bluuebunny/crossref_metadata_2025 huggingface dataset:
Song Variation in the Chiffchaffs (Phylloscopus collybita) of the Western Pyrenees — the Contact Zone between the collybita and brehmii Forms
Authors: Salomon Marc , Hemim Younes
Published: May 2010

Song variation in west‐Pyrenean chiffchaffs was thoroughly analyzed. Intrinsic physical structures of these songs as well as extrinsic contextual ones were processed simultaneously in qualitative and correspondence analyses. The aim was to assess objectively and to describe the song differences between collybita and brehmii, easily perceived in the field, accounting for variation within the groups due to other sources than taxonomic. All songs originate from the contact zone of the two forms, i.e. taxonomically still‐undetermined entities. The following results were obtained:

The main source of song variation is confirmed to be the bird's membership in the collybita or the brehmii form. Each song type has been characterized in terms of physical variable values.

Within these forms, the songs emitted in the same social or temporal contexts are more similar than the songs produced in different contexts. This has been verified intra‐ and interindividually.

Some individuals have songs that share structures of both forms — these are the mixed‐singers described by Thielcke & Linsenmair (1963).

In the sympatric zone, the acoustic differences between collybita and brehmii are strengthened by an acoustic character displacement.
Sex Change in Both Directions by Alteration of Social Dominance in Trimma okinawae (Pisces: Gobiidae)
Authors: Sunobe Tomoki , Nakazono Akinobu
Published: May 2010

The mating system of the gobiid fish Trimma okinawae is one of polygynous hermaphroditism, in which the largest female of a social unit changes sex following the removal of the dominant male. Histological observations of the gonads however, revealed that males have an ovarian tissue within a functional testis. The occurrence of ovarian tissue in the functional male suggests that T. okinawae males should be able to revert back into being functional females. To test this prediction, we placed females in an aquarium and allowed them to change sex. After confirming sex change from female to male, we individually placed new males into another aquarium and added a larger male to each. Our experiments revealed that females change sex and become males upon the removal of dominant males, and that those males changed sex again and became females in the presence of larger males. Sex change in both directions may be advantageous when a male is forced to become subordinate following the take over of the social unit by a larger male.
Maternal Anxiety in Rhesus Macaques (Macaca mulatta)
Authors: Maestripieri Dario
Published: May 2010

Visual monitoring and scratching were used as behavioral indicators of maternal and social anxiety in small captive groups of rhesus macaques. Young infants were especially at risk from other group members during the first weeks of locomotion away from their mothers. Mothers received aggression from other individuals irrespective of their infants' presence or absence. The rate at which mothers scratched themselves increased significantly when their infants moved away from them and when the infants approached or were approached by individuals who frequently harassed them. The rate of maternal scratching and the rate of glancing at the infant and at other individuals when the infant was away decreased as infants grew older and became less vulnerable to harassment. In contrast, the rate of maternal scratching and visual monitoring of other individuals when the infant was in contact remained stable across the first 12 wk of lactation. The rate of maternal scratching increased when the mother‐infant pair was in spatial proximity to the adult male or higher ranking adult females. Although visual monitoring and scratching showed a similar sensitivity to social variables, it is speculated that they might reflect different components of anxiety, namely, anticipation of danger and uncertainty due to motivational conflict. The results of this investigation indicate that a macaque mother's emotional reactivity to a perceived danger for herself and her infant can be measured quite accurately using the rates of visual monitoring and scratching and that the latter represent reliable tools to investigate the emotional correlates of maternal behavior in nonhuman primates.
Size‐assortative Monogamy and Paternal Egg Care in a Coral Goby Paragobiodon echinocephalus
Authors: Kuwamura Tetsuo , Yogo Yutaka , Nakashima Yasuhiro
Published: May 2010

Paragobiodon echinocephalus (Pisces; Gobiidae) inhabits the branching coral Stylophora pistillata. Only the largest two fish bred in a coral irrespective of group size, which was larger in larger corals. Breeding pairs consisted of a male and female of similar body size. Eggs were spawned on the coral branch and guarded by the male parent for about 4 days until hatching. Successive spawning occurred usually one day after hatching. The reproductive success of a pair, measured as the number of newly hatched larvae, was positively correlated with the body size of the male as well as the female. That is, not only female fecundity but also male ability of egg guarding were limited by body size almost equally. This should promote size‐assortative monogamy in the goby.
The Conflict between Nest Guarding and Mate Guarding in Penduline Tits (Remiz pendulinus)
Authors: Schleicher Brigitte , Valera Francisco , Hoi Herbert
Published: May 2010

In penduline tits (Remiz pendulinus), polygynous males build several very elaborate nests successively during one breeding season to attract females. The time and effort invested in nest building is positively related to their mating success. Intraspecific competition for nest material resulting in nest material theft, delays males' nest building progress which in turn decreases their mating success. Therefore, a nest guarding strategy was predicted. In many bird species, males develop some kind of paternity strategy during the female fertile phase. However, as nest building and the female fertile phase frequently coincide, one would expect a trade‐off between these strategies. In this study we determined in particular how nest guarding in males conflicts with their mate guarding behaviour in penduline tits.

Our results show that nest building is costly in terms of a male's time budget. Thieves benefit by increasing their rate of acquiring nest material which reduces the effort invested in nest building. Nest guarding is an efficient strategy to avoid thieves, as indicated by the negative relation between the presence of the male near the nest and the frequency of nest material theft. Nest guarding is required for the whole building period but males, however, increased their mate guarding effort during the peak fertile phase to ensure their paternity. The data suggest that, for the trade‐off “mate guarding versus nest guarding”, paternity insurance seems to be more important.
The Use of Conspecific Chemical Cues for Cannibal Avoidance in California Newts(Taricha torosa)
Authors: Elliott Sean A. , Kats Lee B. , Breeding Jennifer A.
Published: May 2010

Adult California newts,Taricha torosa(Caudata: Salamandridae), prey on both conspecific egg masses and larvae. We used both laboratory and field experiments to determine if newt larvae use conspecific chemical cues to avoid adult intraspecific predators. Larvae showed significant hiding responses when exposed to adult cues in both the field and the laboratory. Larvae did not exhibit significant hiding responses to chemical cues from invertebrate predators.
Aversive Responses of Female Mice to the Odors of Parasitized Males: Neuromodulatory Mechanisms and Implications for Mate Choice
Authors: Kavaliers Martin , Colwell Douglas D.
Published: May 2010

The detection and avoidance of parasitized conspecifics is proposed to have important consequences for the behavior of animals, especially as related to mate choice. A reduction in pain sensitivity (i.e. analgesia) is a major correlate of exposure to real or potential danger and threatening stimuli, facilitating the expression of various active (e.g. fleeing) and passive (e.g. immobilization) defense responses. The present study examined pain sensitivity (latency of a foot‐lifting response to 50 ° C thermal surface) of female mice,Mus musculus, that were exposed to the urine and other odor secretions of male mice subclinically infected with the naturally occurring, enteric, sporozoan parasite,Eimeria vermiformis.A 30‐min exposure to the odors of a parasitized male induced an analgesia in the female mice that was found to be mediated by the increased activity of endogenous opioid peptide systems. A brief 1‐min exposure to the male odors induced a shorter duration and lower amplitude analgesia of a non‐opioid (serotonergic) nature. Maximum analgesic responses were induced by the odors of pre‐infective [5 days post‐infection (PI)] and infective (day 10 PI) males, with significantly lower responses elicited by the odors of post‐infective (day 17 PI) male mice. Exposure to the odors of unparasitized males had no significant effects on the pain sensitivity of female mice. These results indicate that female mice can distinguish between the odors of parasitized and non‐parasitized male mice, and find the odors of parasitized males threatening and/or stressful. These odor‐induced analgesic responses and their neurohormonal correlates may be part of an adaptive preparatory defense mechanism that facilitates the detection and avoidance of parasitized males by female mice and contributes to female mate choice.
The Social Organization of Feral Ovis aries Ram Groups in the Pre‐rut Period
Authors: Rowell T. E. , Rowell C. A.
Published: May 2010

Primates are described as having peculiarly complex social behaviour when compared with other mammals, but the methods and expectations of primatologists also differ from those of other mammalogists, confounding the comparison. A very simple social organization has been described for sheep (Ovis aries). Rams of a long‐established feral flock were observed during the pre‐rut period of three successive years, and their communicative behaviour was described and quantified using individual‐focussed methods commonly applied to primates. Rams were found to form long term relationships and their pattern of interaction was partly determined by these as well as by age and rank. Correlation between the effects of age and rank varied with current demography. There was no correlation between rank and horn size. Rams intervened on behalf of weaker colleagues and supported each other in fights. They showed more affiliative behaviour and associated more closely than did ewes. While the leader of the ewe flock was nearly always the oldest ewe present, leadership of ram flocks was less restricted; when together, rams always followed the ewe flock. Comparison is drawn between monkey and sheep social behaviour, and it is concluded that perceived differences are partly due to differences in the expectations and methods of their respective students.
Comparison of the Hunting Behavior of Four Piscine Predators Attacking Schooling Prey
Authors: Parrish Julia K.
Published: May 2010

Four piscine predator species were observed repeatedly attacking large (> 100,000) schools of flat‐iron herring, Harengula thrissina. The predators could be categorized into two groups. Stalking predators (two species) were slow‐moving, predominantly solitary hunters attacking from positions beneath the school. Attacks were directed at individual prey and the sequence of events was orient‐approach‐strike. Although the stalking species were seen most often and were responsible for the majority of the attacks, capture success was low. The remaining two species were fast‐moving, pelagic hunters regularly occurring in groups of up to 8 individuals. These predators were extremely proficient at capturing prey, either by orienting on individuals (stragglers) or accelerating into the school and ramming their prey (impact attacks). Group size was positively associated with capture success, but not significantly so. Because stalking predators orient towards individual prey, they may suffer from the effect of confusion when attacking schooling prey. Use of the impact strategy, by comparison, may allow predators to overcome the confusion effect either by attacking prey already separated from the school, or by orienting towards aggregated prey rather than particular individuals.
Landmark Territoriality in the Neotropical Paper Wasps Polistes canadensis (L.) and P. carnifex (F.) (Hymenoptera: Vespidae)
Authors: Polak Michal
Published: May 2010

Male Polistes canadensis and P. carnifex aggregate along crests of prominent ridges in Santa Rosa National Park, Costa Rica. At these sites males of both species defend territories (trees and shrubs) by chasing conspecific rivals. Territories do not contain nests or resources that are collected by females. Chasing by territorial males reduces the amount of time spent by intruders in a territory. I describe and contrast male territorial behavior of both species. Some male P. canadensis are territorial while others in the same area exhibit patrolling behavior, flying from one occupied territory to another. Males of P. carnifex exhibit territoriality only. Patrolling in P. canadensis is an outcome of relatively high male density along the ridge, rendering territories in short supply, as shown by the observation that experimentally vacated territories are seized rapidly by formerly patrolling males. Due to a high intraspecific intrusion rate, territorial male P. canadensis spend less time perching and more time flying and chasing intruders from their territories than do male P. carnifex. Males of these two species also differ in the placement of their territories along the ridgeline; P. canadensis occupy territories in saddles while P. carnifex occupy those at peaktops. I show that this divergent spatial pattern is not maintained by competitive exclusion of either species by the other, and I discuss alternative explanations for their separate spatial distributions. Comparative data suggest that males are territorial because females restrict matings to within territories, and I discuss alternative hypotheses to explain this bias in female behavior.
Laughter Punctuates Speech: Linguistic, Social and Gender Contexts of Laughter
Authors: Provine Robert R.
Published: May 2010

The relation between laughter and speech was investigated by describing the position of naturally occurring laughter in the speech stream of anonymous young adults observed in public places. Laughter of both speaker and audience occurred during pauses at the end of phrases or sentences in over 99 % of the sample of 1200 episodes of laughter, indicating that speech has priority access to the single vocalization channel and that a lawful process governs the placement of laughter in speech. Laughter is not randomly scattered throughout the speech stream. Laughter followed both statements and questions and material that did not seem humorous outside of the conversational context. Speakers, especially females, laughed more than their audiences, but the relative amount of speaker and audience laughter depended on the gender composition of a group. Audiences of both males and females laughed more to male than female speakers. These baseline data provide insights into gender differences, normal and abnormal emotional behavior and define variables for future studies of neuro‐and psychopathology.
Information and Patch Exploitation Strategies of the Eastern Chipmunk, Tamias striatus (Rodentia: Sciuridae)
Authors: Bowers Michael A. , Adams‐Manson Robert H.
Published: May 2010

We examined to what extent 15 chipmunks foraging from dishes in the field varied load sizes depending on a predetermined sequence of resource renewal/removal. At 10‐m distances from burrows, chipmunks collected smaller loads when seeds were replenished over sequential trials and larger load sizes when trials were interrupted by removing all seeds for one visit. Similar sequence effects were less obvious at 0 m. Load size also varied with travel time but not in a manner consistent with either long‐term rate maximization or resource tracking. When travel time effects were removed, sequence effects became more pronounced at distances of both 0 and 10 m. The results suggest that chipmunks use past experience in patches to gauge expected returns in the future, and that they devalue resources according to their uncertainty (“future discounting”). That chipmunks varied load sizes with food renewal/removal more at 10 than 0 m from burrows suggests that the degree to which chipmunks devalue future resources may depend on how defendable those resources are.
The Mating Strategy of the Male Short‐tailed Cricket Anurogryllus muticus de Geer
Authors: Lee How‐Jing , Loher Werner
Published: May 2010

Males of Anurogryllus muticus de Geer call with a sound intensity of 92–95 dB SPL/20 cm. The nightly calling time is 198 ± 79.5 min. Singing begins with the onset of darkness, and is under circadian control (τLL = 25.35 h). At 27 ° C, O2‐consumption during rest is 1.7 ml/h/g, whereas for calling O2‐consumption rises to 10.76 ml/h/g. According to the CO2/O2 ratio, A. muticus burns carbohydrates and lipids at rest, but mostly lipids during stridulation (R = 0.8). The type of fuel oxidized is rapidly adjusted to the particular behavior expressed. The testes serve as a reservoir for lipids, and their lipid level rises from 33.2 ± 15.4 μg/mg tissue at the imaginal molt to 95.2 ± 43.1 μg/mg tissue by the age of 30 days, although by that time testis size has shrunk by 90 %. Multiple, brief matings compensate for short calling times due to high energy expenditure. Comparative data for Teleogryllus oceanicus and T. commodus are given, where appropriate.
Delayed Plumage Maturation and Orderly Queues for Status: A Manakin Mannequin Experiment
Authors: McDonald David B.
Published: May 2010

Lek‐mating male long‐tailed manakins (Chiroxiphia linearis) move through three distinct, unambiguously age‐specific, predefinitive (subadult) plumages, and do not attain the definitive (“adult”) male plumage until their fourth year. Males form orderly, generally age‐graded queues for rank in leks. The top‐ranking (alpha and beta) males cooperate in courtship display, although only alphas copulate. Taxidermic model experiments tested the function of the 3‐yr delay in plumage maturation. Reaction to a model manakin in female‐like, first‐year predefinitive plumage was stronger than that to a treatment control or a neutral species but weaker than that to a model manakin in definitive plumage. Reaction to the model manakins resembled mobbing choruses directed at model snakes, indicating that the reaction was a response to a potential threat. The results did not support female mimicry, juvenile mimicry, molt constraints or predator crypticity hypotheses for delayed plumage maturation. Decisive rejection of the first two hypotheses would require further experiments with model females and models of the other predefinitive stages. Nevertheless, none of the four hypotheses is sufficient to explain age‐specific plumage stages. The results were, however, consistent with a status‐signaling hypothesis that suffices to explain successive age‐specific plumages. The reaction to models was often by non‐alpha males, who had no opportunity for copulations. The presence of the models, therefore, appeared to pose a threat to the system of male‐male alliances rather than a risk of stolen copulations. By choosing with high discrimination among leks (queues), females appear to enforce orderly male queuing. The predifinitive plumages, therefore, seem to function as age‐specific badges of status that indicate a male is a queue entrant. The plumages mediate but do not eliminate aggression during the several years of becoming established in lek assemblages.
Song Perception in the Song Sparrow: Importance of Different Parts of the Song in Song Type Classification
Authors: Horning Cynthia L. , Beecher Michael D. , Stoddard Philip K. , Campbell S. Elizabeth
Published: May 2010

Song sparrow (Melospiza melodia) males have repertoires of 6 to 12 song types, each song consisting of four or five contrasting phrases. Song types vary both within individuals (a singer varies successive renditions of a type within a singing bout) and between individuals (neighbors sing slightly different versions of a type), and in both cases this variation is concentrated in the later parts of the song. We speculated that type variation in the later parts of the song might be correlated with a perceptual tendency to classify song types primarily on the basis of the earlier parts of the song. We tested this hypothesis using a laboratory conditioning technique, supplemented by a field playback experiment. In the lab, song sparrows and white crowned sparrows were trained to discriminate between two distinct song types. In test sessions, they were presented with hybrid songs synthesized from varying proportions of the two training song types. For most birds and most song pairs, song classification was influenced by all parts of the song, with the beginning elements being most important. The field playback experiment used song type matching as the response measure. Each subject was presented a hybrid stimulus song consisting of the first half of one of his song types and the second half of another of his song types. Subjects replied with both ‘front matches’ and ‘back matches’ (60% were front matches).
Can Paradise Fish (Macropodus opercularis, Anabantidae) Recognize a Natural Predator? An Ethological Analysis
Authors: Gerlai Robert
Published: May 2010

Predator recognition and avoidance by paradise fish have been studied with allopatric species and model experiments. The effect of sympatric predators has not been investigated. Here I report that reactions of paradise fish towards a sympatric predator (Channa micropeltes) are quantitatively different from those shown towards an allopatric predator or different harmless species of fishes. I investigate the possible cues eliciting this differential response and show that visual as well as olfactory stimuli play roles. Olfactory stimuli from the sympatric predator alone elicit an elevated level of activity from paradise fish; the appearance of the sympatric predator (with or without olfactory stimuli) results in an exploratory and display reaction. I speculate what visual stimuli may play roles in predator recognition in paradise fish and I suggest that previously asserted key stimuli such as the eyes of the encountered heterospecific fish may not differentiate the harmful species from innocuous. I conclude that the antipredatory behavior of paradise fish may be affected by both genetic factors and learning and that the relative importance of the former or latter factor may vary depending on the situation.
A Functional Analysis of Staccato Grunt Vocalizations in the Stumptailed Macaque (Macaca arctoides)
Authors: Bauers K. A.
Published: May 2010

Social interaction analysis was used to evaluate the social effect and function of the Staccato Grunt vocalizations (Chevalier‐Skolnikoff 1974) of stumptailed macaques (Macaca arctoides). Staccato Grunts are used in the highly specific context of an individual expressing friendly interest in an infant stumptailed macaque, as demonstrated in a previous quantitative descriptive study (Bauers 1989). It was hypothesized that these vocalizations function to signal an actor's benign intent when expressing Interest in Infants, that the signals are directed to the infant's mother, and that their use lowers the probability of an aggressive response from the mother. The functional hypothesis predicts that 1. mothers would not direct Staccato Grunts to their own infants; 2. Staccato Grunts would be given with higher probability when the mother of an infant is near (< 1 m), and 3, a mother's tolerance for attention or physical contact directed to her infant should be facilitated by Staccato Grunts. These predictions were supported by the data, based on analysis of the conditional probabilities of two‐event sequences in 554 interactions. It is concluded that Staccato Grunt vocalizations are used pragmatically to acquire access to infants and to reduce the probability of aggressive responses from their mothers. Acoustic characterization of Staccato Grunts, and alternative interpretations of the behavior are discussed.
Behavioral and Physiological Aspects of Reproductive Control in a Diacamma Species from Malaysia (Formicidae, Ponerinae)
Authors: Sommer Kathrin , Hölldobler Bert , Rembold Heinz
Published: May 2010

The reproductive system of a Diacamma species from Malaysia is described. Intact colonies have no queens. Instead one mated worker (gamergate) reproduces. Only a few workers (2%) have weakly developed ovaries. Newly emerged workers possess thoracic appendages, called gemmae, but only one worker retains them, mates and becomes a gamergate. All other individuals are mutilated mostly by already mutilated workers. After the gamergate has been removed this mutilation‐behavior continues for at least 24 h. After three days no more mutilation occurs.

Groups of workers without gamergate start to fight about one week after the gamergate was removed and one worker reaches the alpha‐position and becomes the sole egg layer. When workers emerge in already established groups they are not mutilated. Workers, which were isolated one week earlier than the rest of the group, and thus already escaped inhibition by the gamergate, had a higher chance to obtain the alpha‐position.

To test factors that might influence worker‐dominance, juvenile hormone titer was measured. Juvenile hormone was not detectable in gamergates and alpha‐workers but the amounts of juvenile hormone in non‐reproductive workers increased with age. This is discussed with regard to the situation found in honeybees.
Comparative Analysis of Interaction Duration in Three Species of Gerbils (Genus Meriones)
Authors: Goltsman M. E. , Borisova Natalia G.
Published: May 2010

Goltsman (1977) predicted that in more social species there should be longer durations of social behaviours. We studied durations of 9 behavioural actions (crawling over, crawling under, allogrooming, sniffing, sideways posture, frontal posture, fighting, upright and following) in two experiments with 1‐h introductions of (1) a group member that had been held in isolation for 24 h, and (2) an unfamiliar conspecific, into residental family groups of three gerbil species. Durations of some behavioural actions in these experiments were found to be longer in the most social species, Meriones libycus and M. unguiculatus. Also, we analysed the dependence of duration of agonistic interactions on the sex of the actor, the sex of the reactor, residental status of the actor and on the termination of the interaction. Species differed in the duration of three actions (sideways and frontal postures, fighting) with longer action durations in M. unguiculatus and M. libycus than in M. meridianus. These results support Goltsman's (1977) hypothesis.
Social Status and Feeding in Atlantic Salmon Salmo salar Parr: The Effect of Visual Exposure to a Dominant
Authors: Huntingford F. A. , Metcalfe N. B. , Thorpe J. E.
Published: May 2010

Groups of four Atlantic salmon parr were established and the dominant individual identified. Feeding responses were then observed in the remaining (subordinate) fish housed in one of three conditions: in the same compartment as the dominant fish (full exposure), separated from it by a transparent partition (visual exposure) or behind an opaque partition (isolated). Subordinate parr in the full exposure condition responded to and ate fewer food pellets than did the dominant fish. However, subordinate parr in the visual exposure condition and in the isolation condition fed actively, indicating that neither visual intimidation nor long‐term stress‐induced reduction of appetite were responsible for the reduced food intake of subordinate parr in direct contact with dominants. Dominant parr and subordinates in the visual exposure condition, but not subordinates in the exposed condition, moved further from their feeding station when attacking food items that were contested by a competitor compared with the distance moved for uncontested items. The presence of a competitor therefore forced both dominant and visually exposed subordinates to pay higher costs while foraging.
Effects of Relatedness, Dominance, Age, and Association on Reciprocal Allogrooming by Captive Impala
Authors: Mooring Michael S. , Hart Benjamin L.
Published: May 2010

Wild impala display a highly reciprocal allogrooming system that, by virtue of its frequency and high degree of reciprocity, is unique among ungulates. A herd of 35 free‐ranging captive impala provided opportunity to examine the degree of reciprocity of allogrooming exchanges and the influence of relatedness, dominance, age and association on partner preferences and distribution of grooming between allogrooming partners. As in wild impala, the exchange of allogrooming bouts in the captive impala was highly reciprocal regardless of partners. Kinship and dominance had no influence on partner preference or distribution of grooming between partners. Although mothers showed a significant preference to allogroom with their unweaned offspring, this preference practically disappeared with older offspring. Age‐mates (no greater than 6 mo apart) tended to associate with one another and spatial proximity was positively correlated with grooming partner preference. It was not clear whether impala actively sought out age‐mates for grooming, or randomly chose grooming partners from nearby age‐mates. The failure to find a role for kinship and dominance is counter to what has generally been found in most Old World terrestrial primate studies. The absence of pronounced social influences, coupled with the known effectiveness of grooming in removing ectoparasites, suggest that a utilitarian role, especially removal of ticks, is an important function of the impala reciprocal allogrooming system.
Agonistic Interactions in Juvenile Sticklebacks (Gasterosteus aculeatus) in Relation to Local Predation Risk
Authors: Wright P. J. , Huntingford F. A.
Published: May 2010

Size‐matched groups of three‐spined stickleback (Gasterosteus aculeatus) fry were established using fish from two sites, one with abundant piscivorous predators (the high‐risk site) and the other with very few heterospecific predators (the low‐risk site). Over a period of two months, social interactions within groups were monitored regularly and mean lengths and coefficients of variance in length were tracked. Agonistic behaviour was observed in 45% of observation periods, but was more common in the groups of fry from the low‐risk site, where it was more likely to take the form of direct attack rather than displacement without contact. In both categories of fish, the great majority of agonistic acts were directed to fish of a similar size or smaller. Mean size increased rapidly in all groups. At the same time, the coefficient of variation also increased, approaching 15% after two months in both categories of fish, reflecting differing growth rates among individuals. After three months, the two largest and the two smallest fish from each group were observed individually during an encounter with a model predatory fish. Large and small fish from both sites behaved identically in this test, suggesting that in sticklebacks (unlike guppies, for example) early experience of aggressive attacks from conspecific companions may not influence the development of anti‐predator responses. As has been reported previously, sticklebacks from the high‐risk site responded much more strongly than low‐risk fish.
Socio‐spatial Organization and Activity Distribution of the Alpine Marmot Marmota marmota: Preliminary Results
Authors: Perrin Catherine , Berre Dominique Allaine & Michel Le
Published: May 2010

The behavioural ecology of the Alpine marmot Marmota marmota (Linné, 1758) was studied Jun.—Sep. 1990 in the Vanoise National Park (French Alps). We describe the socio‐spatial structure of a high‐altitude population, to give additional information on the formerly unclear marmot social organization.

The social unit was the family group, with a common home range between 0.9 and 2.8 ha; a slight overlapping occurred (9 to 12.5%). Each home range had a central area of main burrows, where the hibernaculum was located, and peripheral areas.

Space utilization and distribution of activities during the season were analysed. Some activities took place exclusively in the centre area while peripheral parts were used for foraging. This latter increased in Aug. and decreased in Sep., marmots tending to remain more and more at the centre area as the hibernation period approached.
Social Play among Juvenile Bighorn Sheep: Structure, Development, and Relationship to Adult Behavior
Authors: Hass Christine C. , Jenni Donald A.
Published: May 2010

A 27‐mo study of bighorn sheep (Ovis canadensis) was conducted to examine the structure and development of social play among lambs, and to compare that behavior with the behavior of yearlings and adults. Male lambs played more than females and exhibited a larger repertoire. The behavior patterns used by lambs in social play were the same as those used by adults in intrasexual conflict and courtship. However, the repertoire of lambs was more limited than that of adults. Lambs chose partners closest in age to interact with, regardless of sex. Results were consistent with the hypothesis that play serves to develop physical skills and strength.
Variation in Social Structure: the Effects of Sex and Kinship on Social Interactions in Three Lemur Species
Authors: Kappeler Peter M.
Published: May 2010

The effects of sex and kinship on agonistic and affinitive interactions in Lemur catta, Eulemur fulvus, and Eulemur coronatus were examined to provide information on the social structure of these primates. All adult males and females of three captive forest‐living groups served as focal animals for one year. In contrast to many anthropoid primates, social interactions in these lemurs are characterized by predominantly competitive relations among closely related females, with low overall rates of polyadic conflicts. In L. catta, same‐sexed dyads and pairs of closely related individuals had higher proximity‐corrected frequencies of agonistic interactions than male‐female and non‐kin dyads. Grooming interactions, on the other hand, occurred significantly more often than expected in male‐female pairs and between unrelated animals. The top‐ranking male monopolized the majority of male‐female interactions. In E. fulvus, neither sex nor kinship had significant effects on the distribution of grooming and agonistic interactions. Unlike L. catta, grooming and conflicts were observed in all dyads, resulting in more complex social relationships. Male‐female relationships in E. fulvus were characterized by strong affiliative relations between individual male‐female pairs. Social relationships in E. coronatus were generally similar to those in E. fulvus, except for a significant sex effect on the distribution of interactions, but small sample size precluded a final characterization of this rare species.

Collectively, these results suggest that there may be intense competition among individual female lemurs for group membership, even among close relatives in the same matriline. Moreover, interspecific contrasts in male‐male and intersexual relationships indicate fundamentally different male roles in these species. This study revealed that patterns of agonistic and affinitive interactions are not generally predictable from sexual selection theory and interspecific differences in life histories, indicating a need for more quantitative descriptions of social relationships in diverse taxa to identify other ecological and social determinants of social structure.
Essay on Contemporary Issues in Ethology: Variation among Mammalian Alarm Call Systems and the Problem of Meaning in Animal Signals
Authors: Macedonia Joseph M. , Evans Christopher S.
Published: May 2010

Understanding the information conveyed by animal signals requires studies of both production and perception. It is important to determine the relationship between signal morphology and the circumstances of production, the way signaller behavior varies with motivational state and the role of context in mediating responses to signals. Alarm calls are well‐suited to research of this type because they are widespread in birds and mammals and typically evoke unambiguous responses. We review studies of alarm calling in primates and ground‐dwelling sciurid rodents, concentrating especially on whether these signal systems may be viewed as ‘functionally referential’, that is, as conveying sufficient information about an event for receivers to select appropriate responses. Comparisons of the physical, behavioral and habitat characteristics of these species suggest that incompatibility of the escape responses required to avoid different classes of predators may have been an important factor in the evolution of functionally referential alarm calls.
The Complex Acoustic Design of an Advertisement Call in Male Mouse Lemurs (Microcebus murinus, Prosimii, Primates) and Sources of its Variation
Authors: Zimmermann Elke , Lerch Carola
Published: May 2010

During the breeding season sexually active male mouse lemurs produce a trill call used for advertising. The trill call displays a variable, high pitched, complex frequency and amplitude modulated acoustical structure and is given with a high sound intensity. The different sources of its variation in structure and usage have to be determined to understand its complex acoustical design and function. We investigated the vocal morphology of the trill call of males with known age and weight as well as the behavioral context, in order to evaluate sources of its variation. Cluster and discriminant analyses revealed that the structure of trill calls showed a high degree of individual stereotypy in contrast to a high interindividual variability. A set of three distinct variables (fundamental frequency of call onset, bandwidth of 3rd frequency modulation and end frequency of 7th modulation) was sufficient to identify individual senders with almost 90% probability. The structure of the trill call of adult males was independent of age, weight and context and was stable over at least one breeding season. Its individually distinct call structure and use in relation to social status provide the potential for individual recognition and for assessing the “quality” of a male.
Competition among Females for Mates in a Species with Male Parental Care, the Midwife Toad Alytes obstetricans
Authors: Verrell Paul A. , Brown Lauren E.
Published: May 2010

Only males provide parental care in midwife toads (genus Alytes), carrying fertilized eggs entwined around the hind limbs. Although energetic investment in reproduction probably is greater for females, male care may be a limited resource in terms of its quality, and competition among females for access to males might be expected. We videotaped sexual interactions in a group of individuals in the laboratory to determine whether female Alytes obstetricans from Portugal compete for mates. Courtship and mating behavior were largely similar to descriptions of other authors for this species. Males did not exhibit direct aggressive interactions with one another for access to mates. However, females engaged in intense competitive behavior, which included frequent physical displacement of the amplectant male by an unpaired female. One male mated with two females that had competed with one another, suggesting that females may be unable to ensure exclusive access to male parental care.
Demonstration of Strength and Concealment of Weakness in Escalating Fights of Male Swordtails (Xiphophorus helleri)
Authors: Ribowski Alexander , Franck Dierk
Published: May 2010

In the green swordtail (Xiphophorus helleri) confrontations between strange males regularly escalate to high levels of mutual Bites and Fin Grips, even between males differing greatly in size. The original expectation of early game theory models that the behaviours of the ultimate winners and losers are indistinguishable until shortly before the end of the fight could not be confirmed. A significant characteristic of loser behaviour is that the Biting rates are higher before and after escalation. Conversely, Fin Grips are more frequent in the ultimate winners than the losers. However, such behavioural differences are very poor predictors of the outcome of the fight from the viewpoint of a single fighting individual during the contest. Correct forecasts did not exceed 67%. The escalating fights of swordtails are considered as trials of strength in which the stronger male tries to demonstrate strength by the most costly behaviour pattern available, namely Fin Grips, and the weaker male conceals weakness quite successfully by countering with the same tactic and suppressing signs of weakness such as Avoidance behaviour.
Magnetic Orientation in the Savannah Sparrow
Authors: Able Kenneth P. , Able Mary A.
Published: May 2010

Although magnetic compass orientation has been reported in a number of invertebrate and vertebrate taxa, including about a dozen migratory bird species, magnetic orientation capabilities in animals remain somewhat controversial. We have hand‐raised a large number of Savannah sparrows (Passerculus sandwichensis) to study the ontogeny of orientation behavior. Young birds with a variety of early experience with visual and magnetic orientation cues have been tested for magnetic orientation during their first autumn migration. Here we present data from 80 hand‐raised sparrows, each tested several times in both normal and shifted magnetic fields. Birds reared indoors with no experience with visual orientation cues showed axial north‐south orientation that shifted by almost exactly the magnitude of 90° clockwise and counterclockwise shifts in the direction of magnetic north. Other groups of birds with varying early experience with visual orientation cues showed different preferred orientation directions, but all groups shifted orientation direction in response to shifts in the magnetic field. The data thus demonstrate a robust magnetic orientation ability in this species.
Behaviour of Foals before Weaning May Have Some Genetic Basis
Authors: Wolff Anja , Hausberger Martine
Published: May 2010

In this preliminary study on foal behaviour, 13 French saddlebred foals (2–3 mo old) and their dams were observed on pasture. The most important findings are the interindividual quantitative differences in foal behaviour patterns as well as in the amount of mainly foal‐initiated time spent at given distances from their mares. Interindividual differences seem in part due to a sire effect.
Short‐range Navigation of the Weakly Electric Fish, Gnathonemus petersii L. (Mormyridae, Teleostei), in Novel and Familiar Environments
Authors: Cain Peter , Gerin William , Moller Peter
Published: May 2010

We investigated the electrolocation performance of the weakly electric fish, Gnathonemus petersii, in novel and familiar environments. By selectively interfering with the fish's sensory input, we determined the sensory channels necessary for navigation and orientation. The fish's task was to locate a circular aperture (diameter: 64 mm) in a wall dividing a 200–1 aquarium into two equal compartments. To assess the fish's performance, we measured (1) the time it took the fish to locate the aperture, (2) the height at which it contacted the divider, (3) its electric organ discharge rate, and (4) the frequency of divider crossings. In the first experiment (novel environment), 50 naive G. petersii assigned to five groups of 10 fish each (intact, blind, electrically “silent,” blind and “silent,” and shamoperated animals) were tested with the aperture presented randomly in one of three positions (aperture center: 7.6, 17.7, 27.8 cm from the bottom). In a novel environment, G. petersii depend on active electrolocation. Despite the changing aperture position, over the 15 trials, fish with a functioning electric organ found the aperture, whereas those without one did not. The electric organ discharge rate was inversely correlated with the amount of time spent searching for the aperture. In a second experiment (familiar environment) 20 intact fish learned the position of a fixed aperture. When we subsequently denervated the electric organ in 10 of these animals, their performance did not differ significantly from that of their conspecifics. Thus, once the fish were familiar with the aperture's position, they no longer depended on active electrolocation. We interpret and discuss this behavior as evidence for a “central expectation” and discuss its possible role in electronavigation.
Discrimination among Males by Female Zebra Finches Based on Past as Well as Current Phenotype
Authors: Sullivan Matthew S.
Published: May 2010

There are many social and sexual contexts in which individuals should base their interactions with others on the recipient's history of behaviour or morphology over the time in which the two have associated. I tested the ability of female zebra finches to discriminate among males on the basis of their past as well as current phenotype by allowing them to view groups of four males for two hours a day, for four days, while the bill colour of individual males was manipulated with orange and red paint. Four bill colour treatments were assigned to the males in a stimulus set. One male was orange for all four days, one was red for all four days, a third male was orange for the first two days but red for the second two days, and the fourth male was red for the first two days and orange for the second two days. There was a slight, but non‐significant, preference for orange bills when compared on a day to day basis regardless of bill colour history. However, when males were ranked on day 3 and day 4 according to the proportion of the assessment period they had been orange, there was a significant positive correlation between preference on those days and proportion of time orange. A more detailed examination shows that there was an effect of bill colour history independent of current bill colour but not vice‐versa. These results suggest that discrimination is based not only upon instantaneous appearance, but average appearance over the assessment period.
Individual Odors in Djungarian Hamsters (Phodopus campbelli)
Authors: Lai Syau‐Cheng , Johnston Robert E.
Published: May 2010

The sources of scent in Djungarian hamsters (Phodopus campbelli) that may be individually discriminated were investigated using an habituation paradigm. Male Djungarian hamsters were exposed to five presentations of a particular scent from one individual, and then to the same scent from a novel individual. Increased investigation of the scent from the novel individual indicated discrimination of scents from different individuals. Male hamsters distinguished individual differences in scents of other males from the midventral gland, urine, feces, mouth, and the corner of the mouth, which includes the sacculi; they did not discriminate among odors of different individuals when the scents were from the genital region, hindfeet, fur from behind ears or fur from the back. The results indicate that Djungarian hamsters have a repertoire of individually distinctive scents that are located in specific places on the body; these scents are not actively distributed to, nor passively picked up on, other parts of the body. The fact that scents from some areas do not contain individually distinctive information suggests that some sources may be specialized for producing individually distinctive scents.