Showing papers in "Behaviour in 1976"

The Tail Movements of Ungulates, Canids and Felids With Particular Reference To Their Causation and Function as Displays

Abstract: This paper describes the tail movements of ungulates, canids and felids, and the situations which elicit them. In this way the cause and function of tail movements for communication are considered. Tail movements can be divided into dorso-ventral (that is elevation and depression) which are closely associated with changes in postural tonus, and lateral tail movements (tail wagging). These tail movements are reported in detail in pigs, cattle, horses, goats, dogs and cats, together with the contexts that give rise to them. Information from personal observations and the literature in a number of other species is also reported. It is found that tail elevation and a high postural tonus are correlated and indicate a preparation for locomotion, and an increase in pace. In this way upright postures have become of communicative value to indicate a preparation for locomotion, alertness and thus warning. They are also used in confident approach and ofen associated with aggressive intentions. In some species this posture has become exaggerated specifically, to increase its signal value. A drop in postural tonus is shown to be related to fear. Postures of low tonus, combined often with a protective withdrawal of the tail and ears, are characteristic of fearful situations and have therefore become of signal value indicating fear and in social contexts, non-aggression and submission. Exaggeration of these postures is evident in some species. Lateral tail movements originated in association with locomotion (e.g., in fish). It is shown that there is still an association of lateral tail movements with locomotion in the mammals considered, although this is often particularly evident where locomotion is frustrated or inhibited. Cutaneous stimulation has become particularly important in eliciting lateral tail movements in some species. It is shown both from observational and experimental data, that lateral tail movements tend to occur particularly in approach/avoidance conflict and frustrating situations. Lateral tail movements have much in common in cause with preening movements in birds, head shaking and ear flicking which have been shown to occur as transitional activites between bouts of ongoing behaviour. In some cases tail wagging, like preening in birds, has become exaggerated and its association with the above situations ensures that a message is transferred by it with information about the communicators general motivational state. However sometimes it is also associated with a more specific message (e.g., tail wagging as an intention to kick in the horse, or as an indicator of non-aggression and 'friendliness" in the dog). An increase in postural tonus and tail wagging occur in many different situations. What all of them have in common is that the animal is 'excited'. This is defined and it is suggested that 'excitement' could be a useful descriptive term. Thus a common causal model is proposed for the elevation, depression and lateral movements of the tail in ungulates, canids and felids. Although there has been an emphasis in some species on particular types of tail movements in specific situations for use as visual signals, nevertheless most movements of the tail in these widely differing species can be shown to be associated with locomotion, only lateral movements are, in some species also associated wih cutaneous irritation. There is no evidence to suggest however that there has been an emancipation of causation, although some tail movements are exaggerated and otherwise ritualized.

Visualizing interaction and sequential data in animal behaviour: theory and application of cluster-analysis methods

Abstract: The results of behavioural studies can be difficult to assimilate, often because such enormous quantities of data are involved, both as the studies are carried out and often in their final published form. This paper is concerned with data occurring in two-way tables which summarise, for example, the time each individual in a social group spends with every other individual, or the frequency with which every phrase in a bird's song follows every other one. We present some methods of cluster-analysis which help us to produce visual representations of such data. We describe how to build a single-link dendrogram (which is a way of representing a single-link cluster-analysis or SLCA) in Section 3 and a Maximum spanning-tree (MST) in Section 4. We also describe the properties of non-metric Multidimensional scaling (MDS) in Section 5, and B(2) cluster-analysis in section 6. Because methods of cluster-analysis often make fewer assumptions, we use them rather than factor analysis, principal-component analysis or canonical variate analysis. Section 8 compares the results of factor analyses with those of our cluster-analyses. The methods we describe are illustrated with reference to the times eleven free-living chimpanzees were seen together, analysed by SLCA in Section 3, MST in Section 4 and MDS in Section 5. Section 6 shows how B(2) analyses are used for the chimpanzee data, and Section 7 shows their application to data about sequences of phrases in a blackbird's song. In order to begin the cluster-analyses we present, our tables of raw data must be recast as tables of similarities. Section 2 introduces the art of constructing similarities, and Appendix I (1) shows how different kinds of similarity can be constructed from the same raw data. With reference to Appendix I (2b) and also to the data from BAERENDS et al. (1970) study of the incubation behaviour of herring gulls (Section 8), we emphasise that the act of constructing a particular kind of similarity commits one to a particular way of interpreting the data. Moreover, a method of constructing similarities can conceal differences of precision, Appendix I (3). Appendix I (2), examines the problems posed for cluster-analyses by asymmetric tables such as occur when elements precede other elements more often than vice versa, or when an individual in a social group grooms another for longer than vice versa. In Section 8, we illustrate how methods of cluster-analysis help us to interpret association data for 11 chimpanzees, and we examine the consistency of the chimpanzees' patterns of association through two consecutive 4-month periods. We then examine the association data of the whole community to which the 11 belong, and we use three consecutive analyses to show how the males in the community began to split into two sub-groups. We also compare he association data for three captive groups of rhesus monkeys; and we follow one group, comparing 12 consecutive monthly analyses to discover periods of change in that group's social organisation. We apply cluster-analyses to preceding-following tables from WIEPKEMA (1961) and BAERENDS et al. (1970), and we compare our interpretations of the original data with theirs. Finally, we show how cluster-analysis helps us to understand the songs of a blackbird, originally described by HALL-CRAGGS (1962). While we have emphasised the need to produce visual representations of our data, the need to evaluate them statistically remains, and Section 8-4 and Appendix II discuss the statistical methods for comparing dendrograms.

Some Aspects of Research Design and Their Implications in the Observational Study of Behaviour

Abstract: This paper has been concerned with examining the effects of choosing different behavioural parameters to investigate a particular research problem. Social relationships among a set of animals were estimated in seven different ways. Three behavioural parameters (social contacts, grooming and spatial associations) were selected and a number of sampling strategies were used to quantify them. Although the measures yielded results which correlated significantly, there were marked numerical differences between them due to the fact that they measured different aspects of a complex biological system. The differences between frequency and durational measures were investigated and the accuracy of two common durational measures was determined. One-Zero sampling was found to provide a poor estimate of the proportion of time spent grooming, whereas instantaneous or point sampling always gave a reliable estimate. Finally, the relationships between the different stages of research design were discussed. Emphasis was laid on four aspects of choosing parameters to quantify, namely, the precise delineation of the research problem, the validity of the parameters in relation to the research question, the differences between the various measures and the requirements and limitations of the other key features of research design.

The relation of scent-marking, olfactory investigation, and specific postures in the isolation-induced fighting of rats

Abstract: The temporal sequences of acts and postures of rats during tests for isolation-induced fighting were recorded and analyzed. Scent-marking and olfactory investigation, which have been related to fighting by previous studies, were particularly emphasized. From the data a model was constructed for the sequence of behaviors which lead to and maintain isolation-induced fighting. The typical sequence begins with olfactory investigation and scent-marking; the home rat initially investigates the intruder, and the intruder initially investigates the cage. The combination of olfactory perception of a strange male and a familiar environment, it was suggested, serves to trigger an offensive mechanism in the home rat which leads to bite-and-kick attack and offensive sideways posture. The pain of the attack then triggers defensive mechanism in the intruder rat which leads to defensive upright posture and submissive posture. Whereas the functional role of the bite-and-kick attack appears to be simply the infliction of pain and elicitation of defense in the intruder, the function of offensive sideways posture as a threat behavior may be more complex. It is possible that it becomes a conditioned pain stimulus due to its close temporal pairing with bite-and-kick attack, but it is more likely that it produces defense by a process of sensitization. In any case, following the initial attack, the offensive sideways posture continues to elicit defensive behavior by the intruder even when there are no further attacks. The functional roles of the defensive postures were interpreted as positioning the intruder in such a way that the home rat cannot assume the aggressive posture from which attack is launched. Scent-marking behavior was consistent within strains, within individuals, and across different types of measures (accumulation of scent-marking marking material and performance of the stereotyped scent-marking act, crawl-over-dish). Amount of scent-marking was not correlated with attack, however, and its role in isolation-induced fighting remains unclear. In parallel to findings in other rodents, it was observed that scent-marking was diminished in animals after they had been subjected to attack.

Parental Care and the Transition To Independent Feeding in the Young Spotted Flycatcher (Muscicapa Striata)

Abstract: I. In most passerine birds there is a period of parental care after the young leave the nest. The behaviour of wild young Spotted Flycatchers, Muscicapa striata, and interactions with their parents was studied in an attempt to answer the question "When should the young become independent?" The young flycatcher was regarded as predator with two feeding strategies, namely begging for food off the parents and attempting to capture prey (flying insects) itself. 2. The young left the nest when only half grown. As they got older there was a change from self feeding when satiated to self feeding when hungry, a decrease in the rate of pecking at inedible objects and an increase in the complexity and rate of capture techniques employed. Improvement in feeding performance was probably mainly due to continued growth and the parents did not play any part in these changes. 3. The initiative for parental feeding passed from the parents in the early stages to the young later on. As the young got older, the parents became more reluctant to feed them as reflected in the increased rate of chasing after the parents by the young and the increase in the proportion of these chases which resulted in no food. The parents brought large prey to the young when the time taken to take the prey to the young (travel time) was large and only took small prey when the travel time was small. 4. The energy gain per unit effort of begging decreased with age while that for self feeding increased. At 15-16 days after leaving the nest, self feeding became more profitable than begging. At this time the young suddenly increased their rate of capture attempts so that the energy intake by self feeding increased from 30% to 80%. One to two days later the young stopped begging altogether and became independent. It is suggested that the young can assess the profitability of their two feeding strategies and become independent of their parents when the profitability of self feeding exceeds that of begging.

The Behaviour of a Model Animal

Abstract: 1. The paper demonstrates the complex implications of the simple concepts of centres, drives and reciprocal inhibition in behaviour. 2. A model animal is described which can perform a number of discrete activities, each of which is controlled by a separate centre. The centres inhibit each other. The inhibition from each centre acts at the input to each of the others. When a particular centre is active, i.e. generating motor activity, the inhibition from it is sufficiently strong to suppress an equally stimulated rival; but the centre fatigues. Apart from adaptation and summation in the input pathways the model involves no other concepts. 3. In such a system only one centre can be active at a time. 4. The intensity of the activity performed is correlated with its drive only within certain limits and provided that the efficiency of performance remains constant. 5. The intensity of an activity usually declines during a bout and recovers to rebound after an interruption. However, an interruption may have almost any conceivable after-effect. 6. The threshold of a stimulus affecting one activity is influenced by stimuli acting indirectly through the centre controlling the ongoing activity, as well as by stimuli acting directly on the centre concerned. The threshold may not be well correlated with drive. 7. A stimulus which does not immediately elicit an activity may do so if the stimulus is sustained. The frequency distribution of latencies provides insight into the dynamic processes of adaptation, summation and fatigue and the mean latency is usually correlated with threshold. 8. If a transient stimulus elicits an activity, that activity may persist after the stimulus is withdrawn. Activities once started, persist even when the drive level which was necessary to elicit them has been reduced by their performance. 9. Different mechanisms of transition from one activity to another are discussed, together with the mechanisms determining sequences. 10. The test proposed by McFARLAND (1969) to distinguish between competition and disinhibition would classify some examples of disinhibition in the model as competition. No simple way of distinguishing the two processes in the model animal could be found. 11. Changes in bout length generated by the model duplicate the paradoxical results often observed in real animals. When the drive of two activities rises simultaneously, all bout lengths shorten. When only one activity is affected its bout length may lengthen or shorten. 12. Frequency may be positively, inversely or totally uncorrelated with drive. 13. Total time spent in an activity may increase or decrease with rising drive, depending on the changes in bout length that accompany the change in drive. 14. Total work done (e.g., water consumed) depends on both intensity and total time spent in the activity and so over short periods may not be closely related to drive level. 15. The assumption that the behaviour occurring at any time is the one with the dominant behavioural tendency (ATKINSON & BIRCH, 1970) can be applied to the model if behavioural tendency is equated with 'relative drive'. However it is more useful to equate behavioural tendency with 'absolute drive' in the model animal, in which case the above assumption must be abandoned. 16. In general the study shows that on the basis of a simple drive theory, the predicted relationships between many common measures of behaviour are unexpectedly complex. 17. While it is important to be aware of the dangers of oversimple theories, it is also important not to underestimate the limitations of many observations which cannot safely be used to distinguish between simple and complex systems. The fact that simple rules may be used to simulate extremely complex behaviour makes it very difficult to identify the nature of the real complexity which exists in real animals.

Aspects of Necrophoric Behavior in the Red Imported Fire Ant, Solenopsis Invicta

Abstract: Removal of dead ants from the nest (necrophoric behavior) is released solely by contact chemical cues in the fire ant, Solenopsis invicta Buren. Exhaustively extracted corpses do not release necrophoric behavior, but the extracts do when applied to filter paper bits. The necrophoric releaser is absent at death but appears rapidly and reaches a plateau within about an hour. The rate of signal appearance is identical in heat and freeze killed workers, implying a non-enzymatic origin. There is no specialized caste or size of worker which carries out necrophoric labor. In the field, in the absence of slope, corpse-bearing workers head outward from the nest on random radii and drop their corpses at unpredictable distances, making refuse piles rare. There is a positive relationship between slope and the presence of refuse piles, and these are located downhill from the mound. When the headings of necrophoric workers were measured in circular arenas in the lab, the only potential orientational cue (tested : landmarks, light, 5°, 10°, 15° slope) which resulted in non-random distribution of headings was slope. The concentration of the headings was a direct function of the slope and seemed to plateau at about 15°. Corpse-bearing ants show stereotyped behavior upon encountering refuse piles and adding their burden to it. Chemical stimuli probably issuing from the feces in the refuse pile bring about the end of necrophoric behavior and maintain the refuse pile. These chemical cues, as also those initiating necrophoric behavior, must be contacted to be effective.

Predatory Behavior of Yellow Baboons

Abstract: 1. A group of 32 yellow baboons (Papio cynocephalus) in the Masai-Amboseli National Park, Kenya, caught and ate 45 vertebrate prey items during 2519.19 hours of observation. 2. Eighty percent of the prey items were mammals and the most frequently eaten species were African hares (Lepus capensis), vervet monkeys (Cercopithecus aethiops) and neonate gazelle (Cazella granti and G. thomsoni) in that order. The details of predatory behavior for each prey species are described. 3. Rates of predation were significantly higher during the long dry season than during other months of the year, although no correlation was found between total monthly rainfall and monthly rates of predation. A lognormal model however provided a good fit to the monthly rate of predation data suggesting that the rate of predation by Amboseli baboons was affected by several factors that acted multiplicatively with respect to each other and were themselves related to rainfall or dryness. 4. A mean of 2.3 individuals fed directly from the carcass of each prey item. A mean of 3.5 individuals per prey item fed directly or indirectly, i.e., on scraps, from each carcass. In general, both the number of individuals who fed from each carcass and the duration of their feeding bouts was dependent upon the gross body size of the prey item. Adult males fed directly from the carcass of prey items for about three times more minutes than expected from their number in the group; other classes of individuals fed directly from prey carcasses for only one-fourth as many minutes as expected. In general, an adult male would be expected to feed on each category of vertebrate prey at least once per year, while individuals of all other age-sex classes would be expected to feed on most prey categories only once every two years. 5. The most frequent social behavior around prey items was agonistic bouts; no cooperation, simultaneous feeding or specific begging gestures were observed. 6. Estimates of the total number of prey killed annually by Amboseli baboons indicate that baboon predation probably has a negligible effect on prey populations other than vervet monkeys. 7. It is speculated that the need for vitamin B12 underlies baboon predatory behavior, and perhaps that of other primate species as well.

Dyadic Play in Hamadryas Baboons

Abstract: Play behavior was observed in a captive group of four juvenile Hamadryas baboons at the Brookfield Zoo, Brookfield, Illinois, U.S.A.. The group consisted of a male, aged 37 months, a female, aged 28 months and two young males aged 16 and 11 months at the beginning of the 3 month study. Tape recorded commentary of 1006 play bouts was analyzed, and this data was supplemented with material gathered by other methods. Three play behaviors - chase, face-off, and wrestling - and two "adult" behaviors - aggression/submission and grooming - were identified. These behaviors were found to be ordered temporally and socially. Sequences of behavior were nonrandom and highly predictable. Amount of time played, play partnerships and types of play behaviors displayed varied with the age and sex of the animals. The "adult" patterns were found with greater frequency in the older animals, wrestling in the younger ones. The chase-face-off sequence was largely confined to males. These results suggest that the development and sequencing of play are important questions for further investigation.

Field Experiments On the Adaptive Significance of Avian Eggshell Pigmentation

Abstract: A series of four field experiments which tested the camouflage properties of different eggshell pigmentation and marking patterns was conducted. Neither natural (Laughing Gull, Larus atricilla, eggs) nor artificial (khaki, khaki-randomly spotted, and black painted eggs) camouflage patterns conferred any selective advantage, when crows (Corvus brachyrhynchos and C. ossifragus) were allowed extended periods (over 2 hours) to hunt for the eggs. However, a natural eggshell pattern (Japanese Quail, Coturnix c. japonica, eggs) conferred a very strong survival advantage during field tests which were terminated either after half the eggs were discovered or after I hour, whichever came first. The selection index (SI) obtained for the quail eggs was higher than those yielded from other experimental investigations of the survival value of camouflage. The results of these experiments were discussed in view of the different test procedures employed, and the extent to which such procedures are reflective of naturally occuring patterns of crow predation, such as in a gull or a tern colony. A fifth experiment which tested the capacity of pigmented and unpigmented eggshells to shield egg contents from solar radiation was also conducted. Pigmented eggshells provided far less effective solar shielding than did unpigmented ones, and this effect appears to hold over a wide range of eggshell thicknesses. In view of these findings, the dark eggshell pigmentation patterns of open ground nesting birds are seen as an "adaptive compromise." That is, under different circumstances dark eggshell pigmentation may be either advantageous or disadvantageous to species and individuals which possess them. Based upon functional considerations an hypothesis was generated which predicts that natural selection should favor darker eggshell pigmentation patterns among certain avian species with particular types of reproductive strategies nesting in particular types of breeding habitat. Some general evidence in support of this hypothesis was offered, and some suggestions for further comparative tests of this hypothesis are suggested.

Communication Within and Between Family Groups of Siamang (Symphalangus Syndactylus)

Abstract: The close coordination of family groups of siamang (Symphalangus syndactylus) by subtle visual signals contrasts with the very loud and complex calls which figure prominently in relations between groups to space them effectively through the habitat. The siamangs' repertoire of facial expressions, vocalisations, and expressive gestures, postures and movements are contrasted with that of the white-handed gibbon, Hylobates lar. The ways in which siamang move about their small range in a highly coordinated manner, with frequent pauses for resting and grooming, and for feeding, are described. Reference is made to the structure of group calling bouts and to conflicts between groups. There is discussion of the possibility that the group cohesion results from group members becoming able to predict accurately the movements of each other, and of the possible way in which aggressive acts are countered by conciliatory ones.

Temporal and sequential organisation of song in the sedge warbler (acrocephalus schoenobaenus)

Abstract: Temporal analysis has revealed that Sedge Warbler songs are unusually long, some extending over one minute in duration and containing over 300 syllables. They have a characteristic temporal pattern; starting slowly and building up to become faster, more complex and louder in the middle, before fading away towards the end. Song flights were not longer, but more complex in structure, containing twice as many syllable types as normal songs. Some individual differences were found, Bird I sang faster than the other two, and Bird 3 had longer songs which contained fewer syllable types. Sequence analysis revealed that the start section of the song consisted of long, complex patterns of repetition and alternation, usually involving only two syllable types. The middle section was characterised by a sudden switch, which introduced between 5 and 10 new syllable types in quick succession. The end section consisted of a similar pattern to the start, but the two syllable types were selected from the middle section. These were then used to form the start of the next song. Sequence analysis showed that overall syllable transitions were indeterminate, and this was confirmed by following in detail the many and complex relationships of selected syllable types. Even when songs containing the same syllable types were found, their transitions and detailed structure varied enormously. Considering the variable organisation described, the probability of a song type ever being exactly repeated seems remote. Sedge Warbler song is unusual in two respects; in its extreme elaboration and in functioning almost solely in sexual attraction of the female. It is suggested that these two factors are related, and that sexual selection may have played an important part in the evolution of one of the longest, most elaborate and variable of all bird songs.

Responses of Laughing Gull Chicks (Larus Atricilla) To Parental Attraction- and Alarm-Calls, and Effects of Prenatal Auditory Experience On the Responsiveness To Such Calls

Abstract: Confirming previous observations in the gull-colony the parental attraction-call 'crooning' selectively enhanced activity while the alarm-calls 'kow' and 'uk-uk' suppressed activity and vocalizations, even in the absence of additional visual clues. These calls may have had the observed effects in part because of certain acoustic characteristics to which chicks preferentially respond and in part because of specific experiences that chicks may have had with these calls prior to testing. Some of the difference between experiment (a) and (b) in the performance towards 'uk-uk' calls may have been due to the fact that the chicks in (b) were tested later in the season than the chicks in (a). Later hatching chicks may have been physically less well developed and thus less responsive than earlier hatched chicks, or they may have had differential kinds or amounts of auditory experience before they were tested. The present results differ from findings of an earlier pilot-investigation (BEER, 1973) in which recordings of single adult birds evoked no clearcut responses in chicks. However most of those chicks had been several days old and in other experiments it was shown that responsiveness to calls of adults changes with age (BEER, 1970b).Observations. Adult Laughing Gulls utter several distinct calls during the incubation of their eggs and the raising of their chicks. One call referred to as 'uhr' call is frequently heard during incubation in conjunction with rising from the eggs or resettling, and in response to the mate's activities near the nest. 'Crooning' is heard during mate-reliefs in incubation. After hatching this call functions to attract the young to the parent. `Uk-uk' and 'kow' alarm-calls are both uttered when the colony is disturbed by a potential predator, but 'kow' calls can also be heard in purely conspecific disturbances. Experiment I . The responses of day-old chicks, reared by their parents, were investigated towards recordings of some of these calls. Confirming observations in the wild, `crooning' selectively enhanced activity and elicited approach; 'uk-uk' suppressed activity and vocalization and elicited crouching; 'kow' calls had similar effects but to a lesser extent. Experiment 2. Chicks collected at hatching from nests in the gull-colony were compared with chicks hatched in an incubator in order to discover whether the prenatal conditions affected early postnatal responsiveness to 'crooning'. It was found that parent-hatched chicks showed increased activity in the presence of 'crooning' and some of them approached the speaker, whilst incubator-hatched chicks were not activated by these calls. Experiment 3. Younger chicks were compared with older chicks (all hatched in the incubator) for the purpose of finding out to what extent their responsiveness to 'crooning' would change with postnatal age. The results showed that to parentally inexperienced chicks this call increasingly acquires the effects of alarm-calls in that it suppresses vocalization and activity and elicits crouching. Experiment 4. The role of parental calls as experienced in the wild during incubation was examined experimentally. During the last 2 1/2 to 3 days of incubation eggs were repeatedly exposed to different types of calls (or no calls at all), in order to see to what extent and with what degree of selectivity such exposures would affect responsiveness to 'crooning' and 'kow' calls in newly hatched chicks. It was found that prenatal exposure to 'crooning' leads to enhancement of activity and vocalization in the presence of such calls postnatally. Effects of prenatal experience with disyllabic 'uhr' call point into the same direction. Prenatal experience with 'kow' calls does not lead to early postnatal activation in response to 'crooning'. Responsiveness to 'kow' calls was only affected by prenatal exposure to these calls. Discussion. Some previously published studies in this field of research are briefly reviewed and compared with the present findings. The relative contribution of prior experience of parental and filial vocalizations to later responsiveness to parental calls is discussed. Earlier research in the Laughing Gull had shown that parentally inexperienced embryos are selectively activated by 'crooning' till close to hatching. In the present study it was shown that repeated prenatal experience with 'crooning' leads to its attractiveness after hatching. Therefore repeated prenatal (and maybe early postnatal) exposure to this call and related calls seems to function to maintain and. consolidate responsiveness to this call in the neonate. In contrast to 'crooning', 'kow' alarm-calls heard prenatally do not enhance nor suppress motility. Prior exposure to this call does not maintain this apparent indifference, but merely reduces the extent to which it acquires activiy suppressing effects.

Specific Recognition in the Song of Bonelli's Warbler (Phylloscopus Bonelli)

Abstract: The analysis. The song of territorial proclamation of P. bonelli has shown that the most stable parameters were the duration of the song, the number of units constituting them, the lower limit of the acoustic spectrum, and the form of certain elements. The most fluctuating parameters were the factors of duration of sequences and silences between songs, the rhythms in the songs, the upper limit of the acoustic spectrum, and to the form of certain sub-units. The experimentation. The experimentation shows us that the species markers are not always constituted by the least variable parameters. The most important species markers for this bird are: the sense of the frequency modulation against time, the distribution of acoustic energy in the lower part of the spectrum, the purity of the frequencies, and a sufficient duration of the signal. We have introduced the notion of "rejection markers" permitting the bird to reject some signals close to their own, by deciding rapidly and without ambiguity which behaviour to adopt. In the case of P. bonelli as an example we have discussed the relations existing between the individual variability and the fixity of species characters. We have concluded that it is a question of two aspects of the same phenomennon.

Social Behaviour and Communication in the Great Skua

Abstract: [Social behaviour in Great Skuas was observed in a breeding colony at Noss, Shetland, 28 April-2 June 1972, with emphasis on displays and communication. The display repertoire consists of a number of "basic" elements, which occur in different combinations. Motivation of displays was examined with temporal sequence analysis. Association between displays and overt patterns was studied in ten-second time units over a range of ± 100 seconds time lag. Upright postures, Bend, Wing-raising and Long Call showed positive associations mainly with attack and escape. "Squeaking Ceremony" was associated mainly with nest-building patterns, Neck Low with "courtshp feeding", and Staccato Call with copulation. Most agonistic displays were of short duration, whereas "Squeaking" and Staccato Call were performed during longer periods. Signal function of agonistic displays was studied in dyadic interactions, examining occurrence and sequential order of patterns in both individuals. One aspect of the message of a display, probability of subsequent action, was estimated by recording the frequency of attack, stay put and escape following it. The probability of accurately predicting communicator action usually increased if the preceding display was considered. The best predictability was obtained for displays mainly indicating escape, whereas attack was least predictable. Some displays gave similar information about subsequent actions. Closer examination revealed differences in use, depending on position of the rival. There may also be undetected differences in subsequent motor patterns. Long Call and Wing-raising, which are conspicuous at long distance, were most frequently used towards aerial intruders, Upright postures towards nearby intruders on the ground. Besides conveying different messages, different agonistic displays may thus be used for communication with recipients at different positions and distances. The effect of displays on other individuals was studied by recording their responses to different patterns. Results from the analysis of subsequent actions by the same individual permitted some predictions, which were used to test the hypothesis that displays influence the behaviour of recipients. For example, displays indicating high attack probability should more often be followed by escape in recipients than should escape indicators. These predictions in general were confirmed. However, overt patterns and territorial status also had an influence on the recipient's response. To assess the relative importance of one particular factor, cases where the two other factors did not vary were compared. Overt movements had a strong influence and territorial status also played a role. Other factors besides displays therefore are important in the communication process, and need consideration. When allowance was made for the influence of territorial status and mode of approach, a significant association was obtained between the probability of communicator attack subsequent to various displays, and the responses in recipients of these displays. Recipients hence use information about subsequent communicator action provided by displays for adapting their responses, which shows that displays function as signals., Social behaviour in Great Skuas was observed in a breeding colony at Noss, Shetland, 28 April-2 June 1972, with emphasis on displays and communication. The display repertoire consists of a number of "basic" elements, which occur in different combinations. Motivation of displays was examined with temporal sequence analysis. Association between displays and overt patterns was studied in ten-second time units over a range of ± 100 seconds time lag. Upright postures, Bend, Wing-raising and Long Call showed positive associations mainly with attack and escape. "Squeaking Ceremony" was associated mainly with nest-building patterns, Neck Low with "courtshp feeding", and Staccato Call with copulation. Most agonistic displays were of short duration, whereas "Squeaking" and Staccato Call were performed during longer periods. Signal function of agonistic displays was studied in dyadic interactions, examining occurrence and sequential order of patterns in both individuals. One aspect of the message of a display, probability of subsequent action, was estimated by recording the frequency of attack, stay put and escape following it. The probability of accurately predicting communicator action usually increased if the preceding display was considered. The best predictability was obtained for displays mainly indicating escape, whereas attack was least predictable. Some displays gave similar information about subsequent actions. Closer examination revealed differences in use, depending on position of the rival. There may also be undetected differences in subsequent motor patterns. Long Call and Wing-raising, which are conspicuous at long distance, were most frequently used towards aerial intruders, Upright postures towards nearby intruders on the ground. Besides conveying different messages, different agonistic displays may thus be used for communication with recipients at different positions and distances. The effect of displays on other individuals was studied by recording their responses to different patterns. Results from the analysis of subsequent actions by the same individual permitted some predictions, which were used to test the hypothesis that displays influence the behaviour of recipients. For example, displays indicating high attack probability should more often be followed by escape in recipients than should escape indicators. These predictions in general were confirmed. However, overt patterns and territorial status also had an influence on the recipient's response. To assess the relative importance of one particular factor, cases where the two other factors did not vary were compared. Overt movements had a strong influence and territorial status also played a role. Other factors besides displays therefore are important in the communication process, and need consideration. When allowance was made for the influence of territorial status and mode of approach, a significant association was obtained between the probability of communicator attack subsequent to various displays, and the responses in recipients of these displays. Recipients hence use information about subsequent communicator action provided by displays for adapting their responses, which shows that displays function as signals.]

An Experimental Analysis of the Function of Red-Winged Blackbird Song

Abstract: The social role of the male red-winged blackbirds' Ageliaus phoenicetts, advertising song was examined. Territorial male red-wings were captured on their territories and subjected to bilateral sectioning of the hypoglossal nerves where they descend along the trachea. This surgery resulted in males which delivered species atypical songs at the times when they attempted to sing the normal advertising song. A group of control males were captured and treated in the same way as the surgically treated males except the hypoglossal nerves were not sectioned. The following results were obtained: 1) Vocalization altered males were successful in maintaining territories for the remainder of the breeding season. 2) Vocalization altered males were able to mate with females and raise young successfully. 3) Five vocalization altered males returned to the same marsh the following breeding season, one year after the operation and successfully established and maintained territories. It was concluded that the ability to deliver species typical song was not necessary for the establishment and maintenance of a breeding territory under the environmental conditions encountered during these experiments.

Egg Size and the Egg Predatory Behaviour of Crows

Abstract: Patterns of corvid predation on different sized white eggs were studied in a series of field experiments Different sized eggs were set out singly and in simulated nests containing clutches of same sized and different sized eggs The eggs were set out in meadows where they were subjected to intense predation by crows The most common predation method of the crows was to fly off with eggs and to cache (bury) or eat them at a distance from the site of predation The larger eggs were more frequently pecked open at the egg site and were less effectively picked up and carried off by the crows Apparently as a result of the ease of grasping smaller eggs, these eggs were much more vulnerable to predation than were larger eggs These results combined with field observations and previous findings indicate that Corvus predators may exert differential pressures on different sized eggs both within and among clutches, intra- or interspecifically These patterns of crow predation analyzed in terms of the gulls' parental investment among the different eggs within a three egg clutch suggest that smaller third eggs may have been (and continue to be) selected in the evolution of a balanced predator-prey system between crow predators and ground nesting gulls Cooperative aspects of corvid group hunting patterns are also discussed

The role of individual recognition by odors in the social interactions of the Mongolian gerbil (Meriones unguiculatus).

Abstract: This study attempts to determine the importance of individual recognition by odors in the social interactions of male Mongolian gerbils (Meriones unguiculatus). The first experiment tested the effects of anosmia on social interactions. Twentyfour pairs of male gerbils were divided into two groups (experimental and control). Experimental animals were made anosmic by bathing their nasal mucosa with 7% solution of ZnSO4. Control animals were treated with distilled water. Following treatment, control and experimental animals were tested with both familiar and unfamiliar conspecifics, and the frequency and types of social behaviors were compared. The results showed that anosmic animals apparently cannot distinguish between familiar and unfamiliar conspecifics and, therefore, that they treat all other gerbils in the same manner that they treat familiar animals. Control animals, on the other hand, showed significant differences in the frequency and types of behaviors directed towards familiar and unfamiliar conspecifics. The second experiment tested the effects of unfamiliar odors on social behaviors. Twelve pairs of familiar male gerbils were tested under three conditions : with soiled shavings from their own home cage (own familiar odors), with clean shavings, and with soiled shavings from the cage of an unfamiliar pair of conspecifics (unfamiliar odors). The results showed that gerbils can detect unfamiliar conspecific odors and that the presence of such odors can affect the social behaviors of a pair of familiar animals. Pairs of familiar gerbils showed a high frequency of social interactions when in the presence of their own familiar odors, but a reduced frequency when tested with unfamiliar conspecific odors or with clean shavings. It is suggested that this decrease in social behaviors could have been due to changes in levels of arousal or to competing exploratory responses. These experiments thus demonstrate that individual differences in the biological odors of the Mongolian gerbil play an essential role in the recognition of individuals and in the normal pattern of social behaviors of this species.

The Establishment and Reversibility of Dominance Relationships in Jewel Fish, Hemichromis Bimaculatus Gill (Pisces, Cichlidae): Effects of Prior Exposure and Prior Residence Situations

Abstract: Using adult jewel fish (Hemichromis bimaculatus), a highly territorial member of the family Cichlidae, three separate experiments were conducted to investigate environmental factors important in the establishment and maintenance of dominance relationships. In Experiment 1, fish were acclimated for 2 days, while individually housed in an aquarium containing either a ceramic pot or a clump of vegetation. Pairs of fish (one pair member from each treatment condition) met in a separate test aquarium containing one of the two possible cues. After a dominance relationship was established, the same pairs were rematched 24 hours later in the same test aquarium, but with the other cue substituted for the Day 1 cue (e.g., pot instead of vegetation or viceversa). In the Day 1 bouts, the fish with "prior exposure" to the cue present in the test aquarium dominated over the pair member unfamiliar with the cue. On Day 2, the Day I dominance relationship was maintained, even though the cues had been reversed. There was no resistance to being dominated on Day 2, while vigorous fighting typically occurred on Day 1. In Experiment 2, the procedure was the same as that of Experiment 1, except that the dominance encounters occurred in the actual "home" aquaria of the pair members. For example, the Day 1 encounter would take place in the home aquarium containing the vegetation, while the Day 2 rematch occurred in the home aquarium containing the pot. As in Experiment 1, the fish were put into their home aquaria for 24 hours after the Day 1 encounter and then retested for dominance in the other pair member's home aquarium. On Day 1, the resident (in its home aquarium) dominated significantly more often than the intruding pair member (prior residence effect). On Day 2, approximately 36% of the Day 1 dominance relationships reversed. Also, marked fighting usually occurred on both days of testing. Experiment 3 was the same in procedure as Experiment 2, except that the 2 day pre-test acclimation period was increased to 7 days with the expectation of producing more Day 2 reversals, or at least producing greater resistance to the continuation of Day 1 relationships on Day 2 (when the Day 1 loser refought in its own aquarium). The results of Experiment 3 were not significantly different from those of Experiment 2. The three experiments, taken together, show that familiarity with environmental cues produces a dominance advantage when encountering a strange fish not having had this "prior exposure" or "prior residence" experience (Day 1). However, this familiarity with environmental cues was not a strong enough factor to produce reversals on Day 2, when testing took place in a separate aquarium containing one familiar visual cue (prior exposure situation). In contrast, in the prior residence situations of Experiments 2 and 3, with the addition of many more familiar cues (e.g., water, light direction, etc.), significantly more dominance reversals occurred on Day 2. Also, Day 1 losers showed more resistance to being dominated again when they were tested in their own home aquarium on Day 2. In all three experiments, Day 2 dominance decisions were most influenced by the past experience between the pair members (Day 1 dominance decision). However, the additional environmental cues provided by the prior residence situation (Experiments 2 and 3) increased the probability of dominance reversals and fighting on Day 2. Another interesting finding in these experiments was that the pair member that bit first in an encounter usually became dominant. Dominance fighting in this species seems to be both an antecedant and consequence of establishing a territory, with environmental familiarity possibly faciliating these processes.

Agonistic Behavior in the Male Northern Elephant Seal

Abstract: At least 10 behavioral elements were involved in aggressive behavior. The frequency of nine of these among five males was determined. High ranking males were involved in more aggressive interactions than those of low rank, but overt fights were very rare. At least six elements of submissive behavior were observed among males and the frequency of these were determined. Submissive display among males (involving female mimicking behavior) effectively inhibited most overt aggression. Erection and maximal size of the proboscis always coincided with dominance and aggression while a small retracted proboscis coincided with the display of subdominance defence and submission. By the shape of the proboscis and no other criteria alone can the mood of the male be read at any moment. It is suggested that the proboscis has evolved mainly as an agonistic display organ. Adult males recognize each other vocally. It is suggested that the criterium for individual recognition is the structure of the pulse and not the number of pulses they emit in the most characteristic of the four distinct vocalizations that were recorded among males (VO 2). The high ranking males were active 11,5% of the day while the low ranking were significantly less active (6,4%).

Acoustic Features of Wood Duck (Aix Sponsa) Maternal Calls

Abstract: While brooding their young and calling them out of the nest within 36 hr after hatching, wood duck hens utter a species-typical maternal call that their young find highly attractive. We recorded the maternal calls of eleven hens from nest sites in the field to determine the commonalities and variability in various acoustic features of the calls. Our results indicate that the "modal" wood duck maternal call has notes with the following characteristics: I. two independent, apparently nonharmonically-related tones between 900 and 1500 Hz uttered simultaneously; 2. descending frequency modulation - a finding that adds further substance to laboratory findings that indicate maternally-naive wood ducklings use this feature for species identification; 3. increasing amplitude modulation; 4. durations of 40-45 ms; 5. repetition rate of 9.0 notes/s; 6. 19 notes per burst. The variability between hens in the above features was relatively low, thus seeming to provide little or no basis for individual parent recognition, but that possibility remains to be determined experimentally.

The Effect of Female Color, Size, Dominance and Early Experience Upon Mate Selection in Male Convict Cichlids, Cichlasoma Nigrofasciat Um Günther (Pisces, Cichlidae)

Abstract: This study investigates the role of female color, size, and dominance, and the influence of early color experience in mate selection by male Convict cichlids, Cichlasoma nigrofasciatum. Dark wild-type male fish were reared by dark parents in dark schools (dark homogenous group), and by mixed dark and white parents in mixed schools (dark mixed group), until sexual maturity. Correspondingly a white homogenous group and a white mixed group were also established. Each male was then allowed to choose a mate among two dark (mixed group) and two white (mixed group) females. Males tended to spawn more often with dark females and always spawned with dominant females. Female size is positively correlated with female dominance and this may be either as a cause or as an effect of female dominance. Early color experience appears to be unimportant in male mate selection.

Studies On the Behaviour of Cyprinodont Fish Iii. the Temporal Patterning of Aggression in Aphyosemion Striat Um (Boulenger)

Abstract: The fighting behaviour of Aphyosemion striatum is described. Particular attention was paid to the changes that occurred in the pattern of aggression during the course of an encounter. It was shown that the tempo of fights increased, that is, as the fight progressed the number of elements of behaviour per unit time increased. The three most frequent elements were Quivering, Tail Beating and Attacking and it was shown that they succeeded each other, in maximum frequency of expression, in the order given above, throughout a fight. Fin Clamp, occurring at the beginning of fights and, in losers, at the very end, signalled unwillingness to fight. Almost all the elements alternated with Full Display which was indicative of arousal. The increasing level of aggression followed by sudden defeat of one fish could be accounted for in terms of a positive feedback interaction between participants followed by overloading in one animal. A major prediction of this model is that progressive matching in levels of aggression will occur during a fight and this was shown to happen. An adaptive reason for this pattern of aggressive behaviour is proposed, which is that it can minimise the effects of factors unrelated to reproductive fitness in deciding the final outcome of a fight.

Causal and Functional Organization of the Mating Behaviour Sequence in Helix Pomatia (Pulmonata, Gastropoda)

Abstract: Copulation in Helix pomatia is reciprocal. The partners behave identically, but not necessarily at the same time. Eleven different behaviour patterns are recognized and described. The mating behaviour is of long duration, about 8 hours. It can be divided into four phases which occur in a fixed sequence and each of which is characterized by a certain type of behaviour. Also the behaviour within the phases I-III is sequential, and the sequences are usually repeated many times. During phase I the snails adopt a conspicuous upright posture, which also occurs in phases II and III alternating with other behaviour. At the end of phase II a calcareous dart is "shot" into the body of the partner; the place of dart penetration is rather variable. A number of unsuccessful copulatory attempts occur during phase III before copulation takes place. A nearly immobile posture is maintained throughout the post-copulatory phase IV. Mating behaviour occurs in a cyclic manner. A complete (primary) mating sequence may during the next few days be followed by one or more secondary matings which do not include the dart shooting phase, then the next few days no mating takes place until a new primary mating is performed. The number of secondary matings are increased after deprivation of mating. No stimulating effect of dart-shooting on the mating behaviour of the receiver could be found, only decremental effects were observed. There are, however, short and long termed effects of dart-shooting on the actor: it causes the transition phase IT-III and has at least a main influence on the cyclic nature of mating activity. The mating behaviour is a highly complex behaviour as defined by duration, occurrence of phases of behaviour, number of behaviour patterns involving action of the whole body and interaction of individuals. In spite of this the sequential organization of the behaviour is basically determined by endogenous consequences of the behaviour of each individual. Changes of behaviour occur spontaneously or may be triggered by stimuli from the partner, but in the latter case the exogenous stimuli are never decisive for the behaviour to follow. Stimuli from the partner are significant for the functional organization by facilitating, orienting and synchronizing the behaviour of the partners. The sequential behaviour during phases II and III can be explained by increasing shooting and copulatory tendencies, respectively, and threshold differences between successive behaviour patterns. The increase in these tendencies is probably due to a self-stimulatory effect of the mating activities, and these activities again are facilitated by unspecific touch stimuli from the partner. Localized touch stimuli release dart-shooting and sometimes copulatory attempts. Both of these acts are stereotyped, but they are preceded by orientation movements. The orienting and releasing stimuli increase the chance that the dart hits the partner and that the copulatory attempts are synchronized. Several factors are found to he the cause of the high numbers of unsuccessful copulatory attempts. The separation of the first three phases is explained by an inhibitory influence of the shooting tendency above a certain threshold on copulatory behaviour and a disinhibitory effect of dart-shooting. Receptivity is obtained during phase III independently of the copulatory tendency, i.e., male and female tendencies of each individual can be separated. A complete post-copulatory behaviour and probably a temporary reduction of the mating tendency depend on endogenous factors correlated with spermatophore formation and is independent of delivery as well as receipt of the spermatophore. During phase IV all behaviour except the post-copulatory posture is strongly inhibited for about 3 hours, and when this inhibitory influence diminishes, the mating behaviour sequence is terminated and may be followed by phase I of a new mating sequence or other activities.

Sexual Imprinting: Effects of Various Regimens of Social Experience On Mate Preference in Japanese Quail Coturnix Coturnix Japonica

Abstract: The present investigation has focused on the relationship of social experience during different developmental stages and subsequent mating behavior. Japanese quail Coturnix coturnix japonica were employed as subjects in that these avians become sexually mature as early as 42 days posthatch and they readily mate in an experimental apparatus. Four different treatments of exposure to albino Japanese quail were compared on a number of measures to determine how a particular regimen of social experience might affect social behavior in sexually mature males. The four experimental treatments were: First, exposure to normal age-mates only for either the first 5 or 20 days posthatch and then isolation from the 2ist day posthatch (NEX). Second, exposure to albino age-mates for the first 5 days posthatch and then isolation (SEX). Third, exposure to only albino age-mates during the first 20-25 days posthatch and then isolation (PEX). Fourth, exposure to albino age-mates from day 16 through day 25, and then isolation (LEX). The first measure obtained was the experimental virgin male's approach to a confined female in a simultaneous choice test between a normal and albino female. This measure proved to be an unreliable predictor of mate preference except in the case of the NEX group. Hence, except for those cases wherein subjects are reared with typical social objects can one expect that measures such as the approach response be related to more typical social interaction such as mating. The second observation was the mount preference for either the albino or normal female in a simultaneous choice test. Both the NEX and SEX groups selected normals 100% of the time. The PEX group selected albinos in all but one case. The LEX group was essentially equivocal with respect to a preference; 6 selected normal females and 4 selected albinos. This observation demonstrates that it is possible to establish the albino coturnix female as the preferred sexual object on the basis of a program of social experience. The data are discussed in terms of mechanisms that may serve to produce the observed differences among treatment groups. The final observation was whether or not coturnix males would mount albino females (within five minutes) when they were presented alone. This later observation served to differentiate the NEX and SEX groups and suggested that sexual responsiveness toward a particular social object may result from more than a single influence. Again, data from the albino test were discussed in terms of the mechanisms that were thought to be responsible for the observed differences among groups. An imprinting mechanism is thought to be responsible for the selection of albinos in the simultaneous choice test for both the PEX and LEX groups. The rationale for such a conclusion was based on the difference between the SEX and LEX groups in the number of subjects selecting an albino female in the simultaneous choice test. No members of the SEX (early exposure period) group mounted albinos in the simultaneous choice test, whereas 4 LEX's (later exposure period) mounted albinos in the simultaneous choice test. This difference was concluded to have resulted from social experience at a later ontogenetic stage rather than due to the increased duration of exposure in that the LEX group was exposed to normals for 15 days (a greater amount than the 10 day exposure treatment) and the SEX was not exposed to normals at all. A habituation-sensitization mechanism is thought to be responsible for the difference in mounting albino females in the albino test between the NEX group and the SEX and LEX groups. No NEX mounted an albino female, whereas all SEX and LEX males mounted albino females. This interpretation is based on the observation that avians generally manifest increased fear responsiveness toward newer objects after the first few days posthatch, and that experience with novel objects has been shown to reduce subsequent fear responsivity toward the experienced object. Further, it is assumed that in addition to the generalization of habituation from the earlier exposure to albinos there also was some generalization of sensitization to albinos as social objects. The coturnix appears to be a highly suitable species for the further study of those parameters effecting preferences for albinos in a simultaneous choice test.

Stress and Increase of the Corticosterone Level Prevent Imprinting in Ducklings

Abstract: A prior study (WEISS, KOHLER & LANDSBERG, 1976) stated that age increasing within a period of 12 to 28 hrs after hatching the Corticosterone level in blood increases. The hypothesis was that these increase of hormones were one of the factors limiting the sensitive period. This was proved by means of two experiments. 1. Ducklings within the sensitive period could not be imprinted if they were exposed to stress before imprinting. Their Corticosterone level was higher than the one of ducklings 25 to 30 hrs of age, whose sensitive period has already ended. 2. The primary effect of Corticosterone was examined eliciting the secretion exclusively endogenously instead by an environmental stimulus. For this purpose ACTH was applicated. The ducklings showed less liability to be imprinted, however, they showed no increase of Corticosterone. This was only found when the ducklings were exposed to both, application of ACTH as well as imprinting. Evidently, the cells secreting Corticosteronc are only mobilized to a later stronger secretion at the point of imprinting. Applied doses of ACTH, which were to small to prevent imprinting, had caused a comparable increase of the Corticosterone level after the beginning of imprinting as did larger doses of ACTH. The secretion of Corticosterone did not last as long, though, and during imprinting already it decreased underneath the value of ducklings 21 to 25 hrs of age, whose sensitive period is ending at this point. Imprinting eventually is an artificially isolated part of process of early learning. Certainly we are dealing with a multi-dimensional developmental process of the young bird, where it becomes acquainted with the environment and differentiates other stimuli which more and more elicit fear behaviour. Sometimes the growing fear behaviour was held responsible for the termination of the sensitive period. The increase of the Corticosterone level explains the increase of fear behaviour. Only 8% of the Corticosterone level is determined by age so that a series of environmental factors certainly are determining the hormone concentration, also. This is one more hint for rejecting "explanations in terms of purely endogenous changes in motivation" (BATESON, 1964a, p. 100) and pleading for a multi-dimensional system (HINDE, 1962b).

The Development of Sociosexual Behaviour in Free-Living Baboons, Papio Anubis

Abstract: The development of mounting behaviour and the communicatory functions of mounting were studied in a free-living troop of olive baboons in the Gombe Stream National Park, Tanzania, over a period of 16 months. 1. Early mounting attempts by baboon males were disoriented and incomplete. Components of mounting such as penile erection and pelvic thrusting at first occurred in isolation and in inappropriate contexts, but at 10-15 months of age, males became able, rather suddenly, regularly to orient themselves correctly to the female when mounting. 2. From about 10 months of age, thrusts became more rhythmical and increased in number per mount, and at about 12 months, intromission and the ejaculatory pause first occurred. At this age also, the frequency of male mounting reached a peak. Between 20 and 50 months of age, the characteristics of male-female mounting changed rather little, but after puberty, the proportion of mounts in which an ejaculatory pause occurred was twice as great as in younger age groups, and the number of thrusts required to reach ejaculation decreased. 3. Tumescent adult females were available for mounting by young males throughout the year, though young males could not gain access to females whilst they were maximally swollen and in consort with adult males. From about one year of age, males increasingly selected adult females as mounting partners. Male-male mounts, however, continued into adulthood. 4. The presence of cycling females in the troop with which young males could achieve intromission was thought to be particularly important for the development of the orientation and integration of male mounting patterns in baboons. This is supported by studies of captive peer-raised macaques, in which the course of development of male mounting behaviour tends to be delayed compared with that in naturalistic or wild groups of primates. 5. The nature and time scales of development of male mounting patterns in the genera Papio and Macaca appear to be very similar, though in olive baboons, unlike macaques, the ejaculatory pause occurred before puberty. In primates and in other mammals, important changes in mounting development seem to occur both during the early months of life and around puberty. 6. Mounts were observed in the contexts of 'dominance', play, appeasement/greeting, and enlisting as well as in a 'sexual" context. Mounts between males were not always in the direction that agonistic status or play relationships would predict, and for any male-male pair, mounts could occur in either direction. The direction of mounting was dependent on the nature of the communication involved, and in one type of mounting (appeasement/greeting), it was generally the subordinate male that mounted. The general function of non-sexual mounting seemed to be to reduce the likelihood of aggression.

Species Specificity and Individual Variation in the Songs of the Brown Thrasher (Toxostoma Rufum) and Catbird (Dumetella Carolinensis)

Abstract: The Brown Thrasher, like his fellow mimic thrushes, sings a highly variable song. So variable are the individual notes of the song that field identification on the basis of a single burst of song is hazardous. Reliable field identification traditionally has depended on the number of utterances of each sound rather than on the note qualities of the sounds themselves: Brown Thrashers (Toxostoma rufum) seem to utter sounds in pairs, whereas Catbirds (Dumetella carolinensis) do not repeat sound and Mockingbirds (Mimus polyglottos) repeat each sound several times. The purposes of this study were two: first, to establish that the thrasher does in fact distinguish his own song from that of the other mimic thrushes. Second, to develop evidence of the cues used to make the discrimination. Two techniques were used, playback trials and song recording analysis. In playback trials, Brown Thrashers were played samples of Brown Thrasher, Catbird, and Mockingbird song. Some samples were natural recordings and some were artificial samples in which the numerical properties of the songs had been distorted. For comparison purposes, an analogous set of recordings was played to Catbirds. The song recording analyses entailed sonagraphic reproduction of extensive segments of the songs of four thrashers and a careful study of the form, temporal properties, and statistical characteristics of the sounds thus represented. 1) Brown Thrashers clearly discriminate Brown Thrasher song from Catbird song and the basis of the discrimination is the number of utterances of each sound. Thrashers respond more vigorously to Brown Thrasher song than to Catbird song, to doubled Catbird song than to normal Catbird song, and to normal thrasher song than to halved thrasher song. 2) The results do not show that thrashers discriminate their own songs from Mockingbird song. Thrashers do respond more vigorously to normal Brown Thrasher song than to artificially lengthened Brown Thrasher song, but do not respond more vigorously to normal Brown Thrasher song than to normal Mockingbird song nor do they respond more vigorously to shortened Mockingbird song than they do to the normal form. 3) Catbirds can discriminate their songs from the songs of the other mimic thrushes, but they do not appear to make this discrimination on the basis of number. Catbirds respond more vigorously to the normal songs of their own species than to normal songs of the other two species but they do not respond more vigorously to shortened versions of the other species songs nor less vigorously to lengthened versions of their own song. 4) The sonagraphic analysis of thrasher song produced paradoxical results. Despite the importance of the two-ness in the field identification of thrasher song, no reliable property of two-ness was discernible in the sonagrams. Brown Thrashers did not reliably repeat each utterance nor pair utterances. In fact, the numerical properties of their songs, like all of the properties observed, overlapped extensively with the numerical properties of the other two mimic thrushes. However, these properties, like other properties studied, did differ on the average between the song of the thrasher and the song of the other mimic thrushes. The results suggest that the search for a single parameter that immediately distinguishes the songs of the species may be misguided. The songs of the mimic thrushes may differ only in the average value of several parameters and the birds like human observers in the field may have to hear several units of song before they can make a definite species identification. Despite the inefficiency of this process, the birds sing so rapidly and constantly that species identification of their songs would take no longer than species identification of slower but more consistent song.

Thermoregulatory Aspects of Behavior in the Blue Spiny Lizard Scelopor Us Cyanogenys (Sauria, Iguanidae)

Abstract: 1. The thermal relations of blue spiny lizards, Sceloporus cyanogenys, were studied in laboratory habitats which were designed to allow the expression of a large repertoire of natural behavior patterns. Body temperatures obtained with fast-reading thermometers and by radio telemetry from implanted transmitters were correlated with postures and activities. 2. The morning emergence of lizards was found to be cued by light, often in the absence of immediate thermal reinforcement. 3. Two basking postures which altered a lizard's air and substrate thermal interfaces could be distinguished. The environmental and body temperature correlates of these postures were not appreciably different, and the change from one posture to another could not be interpreted as thermoregulatory. 4. When thermal conditions permitted, basking continued up to the attainment of the maximum voluntary body temperature (38.7 C), and was then followed by perching. 5. The body temperature correlates of perching had a range and mean much like the "normal activity range" of other species of Sceloporus (28.2-38.7 C, X= 35.2). 6. Defecation occurred mostly in the morning towards the end of the basking period, but had a broad thermal range (27.5 to 35.7 C). 7. The range of body temperatures during feeding was broad (25.3-38.5 C), but that of foraging was much narrower (34.3-38.7 C).

Predatory Behaviour of Young Turquoise-Browed Motmots, Eumomota Superciliosa

Abstract: Nine young hand-reared motmots were tested for their responses to still and moving models of prey. The birds were given two series of cylindrical models. Series A bore various combinations of 4 cues: ink eye, pin eye, neck and motion. The birds responded significantly to every one, but motion was by far the most highly directing cue tested. Series B bore various colours and patterns, both as solidly coloured models and as present only on one third (either middle or end). The results from the solidly coloured models show (a) the birds were not inhibited by any plain colour tested; (b) they tended to ignore a camouflaged model; and (c) they showed strong aversion to a pattern that resembled a coral snake. The results of the coloured section models indicate that motmots are attracted to the dissimilar section only when it is one of the ends. This attraction to the different end, plus the highly directed response to motion, are probably sufficient to enable motmots to take small vertebrates such as lizards quickly and efficiently.