bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experiments on Winter‐site Attachment in Young Dark‐eyed Juncos
Authors: Nolan Val , Ketterson Ellen D. 
Published: May 2010

AbstractSite attachment in young birds has sometimes been considered to take place during a sensitive phase as the result of an imprinting‐like process. We conducted two four‐year‐long experiments on winter‐site attachment in young migratory dark‐eyed juncos (Junco hyemalis). In both, we caught birds over a range of dates, displaced them to large outdoor enclosures, and released them near the end of winter. In the first experiment, release was at the capture site and all returns next winter were to that site. The return rate did not vary with date of capture and confinement; therefore attachment could have been completed either before capture or after release. The absence of returns to the confinement site suggests that attachment to a place requires that the individual live free there. In the second experiment, release was at the confinement site, and many subjects remained there, probably until they migrated northward. Returns next winter were to both the capture site (the majority) and the confinement‐release site. The fact that a few juncos formed a bond to the confinement‐release site in this experiment reinforces the view that living free is necessary for site attachment. Individuals caught and confined earlier in winter tended to be less likely to return than those caught later. The distribution of returns according to date of capture indicates that attachment was completed at different dates in different subjects, which is not consistent with imprinting during a clearly defined sensitive period. However, young juncos hatch and migrate at various dates. Therefore our experiment does not rule out the existence of a brief sensitive phase for site attachment, its dates varying among individuals because age and/or timing of migration vary.
Homing in the Digger Wasp Bembix rostrata (Hymenoptera, Sphecidae) — Release Direction and Weather Conditions
Authors: Schöne Hermann , Tengö Jan 
Published: May 2010

AbstractWasps were released 500 m S, NW and NE of the nest aggregation. Approaches were over grassland, bush with spinneys, and pines. The sun was visible at releases, but often became concealed by clouds.Homing times are positively correlated with sun cover times. The regression lines indicate a difference between S wasps and NW/NE wasps (S 26, NW 57, NE 66 min). NW wasps appeared to home somewhat better than NE wasps if only the fastest homers were considered.Results are interpreted in terms of the known concepts of sun compass and landmark orientation in relation to familiarity with the release area.
Female Preferences Based on Male Quality in House Mice: Interaction between Male Dominance Rank and t‐Complex Genotype
Authors: Coopersmith Carol B. , Lenington Sarah 
Published: May 2010

AbstractConsiderable evidence indicates that female house mice (Mus domesticus) prefer dominant over subordinate males as mates. In addition, male genotype at the t‐complex seems to be an important characteristic used by females in mate choice. Specifically, female mice that carry a t‐haplotype at the t‐complex prefer +/+ over +/t males as mates. The purpose of the present study was to examine the relative contributions of male dominance rank and male t‐complex genotype to female mating preference when both factors were systematically varied.We tested females of three genotypes (+/+, +/t, and t/t) in a preference apparatus using pairs of stimulus males varying in relative dominance status and t‐complex genotype. In general, when given the choice, females preferred dominant over subordinate males regardless of the male's t‐complex genotype. The preference for dominant males was manifested when both stimulus males were of the same t‐complex genotype but differed in dominance rank. In addition, when forced to choose between a dominant +/+ and subordinate +/t or between a dominant +/t and subordinate +/+, females continued to prefer the dominant male. Preference for dominant males was independent of female genotype. Only when both males were dominant but differed in t‐complex genotype (i.e. one male was +/+ and the other +/t) or when males were unranked (i.e. had not been used in aggressive encounters to determine dominance rank) did females carrying t‐haplotypes manifest preferences for +/+ males. Quite unexpectedly, when both males were subordinate but differed in t‐complex genotype, preferences of all females shifted in the direction of the +/t male.It is not clear from present data whether the propensity of females to give greater weight to male dominance rank than to t‐complex genotype in choosing mates results in greater fitness. However, if these trends are found in natural populations, it would indicate that the role of mating preference in regulating the frequency of t‐haplotypes in wild populations is less straightforward than had been previously thought.
Agonistic Tactics and Size Asymmetries between Opponents in Blattella germanica (L.) (Dictyoptera: Blattellidae)
Authors: Rivault Colette , Cloarec Ann 
Published: May 2010

AbstractIn this paper we investigated the influence of size differences between opponents on the occurrence of different agonistic attack and response tactics displayed during encounters between Blattella germanica (L.) cockroaches of all developmental stages, competing for a limited food source. The two main results were: 1) attack and response tactics varied during development and 2) size asymmetries between contestants influenced agonistic tactics. Developmental stage of initiator influenced the frequency distribution of the three types of attack patterns (Bite, Kick and Jump) and of the four types of response patterns (Retaliation, Escape, Resettle and No Response). The proportion of kicks increased gradually with developmental stage of the initiator whereas the proportion of bites declined during development. In addition, cockroaches adapted their attack tactics to the developmental stage of their opponent. Similarly the response displayed varied in relation to the developmental stage of the attacked individual, the developmental stage of the initiator and the type of attack displayed. During an interaction, animals appeared to be able to evaluate the relative size of their opponent and to evaluate the consequences of the behavioural pattern they displayed. Larger animals tended to minimize the intensity of the agonistic act they initiated. Escalation in interactions was rare and smaller individuals tended to escape when attacked by larger ones. Wrong estimations of the relative size of opponent, when a smaller animal retaliated after being attacked by a larger animal or when a larger animal fled after being attacked by a smaller one, represented only 6% of the records.
The Organization of Song Repertoires in Song Sparrows: Themes and Variations
Authors: Podos Jeffrey , Peters Susan , Rudnicky Tamia , Marler Peter , Nowicki Stephen 
Published: May 2010

AbstractAlthough songtypes are generally considered to be important functional units in birdsong, they have not been well‐characterized in terms of within‐ and between‐songtype variation. We analyzed the song repertoires of 12 adult male song sparrows (Melospiza melodia) from a population in New York. We identified minimal units of production (MUPs), and calculated the degree to which song variants within a bird's repertoire were similar to each other based on an analysis of MUP sharing. Using statistical techniques from numerical taxonomy, we assessed how song variants clustered into songtypes, and we derived quantitative measures of within‐songtype and between‐songtype similarity. We found that birds produced a limited number of songtypes, but constantly produced new song variants within the framework of these types. Most song variants were produced very rarely; over 43% of song variants were produced only once. Repertoires differed in the degree of between‐songtype similarity and in the number of songtypes defined, but there was comparatively less variation in within‐songtype similarity. Between‐songtype similarity and repertoire size were positively correlated. We argue that song sparrow songtypes are probabilistic units of song production, and discuss the functional and evolutionary implications of having vocal motor patterns organized in this way.
Differential Probability of “Coproduction” in Two Species of Macaque (Macaca tonkeana, M. mulatta)
Authors: Petit Odile , Desportes Christine , Thierry Bernard 
Published: May 2010

AbstractThis study aimed to assess the conditions under which monkeys might produce common effects in an instrumental task. One group of Tonkean macaques (Macaca tonkeana) and two groups of rhesus macaques (M. mulatta) were given series of tests in which food incentives were placed under stones of various weights. In the Tonkean group, the simultaneous action of two subjects in moving the same stone was a relatively frequently occurring event: coaction was more effective than individual action for moving heavy stones; however, there were no signs of coordination among partners and no improvement through learning. In rhesus groups, instances of coaction were extremely rare, and rates of agonistic interactions were higher than in the Tonkean group. It is suggested that “coproduction” represented an emergent phenomenon resulting from social interactions and, as such, was dependent on the level of interindividual tolerance.
Cooperation and Prey Capture Efficiency in a Social Spider, Anelosimus eximius (Araneae, Theridiidae)
Authors: Pasquet Alain , Krafft Bertrand 
Published: May 2010

AbstractWe studied the efficiency of the hunt and the characteristics of cooperation during the prey capture in a social spider Anelosimus eximius.Two natural types of prey of roughly the same length (20 mm) were used: grasshoppers (Orthoptera) and moths (Lepidoptera); 128 tests were made on 14 colonies, the smallest with 20 and the largest with 1,700 individuals. Test times were 12.00 h, defined as an inactive period for the spiders and 18.00 h, defined as an active period.Overall capture rate of intercepted prey was 66%: it was higher in large colonies or at 18.00 h, when more spider alerts were triggered by the struggling prey. Characteristics of cooperation during capture did not vary with colony size.Capture rate was higher for grasshoppers than moths (73%‐58%) in spite of similar number of alerts (76%‐87%); so moths must have been more difficult to capture. For both prey types, large colonies capture more rapidly and so had advantages in terms of time gain.We showed that cooperation depended on prey type: more spiders mobilised to attack moths and attack was faster than on grasshoppers. This may be interpreted as an adaptive response of the group to the prey type.
Territory Quality in Mountain Reedbuck (Redunca fulvorufula chanleri): Distance to Safety
Authors: Dunbar R. I. M. , Roberts S. C. 
Published: May 2010

AbstractReedbuck are heavily dependent on cover as a means of evading predators, and Howard (1986a) suggested that males defend cover‐abundant habitat in order to maximize access to receptive females which congregate in these areas. We use a measure of female preference for individual territories, and variations in territory size and quality to test this hypothesis in Chanler's mountain reedbuck (Redunca fulvorufula chanleri). Although the amount of cover within each territory did appear to be important, the height of available slope predicted female preference most precisely. It is concluded that, under certain conditions, the extent of available slopes for predator evasion may be a more appropriate indicator of territory quality.
Visual Assessment of Relative Body Size in a Cichlid Fish, the Oscar, Astronotus ocellatus
Authors: Beeching Simon C. 
Published: May 2010

AbstractIn cichlid fishes, fighting ability, success at nest defense, and fecundity are all positively correlated with body size. Selection should therefore favor the evolution of strategies for the assessment of relative body size during intraspecific interactions. The effect of relative body size on agonistic behavior in the oscar (Astronotus ocellatus) was tested using dummies. As predicted by game theory models, attack was strongly correlated with the size of the dummy relative to the subject. The most intense aggression occurred when dummy size was approximately 75% of subject size. These data support the prediciton that perceived body size asymmetries are important determinants of agonistic behavior in these fishes. Further, the results suggest that oscars can visually assess relative body size, and may estimate relative fighting ability without tests of strength. Subject size was positively correlated with intensity of aggressive behavior. Attack and display frequencies were positively correlated with a subject's body size, while latencies to approach and attack dummies were negatively correlated with subject size.
Special Relationships between Female Asian Elephants (Elephas maximus) in Zoological Gardens
Authors: Garaï Marion E. 
Published: May 2010

AbstractSocial relationships between female zoo elephants were analyzed on three different zoo groups. Interactions were defined as either affiliative or agonistic. The most frequent interactions were found to be touching of the partner's mouth, genital sinus, face and trunk. The calf was the individual involved in most social interactions. Placing the trunk tip into the partner's mouth is a well known behaviour, the correlation between this behaviour and aggression was analyzed and a further function is suggested. Aggressive behaviour was analyzed and the hypothesis derived that rank order has to be established and is flexible in a non‐kin group. The hypothesis that Asian elephant females may form special relationships was tested and confirmed. The following behaviour patterns were determined as indicators of a special relationship: Spatial proximity, partner‐specific reactions to arousal and to vocalizing, and omission of agonistic behaviour. An experiment confirmed the hypothesis that the removal of one member of a special relationship from the enclosure would elicit more arousal behaviour in the respective partner.
Ontogeny of Time Allocation in Black‐tailed Prairie Dogs
Authors: Loughry W. J. 
Published: May 2010

AbstractThe ontogeny of time allocation was studied in a field population of black‐tailed prairie dogs, Cynomys ludovicianus. Pups first emerged from their natal burrows in late May. All individuals in the population, including all pups, were observed for 12 weeks following this emergence. Both cross‐sectional and longitudinal analyses of ontogeny revealed considerable age differences. Upon first emergence, pups were extremely wary and spent most of their time vigilant and little time feeding. As pups aged, they increased time spent feeding and decreased time spent vigilant. Male and female pups behaved similarly. Pups differed from adults in their time allocation patterns and these differences changed as pups aged. Pups were initially more vigilant and fed less than adults, but became less vigilant than adults as the summer progressed. Yearlings behaved similarly to adults. Possible intrinsic (e.g., pup age and weight) and extrinsic (e.g., weather conditions, microhabitat location and coterie composition) influences on time allocation by pups were also examined. In general, extrinsic influences appeared to have more impact on pup behavior than intrinsic ones, suggesting that time allocation by pups may be largely context‐dependent. Overall, the considerable number of age differences argues for more consideration of ontogeny in models of antipredator behavior.
Is the Tonal Quality of Birdsong Learned? Evidence from Song Sparrows
Authors: Nowicki Stephen , Marler Peter , Maynard Alicia , Peters Susan 
Published: May 2010

AbstractSong sparrow (Melospiza melodia) songs are composed largely of pure‐tonal sounds. This paper investigates the role that learning plays in the development of the tonal structure of song sparrow songs, as well as the role that tonal quality plays in determining the suitability of songs as models for learning. 20 birds were trained with both normal pure‐tonal songs and modified songs that included harmonic overtones. The harmonic‐modified songs were obtained from birds singing in a helium atmosphere, the result of which is to perturb vocal tract resonances and thus alter a song's tonal quality. Subjects learned equally well from normal and harmonic models. Birds that learned material from harmonic models reproduced some of this material with harmonic overtones, but the majority of notes learned from harmonic models were subsequently reproduced as pure‐tonal copies. Thus, the tonal structure of songs does not influence young song sparrows in their selection of song models, but there is a strong tendency to reproduce songs in a pure‐tonal fashion, even if learned from harmonic models.
Castration Lowers Aggression but not Social Dominance in Male Haplochromis burtoni (Cichlidae)
Authors: Francis Richard C. , Jacobson Ben , Wingfield John C. , Fernald Russell D. 
Published: May 2010

AbstractAdult males of the African cichlid fish Haplochromis burtoni are either territorial or nonterritorial. In nature and aquaria, only territorial males breed and they have markedly more developed testes than do nonterritorial males. Territorial males are clearly dominant over nonterritorial males of the same age and size, and also exhibit higher levels of aggression. In this study, territorial males were gonadectomized in order to assess the effects of lowered androgen levels on their aggression and dominance status. Completely castrated males showed a pronounced reduction in both testosterone and 11‐ketotestosterone, as well as significantly lower aggression scores than sham‐operated males. Partially castrated males (> 0.005 g gonadal tissue remaining at autopsy) exhibited intermediate levels of both androgen levels and aggression. Surprisingly, in dyadic encounters with normal nonterritorial males of the same size, castrated territorial males retained their dominance despite decreased androgen levels and aggression.
Interspecific Response to Playback of Bird Song
Authors: Møller Anders Pape 
Published: May 2010

AbstractResponses to bird song have usually only been studied at the intraspecific level. I experimentally tested whether playback of the song of the black wheatear Oenanthe leucura in an area in S Spain resulted in responses from conspecifics as well as heterospecific birds by comparing the numbers of individuals singing before and after playback. The number of singing male black wheatears increased considerably, but also the number of singing males of five other passerine species increased significantly. The heterospecific response to playback may be due (1) to interspecific territoriality, (2) to black wheatear song signalling the absence of predators, or (3) to heterospecifics confusing the species‐identity of the singer. The second alternative is considered more likely, since an ecologically wide array of species increased their song rate following playback. The conspicuous dawn (and dusk) chorus of bird song may be augmented by social facilitation due to the singing of conspecifics as well as heterospecifics.
Social Behaviour and Cooperative Breeding in Arctic Foxes, Alopex lagopus (L.), in a Semi‐natural Environment
Authors: Kullberg Cecilia , Angerbjörn Anders 
Published: May 2010

AbstractMost canid species show cooperative breeding at least occasionally. The helper‐at‐the‐den system, when extra adults serve as helpers by feeding and guarding the cubs of an alpha pair, has been observed but not studied in any detail in wild Arctic foxes (Alopex lagopus). During a 3‐months study of arctic foxes in two enclosures of 4 ha each, we measured the social behaviour during the reproductive season. Older foxes dominated younger ones and males dominated females of the same age. A litter with one surviving cub was born in one enclosure. The alpha male increased his rate of urine marking and barking and fed the alpha female both before and after the birth of the litter. However, about 10 days after the birth, the alpha female died. The cub was fed by his putative father, his sister and his brother (both one year old). The one year old female increased her rate of territorial defence, measured as urine marking and barking, when the mother died. The subordinate females were probably suppressed from breeding by the high aggression levels and territorial defence of the dominant females in each enclosure. The dominant female in the second enclosure came into heat after the death of the alpha female (her mother) in the first enclosure. These changes in behaviour can probably be explained by sexual inhibition by the alpha female while she was present. The significance of territorial defence and dominance, inbreeding avoidance, sexual suppression and evolution of helping behaviour are discussed.
Intentional Icons: Towards an Evolutionary Cognitive Ethology
Authors: Bekoff Marc , Allen Colin 
Published: May 2010

AbstractIn most species in which social play has been observed, play‐soliciting signals have evolved. These social signals appear to be important in communicating play intention. Here, using the work of Ruth Millikan as a working guide and canid play bows as an example, we argue that (i) some play signals may be simple “intentional icons” and (ii) senders and receivers are “cooperating devices,” in that the disposition of senders to produce play‐soliciting signals and the disposition of receivers of play signals to respond appropriately to play invitations, have evolved together. Millikan's views of social communication are difficult to render and are virtually untested. However, her stance, while philosophically controversial, is somewhat consistent with early ethological views of social communication. Thus, in combination with classical ethological positions, Millikan's position could serve as a useful guide not only to inform and motivate future empirical research in cognitive ethology, but also to stimulate ethologists to reconsider, in innovative ways, nonhuman animal cognition. To reject the empirical utility of Millikan's theory because of its difficulty or on philosophical grounds would be premature and would represent a confusion of empirical with philosophical issues.
Differences in Neophobia between Naive Song and Swamp Sparrows
Authors: Greenberg Russell 
Published: May 2010

AbstractI measured feeding neophobia in song (Melospiza melodia) and swamp (M. georgiana) sparrows. The experiment had a counter‐balanced design with each species divided into two rearing groups and each exposed to a different set of six objects. I tested sparrows at two months of age by measuring their latency to feed at cups placed at familiar and novel objects. These tests were repeated at six months using an additional four novel objects. In comparison with song sparrows, juvenile swamp sparrows had a significantly and consistently lower latency to feed at novel objects. I found this difference in older birds as well. Feeding latencies at familiar objects were statistically indistinguishable between species. These results suggest that song sparrows are more neophobic than swamp sparrows. I obtained opposite results from similar experiments conducted in the field and using wild‐caught birds in captivity. Greater neophobia in wild swamp sparrows may be a consequence of differential experience between the two species in nature. Differences found between hand‐raised song and swamp sparrows is one of the first demonstrations of interspecific differences in neophobia under similar and controlled rearing conditions. A possible adaptive explanation is that, typically, juvenile swamp sparrows are reared in a simpler, more predictable and hence safer environment and may not require the protection of an aversion to novelty.