STONE TOOLS AND THE UNIQUENESS OF HUMAN CULTURE

There is growing evidence that some species other than the human have behaviour that should be called cultural. Questions arise, then, of how human (and, perhaps, ape) cultures are different from those of other animals and how they have become so different. Human cultures are creative, generating new patterns of behaviour from those learned from others. Stone tool making provided a niche for the recruitment of tools and tool-making processes from one function to another. This is something not yet recorded for apes. This article explores the possible role of stone tools in the emergence of this creativity.     

ASPECTS OF THE FORAGING BEHAVIOUR OF THE SHOEBILL

Guillet, A. 1979. Aspects of the foraging behaviour of the Shoebill. Ostrich 50:252-255.

The foraging behaviour of the Shoebill Balaeniceps rex. in relation to the bird's habitat and morphology, is described. The Shoebill preys on fish in shallow water, and uses platforms of floating vegetation as fishing sites. The Shoebill's behaviour in stalking, detecting and capturing prey is compared with foraging techniques used by herons and storks. The Shoebill uses a peculiar and complicated technique, called “collapsing”, for capturing prey.     

银鹊树群落生物量和能量的分配

 本文研究了安徽大别山天然林内16年生银鹊树和引种于南京的银鹊树幼苗及人工幼林的生物量,分析了光能利用率。研究结果表明：(1)常规芦蒹遮光,一龄苗的生物量为1777.5kg／ha。以一层塑料纱遮光处理的幼苗生物量最大,全光照的幼苗生物量居第二、三层纱遮光生物量最小。(2)天然林内16年生单株银鹊树地上部分干重为107.77kg。(3)8年生人工银鹊树林总生物量为80.63t／ha,其中乔木层平均净生产量为9.563t／ha·a,高于湖南会同、朱亭及江苏南部的杉木林。(4)银鹊树林总初级生产量为1219.18g／m2·a;其中乔木层为956.25g／m2·a,草本及天然幼苗为161.10g／m 2·a,枯枝落叶为101.83g／m2·a．光能利用率为0.527%,其中乔木层的光能利用率为0.417%。     

Comparisons of calling behaviour of different geographical populations of Helicoverpa armigera

Abstract:  The cotton bollworm, Helicoverpa armigera, with worldwide distribution, evolves into different geotypes for adapting to the changes of geographical climates. Comparisons of calling behaviour of the insect collected from the temperate region in northern China (Beijing), the temperate region in north-western China (Kashi) and the tropical region in southern China (Haikou) were investigated in the laboratory as a first step to understanding the influence of reproductive behaviour on its population differentiation. There were more than 80% of virgin females of each population that showed calling behaviour. The age at which the moths of all three populations initiated calling varied significantly. The durations of calling in scotophase and the percentages of females calling also differed between populations. Only a few females of the Beijing and Haikou populations called in the first 2 h after the onset of scotophase, whereas many Kashi females called at this time. However, the main calling peak occurred during the second half of scotophase for all three populations. Females of the Beijing and Haikou populations exhibited similar calling onset times at the same age, whereas the Kashi females initiated calling significantly earlier than those of Beijing and Haikou from nights 3 to 7. The durations of each calling bout and the time spent by both Beijing and Haikou populations were similar to each other at the same age, but were significantly shorter than that of the Kashi population from nights 3 to 7. These results suggest that there are genetic variations not only in pre-period calling but also in the calling behaviour of H. armigera .     

Estimating maximum bite performance in Tyrannosaurus rex using multi-body dynamics

Bite mechanics and feeding behaviour in Tyrannosaurus rex are controversial. Some contend that a modest bite mechanically limited T. rex to scavenging, while others argue that high bite forces facilitated a predatory mode of life. We use dynamic musculoskeletal models to simulate maximal biting in T. rex. Models predict that adult T. rex generated sustained bite forces of 35 000-57 000 N at a single posterior tooth, by far the highest bite forces estimated for any terrestrial animal. Scaling analyses suggest that adult T. rex had a strong bite for its body size, and that bite performance increased allometrically during ontogeny. Positive allometry in bite performance during growth may have facilitated an ontogenetic change in feeding behaviour in T. rex, associated with an expansion of prey range in adults to include the largest contemporaneous animals.     

雄蝇追逐行为的分析

本文报告了在自由飞行条件下雄蝇追逐的行为实验及其分析的初步结果.其结果如下:1.追逐雄蝇水平方向偏转的角速度dF_1线性地依赖于目标蝇水平方位误差角T_1的大小.当目标在前视场中,即空间误差角|G|<π/4时,线性回归直线的斜率约为37**;而当空间误差角|G|>π/4时,线性回归直线的斜率约为6.7.2.追逐雄蝇俯仰方向偏转角速度dF_2在(-(π/2),π/2)的范围内线性依赖于俯仰误差角T_2的大小,其回归直线的斜率约为14.3.雄蝇追逐行为中,水平方位误差角频数分布的直方图呈现为峰值在零点的对称型分布;而俯仰误差角T_2频数分布的直方图是非对称型的,即仰角出现的频数大大超过俯角出现的频数.4.雄蝇主要利用了两蝇间距离变化dD的信息以及目标误差角来控制向前飞行的速度V.当误差角小时(即目标在前视场中),dD一般为负值,说明两蝇间的距离减小,而雄蝇追逐飞行的加速度A却与dD呈现正的线性关系.当误差角大时(即目标位于后视场中),dD一般为正值,说明两蝇间的距离增加.     

THE ORIGINS OF ADAPTIVE INTERSPECIFIC TERRITORIALISM

1. In order to understand fully the evolution of a behavioural trait one must not only consider whether it is adaptive in its present environment but also whether it originated as an adaptation to existing selective forces or as a fortuitous consequence of selection for a different role in other environments (i.e., as a pre-adaptation) or of selection for different traits (e.g., as a pleiotropic effect). In this paper interspecific territorialism is examined in species of humming-birds, sun-birds, tropical reef fishes, stingless bees, stomatopods, crayfish, and limpets as a means of determining its adaptiveness and its origins. 2. Humming-birds form complex assemblages with species sorted out among the available resources. Dominant species establish feeding territories where flowers provide sufficient nectar. A few large, dominant species, usually uncommon, are marauders on others' territories. Subordinate species establish territories where flowers are more dispersed or produce less nectar, or they fly a circuit from nectar source to nectar source when flowers are even more dispersed, a foraging pattern called ‘traplining’, or they steal nectar from the territorial species by being inconspicuous while foraging. Two species, Amazilia saucerottei and Selasphorus sasin, subordinate in one-to-one encounters, are able to take over rich resources by establishing several small territories within a territory of a dominant and forcing it to forage elsewhere. 3. Among humming-birds, territorial individuals attacked not only subordinate competitors but marauding humming-birds and some insects, which stayed in the territory and foraged at will, and seemingly inappropriate targets, such as non-competitors. This suggests that the stimulus for aggression is ‘any flying organism near the food resources’, regardless of its appearance. The behaviour rather than the identity of the intruder is the stimulus. 4. Sun-birds resemble humming-birds to the extent that dominants establish territories on rich nectar sources and subordinates establish territories on less rich nectar sources or steal from the territories of dominants. The diversity of foraging patterns is not so great as in humming-birds, perhaps because so few species of sun-birds have been studied. However, the advantage of territorialism has been measured in the sun-bird Nectarinia reichenowi. Individuals with territories lose much less nectar to competitors than do those without territories. 5. Field work on three species of tropical reef fishes involved a single aggressive species whose individuals attacked a wide range of species intruding on their territories. The stimulus for aggression in Pomacentrus jenkinsi seemed to be an “object moving through [its] territory”. As suggested for humming-birds, the stimulus is the behaviour rather than the identity of the intruder. 6. The relationships found in stingless bees, stomatopods, crayfish, and limpets are simpler. The dominant and subordinate species divide the resources in their habitat, the dominants' aggression preventing the subordinates from using resources that were otherwise available to them. 7. A general pattern emerges. Mutual interspecific territorialism occurs between species that (i) have different geographic ranges, (ii) occupy different habitats, or (iii) use different resources within the same habitat. Examples of two species holding separate territories on the same resources within the same habitat are rare and occur when the dominant species is rare relative to the available resources. These observations are contrary to the usual view that interspecific territorialism is an adaptation that permits co-existence of potential competitors within the same habitat. 8. Interspecific territorialism is sometimes adaptive and sometimes maladaptive, depending upon the species and the situation. 9. The general pattern of occurrence of the behaviour and the general nature of the stimulus for aggression, i.e., the behaviour rather than the identity of the intruder, suggest that interspecific territoriality is a fortuitous consequence of selection for intraspecific territorialism, the latter being not only an adaptation to the presence of conspecific competitors but a pre-adaptation to the presence of competitors of other species, should they occur.     

LETTERS TO THE EDITOR

Cox, George W. 1983. Foraging behaviour of the Dune Lark. Ostrich 54:113-120.

Foraging behaviour of the Dune Lark Mirafra erythrochlamys was studied in a dune environment at the Namib Research Institute, Gobabeb, South West Africa/Namibia in August 1981. Birds foraged for a total of 7 h per day in morning and afternoon periods separated by 3 h of inactivity during the warm midday. The birds exploited a distinctive series of vegetational belts dominated by three grasses. About two-thirds of total foraging time was spent in zones of dead and dormant grasses where seeds were sought by excavating small craters in the sand with the bill. Simples taken in the field, and simulations of bill-cratering behaviour in the laboratory, showed that this behaviour displaced seed-poor surface sand and exposed deeper, seed-rich layers. Birds formed small flocks when foraging for seeds in these zones. The remaining third of foraging time was spent in zones with large, live grass clumps, where insects were sought. Insect foraging was concentrated at the start and end of each activity period, but was most intense just before the midday period of inactivity when temperatures approached 30°C. Rough calculations of energy and water balance suggest that the larks are unable to maintain water balance under the observed conditions on seed food alone, and that this balance is achieved by feeding on insects. It is predicted that relative seed and insect foraging effort varies with temperature and season, as also suggested by limited published data on stomach contents in summer and winter.     

Patchy stomatal conductance: emergent collective behaviour of stomata

Until recently, most scientists have tacitly assumed that individual stomata respond independently and similarly to stimuli, showing minor random variation in aperture and behaviour. This implies that stomatal behaviour should not depend on the scale of observation. However, it is now clear that these assumptions are often incorrect. Leaves frequently exhibit dramatic spatial and temporal heterogeneity in stomatal behaviour. This phenomenon, in which small 'patches' of stomata respond differently from those in adjacent regions of the leaf, is called 'patchy stomatal conductance'. It appears to represent a hitherto unknown type of emergent collective behaviour that manifests itself in populations of stomata in intact leaves.     

Power laws without complexity

Power laws have been invoked in describing the sizes of a wide variety of objects in evolution and ecology. The apparent ubiquity of power laws is commonly attributed to a form of complex behaviour called self‐organizing criticality. It is shown that power law behaviour inevitably arises from the statistics of large values from heavy‐tailed distributions and that such distributions can be generated by processes that do not involve self‐organized criticality. It follows that power law behaviour cannot be taken as prima facie evidence of self‐organizing criticality.     

THE BREEDING BEHAVIOUR OF THE WHITE BOOBY SULA DACTYLATRA*

The aim of this paper is to describe the form and interpret the motivation, function and derivation of breeding behaviour in the White Booby. Attention is paid to adaptive aspects and an effort made to correlate behaviour with environment? particularly colony density and associated degree of competitive behaviour. The absence, simplicity or complexity of certain displays can be correlated with the extent to which highly developed social and /or pair interaction are needed. Throughout I have tried to place White Booby behaviour in the framework of behaviour in the Sulidae as a group and particularly to compare it with Gannet behaviour, since the latter nest more densely than other sulids and show more extreme aggression and greater ritualization of behaviour patterns used in interpair and wider social communications. The White Booby provides an interesting contrast. After a brief account of morphology and voice the points are made that White Booby colonies are generally smaller and much less dense than those of the Gannet or Peruvian Booby and also that White Boobies breed in a wide variety of habitats. Site establishment, pair formation, later pair relations, social interactions, body maintenance behaviour, incubation and care of young are described and an account of behaviour in the young is given. The male establishes the site and shows yes /no headshaking as an aggressive, site-ownership display, often performed after landing. He attracts the female with a sky-pointing display which is homologous with sky-pointing in the Gannet, where, however, it subserves a different and, it is argued, phylogenetically older function, signalling that a bird is about to leave the site rather than serving as an advertizing display. In the White Booby it is thus a good example of a motivationally and functionally emancipated display. When the pair meet, mutual jabbing, a hostile-looking and relatively undifferentiated meeting ceremony, and bill-touching occur. Symbolic nest building plays an important part in White Booby pair behaviour, though the nest is structurally negligible. Nest building is associated with copulation, in which the female is not gripped. Bill-up-face-away is a bill-averting posture used when a booby moves away from its mate. It is probably an appeasement posture and, so far as the situation “I am about to move” is concerned, seems to have taken the place of Gannet sky-pointing, the latter having become the booby's advertizing. Wing rattle is a movement probably partly functional in preparing feathers for flight, but is also used as signal behaviour prior to take-off, particularly during the frequent flights around the breeding area that White Boobies show early in the season. Wing flapping, sometimes with rotary headshaking, is mainly feather maintenance behaviour. The forms of headshaking and head flinging are described. Reciprocal allo-preening occurs; it is suggested that it can do so without disadvantage since White Boobies possess mutual jabbing—an interaction which can accommodate any aggression engendered by the pair pointing bills at each other, as required for reciprocal allo-preening. The average incubation spell in the male is 30 hours and in the female 25 hours; all sulid males show this tendency to spend longer on the site. Seasonally, too, there is a marked sex-difference in site attendance and this is depicted in graphs for different categories of White Boobies. The young are left unguarded from about four weeks of age and move off the site. They are fed about 1.4 times per day. They respond to adult investigation or attack by beak-hiding—an effective appeasement posture. Soon, they perform aggressive territorial behaviour and dispel other young and adults. They return to the site to be fed for around 50 to 60 days after they become free-flying and show all forms of territorial behaviour. The discussion is mainly concerned with the correlation between nesting density, aggression and associated appeasement behaviour. It is concluded that, overall, the White Booby's ritualized postures and displays are less well differentiated than those of the Gannet, though individual behaviour patterns may be more complex. The pair relationship in the White Booby approximates more closely to that normally found in birds, where the male is not outstandingly aggressive to his mate.     

Genetic Evidence for Two T Complex Tail Interaction (Tct) Loci in T Haplotypes

The t complex on chromosome 17 of the house mouse is an exceptional model for studying the genetic control of transmission ratio, gametogenesis, and embryogenesis. Partial haplotypes derived through rare recombination between a t haplotype and its wild-type homolog have been essential in the genetic analysis of these various properties of the t complex. A new partial t haplotype, which was derived from the complete tw71 haplotype and which is called tw71Jr1, was shown to have unexpected effects on tail length and unique recombination breakpoints. This haplotype, either when homozygous or when heterozygous with the progenitor tw71 haplotype, produced short-tailed rather than normal-tailed mice on certain genetic backgrounds. Genetic analysis of this exceptional haplotype showed that the recombination breakpoints were different from those leading to any other partial t haplotype. Based on this haplotype, a model is proposed that accounts for genetic interactions between the brachyury locus (T), the t complex tail interaction (tct) locus, and their wild-type homolog(s) that determine tail length. An important part of this model is the hypothesis that the tct locus, which enhances the tail-shortening effect of T mutations, is in fact at least two, genetically separable genes with different genetic activities. Genetic analysis of parental and recombinant haplotypes also suggests that intrachromosomal recombination involving an inverted duplicated segment can account for the variable orientation of loci within an inverted duplication on wild-type homologs of the t haplotype.     

Socially cued anticipatory adjustment of female signalling effort in a moth

Juvenile population density has profound effects on subsequent adult development, morphology and reproductive investment. Yet, little is known about how the juvenile social environment affects adult investment into chemical sexual signalling. Male gumleaf skeletonizer moths, Uraba lugens, facultatively increase investment into antennae (pheromone receiving structures) when reared at low juvenile population densities, but whether there is comparable adjustment by females into pheromone investment is not known. We investigate how juvenile population density influences the ‘calling'' (pheromone-releasing) behaviour of females and the attractiveness of their pheromones. Female U. lugens adjust their calling behaviour in response to socio-sexual cues: adult females reared in high juvenile population densities called earlier and for longer than those from low juvenile densities. Juvenile density also affected female pheromonal attractiveness: Y-maze olfactometer assays revealed that males prefer pheromones produced by females reared at high juvenile densities. This strategic investment in calling behaviour by females, based on juvenile cues that anticipate the future socio-sexual environment, likely reflects a response to avoid mating failure through competition with neighbouring signallers.     

Different adhesion and migration properties of human HCV29 non-malignant urothelial and T24 bladder cancer cells: role of glycosylation

In tumour cells, alterations in cellular glycosylation may play a key role in their metastatic behaviour. This study used cell lines having very different behaviour in vivo: HCV29 non-malignant transitional epithelium and T24 bladder transitional cell carcinoma. These differences in behaviour might be due in part to differences in cellular glycosylation patterns. Glycan chain analysis of their glycoproteins was performed with the use of specific lectins. The functional role of carbohydrates was studied by treating these cells with swainsonine, an inhibitor of Golgi alpha-mannosidase II, and in vitro adhesion and migration assays. The adhesion of swainsonine-treated HCV29 and T24 cells was increased on fibronectin and type IV collagen by 1.5- and 2-fold, respectively, whereas adhesion on laminin was virtually unchanged after swainsonine-treatment in HCV29 cells and was increased in T24 cells. Swainsonine treatment reduced the rate of T24 cell migration by 20%. We concluded that beta1-6 branched tri- and tetraantennary complex-type glycans have an important function in adhesion and migration in the studied cell lines. These data support the view that oligosaccharides are involved in several steps of the metastatic process.     

Nepotistic alarm calling in the Siberian jay, Perisoreus infaustus

From a life history perspective, parents have an incentive to protect their reproductive investment, and so may provide care even after their offspring are independent. Such prolonged parental care could lead to postponed dispersal of the offspring and thereby facilitate the formation of kin groups. We tested whether alpha birds in Siberian jays protected their independent, retained offspring by giving alarm calls during simulated predator attacks. We compared the responses to predator attacks simulated by flying a hawk model over a dyad of birds on a feeder for dyads composed of an alpha bird and either a relative or a nonrelative. Alpha females were nepotistic in their alarm-calling behaviour, in that they called more frequently when accompanied by their retained offspring than by unrelated immigrants, but alpha males called indiscriminately. This difference in alarm calling could reflect dominance relationships in Siberian jay groups, because the presence of immigrants may be less costly to alpha males, but alpha females are more vulnerable to competition from immigrants. Alarm calls were usually given during escape, when both individuals in the dyad had left the feeding site. However, results of a playback experiment suggest that alarm calls conveyed information about danger and incited an immediate escape reaction. Our results indicate that alarm calling can be nepotistic, and that factors other than kinship influence alarm-calling behaviour. Nepotistic antipredator behaviours are benefits that offspring can gain only in their natal territory. Hence, in the absence of preferential treatment by their parents, offspring may be more likely to disperse and kin groups are prevented from forming.     

IL-15 is required for sustained lymphopenia-driven proliferation and accumulation of CD8 T cells

Naive T cells undergo slow homeostatic proliferation in response to T cell lymphopenia, which is also called lymphopenia-induced proliferation (LIP). IL-7 is critically required for this process, but previous studies suggested IL-15 was expendable for LIP of naive CD8 T cells. In contrast, we show that IL-15 is important for sustained CD8 T cell proliferation and accumulation in a lymphopenic setting, as revealed by truncated LIP in IL-15(-/-) hosts. At the same time, we find that IL-12 enhances LIP by acting directly on the CD8 T cells and independently of IL-15, suggesting distinct pathways by which cytokines can regulate homeostatic proliferation. Interestingly, the memory-phenotype CD8 T cell generated by LIP in IL-15(-/-) hosts are phenotypically distinct from the rare endogenous memory-phenotype cells found in IL-15(-/-) animals, suggesting these cells are generated by different means. These findings demonstrate that cytokine requirements for LIP change during the process itself, illustrating the need to identify factors that regulate successive stages of lymphopenia-driven proliferation.     

蚕豆核仁残体的电镜研究

本文报道了有丝分裂过程中蚕豆(Vicia faba)根端分生组织细胞内一种由核仁物质组成的特殊结构,我们将其称作核仁残体。经常规染色后,可在前期末正在分散的核仁物质中看到由直径15—20nm 的颗粒和纤维组成的核仁残体;前中期时,核仁残体附着在染色体上,其电子密度低于染色体。Bernhard 染色结果表明,核仁残体的主要成分是核糖核蛋白(RNP)颗粒和纤维,一些核仁残体中存在着与染色质染色反应相似的被漂白区。有的核仁残体附着在中、后期染色体上,有的游离存在于细胞质中。本文讨论了核仁残体的成分及其本质等问题。     

Effect of paired encounters on plasma androgens and behaviour in males and females of the spiny damselfish Acanthochromis polyacanthus

Sexually mature male and female spiny damselfish, Acanthochromis polyacanthus (Pomacentridae) were introduced to resident fish of both sexes in paired encounter trials and the effect on activity, agonistic behaviour and plasma levels of testosterone (T) and 11-ketotestosterone (11-KT) in males, and T and 17β-estradiol (E₂) in females, and cortisol in both sexes was determined. Introduced males showed suppressed levels of T in the presence of both resident males and females, whereas resident males showed elevated T in response to introduced males but not females. Plasma 11-KT levels were unchanged in either resident or introduced males. Resident males showed increased activity in the presence of males but not females. Resident females showed an increase in activity when paired with introduced females and greater aggressive behaviour towards females than males. There were no differences in plasma hormone levels in either resident or introduced female fish. Plasma cortisol levels were low in all fish and stress effects did not appear to account for differences in T levels in males. The results of the present study show that elevations in plasma T levels in resident male spiny damselfish are associated only with male presence but that suppression of T in introduced fish occurs irrespective of the sex of the resident. In contrast resident females, which show stronger evidence of aggressive behaviour do not show changes in plasma androgen levels. This suggests that aggressive behaviour in male and female fishes may be mediated by different endocrine pathways.