bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensory Factors Involved in Immediately Postnatal Ewe/Lamb Bonding
Authors: Vince M.A. , Lynch J.J. , Mottershead B. , Green G. , Elwin R. 
Published: April 2008

Abstract
1. Aspects of the ewe which influence the lamb. Lambs were removed from their mothers at birth and tested under one of seven conditions : (1) with the dam in her pen, or, in a circular arena, (2) in the presence of a stationary model ewe, (3) with the same model, but moving, (4) in the presence of a large, headless and legless moving object, (5) with stimulation by the sound of recorded bleats, (6) with tactile stimulation or (7) with no stimulation. Indices of responsiveness included movements of righting and standing, approach to the model, bleating and nosing of the model or the arena. Results showed that lambs tested with the stationary model stood most slowly whereas the presence of the moving model ewe was associated with rapid standing. The groups with no experimental stimulation at all, or with stimulation by the sound of recorded bleats, also stood rapidly. Bleating of the lambs was most prevalent in the group with no stimulation at all. Lambs presented with moving models approached them more rapidly and nosed them more than did those tested with the stationary model. More than any others, lambs in the "stationary model" group were quiescent for long periods. Lambs tested in the presence of their mothers and those given tactile stimulation were consistently low in the rank order for all indices of response; in particular they stood more slowly and bleated less than groups presented with moving models. It is concluded that the dam is a composite stimulus for her lamb; she activates it when she moves but also elicits responses which reduce its early activity. 2. Aspects of the lamb which attract the ewe. Ninety Merino ewes, from each of which the lamb had been removed at birth, were tested in their own pens under one of the following conditions: (i) with their own lambs; (ii) with a warm, moving lamb model soaked in amniotic fluid and accompanied by lamb bleats, or with the same model but (iii) without movement; (iv) without warmth; (v) without bleats or (vi) without amniotic fluid. A seventh group was tested with a white bowl of warm amniotic fluid, also moving and accompanied by lamb bleats. The ewes approached their own lambs and were much more attentive to them, than to any of the models. The model which received the least attention was that (vi) with no amniotic fluid, while the 'model' which received the most was (vii) the white bowl containing amniotic fluid.
Interspecific Aggression By Barrow's Goldeneye: a Descriptive and Functional Analysis
Authors: Savard JEAN-PIERRE L. , Smith James N.M. 
Published: April 2008

AbstractWe describe interspecific aggression and territoriality by a diving duck, the Barrow's goldeneye. Males of this species are strongly interspecifically territorial early during the breeding season, and in winter. Females are interspecifically territorial while tending broods of ducklings. Aggression was strongest against conspecifics, and against the con-generic bufflehead, which shares the same breeding habitat. Other diving ducks, which overlap in diet with goldeneyes, were frequently attacked, while dabbling ducks, with differing feeding habits, were generally tolerated, and were seldom attacked. One dabbling duck, the blue-winged teal, in which the drake resembles the Barrow's goldeneye drake in plumage, was attacked more strongly than other dabblers. We propose that the strong interspecific aggressiveness exhibited by the Barrow's goldeneye, and its congeners the bufflehead and common goldeneye, is a consequence of the strong intraspecific aggressiveness of these species. Selectivity in aggression towards victims of different species can be explained by two hypotheses. Species that have (1) similar diets, and (2) similar plumages to Barrow's goldeneye are selectively attacked.
Mobbing Behaviour, Nest Exposure, and Breeding Success in the American Robin
Authors: Mclean Ian G. , Smith James N.M. , Stewart K. Glenna 
Published: April 2008

Abstract
We tested some costs and benefits associated with variable levels of mobbing response towards nest predators by American robins. Playbacks of robin mobbing calls attracted a major predator of robin nests, the northwestern crow. This demonstrates a potential cost to robins that give mobbing calls. We then used human 'predators' to test whether reproductive success was related to mobbing intensity. We first showed that mobbing responses to humans resembled those shown to a stuffed crow. Second, we demonstrated that responses of pairs of robins were consistent at different tests at the same nest, but were less consistent between different nesting attempts of the same pair. The first result validates our experimental procedure, but the second result suggests that variation in mobbing response is partly determined by characteristics of the nest or nest site, rather than by the level of aggressiveness of the parents. When we compared mobbing responses by robins at exposed and well-concealed nests, robins with exposed nests used extreme responses (swoops and hits) more frequently than those with concealed nests. We did not, however, find an consistent relationship between mobbing intensity, stage of the nestling cycle, or reproductive success. Robins did not respond more strongly late in the nesting cycle, and pairs that responded weakly, or strongly, experienced similar levels of nesting success.
Song Structure and Singing Strategies in the Genus Luscinia in Different Habitats and Geographical Areas
Authors: Sorjonen Jorma 
Published: April 2008

AbstractThe structure of song and song propagation of studied populations of the Finnish thrush nightingale, the Mediterranean nightingale and the bluethroat (L. svecica) are in accordance with the prediction that birds living in less open habitat and usually singing inside the forest canopy, use more whistles and modulated elements and less trilled syllables (especially fast trills) in their songs than the species in more open habitats. However, the effects of the geographical location and other species in song communities are greater than that of habitat. The birds also seem to be able to improve their long distance communication easier by change in singing behaviour than by change in song-structure. The thrush nightingale males in the northern population improved detectability of their song by singing at midnight when most other species in the bird community are silent. At the same time the males increased song length and decreased intersong pauses, which increased their total vocalizing time and improved the receivers' possibility to detect their acoustic information. This strategy presumably improves rapid pair formation, which is important for long distance migrants in the northern latitudes with short favorable season for breeding and subsequent moulting.
Partner Attack Inhibition in the Convict Cichlid, Cichlasoma (Archocentrus) Nigrofasciatum
Authors: Turner George F. 
Published: April 2008

AbstractThe paper investigates the occurrence of submission in relation to the courtship of the biparental sexually dimorphic convict cichlid, Cichlasoma (Archocentrus) nigrofasciatum. It was found that submission by females was not necessary for courtship to proceed and such behaviour was found only in a similar context to fleeing behaviour. The presence of an intruding male, while generally invoking courtship activities, did not reduce the aggressiveness of a resident female towards other conspecifics. Thus any inhibition of aggression was specific to the potential mate only. Similarly intruding males did not attack aggressive resident females, even though no symbolic inferiority was performed. It is suggested that inhibition of aggression towards the partner can occur in the absence of symbolic inferiority and proposed that a new terminology be adopted. Particular activities involved should be named according to postural elements, and the functional category referred to as Partner Attack Inhibition (PAI).
Tactile Communication Between Ewe and Lamb and the Onset of Suckling
Authors: Vince Margaret A. 
Published: April 2008

AbstractA series of experiments shows (1) that the effects of tactile stimulation produced by covering the face and eyes of an unsuckled Clun Forest or Soay lamb elicits a vigorous response which includes elements such as tilting up of the muzzle, lengthening of the neck, munching, mouth opening, curling back of the upper lip in the sucking position, tongue protrusion and apparent reaching and grasping movements of the lower jaw, upper and lower lips and the tongue (2) that these movements are directional in that the neck, head, lower jaw, lips and tongue are usually turned towards the stimulus (3) that before the lamb has attained a standing posture this response appears only weakly and may be replaced by a downward head movement; also it is weakened or disappears after the lamb has sucked (4) a similar response can be elicited by a visual stimulus only more slowly and in a less vigorous form. In Soay, but not in Clun Forest, lambs the response to touch was maintained for longer when the eyes were covered, than when the lambs were able to see (5) touch on the belly of the dam, simulating that produced by a lamb pushing its muzzle up against her, causes her to arch her back upwards, while touch nearer to or on the udder, or in the inguinal area, but not on the back of the udder, is associated with lowering of the tail and an outward movement of the hind leg which exposes the teat. The findings are considered in their relation to the natural situation immediately after birth of the lamb when the interchange of different types of tactile and other sensory stimulation gradually brings both partners into a situation in which the lamb can grasp the teat and suck.
Leaf Size Recognition and Evaluation of Some Attelabid Weevils (1) Chonostropheus Chujoi
Authors: Sakurai Kazuhiko 
Published: April 2008

AbstractLeaf recognition of the female during cradle formation was studied using model leaves, young oak leaves moulded in several shapes; observation of behaviour preceding cutting and numerical analysis of cutting points were carried out. Females repeatedly perform a sequence of walking along the circumference via the leaf apex and then cut the leaf. Circumference length is the most probable determinant of the cutting point. It is hypothesized that females perceive the most protrusive point of the leaf, the leaf apex, and the circumference length by walking. A scheme, which consists of two mechanisms for circumference measurement, for the cutting point decision is proposed. Although females do not adjust the cutting point with respect to the number of eggs to be laid in the cradle, they perceive and use leaf area or something correlative to it, for the decision as to egg number.
Functions of Alliances in Contests Within Wild Gorilla Groups
Authors: Harcourt A.H. , Stewart K.J. 
Published: April 2008

AbstractPrimates frequently support other individuals in aggressive contests among group members. Several functions of such alliances have been suggested, some of them dependent on continued residence of females in the group of their birth. The distribution of alliances in the gorilla (Gorilla gorilla), in which both sexes emigrate, was analysed to investigate constraints on the use of alliances by primates. Functions were inferred on the basis of the identity of participants, it being assumed, for example, that a mother supported its infant against an adolescent male for a different reason than did an adolescent female who supported a dominant female against a subordinate female. Gorillas ally, we suggest, to protect relatives from harm, to provide them with access to otherwise unobtainable resources and, perhaps, to emphasise their dominance over rivals; it seems that individuals might also ally to obtain resources for themselves, and to establish supportive relationships with other group members. The first two inferred functions were the most common, involved in over 80% of alliances. The major contrast with female-resident primates lay not so much in the range of functions for which alliances were used, but in the lack of evidence that gorillas attempted to use alliances to manipulate the dominance status of their kin. Possible reasons for the contrast are that i) the widespread distribution and low quality of the gorilla's main food plants meant that ability in defence competition was not sufficiently advantageous for the benefits of raising the rank of kin to outweigh the costs; ii) the large difference in age among immature gorillas in the study area, which was mostly a consequence of the small group size, made it too costly to use support in contests to raise an individual's rank above that of older peers; iii) the leading male prevented the unequal investment among his offspring that would be entailed if individuals used alliances in contests to raise or reinforce the rank of kin. Currently, these possibilities cannot be distinguished.
Sexual Behavior of Male Northern Elephant Seals: III. the Mounting of Weaned Pups
Authors: Rose Naomi A. , Deutsch Charles J. , Le Boeuf Burney J. 
Published: April 2008

Abstract
1. Up to 50% of weaned northern elephant seal pups, Mirounga angustirostris, present on the Año Nuevo mainland rookery at the end of the breeding season showed evidence (tooth marks and injuries on the neck) of having been mounted by males. 2. Male-inflicted injuries on weanlings ranged from superficial tooth marks to deep gashes and punctures that bled and exposed the blubber. Most marks were superficial. 3. Approximately 0.5 % of all weaned pups died on the rookery from 1969-1990; about 35 % of the dead weanlings showed physical evidence that they were killed by males and males were suspected of having killed most of the rest. 4. Males mounting weanlings displayed many behaviors that are characteristic of male sexual behavior toward adult females and most weanlings responded like non-estrous females. Weanling mounts lasted an average of 2.8 min (N = 81) and were usually terminated when the male did not pursue an escaping weanling. There was no bias in the sex or the size of mounted weanlings. 5. Males also mounted conspecific juveniles (one and two years old), although these interactions were relatively infrequent because most juveniles were at sea during the breeding season. The behavior of males and juveniles during mounting attempts was qualitatively similar to weanling mounts; rarely, yearlings were killed by males. 6. Most mounters (91 %) were subadult males and were observed to mount weanlings only once in a breeding season. Occasionally, a male persisted in mounting weanlings repeatedly, within a season and across years. Weanling mounters did not differ from other males in their proximity to harems or in their copulatory success. 7. The proximate factors leading to weanling mounts appear to be male sexual inexperience, high libido, limited access to adult females, and stimulus generalization. Functionally, male sexual behavior toward weanlings appears to be a low-cost by-product of high male sexual motivation that may enhance a male's reproductive success. Weanlings exhibit behaviors, such as grouping into pods, seeking microhabitat refuges, and resisting mounts, that may reduce the chance of being mounted by a male or of being injured during a mounting attempt.
Broadcast Distance of the Mutual Display Call in the Emperor Penguin
Authors: Robisson Patrice 
Published: April 2008

AbstractIn the colonial emperor penguin Aptenodytes forsteri, the broadcast distance of the mutual display call (the distance over which the individual information conveyed by the call is transmitted) was determined. The variables measured were (1) the sound amplitude that averaged 94.8 dB SPL for birds facing toward the microphone and 85.7 dB SPL for birds facing away, (2) the sound attenuation that decreased with about 6 dB per doubling distance, (3) the ratio of the signal to the background noise of the colony which was 20-25 dB during the rearing period of chicks, and (4) the degradation of the signal structure by the scattering medium (penguin bodies) and distance, which affected the timbre, but not the two fundamental frequencies of the call that produced a beat phenomenon. This distance, 4-7 m indicates that the call is transmitted at short- or medium-range, and corresponds closely to the distance covered between two stops where a parent in search for its chick calls. The beat phenomenon undegraded by the scattering medium and distance is likely to serve individual recognition, assuming there is a relationship between the broadcast distance and the functional structure of emperor penguin call.
Sex-Biased Parent-Offspring Conflict
Authors: Redondo Tomas , Gomendio Montserrat , Medina Rosario 
Published: April 2008

AbstractIn species showing sexual dimorphism, parents may obtain different fitness returns per unit of parental expenditure from sons and daughters. Under these circumstances, parents are expected to invest extra resources in offspring of the most profitable sex. However, it is unclear whether sex-biased expenditure is the result of selection acting on parents, their offspring, or both. Current parent-offspring conflict theory is used to investigate whether sex biases in parental expenditure should be accompanied by sex biases in parent-offspring conflict. It is suggested that, in general, greater conflict should be expected between parents and offspring of the favoured sex. Specifically, greater conflict is predicted among mother-son dyads than among mother-daughter dyads in most polygynous birds and mammals. Data on domestic sheep, as well as empirical evidence available for other species (mainly ungulates), lends support to the prediction. The prediction is further extended to cercopithecine primates, a group which lacks clear sex-biases in parental investment. In this case, differences in fitness returns per unit of parental expenditure between the daughters of dominant and subordinate mothers are positively related to differences in the extent of mother-daughter conflict. The results from this study highlight the important role that selective pressures acting on the offspring phenotype may have played in the evolution of sex-biased patterns of parental investment.
Influence of Prey Movement On the Performance of Simple Detours By Jumping Spiders
Authors: Tarsitano Michael S. , Jackson Robert R. 
Published: April 2008

Abstract
The influence of prey movement on the performance of simple detours by salticids was investigated. Seven species were studied. Two subject species, Portia fimbriata and Portia labiata, are specialized web-invading species that eat other spiders. The other five species investigated (Euryattus sp., Euophrys parvula, Marpissa marina, Trite auricoma and Trite planiceps) are more typical cursorial hunters of insects. We provide evidence that: 1) salticids will initiate detours toward motionless prey; 2) salticids are more inclined to initiate detours toward moving than toward motionless prey; 3) salticids tend to complete detours even when prey that had been moving at the start remains stationary during the detour; 4) prey movement makes the salticid more likely to stalk and attack when prey is only a few centimetres away and in a position from which it can be reached by a straightline pursuit; 5) Portia is more inclined than the other salticids to initiate detours to motionless prey, then to stalk and attack motionless prey when close, than the other salticids are. Mechanisms that might account for Portia being different from the other salticids are discussed.
Sexual Imprinting in the Collared Dove (Streptopelia Decaocto)
Authors: TEN CATE Carel , Hilbers John , Hall Miriam 
Published: April 2008

AbstractAlthough the occurrence of sexual imprinting has been demonstrated for doves, it is less well known how strong this effect is and which factors contribute to it. Therefore we examined whether cross-fostering collared doves (Streptopelia decaocto) to white ring doves (Streptopelia risoria) affected later mate preference and, also, whether the strenght of this preference depended on sex of the experimental birds, on the presence of siblings during rearing, on behaviour of the (foster)parents and on the behaviour of the stimulus birds during testing. Mate preferences were measured during choice tests using either stuffed or living stimulus birds, one of each species. The result showed (1) a strong effect of rearing species, but not of sex or presence of siblings on the later preference, (2) an overall bias towards preferring ring doves over conspecifics, both in tests using stuffed and tests using living stimulus birds, and (3) a tendency for the preference to shift towards collared doves with increasing age or testing experience. The findings indicate the occurrence of sexual imprinting in the collared dove and are compared with data on other species. The overall bias towards the ring dove was unexpected, but we suggest that this 'other species' bias may result from the same mechanisms which are responsible for the occurrence of an 'own species bias' in a number of other species.
Seafinding By Hatchling Sea Turtles: Role of Brightness, Silhouette and Beach Slope as Orientation Cues
Authors: Salmon Michael , Wyneken Jeanette , Fritz Elizabeth , Lucas Mark 
Published: April 2008

AbstractUpon emerging from underground nests, sea turtle hatchlings immediately crawl toward the ocean. The primary cues used in orientation are visual but the nature of the visual cues was a matter of speculation. Hatchlings might also respond to secondary cues, such as beach slope. Experiments were carried out in an arena where specific visual and slope cues, simulating those present at nest sites, could be precisely controlled and manipulated. Subjects were green turtle (Chelonia mydas L.) and loggerhead (Caretta caretta L.) hatchlings. Both species oriented toward the more intensely illuminated sections of the arena. They also oriented away from dark silhouettes which simulated an elevated horizon, typical of the view toward land. Turtles responded primarily to stimuli (both silhouettes and photic differences) at or near eye level. When presented simultaneously with a silhouette and a photic gradient located in different directions, hatchlings oriented away from the silhouette and ignored photic stimuli. Under infrared light, both species oriented down slopes. However in the presence of nocturnal levels of visible light loggerheads ignored slope cues and responses of green turtles to slope were weakened. The data suggest that loggerhead and green turtle hatchlings usually find the sea by orienting away from elevated silhouettes. This is a prominent and reliable cue for species which typically nest on continental beaches.