bluuebunny/crossref_metadata_2025_split huggingface dataset:
Courtship Behaviour in the Melanogaster Species Sub-Group of Drosophila
Authors: Cobb Matthew , Connolly Kevin , Burnet Barrie 
Published: April 2008

Abstract
Descriptions of courtship behaviour are given for seven members of the melanogaster species sub-group: Drosophila melanogaster, simulans, mauritiana, yakuba, teissieri, erecta and orena. A male wing behaviour not previously reported, wing extension, was observed in either 1- or 2-wing variants in all species except melanogaster and simulans. Male wing rowing, previously reported in mauritiana and teissiri, was seen in 1- or 2-wing variants in all species except melanogaster and orena. D. teissieri showed the most extreme form of wing rowing, and yakuba the widest variety of angles of wing vibration. Tapping by the male was observed in all species except simulans and mauritiana, but not always at the onset of courtship and not in every courtship. Extrusion in virgin females was observed in melanogaster and erecta, and abdomen extension in female simulans, yakuba, teissieri and orena. Female wing behaviours were observed in all species except simulans. Wing extension and wing rowing are distinct from vibration and scissoring (behaviours they strongly resemble). There is strong a behavioural connection between these pairs of behaviours, in that wing extension often leads to vibration, wing rowing to scissoring, and vice versa. A mechanical function for licking is proposed, following observation of long duration licking in yakuba. The function of licking is thought to be elevation of the female's abdomen, preparatory to copulation. The relationship between the seven species based on their courtship behaviours was examined using principal coordinates analysis. This suggests that the two cosmopolitan species, simulans and melanogaster, differ most widely in their courtship behaviour, with mauritiana being the most similar to simulans. This finding is assessed in relation to the ecology of the seven species, the role of courtship behaviour in speciation, and the reliability of inferences from behaviour in phylogenetic analyses.
Vervet Monkey Alarm Calls: Manipulation Through Shared Information?
Authors: Cheney Dorothy L. , Seyfarth Robert M. 
Published: April 2008

AbstractHigh-ranking male and female vervet monkeys in Amboseli National Park alarm-call at higher frequencies than do low-ranking males and females. This correlation between rank and alarm-calling does not occur because high-ranking animals have more offspring or close kin than low-ranking animals. Similarly, high-ranking animals do not seem to have greater opportunities to spot potential predators; they do not scan the habitat more than low-ranking animals, nor are they more likely to be in the forefront of group progressions. It seems possible that low-ranking animals may spot predators as often as high-ranking animals, but that they do not always alert other group members to approaching danger. As a further test of the possibility that monkeys may vary the rate of alarm-calling depending on social contexts, an experiment was conducted on captive vervet monkeys in which adult females were presented with a predator in the presence of either their offspring or an unrelated juvenile. Adult females alarm-called significantly more often when with their offspring than with unrelated juveniles. A similar experiment conducted on adult males showed that males alarm-called at higher rates in the presence of adult females than in the presence of other adult males. The results of both experiments and observations suggest that monkeys may vary the rate at which they warn others of danger. The withholding of information may be an effective means to deceive others, because it is relatively difficult to detect cheaters. The possible advantages of selectivity in alarm call production are discussed.
Acquisition of Predator Information By Active and Passive Mobbers in Ring-Billed Gull Colonies
Authors: Conover Michael R. 
Published: April 2008

AbstractMobbing flocks of ring-billed gulls consisted to two groups: individuals whose nests were near to and threatened by the predator (active mobbers) and others from more distant parts of the colony (passive mobbers). This study examined whether either group can learn about the predator from their mobbing experience. The active mobbers quickly habituated to a human intruder near their nests when the intruder was inactive and empty-handed. Conversely, the gulls responded with a greater flock size and flight distance and fewer swoops when the intruder was holding an adult gull. These response patterns persisted even after the adult gull was removed and the human intruder reappeared alone. When the human intruder held a chick, the gulls approached more closely and swooped more than when the intruder held an adult gull. To examine whether passive mobbers learned anything about the human intruder during the earlier tests, the intruder (now empty-handed) moved to a new location 50 m away and repeated the test. The gulls at these sites, also were significantly less wary than naive gulls of the human intruder following tests in which the intruder was empty-handed, and more wary following tests in which the intruder held an adult gull. Because the earlier test sites were situated so that they could not be seen from the ground at the 50 m sites, a gull at the latter sites could only have learned details about the intruder if it or some of its neighbors had become mobbers. Gulls whose nests were 100 m from an owl model or human intruder learned less about it than gulls at 50 m: perhaps because fewer gulls became passive mobbers as the distance between them and the owl or intruder increased. Costs of becoming a passive mobber include an energetic and time cost and some risk of personal injury due to mid-air collisions with other gulls. The number of passive mobbers increased on breezy days perhaps because strong updrafts on those days reduced the energetic costs of flight within the colonies (and hence of being a mobber). These results support the hypothesis that the gulls' predator-attraction behavior allows them to learn about predators from watching predator-conspecific interactions. The opportunity to witness such interactions and learn about predators may be an important secondary benefit of coloniality for these birds.
Structure and Causation of the Dominance Hierarchy in a Flock of Bar-Headed Geese (Anser Indicus)
Authors: Lamprecht JÜRG 
Published: April 2008

AbstractIn a flock of tame, free-flying bar-headed geese (Anser indicus) the structure, stability and causes of the dominance hierarchy among different types of social units were studied. 1. In accordance with field results of other authors, families proved dominant over pairs, pairs over unpaired birds, and single males dominated single females. Single females with young ranked between families and pairs in this study, and lone breeding males whose females were incubating ranked between pairs and unpaired individuals. Contrary to some field studies, no rank differences were found between different-sized families. 2. The dominance value of pairs in winter correlated with subsequent fledging success, and there was some casual evidence that high-ranking males are more likely to obtain a mate. This would result in relating high rank to families, medium rank to pairs and low rank to unpaired birds. Yet as temporarily leaving the mate was promptly followed by a drop in rank and successful breeding by a rise in rank, the social context seems a major cause, and only to a minor extent a consequence of dominance rank. 3. Age correlated more strongly with a pair's rank in winter than weight, tarsus length and upper beak length. Rank in summer correlated highly with rank in the following winter. A positive feedback system age - dominance - fledging success-higher dominance-fledging success' is suggested which could account for the 'delayed breeding' common in geese and swans. 4. In pairs or families male age correlated more strongly than female age with winter dominance. Most opponents were displayed by the male alone, and only the male of a pair got involved in highest intensity aggression (wing-beat fighting). The widowed female of one high-ranking pair was low-ranking in subsequent years when paired with a young low-ranking male. The evidence suggests that the gander alone determines a family's or pair's rank. 5. There was no indication of a positive co-operative effect achieved by joint aggression. Comparison of frequencies of aggressive acts and postures between birds in different social contexts suggested that the presence of the mate and/or offspring increases fighting motivation, thus explaining the dependence of rank on the social context. 6. The stability of dyadic dominance relationships between social units was greater between than within social classes. The hierarchy of social classes can be explained by geese signalling their degree of fighting motivation to each other. Individual recognition of members of other social units seems of minor importance for the hierarchy even in this stable flock.
Temporal Patterns of Feeding Behaviour in Free-Ranging Horses
Authors: Mayes Eleanor , Duncan Patrick 
Published: April 2008

AbstractFeeding was patterned into meals separated by intervals of non-random length. Meal length, which showed a marked circadian rhythm, was positively correlated with the length of the preceding interval (preprandial correlation) in all seasons except the summer. This result implies the existence of a control mechanism which maintained gut-fill high. The organisation of feeding within meals (length of feeding, standing and walking bouts) did not vary consistently between vegetation types, but was strongly influenced by the activity of biting flies.
Acoustic Recognition Between Mother and Cubs in Raccoons (Procyon Lotor)
Authors: Sieber Otto J. 
Published: April 2008

AbstractTwo vocalizations, utilized by raccoon (Procyon lotor) mothers ("chitter") and their dependent cubs ("whistle") to establish and maintain contact among each other, are studied in captive groups containing a total of 6 mothers and their 23 cubs. The paper describes frequency of occurrence of the calls, contexts of the callers, individual variation in the call's structure and the responses of the callees both in uncontrolled situations and in playback experiments. Maternal chitters are most frequently used during the month following the first excursion of the cubs from the litter den by females approaching the cubs or leading them to the food. The frequency of whistling in cubs is high during the nestling period and decrease when they become mobile. The main context of whistling in the cub-mother relationship is answering maternal chitters. Mobile cubs follow their chittering mother silently. The chitters of 4 females differ individually, the main distinctive feature being frequency and pulse rate. The whistles of 12 cubs are individually distinctive, too; duration and frequency measures differ most between individuals. Hence, mothers and cubs have the potential for individual acoustic identification. Seven-week-old nestlings, tested in an experimental arena with successive playbacks, answered maternal chitters on average more often and faster than alien ones, warning grunts or a noise. Mobile cubs approached maternal chitters more often when tested in simultaneous playback experiments. Only 2 of 6 females, however, confronted with whistle-playbacks of their own vs alien cubs in their cages, responded more strongly to calls of their offspring. Results indicate that raccoons may be capable of recognizing family members by acoustic cues alone on a familiar vs strange basis. Advantages of using vocalizations in mother-young relationship and of the potential for acoustic identification and recognition in a solitary mammal are discussed.
The Functional Significance of Vocal Mimicry in Song
Authors: Hindmarsh Andrew M. 
Published: April 2008

AbstractThe results of a study of starling vocal mimicry are summarised and discussed in relation to various possible functional explanations of mimicry. Only one, a hypothesis based on sexual selection, is not rejected outright and even this was seen to have problems. A dif ferent approach yielded a causal hypothesis based on mistakes made during song learning. This causal hypothesis is consistent with all known features of starling mimicry, and can readily be extended to other species, but is probably not consistent with any of the candidate functional hypotheses, including the one based on sexual selection. It is tentatively concluded that there is no additional functional explanation of starling vocal mimicry.
Similar Behaviour and Colour Patterns in 3 Not Closely Related Barbus Species. Is Evolutionary Convergence a Likely Explanation?
Authors: Kortmulder K. 
Published: April 2008

AbstractThe main theoretical issue of this paper is the interpretation of the close similarity of the total behaviour and colour patterns of 3 not closely related Barbus species. The case for evolutionary convergence is easy if the total pattern of each species is interpreted as a collection of evolutionary adaptations to the species' natural habitat. The thorough similarity of the 3 species must then be ascribed to key similarities between their natural habitats. However, it is argued that another interpretation is possible, in which the diverse traits cohere causally and have been acted upon as one whole by natural selection. In the extreme case of this alternative interpretation, the case for convergence may still be won, but it is a Pyrrhic victory: convergence has lost much of its usual meaning. Apart from the above discussion, the reproductive behaviour and spawning colours of the 3 species are described and compared in some detail. Possible functional reasons for a relatively small difference as to the degree of sexual colour dimorphism are discussed in relation to eye sizes and visual discrimination.
Acoustic Communication in Woodhouse's Toad (Bufo Woodhousei)
Authors: Sullivan Brian K. , Leek Marjorie R. 
Published: April 2008

Abstract
We investigated changes in calling behavior of individual male Bufo woodhousei in response to playback of natural and synthetic acoustic stimuli. Males lowered their call rates and avoided acoustic overlap with all stimuli centered at 1.4 kHz; only a high frequency (3.8 kHz) stimulus was ineffective. Even filtered noise centered at 1.4 kHz was an effective inhibitor of calling activity. Variation in rate of amplitude modulation of acoustic stimuli had no apparent effect on male calling behavior. These results are discussed in relation to species recognition in bufonids, and acoustic competition between male anurans in general.
Migratory Orientation and Activity of the Meadow Pipit (Anthus Pratensis): a Comparative Observational and Experimental Field Study
Authors: Orth Gerlinde , Helbig Andreas J. , Laske Volker , Wiltschko Wolfgang 
Published: April 2008

AbstractMeadow pipit migration and orientation was studied by (1) watching visible migration and measuring flight directions with a compass in NW-Germany (1980-1985) and (2) conducting orientation experiments with caged migrants in radial-perch cages (MERKEL & FROMME, 1958). Free-flying pipits migrated SW in autumn and NE in spring in sunny and overcast weather, but on average there was less migration under overcast. In the field migration peaked in the first two morning hours and was almost over by the end of October. Strong migration always corresponded to a minimal scatter of flight directions. In the orientation cages the birds oriented SW in autumn and NNW in spring, but only in sunny weather during the first three morning hours. Activity decreased markedly later in the day (spring), in November compared to September/October and under overcast compared to sunny skies. The more active the birds were, the better was their orientation with respect to the overall mean direction. In general, meaningful orientation in the cages occurred only when migration intensity in the field was maximal. A lack of well-oriented behaviour in the cage is not necessarily caused by an inability to orient, but may be a consequence of low motivation to migrate. A six hour clockshift of experimental birds did not lead to a clear shift of their directional choices, but produced an axial NE-SW orientation in autumn and disorientation is spring. This result does not support the assumption that diurnal migrants orient primarily by means of a sun compass.
The Importance of Vision in Agonistic Communication of the Crayfish Orconectes Rusticus. I: an Analysis of Bout Dynamics
Authors: Bruski Colleen Ann , Dunham D.W. 
Published: April 2008

Abstract1. The importance of vision for efficient agonistic communication was investigated in the rusty crayfish, Orconectes rusticus, a species active both day and night. Agonistic bout dynamics were analyzed from isosexual pairs of males and females interacting under moderate (350 lux) and dim (11 lux) light levels, and in complete darkness (using infra-red video recording). Under dim light we determined the effect of visual light and dark adaptation on communication. 2. As light diminished, bouts became less frequent, but longer, and the crayfish invested more time and performed more acts when resolving bouts. Thus, communication efficiency was clearly lower in the dark than under moderate light, for both sexes. Males performed more acts than females overall, and were generally more aggressive than females. 3. The frequency of visually-mediated behaviours (e.g. Lunge, Follow) decreased in the absence oflight, while tactile behaviours (e.g. Antenna Tap, Chela Strike, Push) were performed more frequently. Males especially performed more highly aggressive tactile behaviours in the dark. It was shown that some behaviours previously considered to be visually mediated (e.g. Meral Spread) are also tactually or proprioceptively mediated, and some behaviours assumed to be tactually mediated (e.g. antennal movements) are probably also visually mediated. 4. Under dim light, crayfish with light-adapted eyes resolve bouts more efficiently in terms of time and energy investment than do dark-adapted animals. This is consistent with the effects of pigment migrations during dark adaptation in the crayfish superposition compound eye, which enhance visual sensitivity, but decrease acuity. We suggest that dark adaptation diminishes a crayfishes ability to deal with the subtleties of visual communication, but may well enhance its ability to detect predators.
Site-Finding Behaviour of Fasciola Hepatica (Trematoda), a Parasitic Flatworm
Authors: Sukhdeo S.C. , Sukhdeo M.V.K. , Mettrick D.F. 
Published: April 2008

AbstractFasciola hepatica is a trematode parasite of the bile duct of herbivores. Site-finding behaviour of this parasite includes a migration from the duodenum through the abdominal cavity to the liver. This study examines the behaviour of the migrating worms at two stages of the life cycle; NEJ - the stage that penetrates the small intestine, and 48HR - the stage that penetrates the liver. Compared to saline controls, crude extracts of duodenal tissue have greater effects on the behaviour of the NEJs while crude extracts of liver tissue have greater effects on the behaviour of 48HRs. Yet, neither NEJs nor 48HRs migrate up gradients of liver extracts or down gradients of duodenal extracts. Stable chemical gradients are difficult to maintain in the motile abdominal cavity and it is suggested that orientation responses play no part in site-finding behaviour. We propose that the major component of site-finding behaviour of F. hepatica is a passive propulsion of the migrating stages through the viscera and along the body wall to the liver.
Vocal Communication in a Neotropical Treefrog, Hyla Ebraccata: Responses of Females To Advertisement and Aggressive Calls
Authors: Bard Kathleen M. , Wells Kentwood D. 
Published: April 2008

AbstractWe investigated the functions of different elements of the complex vocal repertoire of the Panamanian treefrog Hyla ebraccata by testing the responses of females to synthetic advertisement and aggressive calls in two-choice playback experiments. In tests of single-note advertisement calls presented at different rates, females preferred faster calling rates, regardless of the absolute rate of the stimuli. In tests of single-note advertisement and aggressive calls, females preferred advertisement calls. Addition of secondary click notes to aggressive calls made the calls more attractive to females, but multi-note advertisement calls were preferred over multi-note aggressive calls. When females were given a choice of multi-note advertisement calls and single-note calls of the same total duration, they showed no preference. This suggests that multi-note calls are preferred over normal single-note calls because of their longer total duration. When the same experiment was performed with aggressive calls, females showed a strong preference for multi-note calls. This indicates that long aggressive calls, such as those given by males in close-range encounters, may entail some cost to the male in reduced attractiveness to females. Males apparently reduce the costs of aggressive calling by adding click notes to aggressive calls, by giving aggressive calls only when nearby males do so, and by establishing spatial relationships in the chorus before females begin to choose mates.
Beyond the One-Male Group
Authors: Rowell T.E. 
Published: April 2008

AbstractSocial systems are not necessarily equivalent to mating systems. Observation is prerequisite for control of one animal by another. It is not possible without extremely good visibility, which is rare. Nonetheless most social theories assume such control. Neither social position nor copulation guarantee paternity. It is important that biochemical tests provide certainty of paternity in as many studies as possible, so that assumptions about behavioural determinants of reproductive success can be tested. The function of fighting is discussed. Males spend more of their time cooperating than competing, and it is suggested that differences between these may not be so clear. To understand the behaviour of adult males it is necessary to consider behaviour throughout lifetimes, behaviour in all seasons, and behaviour throughout demes. Scepticism towards facile explanations is recommended.
Provisioning Behaviour in a Communal Breeder: an Epigenetic Approach To the Study of Individual Variation in Behaviour
Authors: Jamieson Ian G. 
Published: April 2008

AbstractThis study used an epigenetic approach to examine the development of individual variation in provisioning behaviour in a communally breeding bird, the pukeko. Breeders who are initially 'exposed' to chicks during incubation were the first to brood and provision newly hatched chicks. From the first week after hatching until midway through the provisioning period, there was no significant difference in the percentage of time spent provisioning by breeders and non-breeders suggesting that the maintenance of provisioning is not dependent on increases in hormone levels attained through breeding or incubation, but on stimulations that arise through contact with the chicks. Breeders reduced and eventually stopped provisioning chicks midway through the provisioning period in association with the laying of a second clutch. Social learning, imitation and the 'priming' effect of other behaviours appeared to influence the onset of provisioning in inexperienced or naive juvenile and yearling pukeko. Inexperienced birds initially exhibited a heightened response toward hatchlings which appears to be the result of some sort of novelty effect. Inexperienced yearlings, however, did not provision for as long into the season as experienced non-breeders unless the latter were not present in the group or had stopped provisioning earlier in the season. It is proposed that factors giving rise to and maintaining behavioural asymmetries can best be understood from an epigenetic perspective.