A case report of a male rank reversal in a group of wild white-faced capuchins (Cebus capucinus)

During the course of a study of social relationships in wild, white-faced capuchins at Lomas Barbudal, Costa Rice (May 1990–May 1993), the alpha male was deposed by a subordinate male. The rank reversal was preceded by a decline in proximity maintenance by females to the alpha male, and an increase, in the amount of aggression directed toward the alpha male by the beta female and her female coalition partners. At the time of the rank reversal, females switched from giving thegargle vocalization exclusively to the old alpha male to gargling to the new alpha male; however, juveniles were less consistent with regard to which male they gargled to. At the time of the rank reversal, most adult females reduced the time spent in proximity and grooming with the old alpha male, and increased the time spent in proximity and grooming with the new alpha male. In contrast, juveniles' patterns of affiliation with males did not change in a predictable way following the reversal. The social strategies employed by capuchin monkeys during this rank reversal are compared with those of chimpanzees.     

团体咨询改善小学生社会技能的实验研究

目的:通过实验研究表明团体咨询对改善小学生社会技能方面有重要作用。方法:某小学四年级一个班作为实验组,共41人(其中男生23人,女生18人)。采用前后测设计。对实验组进行十二次团体心理咨询,采用社会技能等级评定表进行前后测,以前后测结果的对照及受欢迎程度的改变值和喜欢他人程度的改变值作为效果指标。结果:在受欢迎程度上,前后测得分在受欢迎组、被拒绝组、低接纳组和女生中差异显著,被拒绝组学生团体咨询效果要优于受欢迎组的;在喜欢他人程度的改变上,低接纳组学生的团体咨询效果要优于高接纳组的;在受欢迎程度的改变上,女生的团体咨询效果要优于男生。结论:团体心理咨询对小学生社会技能的干预有效;采取班级团体心理咨询的方式,团体咨询的效果在人际关系不良的学生及女生中表现得更为明显。     

Chronic social defeat stress-induced enhancement of T-type calcium channels increases burst-firing neurons in the ventral subiculum

The ventral subiculum (vSub), a representative output structure of the hippocampus, serves as a main limbic region in mediating the brain's response to stress. There are three subtypes of subicular pyramidal neurons based on their firing patterns: regular-spiking (RS), weak-bursting (WB) and strong-bursting (SB) neurons, located differently along proximal–distal axis. Here, we found that chronic social defeat stress (CSDS) in mice increased the population of SB neurons but decreased RS neurons in the proximal vSub. Specific blockers of T-type calcium channels inhibited the burst firings with a concomitant reduction of afterdepolarization, suggesting that T-type calcium channels underlie the burst-spiking activity. Consistently, CSDS increased both T-type calcium currents and expression of Cav3.1 proteins, a subtype of T-type calcium channels, in the proximal vSub. Therefore, we conclude that CSDS-induced enhancement of Cav3.1 expression increased bursting neuronal population in the vSub, which may contribute to stress-related behaviors.     

Wealth, status, and fitness: a historical study of Norwegians in variable environments

Wealth and status covary with lifetime reproductive success in preindustrial human populations. Local ecology is likely to modify this association, but details of this presumed relationship are not yet known. We sought to determine whether local ecology modifies the relationship between status and fitness (number of grandchildren). Our approach to the problem was to measure variation in fitness relative to status (landless or with land) and to local ecology (inland versus coastal communities). We also analyzed life history traits that might explain observed variations in fitness. Our results confirm previous findings that both status (landless=9.9 vs. with land=16.5) and ecology (inland=12.3 vs. coast=14.1) affect the number of grandchildren produced by a female in pre-industrial society. We also found that the differences in number of children between the status groups were less pronounced on the coast (landless=12.0 vs. with land=16.1) than inland (landless=7.8 vs. with land=16.8). Our findings are novel because they suggest that the fitness consequences of human status may depend on details of local ecology. We discuss four different mechanisms that could account for these fitness differences: (1) differential reproductive rate of mothers, (2) differential marriage rate of children (3) differential survival rate of children, and (4) different social practices (breastfeeding, inheritance of property and diet).     

Focused grooming networks and stress alleviation in wild female baboons

We examine the relationship between glucocorticoid (GC) levels and grooming behavior in wild female baboons during a period of instability in the alpha male rank position. All females' GC levels rose significantly at the onset of the unstable period, though levels in females who were at lower risk of infanticide began to decrease sooner in the following weeks. Three factors suggest that females relied on a focused grooming network as a coping mechanism to alleviate stress. First, all females' grooming networks became less diverse in the weeks following the initial upheaval. Second, females whose grooming had already focused on a few predictable partners showed a less dramatic rise in GC levels than females whose grooming network had been more diverse. Third, females who contracted their grooming network the most experienced a greater decrease in GC levels in the following week. We conclude that close bonds with a few preferred partners allow female baboons to alleviate the stress associated with social instability.     

食物诱导长爪沙鼠集群贮食的野外实验设计及其在社群研究中的应用

长爪沙鼠为典型的群居性鼠类。在自然条件下该鼠的集群贮食活动随时可为人工投放的种子食物所导引。本文依据组群个体合作贮食的习性,并结合剪趾和染毛双重标记的重捕跟踪方法设计了着重观测社群结构、群内个体序位、领域边界及相关社群行为的野外实验。据2(X)2年5月对4个相邻洞群的观测结果分析表明,应用此法便于在复杂的社群环境中直接确认组群成员及其属性,亦便于分辨同一组群或不同组群成员之间发生的行为事件及相关过程,且能在重复实验中得以验证。为在野外条件下定量研究长爪沙鼠社群行为提供了一种便捷可靠的观测方法。     

Marriage Timing over the Generations

Strong relationships have been hypothesized between the timing of marriage and the familial environment of the couple. Sociologists have identified various mechanisms via which the age at marriage in the parental generation might be related to the age at marriage of the children. In our paper we study this relationship for historical populations. We use a dataset consisting of several hundreds of thousands of marriages contracted in three of the 11 Dutch provinces between 1812 and 1922. We identified the generational links between the brides, grooms, their parents, and grandparents. We studied (a) whether there is a relationship between ages at marriage of (grandfathers) fathers and sons, and ages at marriage of (grandmothers) mothers and daughters and (b) whether this relationship might be explained by social class. We find evidence for a clear effect of the family on age at marriage and substantial intergenerational transmission. The impact that the family of origin has on age at entry into marriage can partly be attributed to social class. We also observed positive effects of grandparents’ age at marriage on their offspring’s age at marriage.

Age-specific differences in the winter foraging strategies of rooks Corvus frugilegus

Summary Foraging efficiency and intraspecific competition were compared between wild adult and immature rooks Corvus frugilegus with respect to flock size. Behavioural time budgets, and observations of prey selection and prey energetic values revealed that adult rooks in large flocks (> 50 individuals) consumed smaller, less profitable prey, but allocated more time to feeding and fed at a faster rate and with greater success than adults in small flocks. By contrast, immature rooks in flocks of more than 30 individuals allocated proportionally less time to feeding, fed at a lower rate and fed with no increase in success rate than when foraging in smaller flocks. Agonistic encounters and the avoidance of adults by immature rooks appeared responsible for such inefficient foraging. Hence immature rooks showed a preference for smaller flocks (< 50 individuals) with low adult: immature ratios while adults preferred larger flocks (> 50 individuals). We discuss the possible influence of competitive disadvantages on immature rook distribution, flock composition and post-natal dispersal.     

Group size and stability: Why do gibbons and spider monkeys differ?

Gibbons and spider monkeys have similar diets, body size, and locomotor patterns. They are therefore expected to be subject to similar socioecological rules. However their grouping patterns differ. Gibbons live in small stable groups, whereas spider monkey form unstable sub-groups that vary from small to large during different seasons. If similar principles apply to the two species, food abundance should vary more for spider monkeys than for gibbons; food density should be similar for the two species when spider monkey sub-groups are the same size as gibbon groups; and the highest level of food abundance should be higher for spider monkeys than for gibbons. These predictions are upheld for a comparison of particular populations ofHylobates muelleri andAteles geoffroyi.     

High levels of Paleolithic Y-chromosome lineages characterize Serbia

Whether present-day European genetic variation and its distribution patterns can be attributed primarily to the initial peopling of Europe by anatomically modern humans during the Paleolithic, or to latter Near Eastern Neolithic input is still the subject of debate. Southeastern Europe has been a crossroads for several cultures since Paleolithic times and the Balkans, specifically, would have been part of the route used by Neolithic farmers to enter Europe. Given its geographic location in the heart of the Balkan Peninsula at the intersection of Central and Southeastern Europe, Serbia represents a key geographical location that may provide insight to elucidate the interactions between indigenous Paleolithic people and agricultural colonists from the Fertile Crescent. In this study, we examine, for the first time, the Y-chromosome constitution of the general Serbian population. A total of 103 individuals were sampled and their DNA analyzed for 104 Y-chromosome bi-allelic markers and 17 associated STR loci. Our results indicate that approximately 58% of Serbian Y-chromosomes (I1-M253, I2a-P37.2 and R1a1a-M198) belong to lineages believed to be pre-Neolithic. On the other hand, the signature of putative Near Eastern Neolithic lineages, including E1b1b1a1-M78, G2a-P15, J1-M267, J2-M172 and R1b1a2-M269 accounts for 39% of the Y-chromosome. Haplogroup frequency distributions in Western and Eastern Europe reveal a spotted landscape of paleolithic Y chromosomes, undermining continental-wide generalizations. Furthermore, an examination of the distribution of Y-chromosome filiations in Europe indicates extreme levels of Paleolithic lineages in a region encompassing Serbia, Bosnia-Herzegovina and Croatia, possibly the result of Neolithic migrations encroaching on Paleolithic populations against the Adriatic Sea.