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Showing papers in "Behaviour in 1982"


Journal ArticleDOI
TL;DR: Time spent looking varied with position within the group; this effect was strongest in closed habitats, where central animals tended to scan least and feed most, and within species, animals inclosed habitats, those with dense vegetation, tended to spend more time in looking than did animals in the open.
Abstract: African antelope may devote a large proportion of their foraging time to looking around. The factors affecting such vigilance behaviour are examined for grazing antelope, five species being studied in detail. The proportion of time spent looking decreased as species body weight increased. Within species, animals in closed habitats, those with dense vegetation, tended to spend more time in looking than did animals in the open. There was some evidence that vigilance, presumably for predators, was shared by group members, but in one species, impala, vigilance apparently increased with group size and with proximity to neighbours. Time spent looking varied with position within the group; this effect was strongest in closed habitats, where central animals tended to scan least and feed most. Vigilance increased as feeding success decreased, partly due to mutual interference between looking and feeding. The possible social, foraging and predator-detection values of vigilance are discussed. A simple model is introduced to help explain the effects of cover and to facilitate further discussion.

326 citations


Journal ArticleDOI
TL;DR: The absence of unequivocal support for the importance of antlers in defence against predators, in heat regulation, in assessment between rivals and in attracting mates leaves open the possibility that, despite their bizarre appearance, antlers evolved as weapons and are retained by selection because of their function in intra-specific combat.
Abstract: 1. This paper reviews evidence for five functional explanations of the evolution of antlers in male cervids: that they are used as weapons in fights; that they allow individuals to defend themselves against predators; that they act as heat radiators during their period of growth; that they advertise an individual's fighting ability and allow males to assess each other without fighting; and that they increase the chances that a male will be selected as a mate by females. 2. There is extensive evidence that antlers are used in fights between competing males. Contrary to some suggestions in the literature, fights are regular during the breeding season and can be damaging. In species where fighting behaviour has been studied in detail, antlers have proved to be effective weapons of defence and offense, and there is no systematic evidence to support the suggestion that antler-less males (hummels) are more successful in competition for females than antlered stags. 3. Though male deer sometimes use their antlers in defence against predators, the absence of antlers in females of most species suggests that this is not their principal function. Nor does it seem likely that antlers evolved as heat-regulating mechanisms - in some species, they are grown during the winter months and there is no tendency for them to be larger in tropical species than in temperate ones. 4. Despite many suggestions, there is no conclusive evidence that males assess each other by their relative antler size and most measures of antler size and shape are not closely correlated with dominance or fighting ability. Nor is there firm evidence that females selectively mate with large-antlered males. 5. The absence of unequivocal support for the importance of antlers in defence against predators, in heat regulation, in assessment between rivals and in attracting mates leaves open the possibility that, despite their bizarre appearance, antlers evolved as weapons and are retained by selection because of their function in intra-specific combat.

257 citations


Journal ArticleDOI
TL;DR: Analysis of the observed patterns of two forms of putative altruism among adult female members of a group of captive bonnet macaques (Macaca radiata) indicates that both kinship and dominance rank influence the distribution and rate of these behaviors.
Abstract: Analysis of the observed patterns of two forms of putative altruism (grooming and coalition formation) among adult female members of a group of captive bonnet macaques (Macaca radiata) indicates that both kinship and dominance rank influence the distribution and rate of these behaviors. Females groom their adult relatives more often and more reciprocally than they groom unrelated females of similar ranks. In addition, females are more likely to support their relatives than nonrelatives and are likely to incur greater risks when they do so. Grooming and coalition formation do not occur exclusively among kin. Females primarily groom higher ranking females and support unrelated females against females lower ranking than themselves. Although females do not preferentially support unrelated females that groom or support them most, they do refrain from harassing lower ranking females that are currently grooming them or a female higher ranking than themselves. Thus, by grooming a higher ranking female a female reduces the probability that she will be harassed by other females. The relationship of these results to predictions derived from several different sociobiological hypotheses is discussed.

233 citations


Journal ArticleDOI
TL;DR: This 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 and size of repertoire is not related to male age.
Abstract: This 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.

232 citations


Journal ArticleDOI
TL;DR: In this article, a method for investigating the behavioral sequences used in forming dominance hierarchies is presented, and the results suggest that hierarchy formation can be best viewed as a developmental process where preceding dominance interactions influence succeeding ones.
Abstract: A method for investigating the behavioral sequences used in forming dominance hierarchies is presented. There are four possible sequences for the formation of the first two dominance relationships in groups of three individuals (triads). Designating the winner in the first relationship formed as the initial dominant, the loser as the initial subordinate, and the animal not involved as the bystander, the four possible sequences are: (1) the initial dominants goes on to dominate the bystander (Double Dominance), (2) the bystander later dominates the initial subordinate (Double Subordinance), (3) the bystander later dominates the initial dominant (Bystander Dominates Initial Dominant), and (4) the initial subordinate later dominates the bystander (Initial Subordinate Dominates Bystander). Although each sequence has an equal probability of occurrence if dominance relationships are formed randomly, two of the sequences have different implications for the formation of the empirically common linear and near linear hierarchies than the other two. Linear and near linear hierarchies are, by definition, composed of all or nearly all triads with transitive dominance relationships (A dominates B, B dominates C, and A dominates C), while hierarchies far from linearity have many triads with intransitive relationships (A dominates B, B dominates C, and C dominates A). Double Dominance and Double Subordinance sequences guarantee the formation of triads with transitive dominance relationships, but the other two sequences can give triads with either transitive or intransitive relationships. Linear and near lincar hierarchies are ensured, therefore, by a preponderance of Double Dominance and Double Subordinance sequences in the component triads of larger groups. In an application of the method developed, sequences of dominance relationships formed in groups of three and four chickens were analyzed. In both experiments Double Dominance and Double Subordinance composed the overwhelming majority of all sequences - 91 % in triads and 87 % in tetrads. A further set of results indicated that intransitive relationships were common in "constructed" triads where chickens met only as component pairs and not in "real" triads where all three met together at the same time. These results suggest that hierarchy formation can be best viewed as a developmental process where preceding dominance interactions influence succeeding ones. This view was characterized as the "jigsaw puzzle" model of hierarchy formation, and it was contrasted with the more classical approach of explaining hierarchy structures by differences in the individual characteristics of group members. Many species beside chickens form linear and near linear hierarchies, and it was hypothesized that Double Dominance and Double Subordinance sequences also compose the majority of sequence occurrences in many of these species. The data available for other species were reviewed and offered tentative support for the hypothesis.

184 citations


Journal ArticleDOI
TL;DR: In this article, it is argued that it is usually best to choose that bout criterion which leads to the fewest within and between bout intervals being assigned to the wrong category, and other possible criteria are considered.
Abstract: Some problems in using log survivor functions to split behaviour into bouts are outlined. It is argued that it is usually best to choose that bout criterion which leads to the fewest within and between bout intervals being assigned to the wrong category. A way of doing this is illustrated and other possible criteria are considered. The influence of misassignment on data analysis is discussed and it is argued that where this is substantial analysis in terms of bouts may not be useful.

170 citations


Journal ArticleDOI
TL;DR: The ability of the pups to anticipate the nursing and the their thermoregulatory self-sufficiency may contribute to shortening the time rabbit does must spend in the nest.
Abstract: Domestic rabbit pups (22 litters of 6 pups each) were raised in plexiglass nest boxes, and their behaviour was studied under various experimental conditions during the first 14 days of life. 1. Rabbit pups show a stereotyped pattern of behaviour closely associated with the once daily nursing visit of the doe until they start to leave the nest on day 13. 2. One to two hours before nursing pups group tightly together and become exposed from the nest material. In young litters these behaviours appear to improve access to the doe's belly and to shorten the time the doe spends in the nest. 3. Rabbit pups are unusual in that they display a vigorous burst of post-nursing activity, i.e. simultaneous urination followed by digging and burrowing around the nest. This activity is triggered by the nursing act and appears to contribute to thermoregulatory efficiency as an insulating cover is quickly regained. 4. Within about 30 minutes pups reaggregate and remain well covered until the next nursing time. 5. The anticipatory uncovering appears to represent a circadian rhythm, and not to be simply due to hunger, as demonstrated in isolated litters deprived of one nursing. 6. Presumably the less time wild does spend in the nursery burrow the less chance there is of predators trapping them or finding the young. The ability of the pups to anticipate the nursing and the their thermoregulatory self-sufficiency may contribute to shortening the time rabbit does must spend in the nest.

151 citations


Journal ArticleDOI
TL;DR: The lauten Rufe der Roten Brullaffen (Alouatta seniculus) wurden wahrend eines Jahres in vier nachbarlichen Gruppen, deren Territorialgebiete sich uberschnitten, beobachtet as mentioned in this paper.
Abstract: Die lauten Rufe der Roten Brullaffen (Alouatta seniculus) wurden wahrend eines Jahres in vier nachbarlichen Gruppen, deren Territorialgebiete sich uberschnitten, beobachtet. Obwohl die Brullaffen aus verschiedenen Anlassen brullten, waren mindestens 94.2% der Rufe jeder der beobachteten Gruppen wahrend des Tages gegen zu nahe, sichtbare Affen gerichtet, besonderes gegen solitare Tiere und gegen nachbarliche Gruppen. Mannchen, die in der eigenen Gruppe keine Konkurrenz hatten, zeigten erheblich hohere Brullraten wahrend des Tages, als solche, die Konkurrenten in ihrer Gruppe hatten. Bei Begegnung verschiedener Gruppen brullten die in geringerer Anzahl vertretenen Mannchen derjenigen Gruppe wesentlich haufiger, als die der Gruppe, die mehr Mannchen aufwies. Diese Beobachtungen zeigen an, dass die lauten Rufe der Roten Brullaffen zur Einschatzung ihrer Gegner verwendet werden, unter Vermeidung alternativer energieaufwendiger Jagden und Kampfe. Es wird vorgeschlagen, dass die Hauptfunktion des Gebrulls der Roten Brullaffen dazu bestimmt ist, die solitaren sowie die untergeordneten Mannchen in den verschiedenen Nachbargruppen von jedem Versuch abzuhalten, sie zu vertreiben und zu ersetzen.

144 citations


Journal ArticleDOI
G.A. Zweers1
TL;DR: The existence of a cerebral comparator-selector mechanism was assumed to describe decision making processes during the adjustment of the pecking system at the start of each step, which has the possibility to adapt each step to either the position and/or the size of the seed.
Abstract: 1. The pecking behaviour of pigeons is described from a frame-by-frame analysis of high speed films and X-ray motion pictures. 2. Each pecking scene has four discrete steps. These steps run from the fixation of the head above the seed to (1) the grasp of the seed by the beak tips to (2) the catching of the seed at the rictus level to (3) the positioning of the seed along the caudal palate to (4) its arrival in the rostral oesophagus. The bird is able to stop the sequence at the very beginning of each step. For example by a refusal to continue after the final fixation, by dropping the seed after the grasp, by ejecting it after the rictus catch when the seed is positioned on the lingual base, and probably also by an ejection following the positioning along the caudal palate. If necessary, an adjustment of the system takes place, prior to each step. Such an adjustment positions the structural elements and/or the seed in the correct mechanical arrangement for the initiation of the next step in the sequence. These adjustments are the preliminary approach at the final fixation, stationing at the grasp, repetition of transport through the mouth to the rictus level, and repetition of the transport type used in the pharynx. The bird has the possibility to adapt each step to either the position and/or the size of the seed. The final approach (step 1) can be a scooping, a straight or a swinging approach of the head depending upon the seed's position, while simultaneously the type of beak opening is adapted to the seed's position and the gape size to the seed's size. Transport through the mouth (step 2) is for a small seed a slide-and-glue mechanism by which the seed is adhered to the tongue and is carried to the rictus level. Usually large seeds are transported by the catch-and-throw mechanism. Intermediate types also occur. For small seeds transport to the caudal palate (step 3) is also a slide-and-glue mechanism, in which the lingual base serves as the adhering element. When large seeds are transported a head jerk is added to this mechanism. Transport into the oesophagus (step 4) for small seeds is a scraping mechanism of the ventral pharyngeal valves which are erected when they are in front of the seed prior to their retraction. An extra laryngeal transporting cycle and head jerk occur when large seeds are swallowed. 3. The slide-and-glue mechanism is extended by prediction of position and structure of glands deduced from the mechanical requirements of the mechanism. After comparison of the deduced glands with a microscopic and scanning electron microscopic analysis of the mouth and pharynx, the position and the structure of the gl. mandibularis anterior, the gl. mandibularis posterior, the gl. lingualis superior, the gl. lingualis inferior and the gl. palatina posterior externa were found to correspond with the prediction. 4. The existence of a cerebral comparator-selector mechanism was assumed to describe decision making processes during the adjustment of the pecking system at the start of each step. This is most clearly shown during stationing, which is a repositioning of the seed after the grasp. The registered position of the seed is compared with a pre-set cerebral template and after the comparison a selector recruits either mechanical units for a positive output (a head jerk and a gape cycle) transporting the seed somewhat caudad, or a negative output (a gape cycle and a lingual cycle) transporting the seed rostrad. 5. The close relationship between the particular positioning of the sensory units and the necessarily coupled recruitment of a set of mechanical units is analysed. For example, during final fixation the visual information must be gathered for the complete composition of the final appraoch. 6. From the stereotyped appearance of parts of the pecking behaviour it is shown that pecking better viewed as a variable sequence of fixed action patterns rather than just one such a pattern, by handling coupling of mechanical units as a constraint resulting from mechanical construction, mechanical operation, positioning of sense organs, availability of neuronal circuits and necessity to learn optimal combination of available mechanical units. Further, it is shown that the shift of the pigeon's food preference to larger sized seeds after trigeminal deafferentation can be explained as a preference for a catch-and-throw mechanism. Finally, it is shown that a partial refinement of an optimal foraging strategy is found even at the lower levels of organization of pecking.

127 citations


Journal ArticleDOI
TL;DR: Repeated mating, rather than a preference for sexually competent males, might function to ensure fertilisation in female sheep and perhaps in other ruminants.
Abstract: TRIVERS (1972) proposed that females may choose to mate with males of high sexual competence (the ability to supply sufficient sperm for fertilisation). This hypothesis was tested by allowing ewes in oestrus to choose between four tethered adult rams, two of high and two of low semen quality. Contrary to the hypothesis, ewes did not prefer rams of higher semen quality and, even though frequent mating can depress the fertilising ability of ram semen, the attractiveness of each ram to oestrous ewes was not lowered by frequent ejaculation. Also, in contrast to TRIVERS' suggestion, semen quality and male courtship vigour were not consistently related either between or within individual rams. Ewes mated repeatedly during oestrus, receiving nearly six ejaculates each on average, and over two thirds of ewes mated with more than one ram. Repeated mating, rather than a preference for sexually competent males, might function to ensure fertilisation in female sheep and perhaps in other ruminants.

94 citations


Journal ArticleDOI
TL;DR: 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.
Abstract: Sexually 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

Journal ArticleDOI
TL;DR: It is argued that top ranking birds are more conservative, and that it benefits them as they have relatively more to lose and less to gain by being exploratory, while the converse is true for mid or low ranking birds, which may benefit by exploiting resources outside the reach of the high ranking birds.
Abstract: The response of six groups of captive, handreared jackdaws, Corvus monedula L. (Aves), to a novel space was tested. Birds were tested in groups and were free to make contact with the novelty or remain in a familiar area. The individual manner of response was related to the social position of the individual. i) Exploratory behaviour occurred in bouts. Familiarization with the novelty was mostly gradual, but in some groups after an initial delay, the entire group began to explore and then to enter the novel space very rapidly ("avalanche"). ii) In each group one or two birds performed most of the early exploration, and termed "initiators". iii) The initiator in each group was distinguished from all others by duration and by frequency measures. Both for approach and for entering of the novel space (a) birds that scored high on the frequency measure, scored high also on the duration measure, (b) birds that scored high on either measure, for the approach, were the most likely to score high on that measure for the entering. iv) In all six groups the "initiators" were sociall mid or low ranking birds. v) Top ranking birds were distinguished from all others by the combination of two features; (a) they did not act as initiators, and (b) they were not the last to peak in their duration inside the novel space. It is argued that top ranking birds are more conservative, and that it benefits them as they have relatively more to lose and less to gain by being exploratory. The converse is true for mid or low ranking birds, which may benefit by exploiting resources outside the reach of the high ranking birds.

Journal ArticleDOI
TL;DR: It is concluded that early experience influenced the sexual preference of females and that they respond to activity differences of males as well as the significance of social displays of males for pair-formation.
Abstract: The sexual preference of mallard females exposed in early life to individuals of either a white or a wild strain was examined in tests in which an individual female was separated by wire from two males, one on either side of the cage. One male was of the same strain as that with which the female was reared (RS male), the second of the other type (NRS male). Inciting to a male by a female was used as the main measure of her preference; inciting to one male was positively correlated with overt aggression directed to the other male. Most females showed a preference for RS males; though this was more often the case with females reared socially with conspecifics than with those which had visual and acoustical contacts only in their early life. Females also tended to prefer the male most interested in her, as expressed by the male's approach, following and staying near. No evidence was obtained that females preferred males belonging to her own strain. Contrary to earlier views it is concluded that early experience influenced the sexual preference of females and that they respond to activity differences of males. Females showed no indications of being able to recognize and respond to the normal nuptial plumage of males independently of such experience. Implications of our findings for pair-formation in nature and the significance of social displays of males for pair-formation are discussed.

Journal ArticleDOI
TL;DR: The results demonstrated how improved post-fledging survival was achieved for juvenile seabirds feeding in the flocks, and support the interpretations put forth by others to explain delayed maturity, reduced clutches in younger birds and prolonged parental care, all characteristic of seab birds.
Abstract: Multispecies feeding flocks of seabirds were studied in Barkley Sound, British Columbia. The flocks occurred during the post-breeding dispersal of migrant adult and juvenile seabirds. A consideration of comparative foraging success indicated that juvenile seabirds were less skilled at locating and capturing prey. Juveniles did not initiate flocks, were less adept at finding food, and had lower feeding success rates. The juveniles appeared to compensate for these inadequacies by using a different foraging strategy than adults. They increased the amount of time spent feeding and appeared to be more attracted to the presence of other feeding birds. Juveniles were less able to recognize good potential feeding areas and accessible food items. Juveniles had a greater tendency to loaf on the centrally located terrestrial loafing sites, thus increasing their chances of sighting feeding flocks. Our results demonstrated how improved post-fledging survival was achieved for juvenile seabirds feeding in the flocks. Our findings support the interpretations put forth by others to explain delayed maturity, reduced clutches in younger birds and prolonged parental care, all characteristic of seabirds.

Journal ArticleDOI
TL;DR: The infective stage juveniles of Neoaplectana carpocapsae, a parasitic nematode of insects, was found to aggregate at point sources heated to temperatures of only 0.3°C or less above ambient in either light or dark conditions.
Abstract: 1. The infective stage juveniles of Neoaplectana carpocapsae, a parasitic nematode of insects, was found to aggregate at point sources heated to temperatures of only 0.3°C or less above ambient in either light or dark conditions. 2. The nematode also aggregated in response to heat conducted from a wax moth larva (about 0.3°C above ambient) in the absence of CO2 or chemical gradients. 3. The responses to heat sources (1° above ambient) occurred over a wide range of ambient temperatures. 4. The apparent response of the nematode to light is at least in part caused by effects of heat from light absorption by the agar medium and nematode. 5. The response to temperature appears to function in host location especially at close range from (within a few mm) the insect.


Journal ArticleDOI
TL;DR: In a free-ranging group of male red deer on the Isle of Rhum, Scotland, that showed a strong dominance hierarchy, the consequences and causes of high social rank were investigated, suggesting that body size is important in achieving high rank.
Abstract: 1. In a free-ranging group of male red deer (Cervus elaphus L.) on the Isle of Rhum, Scotland, that showed a strong dominance hierarchy, the consequences and causes of high social rank were investigated. 2. The reproductive success that individuals achieved in the autumn mating season correlated directly with the rank that they held in the social group in the previous winter. A causal interpretation of this association is suggested by the following results. 3. Rank was not related to age or to antler length in mature stags, so these factors could not be confounding the association. 4. Rank was related to age in young stags, and to a measure of early physical development, suggesting that body size is important in achieving high rank. Body size may also independently affect rutting success. Similarly, experience of winning interactions may influence both social rank and reproductive success. However, body size and experience are likely themselves to have been affected by rank during development, contributing to divergence among individuals of the same age. 5. Rank rarely changes among individuals of the same age, so there will be lifetime differences in rank-related advantages gained.

Journal ArticleDOI
TL;DR: The results of this work are used to draw up the 'rules of movement' for male and female adult D. plexippus and the biological significance of these rules for the resulting patterns of movement and resource usage are discussed.
Abstract: [1. Interactions among flying butterflies, Danaus plexippus, and various densities and dispersions of their milkweed food-plants, Asclepias spp., have been studied using a continuously recording tracking device. 2. Study areas comprising within-patch and edge plants and areas with no plants were not treated uniformly by the butterflies. Regions with plants were visited more frequently than those without and the greatest range of behavioural activities, basking, feeding and ovipositing, occurred about the plants themselves. There was also a geographical bias in usage by both sexes. 3. Distributions of straight line headings of butterfly tracks (i.e. lines joining the first and last points of a recorded track) did not differ from uniformity for either males or females. 4. Incident angles for females but not for males were significantly biassed geographically. 5. Males divided their time equally between flying and pausing and their pauses were made up equally of feeding and basking. 6. Females spent 25% of their time flying and 75% pausing, these pauses comprising approximately 75% basking, 10% egg-laying and 15% feeding. 7. Transitions between particular behavioural states were not all equally likely for females. An oviposition was most likely to be followed by another oviposition or basking; a bask by an oviposition. 8. The mean vectors of tracks in the horizontal plane based on an analysis of 0.75 s fixes along the continuous tracks had a mean direction (R1) of 0.37 for males and 0.22 for females with associated mean angle (ζ values of 0.98 and 1.04 respectively (statistics after BATSCHELET, 1965). 9. There was much less movement in the vertical plane with a mean absolute angle of turn of 8.5° (SD = 13.75) for males, and 12.9° (SD = 19.64) for females. 10. Speed of movement based on the distances moved between successive fixes was 2.38 m/s (SD = 1.15) for males and 1.43 m/s (SD = 0.54) for females. Males moved significantly faster than females. 11. The signs of angles turned through (i.e. left hand vs right hand turns) in successive segments of track were independent both at the first order (two segments) and third order (three segments) level, in both sexes. 12. Move lengths showed significant differences from homogeneity at both first and second order level when the moves were classified as above or below average for each sex. 13. Both sexes were more directional and faster when flying in the open than when within patches of food-plants. Differences in directionality among patch edge, patch centre, and single plant situations occur. The distribution of angles turned through is centred on 0° for males in all areas and is bimodal about 0° and ± 180° for females. This difference between sexes is ascribed to specific, food-plant related activities on the parts of the females. Other minor differences in flight patterns in different parts of the study area are noted. 14. The results of this work are used to draw up the 'rules of movement' for male and female adult D. plexippus and the biological significance of these rules for the resulting patterns of movement and resource usage are discussed., 1. Interactions among flying butterflies, Danaus plexippus, and various densities and dispersions of their milkweed food-plants, Asclepias spp., have been studied using a continuously recording tracking device. 2. Study areas comprising within-patch and edge plants and areas with no plants were not treated uniformly by the butterflies. Regions with plants were visited more frequently than those without and the greatest range of behavioural activities, basking, feeding and ovipositing, occurred about the plants themselves. There was also a geographical bias in usage by both sexes. 3. Distributions of straight line headings of butterfly tracks (i.e. lines joining the first and last points of a recorded track) did not differ from uniformity for either males or females. 4. Incident angles for females but not for males were significantly biassed geographically. 5. Males divided their time equally between flying and pausing and their pauses were made up equally of feeding and basking. 6. Females spent 25% of their time flying and 75% pausing, these pauses comprising approximately 75% basking, 10% egg-laying and 15% feeding. 7. Transitions between particular behavioural states were not all equally likely for females. An oviposition was most likely to be followed by another oviposition or basking; a bask by an oviposition. 8. The mean vectors of tracks in the horizontal plane based on an analysis of 0.75 s fixes along the continuous tracks had a mean direction (R1) of 0.37 for males and 0.22 for females with associated mean angle (ζ values of 0.98 and 1.04 respectively (statistics after BATSCHELET, 1965). 9. There was much less movement in the vertical plane with a mean absolute angle of turn of 8.5° (SD = 13.75) for males, and 12.9° (SD = 19.64) for females. 10. Speed of movement based on the distances moved between successive fixes was 2.38 m/s (SD = 1.15) for males and 1.43 m/s (SD = 0.54) for females. Males moved significantly faster than females. 11. The signs of angles turned through (i.e. left hand vs right hand turns) in successive segments of track were independent both at the first order (two segments) and third order (three segments) level, in both sexes. 12. Move lengths showed significant differences from homogeneity at both first and second order level when the moves were classified as above or below average for each sex. 13. Both sexes were more directional and faster when flying in the open than when within patches of food-plants. Differences in directionality among patch edge, patch centre, and single plant situations occur. The distribution of angles turned through is centred on 0° for males in all areas and is bimodal about 0° and ± 180° for females. This difference between sexes is ascribed to specific, food-plant related activities on the parts of the females. Other minor differences in flight patterns in different parts of the study area are noted. 14. The results of this work are used to draw up the 'rules of movement' for male and female adult D. plexippus and the biological significance of these rules for the resulting patterns of movement and resource usage are discussed.]

Journal ArticleDOI
G.A. Zweers1
TL;DR: The application of a comparator model for the description of the stereotypy of the pecking behaviour for the drinking behaviour showed that the drinking swallowing cycle and the three types of eating swallowing cycles were basically similar and a possible evolutionary scenario for the double-suction mechanism was discussed.
Abstract: 1. The consummatory part of the drinking behaviour of pigeons is studied by a frame-by-frame analysis of high-speed films and X-ray motion pictures. 2. A double-suction or vacuum-pump model is formulated for the mechanics of drinking. Consummatory drinking is a series of similar movement cycles, each transporting one dose of water into the oesophagus. The swallowing movement cycle shows five phases: 1, capillary action of the beak tips; 2, lingual suction; 3, pharyngeal preparation; 4, pharyngeal suction; and 5, oesophageal collection. A double build up of an area of low air pressure occurs. As a result of the retraction of the tongue in the mouth (acting as a piston in a cylinder) low air pressure develops in the buccal cavity and water is sucked into the mouth. Secondly, a lower air pressure area develops in the pharynx as a result of a depression of its floor, so that the water in the mouth is given a momentum caudad, by which it is forced over the larynx into the oesophagus. Neither peristaltic action, nor an alternative lower air pressure area is recorded in the oesophagus. The collection of the swallowed water at the lowest place occurs by gravity. 3. Using the mechanical requirements of the double-suction model the presence and distribution of glands was predicted. As predicted the following glands were found: the gl. lingualis superior et inferior, the gl. mandibularis anterior et posterior, the gl. palatina posterior externa, the gl. cricoarytenoidea and the gl. sphenopterygoidea. 4. The application of a comparator model for the description of the stereotypy of the pecking behaviour for the drinking behaviour showed that the drinking swallowing cycle and the three types of eating swallowing cycles were basically similar. The difference, apart from those of amplitude, was the coupling of the erection of the ventral pharyngeal valves to the pro- and retraction of the linguolaryngeal apparatus. The erection occurs during drinking at the very start of the protraction, but during pecking at the start of the retraction. Further, the consummatory act of drinking is composed of some smaller fixed elementary movement units. These units are fixed for mechanocybernetical reasons. The decision points between these units though masked under normal conditions, were found at the start of the capillary phase and during the preparatory phase by experimental manipulation. 5. A possible evolutionary scenario for the double-suction mechanism is discussed. It is suggested that: 1, the feeding system is maximized for food transport by using the slide-and-glue mechanism rather than using the ancestral catch-and-throw mechanism; that 2, the feeding system was maximized for water transport by using the double-suction mechanism rather than the ancestral tipping-up mechanism; that 3, high selection pressure on fast transport of seeds has occurred and that lack of selection pressure on fast drinking was probable. From this may be concluded that the slide-and-glue mechanism is the primar mechanism and the double-suction secondar. This secondary development is in itself a simple change of coupling of one of the subunits already developed as a pecking submechanism, the erection of the ventral pharyngeal valves. Although this recoupling falls completely within the mechanical boundary conditions of the slide-and-glue mechanism so that no reconstruction of the mechanical part of the system is required, nevertheless some strong selection pressure might be necessary for the evolution of a double-suction mechanism since valve erection was found to be part of different centrally coordinated fixed elementary units in swallowing both during eating and drinking. Such an external selection pressure could not be found. Finally, it was shown that for the explanation of the evolutionary scenario of suction drinking the "monistic adaptationist programme" was not sufficient, and a dualistic neodarwinian approach and a multifactor analysis were advocated.

Journal ArticleDOI
TL;DR: It is suggested that the nuptial coloration of male threespine sticklebacks be interpreted more generally as an indicator of the male's social and physiological status, emphasizing its intimidating effects as well as its aggression eliciting effects for rival males.
Abstract: 1. Territorial male threespine sticklebacks, Gasterosteus aculeatus, do not always attack an intruder (a dummy) with red undersides more than one lacking this feature even when it is presented within their own territory. Males in this study showed an overall tendency to bite a dummy without red undersides more than one with this feature during both simultaneous and serial presentations. 2. Considerable variation in attack rates exists between individual males, but whether or not a given male attacks the nonred dummy more appears to be unrelated to whether he exhibits high or low attack rates. 3. Males showed an increased attack rate after they acquired eggs in their nest, but the tendency for a male to attack the nonred dummy more than the red one appears to be unchanged after he acquires eggs. 4. It is suggested that the nuptial coloration of male threespine sticklebacks be interpreted more generally as an indicator of the male's social and physiological status, emphasizing its intimidating effects as well as its aggression eliciting effects for rival males. This is consistent with the observation that nuptial coloration is capable of increasing avoidance as well as attack in rival males and increasing sexual attractiveness to females.


Journal ArticleDOI
TL;DR: In mixed species flocks of lapwings andGolden plovers, lapwing net rate of energy intake was positively related to the number of conspecifics and the amount of time individuals spent crouching during feeding, but was unaffected by the presence of golden plovers.
Abstract: 1. In mixed species flocks of lapwings and golden plovers, lapwing net rate of energy intake was positively related to the number of conspecifics and the amount of time individuals spent crouching during feeding, but was unaffected by the presence of golden plovers. Plover net rate of energy intake, however, was positively related to crouching tendency, negatively related to the number of lapwings present but unaffected by the number of conspecifics. 2. Golden plovers appeared to join lapwing flocks because they could then crouch more and scan less. The independent negative effect of lapwing number may have been due to feeding interference when there were large numbers of lapwings relative to plovers. 3. When black-headed gulls joined a flock, both lapwings and plovers tended to crouch less and take smaller worms. However, in lapwings these changes appeared to reduce feeding efficiency but plover net rate of energy intake increased as a function of the gull: plover ratio. 4. When gulls were present, the effect of conspecifics on lapwing feeding efficiency disappeared and the presence of plovers had a negative effect. Conversely, in plovers the presence of conspecifics enhanced feeding efficiency and the negative effect of lapwing number disappeared. 5. The arrival of gulls resulted in a decrease in equilibrium lapwing number but no consistent, directional change in plover number. When gulls were present, lapwing number tended to decrease when large numbers of plovers arrived, but increase when small numbers arrived. Increased lapwing number had no significant directional effect on plover number. Changes in lapwing and plover energy intake and species numbers are interpreted in terms of feeding interference and 'dilution' of gull kleptoparasitism. 6. In the absence of gulls, there was no significant directional relationship between increased plover number and lapwing number, but the presence of plovers generally correlated with a reduction in lapwing number. Plover number, however, decreased when large numbers of additional lapwings arrived but increased with small numbers of arrivals. Changes in species energy intake and numbers here are interpreted in terms of feeding interference and time budget changes.

Journal ArticleDOI
TL;DR: Male blackbirds (Turdus merula) were confronted with modified and unmodified playback copies of their own songs presented within the birds normal territories and vocal responses of the birds were recorded and correlated to the playback songs in respect to pattern specificity (song matching) and time specificity (distinct latencies).
Abstract: Male blackbirds (Turdus merula) were confronted with modified and unmodified playback copies of their own songs presented within the birds normal territories (Fig. 1). The vocal responses of the birds were recorded and correlated to the playback songs in respect to pattern specificity (song matching) and time specificity (distinct latencies). The following results were obtained: 1. The initial element of a song played a key role. If it was erased or masked by a pre-element the birds did not match the playback copies. In contrast erasure of the second element or the rest of the song following the second element did not affect song matching (Figs 3, 4). 2. The second element had an additional effect. The matching preference increased with a shortening of the pause between the first two elements, it decreased when the second element was substituted by an alien element (Figs 2, 3, 4). 3. A series of initial elements (identical or different element types) led to an inhibition of song matching. In contrast, copies including a doubling of the first two or three elements had a supernormal effect (Figs 4, 5). 4. Three types of song responses could be discriminated: in type I responses (latency: L = 0.1 s) the birds did not match the stimulus; in type II responses (L = 0.25-0.8 s) song matching was preferred; type III responses (L > 1 s) showed no time specificity towards onset of playback songs, but still a preference of song matching (Figs 6, 7). 5. In general, late matching responses (type III) were less preferred than rapid ones (type II) but the effects of different song modifications remained the same. 6. In type II responses, the temporal triggering of the reply and the recognition of the heard song class were not completely linked. In contrast to the neglectable influence of the third elements they were well able to trigger a reply (Fig. 9).

Journal ArticleDOI
TL;DR: The ability to sing multiple song types may aid males in stimulating females to come into reproductive condition and then copulate, and this result occurred because females habituated to the repeated presentation of a single song type, and showed a recovery in response when song types were switched.
Abstract: Male and femal swamp sparrows (Melospiza georgiana) were tested for differential reaction to four acoustically distinct swamp sparrow song types. We tested males by playing bouts of single song types from speakers placed on male territories. Males gave the same kinds of aggressive responses to each of the four song types, and there were no quantitative differences in the strengths of the responses to the different types. In the experiments with females, we played songs to captive female swamp sparrows previously treated with estradiol, and measured response in terms of copulation solicitation display. Females displayed in response to all four song types, and again there were no quantitative differences in the strength of response to the different types. We conclude that different swamp sparrow song types do not convey different messages to either male or female listeners. Although the identity of the particular song type presented was unimportant, the number of types presented was important, at least to females. Females responded more strongly overall to bouts of four song types than to bouts of single song types. This result occurred because females habituated to the repeated presentation of a single song type, and showed a recovery in response when song types were switched. We conclude that the ability to sing multiple song types may aid males in stimulating females to come into reproductive condition and then copulate.

Journal ArticleDOI
Amotz Zahavi1
TL;DR: The vocal signal is an indicator of the posture and movement of the signaller at the time of vocalization, hence it reveals, by an additional modality, information about the P.M. of theSignaller.
Abstract: 1. The vocal signal is an indicator of the posture and movement (P.M.) of the signaller at the time of vocalization, hence it reveals, by an additional modality, information about the P. M. of the signaller. 2. The vocal signal is a reliable indicator of the motivation of the signaller because cheating would incur the cost of changing the P.M. away from the optimal P.M. for the real motivation. 3. Certain vocal patterns discriminate better than others small differences in the motivation of individuals. 4. The vocal signal which conveys a certain motivation is dependent on a) the strategy used to solve a particular conflict; b) the kind of reliable information which may resolve the conflict; c) the P.M. which conveys best such information; d) the vocal pattern which enables the listener to distinguish between signallers which differ slightly in their motivation.

Journal ArticleDOI
TL;DR: In this article, the relative variability of 204 different feature variables of the wet-my-lips call of the male migratory quail was calculated and analyzed, and the results show that the most stereotyped features (C.V. < 0.015) are those which constitute the rhythm of this call.
Abstract: Based 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.

Journal ArticleDOI
TL;DR: Das Scheinkampfen wurde in einer halb-wilden Bos indicus Herde beobachtet, durch das gegenseitige Kraftemessen soziale Rangbeziehungen entwickelt and bekraftigt.
Abstract: [Ein Scheinkampf zwischen zwei Rindern setzt sich aus folgender Verhaltenssequenz zusammen : 1. Aufforderung; hierbei wird die Spielbereitschaft durch freundlichbeschwichtigende Ausdruckweisen kundgegeben. 2. Hornspiel; die beiden Partner reiben sich gegenseitig mit der Stirn und forkeln behutsam mit den Hornern. 3. Gegenseitiges hin-und-her Schieben. 4. Plotzliches voneinander Ablassen ohne weitere Konsequenz. Scheinkampfen wurde in einer halb-wilden Bos indicus Herde beobachtet. Es kam bei Tieren beiderlei Geschlechts und aller Altersklassen vor. Kalber begannen in der zweiten Lebenswoche miteinander scheinzukampfen. Sie waren ofters in Scheinkampfe verwickelt als erwachsene Rinder. Zwischen den Adulten und den Kalbern kam es nur selten zu Scheinkampfen; diese beschrankten sich fast ausschlieslich auf Mutterkuhe und deren Nachkommen. Ab dem vierten Lebensmonat beteiligten sich mannliche Tiere wesentlich mehr am Scheinkampfen als weibliche. Scheinkampfe zwischen den Geschlechtern kamen selten vor. Die ontogenetische Entwicklung des Scheinkampfens zwischen mannlichen Tieren erwies sich als bimodal: Zwischen dem vierten und zehnten Monat ergab sich eine hohe Aktivitat, der zwischen dem 11. und 15. Monat ein deutlicher Abfall folgte. Ein zweiter, sehr auffallender Anstieg stellte sich zwischen dem 16. und 20. Monat ein. Die Entwicklung des Scheinkampfens erwies sich als unabhangig von jener aggressiv motivierter Verhaltensweisen. Zu Scheinkampfen kam es vornehmlich zwischen Partnern des gleichen Geschlechts, die sich sowohl im Alter als auch im sozialen Rang nahestanden. Es wurde gefolgert, das das Scheinkampfen ein typisch mannliches, nicht aggressiv motiviertes Verhalten ist. Es dient dazu, Bewegungsablaufe zu uben, die im Ernstkampf verwendet werden. Gleichzeitig werden im freundlichen Scheinkampf aggressive spannungen zwischen Herdenkumpanen abgebaut und durch das gegenseitige Kraftemessen soziale Rangbeziehungen entwickelt und bekraftigt., Ein Scheinkampf zwischen zwei Rindern setzt sich aus folgender Verhaltenssequenz zusammen : 1. Aufforderung; hierbei wird die Spielbereitschaft durch freundlichbeschwichtigende Ausdruckweisen kundgegeben. 2. Hornspiel; die beiden Partner reiben sich gegenseitig mit der Stirn und forkeln behutsam mit den Hornern. 3. Gegenseitiges hin-und-her Schieben. 4. Plotzliches voneinander Ablassen ohne weitere Konsequenz. Scheinkampfen wurde in einer halb-wilden Bos indicus Herde beobachtet. Es kam bei Tieren beiderlei Geschlechts und aller Altersklassen vor. Kalber begannen in der zweiten Lebenswoche miteinander scheinzukampfen. Sie waren ofters in Scheinkampfe verwickelt als erwachsene Rinder. Zwischen den Adulten und den Kalbern kam es nur selten zu Scheinkampfen; diese beschrankten sich fast ausschlieslich auf Mutterkuhe und deren Nachkommen. Ab dem vierten Lebensmonat beteiligten sich mannliche Tiere wesentlich mehr am Scheinkampfen als weibliche. Scheinkampfe zwischen den Geschlechtern kamen selten vor. Die ontogenetische Entwicklung des Scheinkampfens zwischen mannlichen Tieren erwies sich als bimodal: Zwischen dem vierten und zehnten Monat ergab sich eine hohe Aktivitat, der zwischen dem 11. und 15. Monat ein deutlicher Abfall folgte. Ein zweiter, sehr auffallender Anstieg stellte sich zwischen dem 16. und 20. Monat ein. Die Entwicklung des Scheinkampfens erwies sich als unabhangig von jener aggressiv motivierter Verhaltensweisen. Zu Scheinkampfen kam es vornehmlich zwischen Partnern des gleichen Geschlechts, die sich sowohl im Alter als auch im sozialen Rang nahestanden. Es wurde gefolgert, das das Scheinkampfen ein typisch mannliches, nicht aggressiv motiviertes Verhalten ist. Es dient dazu, Bewegungsablaufe zu uben, die im Ernstkampf verwendet werden. Gleichzeitig werden im freundlichen Scheinkampf aggressive spannungen zwischen Herdenkumpanen abgebaut und durch das gegenseitige Kraftemessen soziale Rangbeziehungen entwickelt und bekraftigt.]

Journal ArticleDOI
TL;DR: The foetal lamb's sound environment consists of intermittent low frequency sounds associated largely with the ewe's feeding and digestive processes and sounds such as vocalisations from the flock, human voices and other sounds from outside the mother.
Abstract: The sound environment of the foetal lamb was recorded using a hydrophone implanted a few weeks before term in a small number of pregnant ewes. It was implanted inside the amniotic sac and sutured loosely to the foetal neck, to move with the foetus. Results differ from those reported earlier for the human foetus: sounds from the maternal cardiovascular system were picked up only rarely, at very low frequencies and at sound pressures around, or below, the human auditory threshold. Other sounds from within the mother occurred intermittently and rose to a high sound pressure only at frequencies above about 300 Hz. Sounds from outside the mother were picked up by the implanted hydrophone when the external sound level rose above 65-70 dB SPL, and the attenuation in sound pressure was rarely more than 30 dB and, especially at low frequencies, usually much less. However, attenuation due to the transmission of sound through the body wall and other tissues tended to change from time to time. It is concluded that the foetal lamb's sound environment consists of (1) intermittent low frequency sounds associated largely with the ewe's feeding and digestive processes and (2) sounds such as vocalisations from the flock, human voices and other sounds from outside the mother.

Journal ArticleDOI
TL;DR: A detailed review of primate vocal behavior can be found in this article, where the authors reviewed some of the methodological advances which allowed them to achieve state-of-the-art performance.
Abstract: Research on primate vocal behaviour has shown it to be varied, complex and intricate; selected developments of particular interest are reviewed, and the methodological advances which allowed them are described. Primate repertoires are extensively graded, but this continuous variation may be perceived discretely by the animals: some species at least show categorical perception of their calls, which means that the lists of "calls" in the primate literature are largely misleading. In addition, some species show complex patterning which has yet to be properly understood. A rudimentary form of syntax and simple compounding of call meanings has been shown. It is now known that calls can convey population dialect and individual identity, and in certain cases can "refer" to classes of objects in a fashion analogous to that of words in speech. Calls normally give information on the caller's location, but may be specialised to avoid doing so or to do so better, where these are advantageous. Specialisation is also shown in perception, with neurally lateralised apparatus for processing of conspecifics' calls. Long distance propagation of certain calls is enhanced both by signal form and time and manner of delivery. Such calls are well suited for experimental study, and are now among the best understood. Function turns out to be more labile than form in evolution of vocalisations, with homologous calls serving different functions in close relatives; in addition, calls apparently identical in form may mediate several unrelated functions in a single species. Long-range calls are employed especially to coordinate movements where groups are dispersed in areas of low visibility, and in various different ways as components of intergroup spacing systems.

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TL;DR: Das Endresultat hat bewiesen, dass lebenswirtschaftliche Veranderungen einen merklichen Wechsel and eine neue Art of Konkurrenz erzeugcn konnen.
Abstract: Stegastas fasciolatus ist ein allesfressender "Damselfish", der aber in erster Linie von Tiefwasseralgen lebt. Er verteidigt seinen Lebensraum und greift manchmal die anderen Pflanzenfresser an. Wenn eingefangene Fische dem Cichliden Sarotherodon mossambica (Tilapia) ausgesetzt sind, zeigen sie wenig Angriffslust gegen diese Raubfischart, die sie nie vorher kennengelernt hatten. Die Theorie, dass die S. fasciolatus ihre Konkurrenzarten an ihren Fressgewohnheiten erkennen, haben wir bereits untersucht. Damselfische wurden Tilapia ausgesetzt, die trainiert waren, wie Pflanzenfresser oder Planktonfresser zu leben. Das Mas der Angriffslust gegen diese Tilapia und 2 Arten "Surgeonfische" wurde beobachtet. Die Erfahrungen mit planktonfressenden Tilapia ergaben wenig Unterschiercle, bis auf den Ruckgang der Angriffslust gegen andere Tilapia. Erfahrungen mit pflanzenfresscnden Tilapia haben zweierlei Arten von Veranderungen hervorgerufen. Erstens zeigte die Angriffslust gegen Tilapia eine allgemeine Ansteigerung. Zweitens anderte sich die raummassige Verteilung und der Effekt von Reizmitteln, besonders des futterns, qualitativ den Surgeonfischen gegenuber. Das Endresultat hat bewiesen, dass lebenswirtschaftliche Veranderungen einen merklichen Wechsel und eine neue Art von Konkurrenz erzeugcn konnen. Die Art der Veranderung zeigt sich in der Beobachtung der Bewegungen wahrend des Fressens, sei es mit oder ohne Konkurrenz. Weitere Beobachtungen ergaben vorlaufige Ergebnisse in Betracht auf Zusammenhang zwischen der Qualitat des Territoriums und der interspecifischen Angriffslust.