bluuebunny/crossref_metadata_2025_split huggingface dataset:
Individuality in the Voice of the Emperor Penguin Aptenodytes forsteri: Adaptation to a Noisy Environment
Authors: Robisson Patrice , Aubin Thierry , Bremond Jean‐Claude 
Published: May 2010

AbstractThe extreme coloniality in emperor penguins (Aptenodytes forsteri) demands that (1) individual recognition by the mutual display call must be supremely adapted to the total absence of nest sites — landmarks that would facilitate partner reunion, and (2) birds must transmit a precise message through an obstructed and noisy environment. A computerized sound analysis and subsequent data were submitted to univariate and multivariate statistics to determine individual‐specific cues of the call. Temporal patterning of syllables, variables of the power spectrum (frequency and timbre features) and variables of a beat generated by two acoustic sources were analyzed (58 calls from 7 animals). Number and duration of syllables, fundamental frequencies and period of the beat were highly individual, with inter‐ significantly greater then intra‐individual variation, enabling correct classification of the 58 calls. The respective relevance of temporal and spectral cues for individual recognition is discussed. In the acoustically hostile and noisy environment, beat was peculiarly emphasized, as it allowed great precision in the production of an amplitude modulation that was unlikely to be degraded by the environment.
Social Interactions in Isard Kids Rupicapra pyrenaica pyrenaica (Artiodactyla: Bovidae): Possible Influence on Development of Social Bonding
Authors: Richard‐Hansen Cecile 
Published: May 2010

AbstractAssuming that social experiences at an early age may be a determinant factor in the process of formation of social network and attachments, we studied the social interactions of isard, or Pyrenean chamois, kids (Rupicapra pyrenaica pyrenaica) during their first year, to understand “how” sociality arises in isards rather than “why”. Interactions with the mother were affiliative, and approaches of kid to mother or vice versa were generally followed by another “positive” interaction. Interactions between kids were also frequent and playful. Interactions with both mother and peers provided positive reinforcement which may strengthen bonds. However, early interactions of kids with yearlings and other adults provided negative experience, no attachment thus developing from them. Social affinities of adults as well as the social and spatial organization of groups may be understood when ontogenetical history and immediate causality are highlighted.
The Effect of Habitat Structure and Density of Nests on Territory Size and Territorial Behaviour in the Black‐headed Gull (Larus ridibundus L.)
Authors: Bukacińska Monika , Bukaciński Dariusz 
Published: May 2010

AbstractWe studied the effects of vegetation structure and nest density on territory size and aggression in the black‐headed gull (Larus ridibundus). Vegetation structure influenced the types of aggressive behaviour, but not territory size. The proportion of overt aggression (attacks, fights) was highest in barren areas or those with short, sparse vegetation, and lowest in plots covered with dense, tall grass. We explain this by decreased visibility of conspecifics in habitats isolated by vegetation. In such areas, total aggression did not decrease, because the low proportion of attacks and fights was offset by an increase of more moderate (“upright”) displays. Only when nest density was high did the vegetation reduce the frequency of agonistic behaviour — but then it comprised almost exclusively attacks and fights. As expected, greater nest density was related to reduced territory size and an increased proportion of overt aggression. A high proportion of attacks and fights occurred in the plot with the lowest nest density, where at the same time there were also numerous first‐year breeders. We conclude that, when analyzing the effects of habitat conditions on aggressive behaviour, it is important to consider the structure of behaviour, and not only the total frequency of all types of agonistic interactions.
Cross‐species Discrimination of Individual Odors by Hamsters (Muridae: Mesocricetus auratus, Phodopus campbelli)
Authors: Johnston Robert E. , Robinson Tara A. 
Published: May 2010

AbstractGolden hamsters, Mesocricetus auratus, and Djungarian hamsters, Phodopus campbelli, Muridae, were tested for the ability to discriminate between individual odors from both their own species and the other species. Hamsters were tested using an habituation technique, in which differences in time spent investigating familiar and novel scents indicate discrimination of individual differences. Both species showed similar patterns of results when tested with flank gland scents from golden hamsters and ventral gland scents from Djungarian hamsters: The duration of investigation of samples from the same indivídual scent donor declined over trials, indicating recognition of this scent, but then increased when a scent from a novel individual was presented, indicating discrimination of individual differences. Thus, the capacity and tendency to respond differentially to signals from different individuals is not confined to a single species, suggesting the lack of species‐specificity in the signals and perceptual mechanisms involved in individual recognition by scent. This capacity may be common in mammals, and if so suggests the possibility for considerable knowledge of heterospecific individuals.
Experiments on the Responses of a Rejector Species to Threats of Predation and Cowbird Parasitism
Authors: Bazin Ronald C. , Sealy Spencer G. 
Published: May 2010

AbstractWe presented freeze‐dried models of a nondescript sparrow (control), a female brown‐headed cowbird (Molothrus ater, Icterinae) and an avian nest predator to nesting eastern kingbirds (Tyrannus tyrannus, Tyranninae) during the egg‐laying and nestling stages to test for nest defense against the threat of cowbird parasitism. Both kingbird parents responded during 81% of the 183 trials. Kingbirds responded aggressively toward the cowbird model, but only slightly more so than to the control, and less than to the predator model. The level of aggression directed toward the predator increased between the laying and nestling stages. The results suggest that kingbirds at Delta Marsh, Manitoba, did not recognize the cowbird as a unique or dangerous threat, possibly because of low selection pressure on this rejector species for aggressive nest defense against cowbirds.
Pedogenetic Sociogenesis via the “Sibling‐route” and some Consequences for Stegodyphus Spiders
Authors: Wickler Wolfgang , Seibt Uta 
Published: May 2010

AbstractCooperative social life originated independently at least 3 times in the eresid spider genus Stegodyphus. The ultimate and proximate factors for sociogenesis have been analyzed in two African social species, S. dumicola and S. mimosarum.

More profitable hunting as the ultimate benefit of sociality can explain group sizes up to 30 individuals. Most groups are much larger, reducing average female fecundity. They benefit mainly from the shelter against predators provided by the compact silk nest as a heritable resource.
Sociogenesis is not based on extended maternal care but on interattraction and tolerance of juvenile spiders, retained throughout life in females. Their neotenic sociality came to overlap with advanced (pedomorphic) sexual maturity. This evolutionary pathway towards sociality is called the “sibling‐route”.
Negative side effects, accumulating with group size, may make sociality in Stegodyphus evolutionarily unstable.
Maternal Anxiety in Rhesus Macaques (Macaca mulatta)
Authors: Maestripieri Dario 
Published: May 2010

AbstractThis study assessed the extent to which emotional reactivity to the social environment influences maternal behaviour in macaques. Visual monitoring and scratching were used as behavioral indicators of maternal and social anxiety in small captive groups of rhesus macaques. Maternal visual monitoring of the infant and of other individuals proved better predictors of individual differences in maternal protectiveness than did characteristics of the mother‐infant dyad such as maternal age, experience and dominance rank, number of immature offspring present in the group, or sex of the infant. Unlike visual monitoring, maternal scratching was not linearly related to protectiveness. Mothers displaying low or high rates of scratching ranked low on protectiveness, and the most protective mothers were those who displayed intermediate levels of scratching. Although individual differences in maternal and social anxiety seem to be mediated by maternal age and experience, they might also be influenced by genetics and early experience.
Influence of Litter Gender Composition on Subsequent Maternal Behaviour and Maternal Aggression in Female House Mice
Authors: Musi Barbara , de Acetis Luigi , Alleva Enrico 
Published: May 2010

AbstractIt has been suggested that the sex‐dependent pattern of mother‐pup interaction that occurs early in infancy can affect some aspects of the animal's behaviour repertoire in adulthood. The aim of this study was to investigate the effects of litter gender composition (LGC) on subsequent maternal behaviour and aggression in the female house mouse. Albino mouse litters were reduced at birth to six pups according to two conditions: FM (3 females and 3 males) and FF (all females). At weaning (day 21), all mice were rehoused in unisexual groups. At adulthood (70–90 days) the females were mated and litters culled at birth to 6 pups (3 females and 3 males). On days 2, 4, and 6 after delivery the females were tested for maternal behaviour (10 min) and retrieval of pups. On day 6, at the end of the recording of maternal behaviour, the females were also tested for maternal aggression towards a strange adult male conspecific (5‐min exposure). In absence of differences in maternal behaviour scores, FM females showed shorter latencies for retrieval of the first pup on postnatal days 2 and 4. Maternal aggression was also significantly affected by the two conditions. FM females showed higher scores of both duration and frequency of aggressive grooming, defensive upright postures, fleeing and of the number of attacks. FF females spent more time self‐grooming, crouching, and on nest. These results support the hypothesis that a series of factors, such as olfactory, tactile, and acoustic stimulation provided by the pups, the variation of maternal behaviour depending upon LGC, and the qualitative and/or quantitative variation in social interaction with the opposite sex in infancy, contribute to the broad interindividual plasticity to cope in different environmental situations.
Mechanisms of Change in the Ontogeny of Black‐tailed Prairie Dog Time Budgets
Authors: Loughry W. J. 
Published: May 2010

AbstractThis study examines the behavioral mechanisms underlying changes in the time allocation patterns of black‐tailed prairie dog (Sciuridae: Cynomys ludovicianus) pups. Previous analyses of time budgets had revealed substantial differences between pups (young of the year) and adults, and that pup time budgets changed significantly over time. This paper shows that these differences were due to two mechanisms: pups generally differed from adults in the frequency of performance of different behaviors; however, changes in pup behavior over time were due to changes in both bout frequencies and durations. Other influences on bout durations were also examined. Time of day dramatically affected the duration of most behaviors, with vigilance bouts longest in the morning and feeding bouts longest in the evening. The presence of a pup's mother above ground and the height of the vegetation a pup was in had much less influence on bout durations. Multiple regression analyses were used to identify other potential influences (e.g., weather and social conditions) on bout lengths. Of these, the distance of a pup from the nearest burrow produced the strongest relationships.
The Effect of Weaning Weight on Offspring Fitness in Wild House Mice (Mus musculus domesticus): A Preliminary Study
Authors: Krackow Sven 
Published: May 2010

AbstractSex allocation theory is frequently applied to mammalian reproductive traits although the basic assumptions are rarely assessed. In particular, it has been proposed that the finding of negative correlations between sex ratio (percentage males) and litter size in a variety of mammals could ultimately be seen as an adaptation according to the Trivers‐Willard hypothesis. Thereby it is supposed 1) that individual young of small litters are weaned at heavier weight than young of larger litters, 2) that this litter‐size effect on individual weights persists into adulthood, and 3) that such small weight advantages increase male fitness more strongly than female fitness. In this study, during each of 4 trials, I introduced 4 male and 4 female mice from 8 different litters of wild‐caught breeding pairs to a semi‐natural enclosure and followed up the social and reproductive events for about 10 weeks. It appeared that small weight differences attributable to litter size variation had a significant positive effect on male fitness, but not on female fitness. As the sample size was small and the social development did vary considerably between trials, this result deserves further clarification.
Two Male Types of the Common Earwig: Male‐male Competition and Mating Success
Authors: Radesäter Tommy , Halldórsdóttir Hildur 
Published: May 2010

AbstractA field‐collected sample of earwigs (Forficula auricularia) showed considerable variation and a bimodal distribution in male forceps lengths. Males could be separated into brachy types (74 %) with small forceps and macro types with long forceps. Female forceps lengths and the body length distributions of both males and females were unimodal. Staged encounters between males, matched for body size but of different forceps type, demonstrated a significant advantage for macro males in aggressive interactions. In experiments with more than one male together with a female, macro type males were able to dislodge and take over females already in copula. Males of the macro type achieve both a larger proportion of the copulations and significantly longer copulations. Experiments in the laboratory, where virgin females were placed in petri dishes with males of different types, revealed no difference in latency time to copulation. Neither was there any indication of female choice before copulation in experiments where females could choose between the two male types.
Experimental Changes of Hierarchical Rank in Polistes dominulus Christ Foundresses
Authors: Pratte Michel 
Published: May 2010

AbstractBehavioural profiles of Polistes dominulus foundresses were studied after changes of hierarchical rank induced by transferring wasps between trigynous associations. Females were ranked on the basis of postures adopted in dyadic encounters, while time spent by individuals on 8 behavioural items was recorded and compared. A multivariate analysis showed that behavioural profiles depended mainly on the wasps' current rank. The previously held rank had little effect on the behaviour of females concurrently having beta rank, whereas some differences were observed among alpha females depending on their previous rank. Alphas that were previously betas spent more time at the nest, but were less active there than inveterate alphas. The profile characteristics of alpha rank seem to take longer to acquire than the beta profile. It is suggested that adopting the profile characteristic of a given rank may involve first occupying the territory consisting of the nest, secondly gradually producing appropriate responses to the various stimuli emanating therefrom, and thirdly, undergoing specific physiological changes.
Weaning and Parent‐offspring Conflict: Variation Relative to Interbirth Interval in Bison
Authors: Green Wendy C. H. , Rothstein Aron , Griswold Joseph G. 
Published: May 2010

AbstractWeaning and parent‐offspring conflict were examined in bison (Bison bison). Maternal care and interactions with offspring during the first year were compared between mothers that did or did not conceive 4–5 mo postpartum; unlike barren mothers, pregnant mothers ceased nursing late in the first year. Pre‐estrus nursing bouts were shorter for pregnant mothers; however, neither overall nursing time nor other forms of maternal care differed between groups. Offspring of pregnant mothers spent more time resting in Months 1–5; their grazing time also increased more slowly, suggesting higher rates of parental investment for pregnant mothers. For both groups, time spent suckling decreased due to decreasing bout frequency rather than duration. As soon as mothers differed in reproductive status, nursing time and frequency diverged dramatically, increasing for barren while decreasing for pregnant mothers. However, interactions with offspring differed little. The percentage of suckling bouts ended by calves decreased in Months 1–9 for both groups. Frequencies of rejected suckling attempts and maternal aggression increased in Months 2–4 but not subsequently. Contrary to the expectation that parent‐offspring conflict is associated with the end of nursing, maternal aggression and nursing interruptions decreased in frequency with time. Because changes in interactions were gradual, there was no clear weaning period, i.e. when maternal care decreases most and conflict increases. Such changes were greatest in Months 1–3; however, suckling continued for 6–18 mo afterward. It appears that weaning occurs gradually, through maturational changes more than through parent‐offspring conflict.
Functional Monogyny and Dominance Hierarchy in the Queenless Ponerine Ant Pachycondyla (=Bothroponera) sp. in West Java, Indonesia (Hymenoptera, Formicidae, Ponerinae)
Authors: Ito Fuminori 
Published: May 2010

AbstractSocial organization of the queenless ponerine ant Pachycondyla (Bothroponera) sp. was studied in Bogor, West Java, Indonesia. Colonies had no morphologically distinct queens. Worker number per colony was 11 on average. Most colonies contained multiple mated workers (gamergates), however, only one of them laid eggs, whereas additional gamergates were sterile or ovipositing at a low rate, indicating that this ant species shows functional monogyny. Some virgin workers also developed their oocytes and actually laid eggs. Ritualized dominant — subordinate behavior was frequently observed and a linear dominance hierarchy was established among workers. The topranking individual was a fertile gamergate. Sterile gamergates positioned in lower ranks and they often engaged in foraging. Among virgin workers, callows and young workers monopolized higher ranks.
When Does Previewing the Landscape Affect Pigeon Homing?
Authors: Braithwaite Victoria A. 
Published: May 2010

AbstractThe importance of visual landmarks during homing in pigeons (Columba livia) remains a contentious issue. Three experiments which explore the role of visual landmarks at release sites are reported here. The effects of releasing homing pigeons after a 5‐minute period in either a clear or an opaque sided release box were investigated. In the clear sided box pigeons were able to observe local surroundings at a release site, but this view was obstructed in the opaque sided box. In experiment 1 pigeons were released from familiar locations close to home (between 2 and 5.6 km): being unable to view landmarks prior to release significantly slowed homing speeds. In experiment 2 pigeons were released at familiar locations further from home (between 8.4 and 10 km): being unable to view landmarks prior to release did not significantly affect homing speeds. In experiment 3 pigeons were trained to home from distant release sites but were tested at closer, unfamiliar sites located on the likely homing routes used by the pigeons in training. No significant difference in homing speeds were observed when pigeons were released from either the clear or opaque sided box. The significance of these results for understanding the role of visual landmarks within a pigeon's familiar area is discussed.
Homing after Displacement in Open or Closed Containers by the Digger Wasp Argogorytes carbonarius (Hymenoptera, Sphecidae)
Authors: Schöne Hermann , Harris Anthony C. , Schöne Hedwig , Mahalski Pauline A. 
Published: May 2010

AbstractInitial orientation and homing time were recorded in Argogorytes carbonarius after displacement in “open” and “closed” containers during two periods: “first” release dates and “later” release dates. At the later releases “closed” wasps homed much better than at first releases and better than “open” wasps. At the first releases, on the other hand, the “open” wasps homed (slightly) better than the “closed” wasps. An interpretation relates the better homing of “closed” wasps at the later trials to route learning at the first trials and discusses the differences and peculiarities of homing from familiar terrain and of home orientation by path integration.
Role of Geosmin, a Typical Inland Water Odour, in Guiding Glass Eel Anguilla anguilla (L.) Migration
Authors: Tosi Laura , Sola Carla 
Published: May 2010

AbstractOdours are one of the most important cues in anadromous migration in fish, but to date the substances responsible for freshwater attractiveness are not well‐known. This is the first report on the behavioural response of a long‐range migrating fish, the eel, induced by geosmin, an odorant produced by actinomycetes, which is widely distributed in freshwater. The high sensitivity of glass eels towards very diluted solutions of geosmin, the avoidance elicited by the unnatural combination of marine salinity and earth smell, and evidence of a strong attraction as the level of salinity is reduced, indicate geosmin to be identified as an important inland water marker involved in the orientation of glass eels towards freshwater.
Female Mate Preference and Male Mating Success of Ayu Fish, Plecoglossus altivelis (Osmeridae) under a Promiscuous Mating System
Authors: Iguchi Kei'ichiroh , Maekawa Koji 
Published: May 2010

AbstractThe ayu, Plecoglossus altivelis, is known to show wide variation in adult body size. We examined the spawning behavior in experimental spawning groups of fish in which male body size varied. Males never competed with each other for females or spawning site, while females spawned repeatedly, 17–97 times depending on body size, with previous or novel males. Males exhausted their sperm after a single mating episode, on average, regardless of body size. Moreover, repeated sperm production apparently reduced the residual lifespan. Females preferred mating simultaneously with more than one male and allowed males of body size similar to their own to mate more frequently. Thus the largest male within a spawning group was not always the most successful at mating, but mating success of any given male appears to depend upon body size distribution of females within the population. Female mate preference has apparently evolved to ensure complete fertilization under circumstances where males have been selected to economize sperm output during any one mating episode.