Effects Of Kinship Research Articles

Social organization of cooperatively breeding long‐tailed tits: kinship and spatial dynamics

Summary Long‐tailed tits Aegithalos caudatus L. are cooperative breeders in which breeders that have failed in their own breeding attempt become helpers at the nest of relatives. We investigated the effects of kinship on the spatial dynamics of non‐breeding flocks of long‐tailed tits in order to determine the information available on the kinship of other members of the population from their use of home ranges. A novel method of home range analysis was devised based on ‘convex hull peeling’. This method takes into account the dispersion of all fixes within a home range and permits the quantitative analysis of home range use. In addition, the method allows the extent of overlap between adjacent home ranges to be determined and the use of those areas to be investigated. Non‐breeding flocks of long‐tailed tits were composed mainly of relatives, but also included unrelated immigrants. Flock ranges were large and there was extensive overlap between adjacent flocks. The degree of range overlap was significantly affected by the relatedness of flocks. If two flocks contained close relatives they were more likely to overlap than two flocks containing non‐relatives. Moreover, the amount of overlap was significantly greater for two adjacent related flocks than for two adjacent unrelated flocks. The use of overlapping areas of non‐breeding ranges of long‐tailed tit flocks was also influenced significantly by relatedness. Overlapping flocks that were unrelated to each other usually avoided areas of overlap, while related flocks did not generally show such avoidance behaviour. Kinship has significant effects on the spatial dynamics of non‐breeding flocks of long‐tailed tits and therefore flock behaviour can provide information on the relatedness of other members of the population that might be important for helping decisions in this cooperatively breeding species.

Growth and Metamorphosis of Bufo melanostictus Tadpoles: Effects of Kinship and Density

Growth and metamorphosis of the toad Bufo melanostictus was studied by rearing tadpoles of different sibships in isolation or in groups of siblings and nonsiblings (mixed rearing) under crowded and uncrowded conditions. All tadpoles survived and metamorphosed successfully. Growth rate and dura- tion of metamorphosis of tadpoles reared in isolation were similar among the six sibships regardless of genetic differences. Tadpoles reared in sibling groups metamorphosed in 25 days, whereas those reared with nonsiblings metamorphosed between days 30-35. The largest mean body mass at metamorphosis was for sib groups reared in lower densities. When reared with siblings, growth was uniform, resulting in the production of bigger toadlets and a narrow spectrum of size classes. Mixed rearing retarded growth rates, increased larval duration, and produced smaller individuals at metamorphosis, resulting in extreme vari- ability in size classes, especially under crowded conditions. Our study shows that both kinship and density affect larval duration and size at metamorphosis in this species.

Mortality responses to rice price fluctuations and household factors in a farming village in central Tokugawa Japan

Drawing data from the annual local population registers called shumon-aratame-cho (SAC), this study examines the patterns and covariates of mortality by sex and life stage in the farming village of Nishijo in central Japan in 1773–1869. The discrete-time event history analysis of mortality in the village offers three major findings. First, mortality responses to rice price fluctuations varied greatly by residents' sex and life stage. Second, coresident kin were important for survival throughout the life course, though the magnitude and nature of the mortality effects of coresident kin differed across sex and age groups. Third, household resources and positions that individuals occupied within a household influenced chances of survival especially in adult and elderly years.

Menopause and the transmission of women's knowledge: African American and white women's perspectives.

Recent menopause literature does not sufficiently explore women's attitudes on the transmission of knowledge about menopause from sources other than biomedical providers. Analysis of 70 interviews with African American and Euro-American women shows that their perceptions of the intergenerational transfer of knowledge about menopause from their mothers shaped their attitudes toward menopause and the health-care technologies surrounding it. African American women who grew up in the segregated South frequently expressed that their mothers provided them with the knowledge and power to negotiate difficulties during the menopausal process, while many middle-class Euro-American women expressed that their mothers did not. Drawing on literature that examines the effects of race, class, and kinship on mother/daughter relationships, this article explores the reasons for this divergence.

The effects of kinship and density on growth and metamorphosis of the bronze frog (Rana temporalis) tadpoles

Five clutches of Ranatemporalis eggs collected along a stream were reared separately until formation of Gosner stage 25 tadpoles. The effect of kinship and density was then studied by rearing ten siblings in 1 (sib 1) or 5 (sib 5) l water, and mixed rearing of ten tadpoles (2 from each of the 5 clutches) in 1 (mix 1) or 5 (mix 5) l water; each group replicated five times. In all the groups tadpoles showed a sigmoid growth curve. Both kinship and density interacted to affect mean proportions of individuals reaching metamorphic climax (MC), mean body mass, and size frequency at MC (day 79). The proportion of tadpoles reaching MC was highest in sib 5 (82%) followed by mix 5 (77%), sib 1 (73%), and mix 1 (64%) groups. Crowding plus mixing significantly lowered the median developmental stage mean body mass and broadened the spectrum of developmental stages or size classes at MC. The size difference of individuals at MC was inversely related to density of rearing. Frequency of different developmental stages was comparable in sib 1, sib 5, and mix 5 groups. Interestingly, small individuals were significantly greater in number in the mix 1 group compared to sib 1. The above findings suggest that genotypic heterogeneity in conjunction with crowding retards growth rate of tadpoles in comparison with those reared in a genetically homogenous (sib) environment. Further, they suggest that the adverse effect of mixed rearing is context dependent.

Peacocks lek with relatives even in the absence of social and environmental cues

Lek mating systems are characterized by males displaying in groups. The main benefit from group display is thought to be an increase in the number of females arriving per male. However, when mating success is highly skewed it is not clear why unsuccessful males participate in group display1. In theory, all males on leks could obtain indirect fitness benefits if displaying groups consisted of related individuals2. Here we present two independent sets of data that show that peacocks (Pavo cristatus) display close to their kin. DNA fingerprinting showed that males at Whipsnade Park were more closely related to males within the same lek than to males at other leks. Separately, we found that after an experimental release of a mixed group of related and unrelated males, brothers (paternal sibs or half-sibs) established permanent display sites very close together. This result is unexpected, as the released birds could not become familiar with their brothers during their development. The released young were hatched from eggs that had been removed from their parents shortly after laying and mixed with the eggs of non-relatives. These data indicate that birds can evolve a means of kin association that does not involve learning the characteristics of relatives or the use of environmental cues. If social learning is not necessary for kin association then kin effects may be of more widespread importance in avian social interactions, and in particular in the evolution of lek mating, than previously appreciated.

Determinants of self-care arrangements among school-age children

This study investigates determinants of self-care arrangements among school-aged children. The study finds that mothers'hours of work increase the likelihood of self-care arrangements. However, accompanying results suggest that maternal work and use of self-care does not imply school children are unsupervised. Effects of kin, older siblings, the cost of care and use of only maternal care previously suggest that self-care is chosen only when special conditions are satisfied. When those stipulations are meet, self-care has a higher likelihood of use.

Microsatellite markers reveal the potential for kin selection on black grouse leks

The evolution of social behaviour has puzzled biologists since Darwin. Since Hamilton9s theoretical work in the 1960s it has been realized that social behaviour may evolve through the effects of kinship. By helping relatives, an individual may pass on its genes despite negative effects on its own reproduction. Leks are groups of males that females visit primarily to mate. The selective advantage for males to join such social groups has been given much recent attention, but no clear picture has yet emerged. Here we show, using microsatellite analysis, that males but not females of a lekking bird (the black grouse, Tetrao tetrix ) are genetically structured at the lek level. We interpret this structuring to be the effects of strong natal philopatry in males. This has the consequence that males on any specific lek should be more related than expected by chance as indicated by our genetic data. Our results thus suggest that kin selection is a factor that needs to be considered in the evolution and maintenance of the lek mating system in black grouse and sheds new light on models of lek evolution.

Effects of kinship on growth of a live-bearing reef fish

The influence of genetic relatedness on the individual performance (e.g. growth, development) of animals is often tied to agonistic or cooperative behaviors among conspecifics, and studies of the effects of kinship have produced mixed results. To explore genetic relatedness independent of these behaviors, we investigated the effects of kinship on the growth of the kelp perch Brachyistius frenatus, a live-bearing, planktivorous marine reef fish that is capable of only limited dispersal. Although juveniles occur in aggregations and compete for food resources, they do not exhibit overt aggressive or cooperative behavioral interactions. We hypothesized that under competition and in the absence of these behaviors, sibling and non-sibling groups of juvenile B. frenatus raised at the same densities in the field would not differ in average growth, but that siblings would exhibit lower variation in growth, simply due to genetic similarities in inherent growth rates. Pregnant, female kelp perch were collected and placed in cages until parturition was complete. Groups of young, recently born from the same mother or from different mothers, were then raised in the field for 9 wk. Our results revealed that average growth rates were similar between sibling and non-sibling treatments. While variation in growth increased initially in non-siblings, siblings showed little such variation. This divergence, however, was not consistent over the duration of the experiment, and variation in the growth of siblings ultimately converged with that of non-siblings. Effects of genetic relatedness would be most likely to manifest themselves early after birth, before environmental factors exert their influence, and this may explain the initial separation but eventual convergence in variation in growth between sibling and non-sibling treatments. For B. frenatus and other organisms that will encounter relatives and compete for resources without overt behavioral interactions, the degree of kinship may play a minor role in the demography of local populations.

THE STRUCTURE OF SOCIAL RELATIONSHIPS AMONG FEMALE SAVANNA BABOONS IN MOREMI RESERVE, BOTSWANA

Abstract Here we examine the effects of maternal kinship, reciprocity, and dominance rank on the social relationships of female baboons (Papio cynocephalus ursinus) in a well-habituated, free-ranging group in the Okavango Delta of Botswana. These data are useful for testing comparative hypotheses about the ecological and demographic factors that shape the evolution of social organization in primates and other animals. In this group, adult females had well-differentiated grooming relationships with one another, and limited their grooming to a relatively small subset of available partners. Although there were 19 adult females in the group, the average female groomed only 8 other females, and devoted at least 5% of her grooming to only four other females. Females groomed maternal kin at significantly higher rates and for significantly longer periods than they groomed other females. The bias in favor of maternal kin was not an artifact of a general attraction toward females of adjacent rank. However, members of high-ranking lineages did devote a relatively greater fraction of grooming to maternal kin than members of low-ranking lineages did. Females most often groomed the females from whom they received the most grooming and grooming was very evenly balanced within the majority of dyads. Female rank had little impact upon grooming patterns and there was no evidence that females competed overtly over access to high-ranking partners.

Physical work causes suppression of ovarian function in women.

The suppression of reproductive function is known to occur in women engaging in activities that require high energetic expenses, such as sport participation and subsistence work. It is still unclear, however, if reproductive suppression is a response to high levels of energy expenditure, or only to the resulting state of negative energy balance. To our knowledge, this study provides the first evidence that work-related energy expenditure alone, without associated negative energy balance, can lead to the suppression of reproductive function in women. We document suppression of ovarian function expressed as lowered salivary progesterone levels in women from an agricultural community who work hard, but remain in neutral energy balance. We propose two alternative evolutionary explanations (the 'pre-emptive ovarian suppression' hypothesis and the 'constrained down-regulation' hypothesis) for the observed results.

Models of Red Grouse Cycles. A Family Affair?

The lack of parameterised models showing how intrinsic factors might affect population dynamics has contributed to the belief that they are unlikely to explain population cycles. In this paper we use mathematical models to show how a social process, differential territorial behaviour between kin and non-kin, might drive red grouse (Lagopus lagopus scoticus) population cycles. We develop a simple age-structured population model which has space as a limiting resource and examine two versions of it. The first contains no kin effect and is incapable of cyclic behaviour. The second, containing a modification to reflect the effect of kinship on recruitment, shows oscillatory behaviour over most of the parameter space and produces realistic output (period, amplitude, age structure, recruitment), while its quasi-cyclic behaviour is shown to be robust under random parameter variations. Further parameterisation with field data from two study sites in north-east Scotland yields output which resembles the course of observed population cycles. The model predicts that a young cock present in autumn will have a greater probability of recruitment into the territorial population during the increase than during the decline phase of the cycle. This is consistent with field data. The model further predicts that such fluctuations in the probability of recruitment will be synchronous with fluctuations in the size of kin-clusters.

Proximity and threats in highland ponies

Re-analysis of highland pony data of Clutton-Brock et al. [Clutton-Brock, T.H., Greenwood, P.J., Powell, R.P., 1976. Ranks and relationships in highland ponies and highland cows. Z. Tierpsychol. 41, 202–216.] suggests that rank- and age-like ponies tend to have similar patterns of physical spatial proximity to others. This may also be the case for patterns of threat involvement, but it is less clear. Beyond individuals' overall tendencies to be near others, proximity is greater for pairs with less difference in age and in which there is frequent grooming; effects of rank and height difference and kinship do not significantly improve fit. Beyond individuals' overall tendencies to be involved in threats, threats are more frequent in pairs with less difference in age, more difference in rank, and more grooming; effects of height difference or kinship do not significantly improve fit. Results illuminate the connection between demographic characteristics and social relations.

Intragroup Variation in Conciliatory Tendencies in Captive Japanese Macaques

Nonhuman primates have been observed to exchange friendly gestures soon after an agonistic episode, a behaviour labelled reconciliation. Frequency of reconciliation has been shown to vary both within and between primate groups. This study used both univariate and multivariate analyses to investigate intragroup variation in the frequency of reconciliation in captive Japanese macaques (Macaca fuscata). Frequency of reconciliation was lower during the mating season, and was also affected by the intensity of aggression and by the sex and age combination of the opponents. On the contrary, outcome of aggression and number of aggressors did not influence the frequency of reconciliation. Kin reconciled more than nonkin, and individuals with a good social relationship reconciled more than those with a bad or weak relationship. The effects of kinship and relationship quality appeared to be independent since among individuals with a good relationship, kin reconciled more than nonkin, while among nonkin, individuals with a good relationship reconciled more than those with a bad or weak relationship. Our results show that Japanese macaques are highly flexible in their conciliatory behaviour, and highlight a possible role of reconciliation in the negotiation and management of primate social relationships.

Markets, Networks, and Risk: An Analysis of Labor Remuneration in the Lake Victoria Fishing Industry

This study applies concepts from Habermas' Theory of Communicative Action to the problem of identifying the circumstances under which networks replace markets as the primary governance mechanism for economic activities. The suggestion derived from this theory is that markets govern economic activities tied to material phenomena; whereas networks control such activities when they are tied to social relationships. This suggestion is subjected to an empirical test. Labor transactions in the Lake Victoria fishing industry are used to test the hypothesis that risk factors arising from natural contingencies will distribute according to a risk market model, whereas those arising from social relationships will be distributed through a logic of social power tied to networks and identities. The hypothesis is generally supported by data on the effects of kinship and, more strongly, ethnicity.

The Effects of Kinship on Interactions between Tadpoles of Rana Cascadae

The Effects of Kinship on Interactions between Tadpoles of Rana Cascadae

THE EFFECTS OF KINSHIP ON INTERACTIONS BETWEEN TADPOLES OFRANA CASCADAE

In a series of four field and mesocosm studies, we examined the effects of kinship on growth, survival, and aggregation behavior in tadpoles of the Cascades frog (Rana cascadae) under different ecological conditions. (1) Field observations of tadpole aggregations revealed ecological factors that may interact with kinship to influence tadpole interactions. (2) In an experiment conducted in mesocosms, food distribution, predator presence, thermal heterogeneity, and kinship all interacted to influence tadpole dispersion. (3) In a field experiment conducted in natural ponds, kinship significantly influenced group size at artificially established food patches. (4) In a field enclosure experiment, density, access to the substrate, and kinship all interacted to significantly influence growth and survivorship of tadpoles. Subsequent analysis revealed that kinship affected the distribution of individual tadpole body size: mass was more skewed (i.e., more small individuals) in groups of mixed relatedness than in kin groups. The interaction among kinship, density, and substrate factors resulted in context-dependent effects on tadpole size distribution and survivorship. Our results demonstrate that kinship factors can influence competitive interactions between tadpoles depending upon the ecological conditions, and they provide a functional explanation for kin-discriminating behavior observed in tadpoles of R. cascadae. Kinship-mediated competition may be particularly important for recruitment in size-structured populations.

Effects of kinship on aggression and RNA content in juvenile Arctic charr*1

Effects of kinship on aggression and RNA content in juvenile Arctic charr*1

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.

Schooling preferences for familiar fish vary with group size in a wild guppy population

The ability of fish to recognize and preferentially associate with familiar conspecifics has been well documented in a series of laboratory experiments. In this paper we investigate the schooling preferences of wild female guppies, Poecilia reticulata, in the Upper Tunapuna River in Trinidad and confirm that they do indeed prefer to associate with familiar individuals. The guppies in this river occur in a series of pools that become isolated during the dry season. These fish interact solely with other individuals in their pool for periods of several months at a time and thus have ample opportunity to become accustomed to one another. Our study also reveals that the tendency of female guppies to school with familiar fish declines as the group size in which they naturally live increases. Preferences are strong when there are small numbers of females in a pool, but diminish thereafter. This indicates that the expression of familiarity is constrained by group size. The basis of recognition and the consequences of schooling preferences for familiar individuals are discussed.