bluuebunny/crossref_metadata_2025_split huggingface dataset:
Joint Nesting in a Digger Wasp as an Evolutionarily Stable Preadaptation To Social Life
Authors: Brockmann H. Jane , Dawkins Richard 
Published: April 2008

AbstractOne suggested evolutionary origin of insect sociality is joint nesting by females of the same generation. Long before selection favoured joint nesting itself, it might have favoured some other incidental preadaptation such as the habit of 'entering' abandoned burrows, found in the usually solitary wasp Splaex ichneumoneus. We have comprehensive economic records of individually marked wasps. There is little evidence of consistent individual variation in nesting success. Wasps often abandon the nests they have dug, and other individuals adopt or 'enter' these empty burrows. 'Dig/Enter' is a good candidate for a mixed evolutionarily stable strategy : digging and entering decisions are not characteristic of particular individuals; the probability of entering is not conditional upon whether it is early or late in the season; there is no correlation between an individual's size and her tendency to dig or enter; there is no correlation between an individual's egg-laying success and her tendency to dig or enter; individuals do not choose to dig or enter on the basis of immediate past success; individuals do not dig and enter in runs, nor do they alternate; wasps do not choose to dig or enter on the basis of how long they have been searching. At one study site digging and entering decisions are roughly equally successful, but at another entering decisions are perhaps slightly more successful. Entering wasps seem not to distinguish empty, abandoned burrows from burrows that are still occupied. As a consequence of indiscriminate entering, two females sometimes co-occupy the same burrow. Co-occupation should not be called 'communal' because the wasps usually share the same brood cell, not just the same burrow. One might expect that wasps would gain some benefit from co-occupying, but they do not, for a number of reasons: only one egg is laid in a shared cell, and obviously only one of the two wasps can lay it; two wasps together do not fetch noticeably more food than one alone; two wasps together are no quicker at provisioning a cell than one wasp alone; wasps sometimes duplicate each others' efforts when they co-occupy a nest; co-occupying wasps often have costly fights. About all that can be said for joint nesting is that it may reduce parasitism. The risk of joint nesting is the price wasps pay for the advantages of taking over an already dug and abandoned burrow. A mathematical model assuming 'dig/enter' as a mixed evolutionarily stable strategy has some predictive success. If the parameters changed quantitatively, the Sphex model could come to predict selection in favour of joint nesting as such. The selection pressures would have to be very strong to overcome the demonstrated disadvantages of co-occupying. Variants of the Sphex model may be applicable to other species, and may help our understanding of the evolution of group living. The theory of evolutionarily stable strategies is relevant not just to the maintenance of behaviour but to its evolutionary change.
Calls as Reinforcers in Bullfinches
Authors: Wilkinson Roger 
Published: April 2008

AbstractA perch-hopping operant was used to test the reinforcing effect on bullfinches of two classes of their vocalisations. Two reinforcement indices were computed for each individual, there was no correlation between these indices. For four out of six bullfinches tested with loud calls at least one of these indices was significantly high. None of the six bullfinches tested with distress screams had indices that differed significantly from the neutral values. Group data for the median rate of perching during operant levels, test and extinction sessions were interpreted to suggest a pesitively reinforcing effect of loud calls and a punishing effect of distress screams. Problems posed by the use of the perch-hopping operant are discussed.
Time-Budgets of Camargue Horses Ii. Time-Budgets of Adult Horses and Weaned Sub-Adults
Authors: Duncan Patrick 
Published: April 2008

AbstractTime-budgets of adult and weaned sub-adult horses were studied in a small population of Camargue horses living in semi-liberty. The categories of activities used were: Standing resting, Lying flat, Lying up, Standing alert, Walking, Trotting, Galloping, Rolling and Foraging. The main differences in time-budgets were related to age and to sex : young horses spent more time lying (sleeping), males spent more time standing alert and in rapid movements (trot, gallop), while usually foraging less than did the adult females. During the three years of the study the population increased from 20 to 54 horses and there were considerable changes in social structure as the number of adult males increased. Associated with these developments there were some changes between years in the time-budgets: the most striking of which was a general trend for all horses to spend less time lying. Nonetheless the time-budgets showed a considerable constancy across years and age/sex-classes, especially with regard to time spent foraging. This conclusion may provide a clue as to why horses have an unusual social system based on long term relationships between a male and the females of his harem.
Ritualization and the Evolution of Movement Signals
Authors: Zahavi Amotz 
Published: April 2008

AbstractIt is suggested that the competition among individuals to display their advantage over others and the interest of individuals to display their motivation in a reliable way have been responsible for the evolution of ritualized signals. Small differences between displays can only be perceived against a standard mode of display. Experience is often needed to determine the nature of the variance which is displayed. It is suggested that the stereotyped ritualized species specific movements have evolved as a byproduct of the competition among individuals to display differences and not because of the advantage of displaying specific differences.
The Behavioural State During Climax (Hatching) in the Domestic Fowl (Gallus Domesticus)
Authors: Bakhuis Walter L. , Bour Harry L.M.G. 
Published: April 2008

Abstract
In the last decade it has been proposed that climax behaviour (CB or hatching) in the chick, Gallus domesticus, occurred during episodes of paradoxical sleep (PS). In recent experiments, however, eye opening, a sign of wakefulness, was seen during CB. The present study was designed to decide whether CB is related to PS or wakefulness. Behavioural and polygraphic criteria were employed, and drugs (melatonin and amphetamine) were administered. Melatonin suppressed wakefulness, hatching and PS, but the reappearance of PS did not coincide with that of CB. Amphetamine suppressed PS, but, except for a short period of ataxia, it did not inhibit CB. Lowering of ambient temperature stimulated wakefulness without interfering with CB. Whereas hatching is characterized by vigorous movements, only weak movements could be detected during PS. In view of these findings, it is concluded that CB is related to wakefulness and not to PS. Reports on mammals also indicate that strong movements seen during early stages of development, are not related to PS.
After-Effects of Allogrooming On Proximity and Locomotion in Pairs of Stumptailed Macaques (Macaca Arctoides)
Authors: Goosen C. 
Published: April 2008

AbstractLaboratory experiments in pairs of stumptailed macaques were aimed at testing the hypothesis that allogrooming behaviour causes a subject to remain close to the partner for a certain period of time. In that case, allogrooming could indeed be regarded as a cohesive force among members of a socially living, natural group. In the experiments, six females were used as subjects; six males were used as partners. Recording concerned various behaviour items (allogrooming, proximity, locomotion, among others) of a subject during her stay in the observation cage. The partner could be present in a compartment adjacent to the observation cage but separated from it by a plexiglass partition sheet. Three experimental situations, each lasting 15 minutes, were used: t) tactile partner situation in which allogrooming could occur through a slit in the plexiglass sheet between subject and partner; v) visual partner situation, with the partner present behind a sheet without slit; and n) no partner situation when the compartment is empty. These situations occurred during two immediately following observations. The order being so as to enable study of 1) effect of differences in immediate situation; 2) changes with time; 3) effects from differences in previous experience. Results confirmed earlier findings that the visual presence of a partner induces in the subject a tendency to be close to the partner and that, if allogrooming is permitted, proximity is enhanced as a consequence of allogrooming. However, there was no evidence in support of the hypothesis that, after allogrooming the partner for some time, the subject would be more in proximity to the male than after it had had no such allogrooming experience. The results showed rather an opposite trend to less proximity and more walking after having groomed a partner for some time, suggesting that the subjects sought contact with the animals in the normal housing quarters which had been left just prior to the beginning of the observations. In view of this, it seems that, if allogrooming acts as a cohesive force between members of a natural group, it docs not act directly upon a tendency to remain close to the (former) allogrooming partner.
Developmental Relationships Among Social, Manipulatory, Postural and Locomotor Behaviours in Olive Baboons, Papio Anubis
Authors: Chalmers N.R. 
Published: April 2008

AbstractIt is argued, that, when studying the development of social behaviour, it is valuable to investigate simultaneously several classes of social behaviour, plus locomotor, postural and manipulatory abilities. Such an approach may reveal that seemingly diverse behaviours have common ontogenetic precursors or depend upon common underlying abilities. In olive baboons, components of feeding and mouthing-and-wrestling are shown to derive from common ontogenetic precursors. Evidence suggests that mounting, riding dorsally, mouthing-and-wrestling and bipedal standing depend upon the ability to maintain postural control under difficult conditions. Some social behaviours, like grooming and presenting, appear later in development than the postural and locomotor behaviours that are used in those social behaviours. The age at which these social behaviours first appear does not seem, therefore, to be a simple function of the age at which the underlying sensori-motor skills first appear. Some vocalizations and gestures are performed in specific contexts, others are not. The contexts which evoke some of them change with age. The rationale for identifying 'precursors' of adult social behaviours is discussed. One behaviour may be the precursor of another by virtue of its form or function, or by virtue of the fact that it is controlled by a mechanism that is the precursor of a mechanism controlling the later behaviour. An early behaviour that is a precursor of a later behaviour according to one of these criteria may not necessarily be its precursor according to another. The extent to which it is valid to split an infant's activities into different classes of social behaviour is questioned.
Sexual Selection and the Evolution of Complex Songs Among European Warblers of the Genus Acr Ocephal Us
Authors: Catchpole Clive K. 
Published: April 2008

AbstractAn attempt has been made to explain why the songs of Acrocephalus warblers have become so complex during their evolution. A considerable body of evidence has implicated sexual selection, and two predictions from sexual selection theory have been tested. First, males with more complex songs should attract females for pairing before their rivals with simpler songs. This prediction has been confirmed, when a strong inverse correlation between syllable repertoire size (song complexity) and pairing date (female choice) was obtained in a population of sedge warblers. No significant correlation was obtained between male arrival date and pairing date. Assuming that the first (usually older) males back should select the best territories, then territory quality appeared to have little or no significant effect upon female choice. The second prediction tested was that due to increased sexual selection pressure, males of polygynous species should have evolved more comples songs than males of monogamous species. Of the six common European Acrocephalus species studied, four are monogamous and two polygynous. The prediction was not upheld, as the four monogamous species had long, complex and variable songs, and the two polygynous species had shorter, simpler and less variable songs. The explanation for this apparent paradox can be found in the different relationships between female choice, feeding ecology and parental investment in monogamous or polygynous Acrocephalus species. In polygynous species, a female must ensure the territory contains enough resources to enable her to feed the young and should base her choice primarily upon territory quality. In monogamous species, a female must select a male who will help her to feed the young, and should base her choice more directly upon male quality. The songs of polygynous species have therefore evolved primarily through indirect (intrasexual) sexual selection pressure, which has produced shorter, simpler and more stereotyped songs more suited to male-male interactions and a territorial function. The songs of monogamous species have evolved primarily through direct (intersexual) selection pressure, which has produced the long, complex and variable songs which females find more attractive.
Sex Ratio and Optimal Male Time Investment Strategies in Asellus Aquaticus (L.) and a. Meridianus Racovitza
Authors: Manning J.T. 
Published: April 2008

AbstractA. aquaticus and A. meridianus have a passive phase in which the male carries the female for some days before moulting and copulation are possible. The effect of varying male: female ratios (0.5:1; 1:1; 1.5:1) is discussed in this paper. It was found that an increase in the proportion of males led to: a) earlier initiation of the passive phase; b) lower gain rates from paired females; c) an increased tendency for males to leave females; d) a reduction in the strength of the association between the timing of pairing and oviposition. The relevance of these observations to models of optimal female guarding and foraging strategies is discussed.
Communication During Monocular and Binocular Looking in European Jays ( Garr Ul Us G. Glandarius)
Authors: Bossema I. , Burgler R.R. 
Published: April 2008

Abstract
Some aspects of communication during monocular and binocular looking by dominant jays at subordinate cage mates were studied. The probability that each type of looking was followed by attack in the sender was measured in standardized external situations. The signal value of the various signal situations for recipients was measured by determining the probability that they reacted with retreat during signalling. It was found that the higher the likelihood that a signal situation was followed by overt aggression in the sender, the more a recipient reacted with overt escape.
Communication By Agonistic Displays: a Discussion
Authors: Van Rhijn Johan G. 
Published: April 2008

AbstractThis paper discussed the information content of threat signals. It was an attempt to explain the inconsistencies between the points of view of model-builders using game theory as a tool (represented in a paper by CARYL in 1979 in this journal), and of the (mainly field-) ethologists spending a considerable part of their time observing animals in groups (expressed for instance in the paper by BOSSEMA & BURGLER in this issue). Arguments were presented for the transfer by threat signals of both information about intentions (motivation), and information about "resource-holding potential" (strength, ownership, etc.). Individual recognition was expected to be associated with honest signals about intentions. CARYL'S deviating findings could not be attributed to an absence of individual recognition in the animals he considered. His findings could also not be explained very well by the fact that he hardly considered subtle signals, although the present paper argued that information about intentions is mainly given by subtle signals, and information about resource-holding potential by elaborate action patterns. Imperfect methods in the papers cited by CARYL were considered as the most important source for the deviations. Finally it has been discussed to what extent observational data as presented by BOSSEMA and BURGLER help in solving problems raised by the model-builders. The occurrence of frequent, short escalations has been suggested as a mechanism for preventing bluff. The evolution of graded warning-signals could be related to (1) the low cost of a warning as compared to an attack, and (2) the settlement of a conflict on the basis of differing motivations. This paper considered the possibility of heterogeneous summation of (already known) information about the resource-holding potential of an opponent, and the information about its intentions (from the displays).
Cohesive Relationships in a Cattle Herd (Bos Indicus)
Authors: Reinhardt Viktor , Reinhardt Annie 
Published: April 2008

AbstractCohesive relationships were studied in a semi-wild cattle herd and traced over periods of three to five years. It became evident that mother cows prefer their female and male progeny over non-related calves as grooming and as grazing partners. These associations could always be verified during the first three years and often during the fourth and fifth year as well, the descendants already being sexually fully mature. Comparable personal attachments also existing between siblings, the ensuing family units were strikingly stable and cohesive. Interindividual associations lasting for several years could also be found between non-related descendants of the herd but also between non-related cows. The analytical data led to the conclusion that in natural cattle herds the social structure is based on matriarchal families which in their turn are interconnected by means of friendship relationships between non-kin partners.
Vocal Recognition of Recorded Lambs Voices By Ewes of Three Breeds of Sheep
Authors: Shillito Walser Elizabeth , Hague Peter , Walters Eurof 
Published: April 2008

Abstract
Vocal recognition of lamb's voices by their dams was investigated in Border Leicester, Jacob and Soay sheep, using recordings of lambs voices which were played to ewes simultaneously with presentation of a moving model lamb when the lambs were 15-20 days and 40-50 days of age. The number of bleats made by the ewes during playback of own and alien lamb voices was recorded and then the number of times a ewe bleated in answer to a lamb's bleats within 2 s of hearing the lamb bleat was counted. At both age groups the ewes bleated more in response to recordings of their own lambs than to alien lambs, and answered their own lamb's bleats more than alien bleats. The frequency of the ewes bleats increased more to their own lamb's bleats than to alien bleats. The Soay ewes bleated less than the other breeds and the Jacob ewes were the most vocal.
Behavioural Differences Between Zebrafinch and Bengalese Finch (Foster) Parents Raising Zebrafinch Offspring
Authors: TEN CATE Carel 
Published: April 2008

AbstractSexually mature zebrafinch males show a sexual preference for the species which has raised them. IMMELMANN (1972 a, b) stated that such a preference develops more readily if zebrafinch males were exposed to their own species than to Bengalese finches. The explanation for this phenomenon has been the supposition that an initial bias for the own species exists which is independent of post hatch experience. This hypothesis presupposes the absence of differences in behaviour between zebrafinch and Bengalese finch parents raising zebrafinch offspring. To investigate this supposition, the parental behaviour of zebrafinch and Bengalese finch (foster)parents raising zebrafinch offspring was observed. This was done in pure pairs (male and female of the same species) as well as in mixed pairs (male and female of different species). Differences between both species were found in parental care, and in clumping, allopreening, aggressive and sexual behaviour directed to zebrafinch young; most clearly in mixed, but often in pure pairs too. These differences were present from a few days after hatching till the moment of separating parents and young at about day 57. The kind of differences gradually changed during this period. Zebrafinch young are thus not exposed to equivalent experience with zebrafinch and Bengalese finch parents. The observed differences in experience may underly the more readily developing preference for zebrafinch than for Bengalese finch. This alternative should be explored more thorougly before the initial bias hypothesis is accepted.
The Role of Silences and Elements in the Recognition of a Dialect in the Corn Bunting
Authors: Pellerin Martine 
Published: April 2008

AbstractThis study concerns the mechanisms of dialectal recognition in the corn bunting, Emberiza calandra. Thanks to a microprocessor which guided a synthetizer, we synthetically reproduced one of the 3 natural songs of the Claville dialect. After having tested this synthetic song on the birds of this locality, we modified, in succession, its different physical parameters. The results obtained show that the recognition of this dialect depends on both the temporal distribution of silences and on that of elements. Dialectal recognition, like specific recognition, therefore implies the association of several parameters.
Song Types in a Population of Great Tits (Parus Major): Their Distribution, Abundance and Acquisition By Individuals
Authors: Mcgregor Peter K. , Krebs John R. 
Published: April 2008

AbstractThis 6-year study of song acquisition in a marked population of great tits suggests that songs are learned both before and after dispersal, songs are not learned from fathers. The spatial and temporal distribution of songs in the population is also discussed. There is a decline in the proportion of the song repertoire shared with increasing distance from a male, but there is no consistent pattern of song type grouping, some songs are clumped while others are not. Size of repertoire is not related to male age. These results are discussed in relation to laboratory studies of song learning, song dialects and functional hypotheses concerning song learning.
Stereotyped Feature Variables Are Essential Constituents of Behavior Patterns
Authors: Schleidt Wolfgang M. 
Published: April 2008

AbstractBased on theoretical consideration one can except that among the many variables one can measure in a behavior pattern those variables which are most stereotyped should be most useful to characterize a particular pattern. In order to explore the utility of this assumption, the relative variability of 204 different feature variables of the wet-my-lips call of the male migratory quail (Coturnix coturnix coturnix L.) was calculated and analyzed. The results show that the most stereotyped features (C.V. < 0.015) are those which constitute the rhythm of this call.