bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental Influences on Infanticide in Columbian Ground Squirrels
Authors: Dobson F. Stephen
Published: May 2010

Infanticide of preweaned and weanling juvenile Columbian ground squirrels (Spermophilus columbianus) has been previously reported, but its prevalence in most populations is poorly known. I examined evidence of infanticide in a six‐year study of four populations in southwestern Alberta, two of which received an experimental supplementation of food for two years. Evidence of infanticide of weanling ground squirrels was uncommon, except for one population and year (previously supplemented population at 1580 m elevation in 1984) in which 9 dead young were found, suggesting an increased rate of infanticide. The rate of total loss of pre‐weaned litters also increased at 1580 m in 1984. At higher elevation sites (2100 m), however, no evidence of infanticide was found under experimental or unmanipulated conditions. One factor that might have influenced the rate of infanticide of weanlings was their degree of development when they first emerged from natal burrows. A review of studies of 11 populations of Columbian ground squirrels suggested that under natural conditions, infanticide may have differed among environments. Differences in density among populations appeared to have little influence on the rate of infanticide, but elevation was significantly negatively associated with infanticide.
Invasion of the Nest of Polistes dominulus by the Social Parasite Sulcopolistes sulcifer (Hymenoptera, Vespidae)1
Authors: Turillazzi S. , Cervo R. , Cavallari I.
Published: May 2010

The main characteristics of invasion of a Polistes dominulus Christ colony by a female of Sulcopolistes sulcifer Zimmermann can be summarized as follows: the parasite is usually attacked by Polistes while still approaching the nest. The parasite fights all opponents on the ground, both foundresses and workers, some of which can be very aggressive even off the nest. Others succumb to the parasite immediately on the very first encounter. Sulcopolistes' strategy is to fight one adversary at a time and then return rapidly to the nest. In this way it is easier for her to defeat the hosts one after another, and to usurp nests with a high number of workers. While fighting on the ground the parasite never used its sting, but tried to bite the legs off its victims. The alpha foundress is the one which attacks the parasite most aggressively, which in turn is particularly aggressive towards her. Beta females on bigynic and gamma females on trigynic foundations are less aggressive than their nestmates of higher hierarchical status. After nest conquest, dominance activity of the parasite increases, and she offers drops of liquid to nest occupants during encounters. When not interacting with the hosts, Sulcopolistes performs an intense nest inspection and carefully strokes the nest surface and internal parts of some cells with her abdominal sterna.
Social Organization and Sexual Interactions in Australian Brush‐turkeys (Alectura lathami): Implications of Promiscuity in a Mound‐building Megapode
Authors: Jones Darryl N.
Published: May 2010

Unlike most other megapodes (family Megapodiidae), Australian brush‐turkeys showed no evidence of prolonged pair‐bonding. Adult males and females exhibited spacial and temporal independence throughout the breeding season. Males remained close to their mounds and allowed females to lay only after copulation. Multiple copulations, often forced, occurred frequently as females excavated laying holes. Both sexes copulated promiscuously, and males accepted eggs despite a low certainty of paternity. However, the costs of cuckoldry were probably small and less than the fitness benefits derived from using mounds primarily as a means to increase female encounter, copulation, and fertilization rates.
Polygynous Mating System of Trimma okinawae (Pisces: Gobiidae) at Kagoshima, Japan with a Note on Sex Change
Authors: Sunobe Tomoki , Nakazono Akinobu
Published: May 2010

Mating system, social structure and reproductive behaviour of the gobiid fish Trimma okinawae were studied at Akamizu, Kagoshima, Japan. Mating system of this species is polygyny. There were two types of habitat‐related distribution patterns of male and female home ranges: females have home ranges outside a small territory of the male; female home ranges are covered by male territory. Spawnings take place with a cycle of four to five days during the spawning season of June to Sept. In the morning of the day of spawning, males stay at the spawning sites. Females visit the site and spawn with the male. On days between spawnings males exhibit courtship displays at female home ranges. Higher reproductive success is not connected with frequency of such courting of the male, but with male size. The largest female of a social unit changes into a male when the dominant male is removed, which shows that T. okinawae is a hermaphrodite.
Female Choice in Humans: A Conditional Mate Selection Strategy of the Krummhörn Women (Germany, 1720–1874)
Authors: Voland Eckart , Engel Claudia
Published: May 2010

The suitors' ownership of land influenced the marriage age of the women in the Krummhörn population (Germany, 1720–1874). This led to a characteristic distribution of the categories of land ownership of husbands by the wife's age at marriage: the younger the brides, the higher was the percentage of high‐status males among their bridegrooms. But the natal status of brides did not exert any significant influence on their age at marriage. Moreover, socially hypergamous women married younger than those whose marriage meant a social drop. We have interpreted these findings as the expression of a conditional female choice strategy with age‐dependent decrease in demands on a marriage partner: “If you are young, be very choosy and marry only a high‐quality mate; the older you become, the more you must reduce your initial standards!” On the average this strategy was adaptive, because in this population land ownership correlated with the local reproductive success of a family.
The Aggression‐releasing Effect of the Eye‐like Spot of the Oyanirami Coreoperca kawamebari, a Freshwater Serranid Fish
Authors: Kohda Yasutoshi , Watanabe Munetaka
Published: May 2010

An aggressive oyanirami, a freshwater fish, makes its opercular eye‐like spots conspicuous and spreads the gill covers to its rival. The eye‐spot is a main component of the color pattern of an aggressive fish. The color pattern releases aggressive actions of a conspecific fish. Using dummies, we found that the presence of the eye‐spot was important to aggression‐releasing, and this was independent of its location.
Confronting Snakes in the Burrow: Snake‐Species Discrimination and Antisnake Tactics of Two California Ground Squirrel Populations
Authors: Towers Steven R. , Coss Richard G.
Published: May 2010

The purpose of this study was to investigate phylogenetic and ecological factors that shape encounters between California ground squirrels and snakes in the burrow setting. Ground squirrels were video taped while interacting in a simulated burrow with either a venomous rattlesnake or a lessdangerous gopher snake. Squirrels from a population where snakes are rare treated both snake species with greater caution than did squirrels from a snake‐adapted population. High physiological resistance to rattlesnake venom in the snake‐adapted population was associated with more intense rattlesnake harassment. Squirrels from both populations treated the rattlesnake as the more important predator, as inferred from higher levels of harassment and escape‐motivated behavior while interacting with the rattlesnake.

We conclude that the tightly constraining ecology of burrow encounters with intruders supports the expression of competent antipredator behavior in ground squirrels. We view adaptations such as snake‐species discrimination as embedded in the ecological relationship between snakes, ground squirrels, and the architecture of the burrow setting.
Phylogenetic Analysis of the Evolution of Display Behavior in the Neotropical Manakins (Aves: Pipridae)
Authors: Prum Richard O.
Published: May 2010

Phylogenetic systematic methods were applied in an investigation of the evolution of lek display behavior in the Neotropical manakins (Aves: Pipridae). Results of a previous investigation of the syringeal morphology of manakins were used as a behaviorally independent estimate of the phylogeny of the family. Three phylogenetic analyses of 44 display characters wer
Pigeon Homing: The Effect of Local Experience on Initial Orientation and Homing Success
Authors: Grüter Meinhard , Wiltschko Roswitha
Published: May 2010

A series of experiments was conducted to study how local experience and
Individual Life History and Song Repertoire Changes in a Colony of Starlings (Sturnus vulgaris)
Authors: Adret‐Hausberger Martine , Güttinger Hans‐Rudolf , Merkel Fritz W.
Published: May 2010

Observations were made over two years in a small colony of starlings to look at possible changes in the songs of each male, taking into account its life‐history and breeding status. Each male sings two categories of song: warbling, a long, complex and mainly individual song, and loud and simple whistles. Within the latter, some are species‐specific whereas others characterize the individual in its colony. Over two years very few changes were observed for the species‐specific whistle themes and all birds shared the same variant. But the birds changed their individual whistle types almost completely from one year to the next. Changes in warbling song may depend on age: one bird changed his repertoire of motifs completely between his first and second year of life, whereas other older males merely added some new motifs to their repertoire of the previous year. Such results show that adult starlings in the wild, even older birds (7 years old), may still be able to acquire new structures. The new elements appeared in the fall and were kept at least until the following breeding season. All songs were very stable throughout a given breeding season. Although individual repertoires increased with age, large differences in repertoire size were found in same age individuals. First data suggest that breeding status (e.g. polygyny) and repertoire size may be related.
Sexual Differences in Aggressive Behaviour of the Apennine Chamois
Authors: Locati Maurizio , Lovari Sandro
Published: May 2010

The aggressive behaviour of female and male Apennine chamois has been compared quantitatively. As opposed to what males did, females significantly attacked each other less often; preferred to gore body regions with a low risk of lethal injury, made a greater use of direct forms of aggression; seldom interacted with the opponent before attacking and gored it more often. Front clashing and fighting were very rare in both sexes. Females live in resident kin‐groups, while young males disperse and adults are solitary. To a large extent habitat separation occurs between the sexes. Sexual differences in patterns of aggressive behaviour may be related to the different gregariousness of females and males, probably influenced by resource availability in the habitats they use. Chamois sexes are nearly monomorphic, females bearing slightly less hooked horns than males. This species may have evolved strongly hooked weapons as a first step to advanced wrestling or butting type horns from the ancestral stiletto shape, as goats and sheep, as well as deer, have done.
Structural Variations in the Begging Calls of Nestling Magpies Pica pica and their Role in the Development of Adult Voice
Authors: Redondo Tomas , Exposito Francisco
Published: May 2010

Like most corvids, adult magpies (Pica pica) have harsh vocal repertoires characterized by a wide distribution of energy over the frequency scale. Shortly after hatching, begging calls of magpie nestlings have a tonal quality but become increasingly noisier as they develop. The appearance of harsh structures in the calls is closely related to a process of frequency modulation which ends at about 16–18 days. At this age, nestlings suddenly develop genuine harsh calls, typical of fledglings and adult birds. During development, similarities can be observed between frequency modulation and noise production, suggesting that nestlings acquire the ability to produce adult harsh vocalizations by modulating their begging calls. This hypothesis does not explain, however, why genuine harsh calls develop without transitional forms being evident in the preceding begging calls. Also, intra‐ and interspecific differences in modulation rates do not cause differences in noise production in the way that this hypothesis would at first suggest. Frequency modulation and noise production do not seem to be involved in the ontogeny of the adult voice. It is suggested that both features contribute to call degradation in the environment, in order to compensate for the increasing risks of nests being detected by predators due to the more detectable calls of older nestlings.
Population Differences in the Schooling Behaviour of Newborn Guppies, Poecilia reticulata
Authors: Magurran Anne E. , Seghers Benoni H.
Published: May 2010

Population differences in the schooling behaviour of adult guppies (Poecilia reticulata) from Trinidad have previously been well documented. This paper demonstrates that variation in schooling behaviour is also present in newborn fish. Guppies from the Aripo River of Trinidad display well‐developed schooling behaviour from birth. In addition to forming cohesive and polarized groups, these newborn fish also exhibit predator inspection behaviour. Newborn guppies from the Paria River perform inspections but, unlike the Aripo fish, are poor schoolers. Population variation in behaviour at birth does not necessarily reflect the pattern observed in the adult fish. As adults, guppies from the Upper section of the Aripo River have a much lower schooling tendency and are less wary during inspection than the downstream Lower Aripo guppies. At birth, however, the schooling behaviour and inspection behaviour in the two populations is identical. These results suggest that different selective pressures operate on adult and newborn guppies in Trinidad.
Social Entrainment of Circadian Activity Rhythms in Common Marmosets, Callithrix j. jacchus (Primates)1
Authors: Erkert Hans G. , Schardt Ursula
Published: May 2010

Long‐term recordings of the locomotor activity of 9 common marmosets, Callithrix j. jacchus, show that under certain preconditions, social entrainment of the free‐running circadian rhythm can occur in these non‐human primates. However, there exist considerable interindividual differences in the Zeitgeber effect of the various forms of social contact. Findings indicate that both the level of acquaintance and the individual differences in spontaneous period of individuals involved are important, and that daily, or circadian, social cues have a cumulative effect. Because of the low Zeitgeber strength of social stimuli, however, desynchronization of different individual rhythms can arise spontaneously among animals kept as a pair in the same cage, even after months of harmonized free‐running rhythms. It is discussed that social entrainment in primates and other mammals is more likely to be a coincidental, rather than an essential, characteristic of the circadian system. Arousal triggered by social stimuli is thereby ascribed a key role.
Searching Image in the Pigeon: A Test of Three Hypothetical Mechanisms
Authors: Bond Alan B. , Riley Donald A.
Published: May 2010

The searching image hypothesis was originally proposed to account for the observation that animals selecting among disparate foods often consume an excess of the more common types. The hypothesis states that animals searching for a particular cryptic food item focus on visual features that are characteristic of that item, thereby facilitating its discrimination from the background. A change in stimulus discriminability is not, however, the only feasible explanation for the effect. One alternative is a simple change in response bias, an increased predisposition to respond to food‐related stimuli. Another possible hypothesis derives from the fact that the amount of time that an animal has available for examining each stimulus is not fixed. This “caution” hypothesis attributes improvements in stimulus detection to changes in the amount of evidence that the animal acquires before making a response.

To distinguish among these alternatives, we developed an accumulator model of visual search, which included discriminability, response bias, and caution as explicit, independent components. The consequences of varying each parameter in the model were evaluated by computer simulation, generating predicted effects of each hypothetical mechanism on response time and accuracy. The predictions were then tested using pigeons searching for images of natural, cryptic food grains. The results provide strong support for the discriminability hypothesis, but suggest that secondary changes in caution may also be involved.
Territoriality and Site‐related Dominance: On Two Related Concepts in Avian Social Organization
Authors: Oberski I. M. , Wilson J. D.
Published: May 2010

Territoriality and site‐related dominance are concepts used commonly in studies of avian social organization, but the relationship between them is rarely made explicit. One reason for this is that site‐related dominance can be studied both at the level of individual dyadic dominance relationships (DDRs) and by combining all the DDRs of a bird to calculate an index of its social status; a measure of its overall ability to dominate other members of the population. This difference is illustrated by reference to published work on the Steller jay Cyanocitta stelleri, and data from our own study of a winter population of great tits Parus major. A recent review of dominance and territoriality emphasizes that territories are just one extreme of a continuum of forms of site‐related dominance, measured as the pattern of spatial variation in social status. Ecological and behavioural correlates of different forms of site‐related dominance are therefore discussed with special reference to the non‐breeding social organization of the Paridae, to illustrate the empirical questions posed by an understanding of the various forms of site‐related dominance that may occur in different species and in different populations of the same species.
Influence of the Visual Environment on the Choice of Laying Site of the European Quail (Coturnix c. coturnix), Single or Paired, under Experimental Conditions
Authors: Michel Raoul
Published: May 2010

Second generation European quail, descended from parents captured in their natural habitat, were reared in an aviary. The choice of laying site was observed using simplified environments containing dominant visual factors found in the natural habitat. Females were either single or paired. Visual characteristics were taken into account in the selection of a laying site. Pairing does not modify this behaviour and it was found that a confined space was preferable to a large space. The chosen laying site is not less well illuminated than other areas available. A visually achromatic structure is very attractive, vertical stripes being preferable to horizontal ones. Green is much more attractive than the colour ochre. Vertical presentation of these colours does not modify site choice. Green does not modify the relative attractiveness of visual forms available, vertical green stripes being preferable to horizontal ones. No preference is demonstrated when the most attractive components, vertical and green, are in competition. These results are in concordance with observations made concerning their natural habitat.
Behaviour Associated with Ultrasonic Vocalizations in Six Gerbilline Rodent Species
Authors: Dempster Edith R. , Dempster R. , Perrin M. R.
Published: May 2010

Encounters were staged between male and oestrus‐induced females of the same or different taxa of the species/subspecies Gerbillurus paeba paeba, G. p. exilis, G. tytonis, G. setzeri, G. vallinus and Tatera brantsii. Each encounter lasted 20 min; converted ultrasonic emissions were recorded on videotape simultaneously with visual images. Videotapes were transcribed and sequences of acts and vocalizations were recorded.

The frequency of acts was compared separately with the number of ultrasonic vocalizations during and after acts by χ2 contingency table analysis, followed by partitioned χ2 to identify individual acts which contributed significantly to the overall χ2 value. Vocalizations occurred significantly more frequently than expected during sexual and/or huddling behaviour in all species‐groups; and significantly less frequently than expected during exploratory, watching and/or submissive behaviour. Vocalizations were uncommon during investigative behaviour in all taxa, and aggressive behaviour in Gerbillurus taxa, but occurred significantly more frequently than expected after these behaviour categories in all taxa.

Analysis of vocalizations immediately following acts verified the interpretations of function of vocalizations during acts. Ultrasonic vocalizations clearly play an important role in the communication of six taxa of southern African gerbils.
Parent‐Offspring Conflict over Independence in the Herring Gull (Larus argentatus)
Authors: Graves J. , Whiten A. , Henzi S. P.
Published: May 2010

Observations on 24 focal nests revealed that, at the time when parental investment in feeding fledging chicks declined, chicks showed a marked increase in begging, particularly in larger broods, whilst parents became less responsive to begging. That chicks suffer a cost from early termination of investment is indicated by the fact that third‐hatched chicks, who had attempted (unsuccessfully) to initiate more feeds, were absent from the territory first, rather than the more mature first‐ and second‐hatched chicks. Taken together, these results and related inter‐ and intra‐brood contrasts in behaviour are interpreted as offering support for Trivers' theory of parent‐offspring conflict over the termination of investment.
Conceptual Issues and Methodology in Kin‐recognition Research: A Critical Discussion
Authors: Gamboa George J. , Reeve Hudson K. , Holmes Warren G.
Published: May 2010

We operationally define kin‐recognition and discuss methodological and conceptual issues that arise in its study, citing examples from the literature that illustrate particular points. We define and examine three components of kin‐recognition (expression, perception, and action), and discuss why some experimental designs fail to distinguish among the components. We also point out ways that experimental designs might be modified to unlink the components.

We discuss three general issues central to assays of kin‐recognition: the functional significance of assays, multiple‐ and single‐behavior assays, and potential biases in assays. The potential biases we consider are nonblind behavioral assays and the pooling of dependent data. We also examine negative results and, in particular, those factors that can produce negative results when recognition ability is present. Finally, we discuss kin‐recognition in natural contexts, emphasizing the potential dangers of uncritically extrapolating the results of laboratory studies to field contexts.
Social Behavior and the Ontogeny of Foraging in the Kea (Nestor notabilis)
Authors: Diamond Judy , Bond Alan B.
Published: May 2010

Kea are omnivorous parrots endemic to the high mountains of the South Island of New Zealand. Over a two‐year period, we recorded quantitative behavioral data from 38 banded male kea foraging at a refuse dump outside Arthur's Pass National Park and analyzed the effects of social factors on the ontogeny of foraging. Members of the four distinguishable age classes — fledglings, juveniles, subadults, and adults — displayed characteristic differences in foraging ability and in the social behavior used to obtain access to resources. Adults performed most of the excavation that uncovered new food resources. Fledglings explored and manipulated objects almost continuously, but they discovered little food on their own and were commonly fed directly by adults. Juveniles obtained the highest foraging yields for the amount of time spent searching of any age class, aided by appeasement behavior that gave them preferential access to foods discovered by adults. Kleptoparasitism served as a primary foraging strategy for subadults, who were otherwise poor at discovering and retaining food resources. Social factors influence the acquisition of foraging expertise in the Kea in different ways at different stages of development.
Selective Acceptance of Alien Host Species Pupae by Slaves of the Dulotic Ant, Harpagoxenus sublaevis (Hymenoptera, Formicidae, Myrmicinae)
Authors: Schumann Ralf , Buschinger Alfred
Published: May 2010

The European slave‐making ant, Harpagoxenus sublaevis, has up to three host species which occasionally are found all together in one colony. Colonies with only Leptothorax acervorum slaves, or with both L. acervorum and L. muscorum, are frequent, whereas colonies with only L. muscorum slaves are rare, although young H. sublaevis queens found their colonies about equally frequently with either of the two main host species. We demonstrate here, that the two host species exhibit an asymmetric acceptance behavior towards each other's pupae: L. muscorum workers accept L. acervorum pupae, both in non‐enslaved colonies and as slaves in H. sublaevis nests, whereas L. acervorum never accepted L. muscorum pupae. Origin and meaning of this behavioral difference are unknown. The findings, however, might be very important with respect to host specificity and host‐parasite interactions also in other slave‐making ants.
The Development of Play in the South American Fur Seal
Authors: Harcourt Robert
Published: May 2010

Play behaviour in the juvenile South American fur seal (Arctocephalus australis) is described for the period of dependence on the mother (up to 32 months). Play does not appear to be a unitary category of behaviour, but may be separated into four distinct types: terrestrial social and solitary play and swimming social and solitary play. These four types show different development profiles, and appear to serve different functions. Terrestrial solitary play and the two swimming play forms appear to be juvenile specializations, the first to enable very young seals to gain motor skills rapidly in order to avoid dangers from conspecifics, the second two to enhance antipredator behaviour and foraging ability during the gradual transition to independence. In contrast, social play may be best thought of as gaining social skills necessary in adult life, prior to dispersal post‐weaning. Juvenile fur seals which do not wean in their first year show an upsurge in social play which is not seen in the other play types. This upsurge coincides temporally with the peak of social play of the new cohort, and is presumably elicited by them.
Territorial Behaviour by a Clan of Spotted Hyaenas Crocuta crocuta
Authors: Henschel Johannes R. , Skinner John D.
Published: May 2010

Territorial behaviour of a clan of spotted hyaenas, Crocuta crocuta, was investigated in the Kruger National Park over a period of 27 months. These hyaenas were highly territorial, spending ⅕ of their total activities on territory patrol by scent‐marking intensively and monitoring 64 marking posts, particularly in border regions. Females, the more philopatric sex, were most active in territory defence. Local intensity of territorial activities by residents within their 130‐km2 territory was directly proportional to intrusion pressure by neighbours. When clan size was reduced, the ability to defend disputed land declined and larger neighbouring clans appropriated parts of the territory. We propose a relationship between resource distribution, intrusion pressure and territory defence.
The Effect of Parental Food Supply on Parental Feeding and Squab Growth in Pigeons, Columba livia
Authors: Mondloch Catherine J. , Timberlake William
Published: May 2010

The growth and survival of nidicolous birds is determined by variables affecting the frequency and allocation of parental feedings. We manipulated adult pigeons' food supply and measured the effect of food availability and hatching order on the frequency and allocation of parental feeding, squab growth, and parental weight loss. Food availability did not affect any of the dependent variables during the first week, when squabs are fed crop milk. Throughout the remainder of the nestling period, when squabs are fed foraged grain, parents in the food‐poor condition delivered fewer regurgitations and lost more weight, and then squabs gained less weight. Within broods, neither the allocation of parental feedings nor squab growth was differential, even in the food‐poor environment. Apparently, production of crop milk is buffered from the parents' food supply, thus allowing both squabs to grow rapidly during the first few post‐hatch days. The result is nondifferential feeding and growth within broods and delayed effects of food availability on the overall frequency of parental feeding, parental weight loss, and squab growth.
Differences in Aggressiveness in the Midas Cichlid Fish (Cichlasoma citrinellum) in Relation to Sex, Reproductive State and the Individual
Authors: Holder Jennifer L. , Barlow George W. , Francis Richard C.
Published: May 2010

The Midas cichlid, Cichlasoma citrinellum, is monogamous and biparental. Because of competition for limited spawning sites and intense predation on their young, vigorous defense of their territory is essential. Although both sexes engage in defense, they differ in aggressiveness.

The aggressive responses of both sexes were measured by counting the number of bites and bumps each fish directed toward its own mirror image. The size of the fish's genital papilla was also recorded to estimate its reproductive state.

Compared with females, males had higher median mirror scores with greater variance. The scores of individual males were also more consistent through time than were those of females. Females close to spawning had the highest mirror scores, whereas male scores were highest early in the reproductive cycle.

Selection has apparently favored aggressiveness in both sexes. We argue, however, that differences in aggression are the result of selection acting dissimilarly on the two sexes.
Individual Behavioural Strategies Associated with Predator Inspection in Minnow Shoals
Authors: Murphy K. E. , Pitcher T. J.
Published: May 2010

When confronted with a live pike, Esox lucius, European minnows, Phoxinus phoxinus, showed individual differences in rate of predator inspection. Predator inspection behaviour, in which single individuals or small groups approached the predator, was ordinated with several other behavioural parameters using principal components analysis. Individual minnows showed one of two strategies. Fish with high inspection rates were bolder, skittered more frequently and fed more persistently than fish with low inspection rates. Fish with low inspection rates showed the opposite strategy. Individuals did not show habituation of predator inspection during trials or over the experimental period.
Decisions during Phonotaxis in the Bushcricket Requena verticalis (Orthoptera: Tettigoniidae): Do Females Change Direction to Alternative Male Calls?
Authors: Schatral Andrea , Bailey Winston J.
Published: May 2010

Female bushcrickets (Requena verticalis, Listroscelidinae, Tettigoniidae) show a preference between male calls that differ in three parameters, temporal structure, frequency and intensity. In a two‐choice speaker situation they prefer louder calls, songs in which the upper part of the frequency spectrum occupies higher frequencies and calls with short chirps rather than those with longer chirps. In an experiment females were offered an alternative call while orienting to a model of their conspecific song. The alternative call was demonstrably preferred by females when presented in a paired‐speaker trial. Two motivational states were identified where females moved slowly or quickly to a sound source. Movement patterns were associated with the form of stimulus and slow females were discriminatory of male calls while fast females were not. Slow females changed speaker preference when the alternate speaker broadcast a call model with the higher frequency peak or the song model with the shorter chirps. By comparison fast moving females only changed course when the alternative sound source was louder.
Loss of Nesting Behavior and the Evolution of Viviparity in Reptiles
Authors: Jones Richard E. , Propper Catherine R. , Rand Matthew S. , Austin Harriet B.
Published: May 2010

Presence or absence of nesting behavior during spontaneous or hormone‐induced oviposition was determined in captive, oviparous lizards (Anolis carolinensis and Sceloporus undulatus). The occurrence of nesting behavior [digging of a nest cavity, covering the egg(s) with substrate] was determined directly by observation of ovipositing females as well as indirectly by whether eggs were covered (buried). Under uncrowded conditions in large terraria, most females of both species nested. However, under crowded conditions (S. undulatus), or in small cages (A. carolinensis), females oviposited without displaying species‐typical nesting behavior. Facultative suppression of nesting behavior during oviposition can occur in nature as well, and this inhibition of behavior may be adaptive. We hypothesize that the absence of nesting behavior in viviparous lizards may be controlled by physiological mechanisms similar to those that control facultative suppression in closely related oviparous species.
Language Acquisition and Form in a Bilingual Environment: A Framework for Studying Birdsong in Zones of Sympatry
Authors: Pepperberg Irene M. , Schinke‐Llano Linda
Published: May 2010

Parallels drawn between critical variables (e.g., the effects of live input and social interaction) in first and second language acquisition and, respectively, species‐specific and allospecific song learning have led to insights into the vocal behavior of both humans and birds. We propose that these parallels can be extended further. Because studies of human behavior in multilingual environments suggest that the potential for bilingualism and the particular forms of bilingualism that develop may be attributed to specific contextual constraints, we suggest that contextual factors may similarly affect the singing behavior of birds in zones of sympatry. We therefore describe various types of human multilingual behavior, discuss factors that may contribute to the development of such behavior, and describe and predict some appropriate avian parallels.
Sources of Acoustic Variation in Rhesus Macaque (Macaca mulatta))Vocalizations
Authors: Hauser Marc D.
Published: May 2010

All species in the genusMacacaproduce a set of harmonically rich vocalizations known as “coos”. Extensive acoustic variation occurs within this call type, a large proportion of which is thought to be associated with different social contexts such as mother‐infant separation and the discovery of food. Prior studies of these calls have not taken into account the potential contributions of individual differences and changes in emotional or motivational state. To understand the function of a call and the perceptual salience of different acoustic features, however, it is important to determine the different sources of acoustic variation. I present data on the rhesus macaques' (M. mulatta) coo vocalization and attempt to establish some of the causes of acoustic variation. A large proportion of the variation observed was due to differences between individuals and to putative changes in arousal, not to differences in social context. Specifically, results from a discriminant‐function analysis indicated that coo exemplars were accurately assigned to the appropriate individual, but vocal “signatures” were more variable in some contexts than in others. Moreover, vocal signatures may not always be reliable cues to caller identity because closely related individuals sound alike. Rhesus macaque coos evidently provide sufficient acoustic information for individual recognition and possibly kin recognition, but are unlikely to provide sufficient information about an external referent.
Social Organization of North Island Brown Kiwi: Long‐term Pairs and Three Types of Male Spacing Behaviour
Authors: Taborsky Barbara , Taborsky Michael
Published: May 2010

We observed 51 kiwi by radiotracking for an average period of 2.3 months each, in Waitangi State Forest, New Zealand. Spacing data for more than one reproductive season are available from 27 individuals, with intervals of up to six years for some of them. Females have a high potential for polyandry, especially in the Waitangi population with a male‐biased sex ratio of 1.4: 1. However, behavioural evidence suggests a monogamous mating system with long‐term pair bonds. Pair members tend to stay close to each other and nearly all observed social interactions were between them. We show that there are three types of male spacing behaviour, which are related to the pairing status. A surplus of fully grown males (22.1% in 1986, 37.3% in 1987) remained unpaired. About half of these bachelor males maintained territories, which were twice the size of paired males' territories. This probably serves to recruit mates. The other half of unpaired males used huge home ranges of six times the size of paired males' territories, overlapping several territories of conspecifics. We have no evidence that these floaters take part in reproduction.
Post‐conflict Behaviour in Long‐tailed Macaques (Macaca fascicularis)
Authors: Aureli Filippo , Schaik Carel P. van
Published: May 2010

We studied the occurrence of social interactions characterizing post‐conflict situations in a group of long‐tailed macaques. Victims of agonistic conflicts showed reconciliation: they had more affiliative contacts with the former aggressor after a conflict than in control periods. There was no evidence for consolation: victims did not contact other groups members than the former aggressor, or specific subsets of group members, earlier after a conflict than in control periods. Victims did not exchange more affiliative contacts with either their own kin or the aggressor's kin during post‐conflict periods. Even though the time spent in allogrooming did not increase after agonistic conflicts, former aggressors were the only group members with which the victim increased the grooming exchange relative to other group members. The victim characteristically showed an increase of agonistic behaviour in post‐conflict situations, a phenomenon labelled redirection. This increase was most pronounced in the first minute after a conflict. The aggressor's kin were targets of post‐conflict aggression relatively more often than other group members. We also examined the interdependence between the only two post‐conflict social events that we could operationally define, namely reconciliation and redirection. Reconciliation occurred more frequently after redirection had taken place, whereas redirection was less likely after reconciliation had taken place. These results indicate that (1) achieving reconciliation has the highest priority for the victim, and (2) aggressors are more likely to grant reconciliation after the victim redirected aggression.
Post‐conflict Behaviour in Long‐tailed Macaques (Macaca fascicularis)
Authors: Aureli Filippo , Schaik Carel P. van
Published: May 2010

After being the victim of an agonistic conflict, long‐tailed macaques increased the rate of tension‐related activities such as scratching, body‐shake and selfgrooming. This increase indicates that they experienced physiological changes preparing them to cope with the uncertainty of the post‐conflict situation. Indeed, victims of agonistic conflict experienced a higher risk of renewed attacks. However, victims were also involved in social interactions characteristic of post‐conflict situations, namely reconciliation and redirection. These two post‐conflict social events reduced the rate of scratching, body‐shake and selfgrooming. This suggests a faster termination of the stress response. Indeed, the two social events also decreased the likelihood of renewed attacks, one of the causes of the state of uncertainty. Reconciliation is more effective than redirection in this process probably because the restoration of the relationship with the former aggressor allows the victim to resume control of the situation.
Laughter: A Stereotyped Human Vocalization
Authors: Provine Robert R. , Yong Yvonne L.
Published: May 2010

Laughter is a common, species‐typical human vocal act and auditory signal that is important in social discourse. In this first quantitative description of laughter, we identified stereotyped features of laugh‐note structure, note duration (x̄ = 75 ms), internote interval (x̄ = 210–218 ms), and a decrescendo that contribute to laughter's characteristic sound. Laugh‐notes and internote intervals have sufficient temporal symmetry and regularity to pass the reversal test; recordings of laughter sound laugh‐like when played in reverse. The stereotypic, species‐typical character of laughter facilitates the analysis of the neurobehavioral mechanisms of laugh detection and generation and the more general problems associated with the production, perception, and evolution of human auditory signals of which speech is a special case.
Harassment of Immigrant Female Mountain Gorillas by Resident Females
Authors: Watts David P.
Published: May 2010

Resistance to immigration, at least into groups larger than optimum, is an expected manifestation of competition among females in mammals with female transfer and has been reported for several such species. Contrary to this expectation, it had not been seen in mountain gorillas. The transfer of a large number of females into an already large group in 1984–85, however, provoked frequent harassment of the immigrants by resident females. The rate of harassment gradually declined, but was still high compared to smaller groups after three years. The male responsible for most mating activity often intervened to stop harassment between females, and immigrants seemed to use him as a shield against harassment. All immigrants stayed with the group, but three residents eventually emigrated. Several factors probably contributed to the difference from earlier observations: the large number of females, the high degree of relatedness among residents and, perhaps most importantly, constraints on male ability to control female conflict. Several aspects of competition may underly harassment, but its significance for reproduction is unclear.
The Role of Cannibalism in the Reproductive Ecology of the Threespine Stickleback
Authors: FitzGerald Gerard J.
Published: May 2010

This essay describes the role of cannibalism in the reproductive ecology of the threespine stickleback. I describe the various types of cannibalism and discuss how cannibalism has influenced the evolution of male and female reproductive tactics. Differences in the patterns of cannibalism between the sexes, among populations, and between closely related species of sticklebacks are also discussed. Special attention is paid to filial cannibalism and its possible adaptive significance. I also examine the various tactics sticklebacks use to minimize cannibalism as well as the possible consequences of cannibalism for their population dynamics. Because cannibalism occurs in many other animals, I attempt to indicate how the findings of studies of cannibalism in sticklebacks relate to the reproductive ecology of other species.
Temporal Segmentation in Hand Movements of Chimpanzees (Pan troglodytes) and Comparisons with Humans
Authors: Kien Jenny , Schleidt Margret , Schöttner Bernd
Published: May 2010

Hand movement action units in chimpanzees show temporal segmentation similar to but shorter than that in humans; median durations are 0.9 s in non‐repetitive behaviour and 2.4 s in repetitive behaviour (vs. 2.0 s and 3.0 s in humans: Schleidt 1988; Feldhütter et al. 1990). In neither chimpanzees nor humans does one repetition of a movement within an action unit increase the duration of the action unit; each further repetition of movements in the action unit tends to prolong it by only 0.5–1 s. Thus, in both chimpanzees and humans, there appears to be some presyntactical planning in advance in repetitive hand movements. The quantitative differences in segment length may reflect uniquely human abilities of timing or sequencing muscle contractions. These findings fit well with current hypotheses that syntactical ability in language could have evolved from motor organisation.
Nursing Behavior in Mexican Free‐tailed Bat Maternity Colonies
Authors: McCracken Gary F. , Gustin Mary K.
Published: May 2010

The nursing behavior of Mexican free‐tailed bats (Tadarida brasiliensis mexicana) was examined in two large maternity cave roosts during six nursing seasons. After depositing pups in large creches, adults return to these creches two or more times daily to nurse. Densities, movements, and roosting associations of pups in creches were documented, and a night‐vision device and infrared‐sensitive video system were used to observe female‐pup reunions and nursing affiliations. Densities of young (< 15 d) pups in creches averaged 4000 pups/m2. Pups moved independently of one another between milk meals. Stable roosting associations among pups were absent, and females evidently could not predict where a given pup would be relocated. Upon returning to the creche, females searched for and relocated pups using vocal and olfactory cues. Experiments with marked individuals demonstrated that females nursed the same pups on subsequent nights. These same experiments indicated that female/pup recognition was mutual and that the pup participated in reunions by moving toward its putative mother. However, pups also attempted to suckle from other females and 35 instances of apparently successful milk “theft” were observed. Observed milk theft was insufficient to account for the frequency of alloparental nursing that was estimated independently using genotype tests. The high densities of bats within roosts and the lack of stable roosting associations among individuals argue against selection for shared nursing via kin selection and/or reciprocity. Errors in pup recognition, milk‐dumping by females, and adoption by mothers whose own pup had died may occur, but high pup survival to weaning suggests that adoption is rare. The estimate of alloparental nursing obtained from genotype tests may be inflated as a result of increased opportunities for milk theft caused by our disturbance of adults. Current evidence suggests that energetic costs to females of alloparental nursing and searching for pups are compensated by mutualistic benefits obtained from aggregative roosting.
The Response of the Tidepool Sculpin, Oligocottus maculosus, to Chemical Stimuli from Injured Conspecifics, Alarm Signalling in the Cottidae (Pisces)
Authors: Hugie Don M. , Thuringer Pamela L. , Smith R. Jan F.
Published: May 2010

The tidepool sculpin, Oligocottus maculosus, a small, cottiid fish of the Pacific coast of North America, shows reduced movement, less feeding activity, a greater tendency to attach itself to the substrate, and a shift from exposed areas to shelters and crevices when presented with water that has contained injured conspecifics. This alarm reaction does not occur in response to water that has contained uninjured, but disturbed, O. maculosus, or injured guppies, Poecilia reticulata, O. maculosus are not toxic or distasteful to piscine predators. They do possess large, epidermal sacciform cells that may contain the active chemical(s) released by injured individuals. This is the first report of chemical alarm signalling in Cottidae.