The sprawls index showed shifts towards a more equal population distribution. Later, large amounts of migration research (Fielding 1987, Findlay & White 1986, Champion 1989) have shown that, despite the fact that the changes took place in different countries at different times, the majority of countries have passed deconscentration stages at some period of development. In 1989, Fielding concluded that most of the countries in Western Europe have records of counterurbanisation from the 1970s. In the 1980s, signs of reurbanisation of towns were found (Ogden & Hall 2000). Although in 1990 the changes towards concentration occurred in many countries, there was no clear understanding of a general future trend. The question remained--was deconcentration a major shift in population redistribution (see Zelinsky 1971, Frey 1995, Long & Nucci 1997, Wardwell 1977, Johnston & Beale 1994, Champion 1992), a mere temporary exception in a long process of concentration (Champion 1989, Fielding 1993, Frey 1987, Frey 1988, Johnston & Beale1994), or something else. Once again, metropolitan centres had started to grow, and the reasons were diverse and complex, sometimes the growth was related to commuter dormitories, sometimes to retirement settlements. The latest Europe-wide research project (Rees & Kupiszewski 1999) reported different concentration and deconcentration results for different countries. The picture has been unclear also in Estonia. Low reliability of data and different methods used to study migration, have given variable results. …

Worker age, size and social status in queenless colonies of the ant Leptothorax gredleri

Workers in queenless colonies of the ant Leptothorax gredleri form dominance hierarchies by antennation bouts and biting. The frequency of aggressive interactions peaked when the ants became active again after hibernation, a second time in summer, when new workers eclosed from overwintered brood, and a third time when we experimentally removed the queen. High-ranking individuals were more active and had greater ovarian development than their low-ranking nestmates. We investigated what proximately determines a worker's social status. Neither age, previously shown to affect hierarchy rank in several other social insects, nor levels of fluctuating asymmetry appeared to be important in worker rank orders inL.gredleri . High-ranking workers were on average larger than low-ranking individuals and body size and rank were correlated in four of five colonies investigated. However, individuals of similar age but different social status did not differ in size.

Effects of kinship on aggression and RNA content in juvenile Arctic charr

The behaviour of juvenile Arctic charr Salvelinus alpinus was studied in groups of four siblings composed of familiar and unfamiliar individuals or in mixed groups of four where both siblings and unrelated individuals were present. The frequency of aggressive acts was significantly higher in the mixed groups compared to the pure sibling groups and the difference was present at all levels of the hierarchy rank order, based on a dominance index, except the lowest ranked individuals. The difference was significant after but not before feeding, implying that competition with non‐kin for a food resource increased the aggression. No significant difference in weight gain was observed between sibling and mixed groups during the 6 days of the experiment, but the RNA contents of lateral musculature in dominant individuals from sibling groups were significantly higher than the corresponding fish in the mixed group, suggesting a difference in growth rate when the experiments ended. No significant difference in RNA content was observed between subordinate fish of the two treatments, i.e. siblings v. mixed.

Health Profile of Danish Army Personnel

The purpose of the present study was to delineate a health profile of professional Danish army personnel. Two-hundred twenty officers, noncommissioned officers, and gunners on active duty at Varde Barracks, housing the South Jutland Artillery Regiment and the Danish Army Artillery School, were asked about their physical and psychological health, interpersonal relations, and working conditions as well as their dietary, drinking, and smoking habits. Measurements were made of resting pulse rate, blood pressure, height, weight, waist and hip girth, and pulmonary function. The ratio of waist-to-hip girth and body mass index (BMI) were calculated. Psychological well-being was evaluated using the 12-item version of the General Health Questionnaire (GHQ). Psychosomatic symptoms were frequently reported, but very few of those surveyed appeared to have psychiatric disorders as measured by the GHQ. Also, somatic health problems were frequently reported, the most frequent being lower-back pain, mild chest pain, and sensory disorders. Differences in interpretation and reporting of "lasting health problems" may explain the relatively high score for this question. The interpersonal relations, both upward and downward in the hierarchy rank order, received high scores. Compared with the general population, alcohol consumption was very low, whereas smoking-in particular heavy smoking-was much more frequent among professional Danish army personnel. Lung function testing showed significantly poorer mean values of forced expiratory volume in 1st second of expiration and mean forced expiratory flow 25 to 75% of forced vital capacity among smokers compared with nonsmokers, although the mean values for the whole group of both smokers and nonsmokers were well above reference values for all lung function parameters. The frequency of moderately overweight individuals (25 < BMI < or = 30) was significantly higher among the male army personnel than in the general population, whereas this was not the case for obesity (BMI > 30). Abdominal obesity, regarded as an independent risk factor for the development of ischemic heart disease, stroke, diabetes, hypertension, and all-cause mortality, was present in 5%, and 3% belonged to the highest-risk group by having a low BMI as well as abdominal obesity.

Male display rate reveals ejaculate characteristics in the Trinidadian guppy,Poecilia reticulata.

Previous work (Reynolds and Gross 1992) has demonstrated that mate choice enables female guppies, Poecilia reticulata , to obtain heritable benefits (‘good genes’) for their offspring. It is not yet known whether males also signal their functional fertility, that is, their viability as fathers, to female guppies. Our study tested the hypothesis that a male9s behaviour reveals characteristics of his ejaculate. We uncovered a strong correlation between display rate and sperm number in male guppies derived from two wild Trinidadian populations. This result indicates that information on the functional fertility of potential mates is available to females. However, our investigation also found a significant relationship between the frequency of sneaky mating and sperm number. Female guppies in wild populations, particularly those experiencing a high predation regime, are constantly subjected to sneaky mating attempts. As the males responsible for these sneaky matings have highest reserves of sperm they may have the capacity to undermine female choice. The implications of these findings for sperm competition are discussed.