Showing papers in "Behaviour in 1980"

An Ecological Model of Female-Bonded Primate Groups

Abstract: 1. Multi-female groups of primates fall into two main classes, (a) female-bonded (FB) and (b) non-female-bonded (non-FB). A model is presented to account for the evolution of FB groups in terms of ecological pressures on female relationships. 2. The model suggests that FB groups have evolved as a result of competition for high-quality food patches containing a limited number of feeding sites. Groups are viewed as being based on cooperative relationships among females. These relationships are beneficial because cooperators act together to supplant others from preferred food patches. 3. Ecological data support the model for most FB species, but not for Theropithecus gelada or Colobus guereza, whose foods are not found in high-quality patches with limited feeding sites. Non-FB species conform to expectation, either because they do not use high-quality patches, or because feeding competition has disruptive effects during periods of food scarcity. 4. The behaviour of females differs as expected between FB and non-FB species in group movements and in inter-group interactions; in both contexts females are more involved in FB species. 5. Multi-male groups tend to be found in non-territorial FB species. The presence of several males per group is suggested to benefit females by raising the competitive ability of the group in inter-group interactions. 6. Competitive relationships among females are more strongly marked in FB groups than in non-FB groups. The model suggests that relationships in most FB groups are ultimately related to feeding competition.

Sexual Selection and the Evolution of Complex Songs Among European Warblers of the Genus Acr Ocephal Us

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

Social Behavior Patterns as Determinants of Reproductive Success in the Guppy, Poecilia Reticulata Peters (Pisces: Poeciliidae) an Experimental Study of the Effects of Intermale Competition, Female Choice, and Sexual Selection

Abstract: The reproductive success of competing male guppies, Poecilia reticulata, was measured and compared to various features of social behavior and secondary sexual coloration. The most important determinant of reproductive success was the rate at which a male courted females relative to those of other males. Males with higher display rates have a greater chance of encountering a receptive female and are preferred by females. Males adjust their display rate in such a way as to be just noticeably more active than a competitor, and inbred strains differ in the maximum rate at which males can court females. No other factor is able to offset the disadvantage of displaying at a relatively low rate. Sexual selection has resulted in the maximization of courtship activity in natural populations. If males court females with equal frequencies, those which also inseminate females through gonopodial thrusting without female cooperation have a selective advantage. Because poeciliid females store sperm, inseminations through gonopodial thrusting can reduce the reproductive success of competitor males which copulate only following a display. A mixed strategy of displaying and gonopodial thrusting is more successful than either pure strategy. The result is a mating system which partially ignores female choice mechanisms. Intermale aggresssion was found to be maladaptive. Males which displayed at higher rates than competitors were less successful if they were also more aggressive than the competitors, than when they were non-aggressive or the competitors were more aggressive. Males were not able to reduce a competitor's courtship display rate through aggression. It was hypothesized that the low level of aggression in natural guppy populations is attributable to the fact that variance in size of males is low and fights would be lengthy before a winner could be determined. This would subtract from time available for courtship, and female preference for high-displaying males would select against aggressive phenotypes. There was little evidence that conspicuousness of male coloration influences female choice of males. Dull males with high courtship display rates were significantly more successful than conspicuous males with low display rates. It was concluded that females prefer conspicuous males only if all males exhibit equal courtship display rates. The frequency of male color patterns in a population did affect reproductive success. Males with rare color patterns sired more offspring than expected given their frequency. The mechanism by which a rare male effect was achieved depended on the relative mating success of phenotypes in control populations (all phenotypes occurring with equal frequency). If a normally preferred phenotype was rare, females continued to prefer that phenotype over the common phenotype. If a normally unpreferred phenotype was rare, females mated with that phenotype in addition to the preferred phenotype, and the rare male effect was thus achieved by multiple inseminations. Females also tended to mate with more than one male in polymorphic populations, and it was concluded that certain female choice patterns with frequent multiple inseminations can maintain a polymorphism in addition to a pure rare male effect. It was hypothesized that courtship displays and conspicuous male coloration are sexually selected characters which evolved in response to the occupation of invariable habitats or specialized ecological niches by a sexually monomorphic ancestor with only gonopodial thrusting as a means of inseminating females. A subsequent reinvasion of variable habitats resulted in female choice mechanisms which maximize the level of heterozygosity of their offspring, thus resulting in polymorphic populations. The coloration of male guppies is a phenotypic cue which influences female choice in such a manner that they mate with those males with whom they most probably have the fewest genes in common.

Social Rank and Food Access in Red Deer Stags

Abstract: The behaviour of a free-living group of male red deer (Cervus elaphus L.) on the Isle of Rhum, Scotland, was studied throughout the year to investigate the relations between social dominance and food access. The study is based on the collection of agonistic interactions between members of the study group outside the rutting season. Analysis of these confirmed that dyadic dominance relationships summate to a very clear agonistic hierarchy, while seasonal changes in frequency and type of interactions suggested that rank in the hierarchy may affect access to food through direct feeding interference. This would constitute a selective advantage of the acquisition of high rank. A behaviour pattern in which a stag displaces a subordinate and takes over his feeding-site is proposed as a mechanism of direct feeding interference. It occurs throughout the year, but with a frequency closely related to changes in food availability and quality. The proportion of such interactions that an individual wins is related to his rank, so advantages gained from this behaviour would primarily benefit high-ranking stags. These are likely to consist of improved body condition and winter survival. The importance of high rank in obtaining access to limited food was supported by the results of a simple experiment providing a small area of fertilized grass. Most of the grazing in the area was due to the highest-ranking stag present at any time.

Time-Budgets of Camargue Horses Ii. Time-Budgets of Adult Horses and Weaned Sub-Adults

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

Breeding Season Time and Energy Budgets of the Polyandrous Spotted Sandpiper

Abstract: The study was conducted from early May to early August 1975-77 on a 1.6 ha island in north-central Minnesota. All breeding spotted sandpipers were colour-ringed. Time budgets were determined for 10 females and 23 males by instantaneous sampling (at 15-second intervals) of 10 predetermined behaviours. A total of 1,899 30-minute samples (2 birds each) yielded 308,817 data points when birds were visible. Terrestrial arthropod abundance was sampled by cylindrical sticky traps at 12 locations for 48 hours per week. Temperature, wind direction and velocity, and cloud cover were recorded at the time instantaneous samples were conducted. Basal metabolic rates were calculated separately for each sex as a function of body weight. Energy budgets were estimated by extrapolation from time budgets. Caloric and calcium content of principal food items and sandpiper eggs was determined with a Parr adiabatic oxygen calorimeter and a Perkin-Elmer atomic absorption spectrophotometer. During prelaying, females foraged more than males, preened less and flew less. During laying, females foraged, rested, and engaged in agonistic activity more than males. Males spent more time preening, flying, nest building and incubating than their mates. All behaviours differed between sexes during incubation as females spent more time than males in all activities except nest building and incubation. Sex differences were the result of differential strategies to maximize reproductive success and differing energy requirements due to size dimorphism and the energy costs of egg production. Time spent in all behaviours varied among stages of the breeding cycle due primarily to changes in foraging and incubation requirements. Foraging varied by time of day but the pattern of this variation changed among stages of the breeding cycle due principally to diurnal variation in incubation and brooding time. With the exception of the incubation period when only courtship and agonistic behaviour did not vary diurnally, most behaviours did not show diurnal variation. When females helped their mates, nests were incubated a greater proportion of the time than when males incubated alone. Terrestrial arthropod abundance exhibited 2 major peaks each year about 4 weeks apart. Each year a different territory produced the most food over the season as a whole. Time budgets varied among clutches, among territories, and among years but these dif ferences were largely explicable by changes in food abundance. Food abundance consistently influenced foraging time for both sexes. Other activities correlated less consistently with food abundance. Decreases in foraging time, due to higher food levels, were compensated for primarily by increasing time spent in maintenance activities. Temperature, wind, and cloud cover had less influence on time budgets than food abundance, especially for females. Eggs averaged 5.6 Kcal/g dry weight and 1.3 Kcal/g fresh weight. Each egg cost a female 17.8 Kcal to produce. On days of peak egg formation costs, this represented an increase of 94 % (prelaying) to 102 % (laying) in the daily energy expenditure (DEE) of females. For activities other than egg formation, foraging received the most energy expenditure during all stages of the breeding cycle except for males during incubation. Both sexes had minimal DEE's during the incubation period. A clutch of 4 eggs totaled 1.7 times a female's total body calcium. Analysis of principal food items indicated that it was unlikely that females totally relied on these organisms as a calcium source. Energy expended in foraging was typically lower during periods of food abundance than periods of food scarcity. DEE usually increased as food changed from abundant to scarce. Required foraging efficiencies (RFE) decreased as food abundance decreased, indicating that birds had to expend greater amounts of energy to obtain a given quantity of food as food levels dropped. For polyandry to evolve, males must assume most or all of the parental duties. Data of the present study support the hypothesis of EMLEN & ORING (1977) that a male increases his individual fitness by conducting most parental care because the low success rate of individual nesting attempts (due to factors such as high predation rates) places a high priority on the female's ability to provide replacement clutches for the male. A female can produce replacement clutches faster if freed from incubation duties, as this allows her more time to forage. Once male parental care has evolved, sequential polyandry can readily evolve where fewer replacement clutches are required (e.g., where predation rates are less than average) and "surplus" males are available.

Invasion of the Forest By an African Savannah Monkey: Behavioural Adaptations

Abstract: Tantalus monkeys, a race of the savannah species Cercopithecus aethiops, have invaded the cultivated forest of Bakossi in south-west Cameroon during the last seventy years and become important agricultural pests. The cultivated forest is a new habitat to which they are well adapted by virtue of their eclectic diet, their habit of foraging away from tall trees, their semi-terrestriality, their flexible group size and their cryptic nature. The indigenous related species of the rainforest are less able to exploit the changed habitat, probably because they are insufficiently terrestrial or cryptic and they typically forage among the trees that provide their refuge. As a result of their conflict with the farmers whose crops they raid, the forest tantalus monkeys contrast with conspecifics in the savannah by their less predictable ranging patterns, their quieter call repertoire, a striking and consistent male pattern of vigilance behaviour and their habit of hiding from dogs rather than giving the loud alarm calls that are invariably given where canids are not associated with man.

Chaffinch Song Types: Their Frequencies in the Population and Distribution Between Repertoires of Different Individuals

Abstract: In a population of chaffinches (Fringilla coelebs) some song types are produced by many individuals while others occur only in the repertoire of single individuals. This frequency distribution of song types fits that predicted from a model for the frequency of neutral alleles, suggesting that song types are copied at random rather than some being favoured over others. Both comparison with this model and computer simulations suggest that the "mutation rate" in song copying is around 15%, changes in this case arising either through immigration or because of inaccuracies in copying. Such a rate of change would also lead the songs present to change with time to much the same extent as we have found. No evidence could be found that particular combinations of song types tended to occur more often than expected in the same repertoire, suggesting that repertoires are built up by copying from more than one individual. Rare songs (those unique to a particular individual in the population) do, however, tend to cluster in the same repertoire, probably because some of the birds possessing them are immigrants. Repertoire size clusters at around 2-3 song types but is not significantly different from that predicted if birds can learn the same song type more than once so that their observed repertoire size is smaller than that which they actually possess.

Sexual Competition in Scatophaga Stercoraria: Size- and Density-Related Changes in Male Ability To Capture Females

Abstract: The behavior of males near the oviposition site of Scatophaga stercoraria is highly variable, being dependent on male size and on male density conditions. At low density males are often territorial with dominance relationships, the largest male often initiating high intensity attacks. At high densities attacks are much less intense, with more symmetrical interactions among males. Large males are most active under all density conditions. Absence of small males from high density pats, even though there is no apparent attempt to exclude these males, appears to occur for two reasons: Small males may suffer proportionately more harm in interactions than larger males, and success of these males in retaining captured females is extremely low, as shown by extreme differences in takeover rates relative to male size. My finding (BORGIA, 1980a, 1981) that large males are relatively more successful in capturing females under conditions where there are few pats can be explained in terms of these results. However, unlike predictions from avian mating system models, lower variants in male reproductive success occurs not because more powerful males actively exclude others from a more restricted resource base, but as an indirect effect of large males searching for mates. Differences in male behavior under varying density conditions, and by males of different size, show the extreme adaptability of male behavior in Scatophaga. These findings agree with ALCOCx's (1979) suggestion that insect behavior is much less stereotyped than is commonly believed.

Grooming in Norway Rats: the Development and Adult Expression of a Complex Motor Pattern

Abstract: In two experiments detailed observations and quantitative analyses were made of the development and adult expression of grooming in laboratory rats. In the first experiment, 5 litters of rat pups were observed each day from 0-28 days of age, and grooming movements were recorded on paper. Forepaw wipes of the nose appeared by Day 3, followed by eye wipes (Day 6) and ear wipes (Day 8). These movements were integrated into normal-appearing head grooming on Day 11. The mouth was used to groom posterior portions of the body beginning on Day 14 with the belly, and continuing subsequently with hip (Day 15), back (Day 18), and the anogenital region and tail (Day 20). Thus, these aspects of grooming followed a general cephalocaudal progression. In contrast, the development of scratching of the head and body, which began on Day 6, did not follow a systematic order. In the second experiment, 5 adult male rats were observed in glass aquaria, which also served as their living compartments, and bouts of grooming were recorded on videotape for later analysis. Sequential and spatial characteristics of movements were determined by replaying the videotapes in slow motion, while temporal characteristics were determined by a frame-by-frarne analysis of the tapes. This experiment revealed a cephalocaudal progression of acts within bouts of grooming: grooming usually began with the paw-lick- nose-wipe sequence and progressed from there to eye wipes and ear wipes. Mouthing of the torso followed, usually beginning with more anterior portions and terminating with more posterior portions. Scratching with the hindpaws was unpredictably interpolated into the grooming sequence. The experiment also revealed that transitions between grooming different parts of the body were predictable from the spatial and temporal characteristics of the grooming. That is, the last stroke in chains of nose, eye, or ear wipes was reliably slower than previous strokes in the chain, and also tended to be incomplete. Thus, the order in which grooming of specific body areas emerges during early development follows an anterior-posterior progression, and this progression closely parallels the sequence in which body areas are groomed by adult rats. Furthermore, in adults these movements obey specific temporal and spatial rules which can be used to predict transitions of grooming from one body area to the next. This parallel between the ontogenetic and adult expressions of grooming may reflect, respectively, the maturation and activation of genotypically determined, functional units in the central nervous system. In addition, theories now being applied to the problem of transitions between different motive systems (e.g., eating and drinking), may be extended to account for transitions within a motive system (e.g., from grooming of one part of the body to the next).

Courtship Behaviour of Nasonia Vitripennis (Hym., Pteromalidae): Some Qualitative, Experimental Evidence for the Role of Pheromones

Abstract: Chemical stimuli appear to play a role in the reproductive behaviour of the parasitic wasp Nasonia vitripennis. We produced qualitative evidence for their function a) in sex recognition (males discriminate conspecific males and females); b) in courtship (males appear to release a pheromone with the extrusion of their mouth parts during "head nodding") ; and c) in territorial behaviour (males mark the place where they have copulated; they may take up a residence in such a place over days).

Ritualization and the Evolution of Movement Signals

Abstract: It is suggested that the competition among individuals to display their advantage over others and the interest of individuals to display their motivation in a reliable way have been responsible for the evolution of ritualized signals. Small differences between displays can only be perceived against a standard mode of display. Experience is often needed to determine the nature of the variance which is displayed. It is suggested that the stereotyped ritualized species specific movements have evolved as a byproduct of the competition among individuals to display differences and not because of the advantage of displaying specific differences.

Interactions Between Males and Unweaned Barbary Macaques: Testing the Agonistic Buffering Hypothesis

Abstract: 1. Observations of wild Barbary macaques in the Moroccan Middle Atlas revealed more male interaction with unweaned monkeys than has been described for other Cercopithecoidea. 2. Adult, subadult and juveniles males were all involved. On the birth of a new season's babies the males interacted with them and virtually ignored the infants (still unweaned) from the previous birth season. They continued to interact with the new babies when these were infants. 3. Adult and subadult males approached mothers with babies, sat with them, removed their babies and cared for them. Babies were rarely threatened, or attacked, but in agonistic interactions infants were treated more like juveniles. 4. Close non-agonistic interaction between males occurred in the presence of babies (type b interactions). This was initiated by males taking babies to other males, or by males without babies approaching those with them. A framework (based on the most consistently repeated behavioural elements) is presented for describing the seven phases of these complex interactions. 5. Elements of male-care and type b interactions often punctuated play bouts between infant and juvenile males and babies. The interactions involving males, babies and non-maternal females are also briefly described. They were far less frequent than type b interactions and female-care interactions. 6. Individual males and babies did not interact with each other equally often. Particular male-baby partnerships occurred regularly in the context of both male care and type b interactions. The males' rank did not determine these relationships. 7. Examination of nearest neighbour records revealed that the presence of a baby near a male was associated with a clumping of other individuals (particularly other males) near the male. Infants did not have this effect. 8. Most friendly approaches given to and received from males (particularly those to and from other males) were in the presence of babies. 9. There was a relationship between agonistic rank and approaches between males in the presence of babies. Between unlike age classes and between adults, an approacher carrying a baby was usually subordinate. Most approaches to males in possession of babies were by subordinates but there were exceptions. 10. Males carried babies away from and left babies with males both dominant and subordinate to themselves. This showed how limited competition for babies was between males. 11. There was a higher probability of a male being threatened if he made a friendly approach in the presence of a baby. However, it seemed that males found the risk of receiving an aggressive response acceptable because it was coupled with a higher probability of non-agonistic interaction with males who could rarely be approached without a baby present. 12. Low ranking males approaching high ranking males positioned themselves so as to judge the response of the approached male and they also drew the baby to his attention. Several behaviour patterns were used to maintain proximity with other males. Most male-male grooming occurred in the presence of babies. 13. The results confirmed the importance of a baby's presence in the dynamics of male-male interaction and justify the use of the term 'agonistic buffering'. The behaviour between males of considerably different rank (e.g. between subadults and adults; juveniles and adults) most clearly fitted the agonistic buffering hypothesis. The behaviour between males of more similar rank (e.g. adults and adults) was less consistent and did not fit the hypothesis so closely.

Yawning in an Old World Monkey, Macaca nigra (Primates: Cercopithecidae)

Abstract: The yawn of the black ape appears to be structurally homologous to the behavior pattern widely described for other vertebrates, even in its finer details. The pattern is highly stereotypic, showing only minor structural variants and not exhibiting any tendency to grade continuously into other expressive or communicative behavior patterns. The yawn occurs in many different contexts, in association with a variety of social and nonsocial situations. Yawns tend to be occur in contexts which elicit some level of stress in the performer. Yawns commonly follw "demonstrations" in which a performer vigorously manipulates an environmental object, with the result of producing a loud noise which draws the attention of others. Adult males yawn significantly more frequently than any other age-sex class. The highest ranking or alpha male tends to yawn at a higher rate than other group members, and in at least one case this was found to be true even following a dominance reversal involving alphas. An ontogenetic trend appears in males: yawning rates increase with age. The most dramatic change occurs during adolescence preceding the eruption of permanent canine dentition. Typical adult male rates are probably reached prior to the completed eruption of the canine teeth.

Social influences on biological rhythms

Abstract: Little attention has been given to the influence that social factors may have on biological rhythms. We maintain that this neglect stems from historical and technological circumstances in that most research in chronobiology has been aimed to discover the physiological basis for rhythmicity and that it is very difficult to study the rhythms of interacting animals. We review selected elements of the somewhat scattered literature that deals with social influences on circadian, ultradian and infradian rhythms. We find that social factors have been shown to result in the synchronization, desynchronization and disruption of biological rhythms in a wide range of organisms. By employing a time-lapse video tape recording system we were able to study the individual activity of interacting tegu lizards (Tupiranmbis teguixin). We found that some individuals demonstrated (1) social synchronization, (2) the formation of "time-territories", (3) free-running rhythms against a LD 12:12 lighting schedule, and (4) apparent arrhythmicity. We related these phenomena to the social hierarchy of the lizards. Lizards ranked intermediate often occupied time-territories separate from the dominant lizard, and under certain conditions the lowest ranking lizard exhibited a free-running rhythm that was completely uncoupled from the lighting cycle. Under other conditions the lowest ranking lizard was socially synchronized. Also using closed circuit television techniques, we studied the running wheel rhythms of three individually marked female laboratory rats housed in the same cage in continuous dim red light. The rats could compete for the running wheel by synchronizing their activity or minimize competition by desynchronizing their activity. An inspection of the raw activity data revealed that omega X was displaced from D and S, thus occupying a separate time-territory, while D and S were closely ranked socially and closely synchronized in time. Cosine curves were fit by computer to the data of each rat using the least squares method. The percent rhythm (the percent of the total variability explained by the cosine curve) and the period length (the duration of one complete cycle of the rhythmic variation) proved to be particularly useful. We found that the free-running period lengths of D and S were nearly identical while that of omega X was quite different. So omega X's rhythm was not only displaced but also uncoupled from D and S. While housed with D and S, omega X's percent rhythm was very low and erratic. However, when D and S were temporarily removed from the activity cage, the percent rhythm of omega X rose markedly and its period length increased to a value nearly identical to that of D and S from before. Upon reintroduction of D and S to the home cage, omega X became displaced from the latter : its percent rhythm dropped dramatically and its free-running period length was again much different from D and S. We explore the possibilities (1) that disturbances of the timing of rhythms could affect individual fitness at the level of ecological and social intergration, (2) that crowding may cause rhythm reschedulings and disruptions that produce effects similar to those documented in "jet-lag", (3) that time-territoriality could be a mechanism involved in the partitioning of resources among individuals in natural populations. Finally, (4) commonly housed animals even in controlled laboratory environments can modify one another's activity and perhaps physiological rhythms. This could confound attempts to control for biological rhythmicity using controlled lighting schedules. Thus, an awareness of the interaction of social behavior with rhythms may help physiologists and behaviorists to collect more reproducible data in the future.

Display, Timing and Function of Wing Movements Accompanying Antiphonal Duets of Cichladusa Guttata

Abstract: I. The antiphonal duets of Cichladusa guttata (Turdidae, Aves) are often accompanied by spectacular wing movements. We have analysed the display, timing, coordination and function of this behaviour using sound films, audio and video recordings of free living and captured birds (Figs 1, 2). 2. The vocal duet contribution of the members of a pair appear well coordinated in timing, normally with no overlap of notes. Specific types of duet notes of the male or the female can release wing beats in the male (response time: 380 ± 80 msec.), but not vice versa. Additionally, note utterance can trigger the wing beat start (reaction time 30 ± 15 msec.) in the same bird, which is normally the male (Figs 4, 5, 6, 7, 8). 3. Wing beat performance is also affected by two further variables: "duet activity" and "wing beat periodicity". The duet activity which changes relatively slowly can be estimated from parameters of the behaviour (vocal density, vocal power, etc.). Auditory stimulation with conspecifics songs raises duet activity and thereby facilitates wing movements. This does not affect the "component of wing beat periodicity", which has a cycle length of 540 msec. (Fig. 3; Tab. i). 4. Normally, both wings are moved synchroneously. Experiments with restricted space on one side of a songster showed that wing beats can be blocked unilaterally. While a space restricted wing remained unmoved the other wing operated in full coordination to the duet program. 5. Due to the different affectations wing "escort" is optional. It occurs regularly, but, with high flexibility. When the variables promoting wing beats result in high values, high wing beats occur, when the values are low, low or no wing beats are observed (Fig. 9). 6. (Wing beats are supposed to support the general function described for the vocal duet contributions.) Specific functions discussed for the non-vocal contributions are: focussing and directing of attention (spectacular display via an additional signal channel; avoidance of habituation (optional and flexible occurrence) ; preventing distance signalling from disturbances in the acoustic channel (noise produced by birds singing simultaneously) ; distance measurement by identification of phase shifting between vocal and non-vocal behavioural rhythms.

Predatory Behaviour in Domestic Cat Mothers

Abstract: This study documents quantitatively the change in predatory behaviour of domestic cat mothers as their kittens develop. Predatory behaviour in mother cats was found to decline as that of their offspring increased. Before kittens were 8 weeks old, mothers were more likely to interact with prey if their kittens had not been on the prey for a time; they led in interactions with prey. Kittens were found to show increased rates of predatory behaviour patterns in the presence of their mother. This paper then goes on to examine some of the mechanisms by which mothers are able to bring about such an improvement in their kittens' predatory behaviour. It was found that kittens interacted more frequently and for longer with prey following the mother's bouts. Kittens were more likely to quickly follow another cat on the prey than wait more than 10 seconds. However when siblings only were considered, they were less likely to follow a sibling in less than 10 seconds of it having been on the prey. After the eighth week, kittens attended to prey by themselves more often than would be expected by chance, whereas in the early weeks of exposure to prey, they were more likely to attend to prey while their siblings or their mother was watching prey.

Communication by agonistic displays - a discussion

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

Species Identification of Song By Indigo Buntings as Determined By Responses To Computer Generated Sounds

Abstract: Species recognition of song by indigo bunting, Passerina cyanea, was studied in playback experiments to territorial males. Experimental recordings included computer simulations and actual bunting sounds. In all, 238 playbacks were carried out with 34 test songs. Actual bunting songs were from Kentucky, U.S.A. and the local population at Chaffeys Locks, Ontario, Canada. One syllable-type from the latter song was repeated to form a unique song, which also served as a model for some simulations. Simulations were of three general kinds: single syllable-type, multiple syllable-type, and general syllable features. The latter series tested general attributes of syllables including sound duration, frequency, amplitude and continuity, with typical ranges and modulation rates. Using 12 variables of response, results were analyzed by univariate and multivariate techniques. Results were as follows: 1. Actual songs were the strongest stimuli (Kentucky then Ontario). 2. General feature simulations all elicited no detectable defense response. 3. Single syllable-type simulations elicited stronger responses as they approached physical attributes of the model. Responses to some simulations could not be significantly discriminated from the model. 4. Manipulation of frequency-time structural detail illustrated that variations of less than about 100 Hz in 10 ms do not affect response. Amplitude variations up to twice the modulation rate in five ms, do not affect response. 5. Multiple syllable-type simulation of the first seven types in the Ontario song elicited responses that were significantly stronger than any other simulations. 6. Multiple syllable-type simulation in which subsegments (unidirectional frequency modulations) were reversed in direction elicited moderate responses. From these results, the following conclusions could be made: 1. As adults, indigo buntings recognize song syllables as approximations of culturally transmitted types. 2. Numerous parameters are used for cues. 3. Effects of some cues are additive. 4. Models of syllable-type distribution, recognition, and learning were discussed.

Sex Ratio and Optimal Male Time Investment Strategies in Asellus Aquaticus (L.) and a. Meridianus Racovitza

Abstract: A. aquaticus and A. meridianus have a passive phase in which the male carries the female for some days before moulting and copulation are possible. The effect of varying male: female ratios (0.5:1; 1:1; 1.5:1) is discussed in this paper. It was found that an increase in the proportion of males led to: a) earlier initiation of the passive phase; b) lower gain rates from paired females; c) an increased tendency for males to leave females; d) a reduction in the strength of the association between the timing of pairing and oviposition. The relevance of these observations to models of optimal female guarding and foraging strategies is discussed.

The Relationship Between Sex and Aggression in Convict Cichlids (Cichlasoma Nigrofasciatum Günther)

Abstract: C. nigrofasciatum have been widely used as a preparation in the investigation of aggressive (threat/attack) behavior because of their reputation as a highly aggressive species. They have also frequently been used in studies of learning processes, especially habituation. The reproductive and aggressive behaviors of the family Cichlidae have been described extensively, however, the sexual behavior of C. nigrofasciatum has been treated only cursorily. Several investigators have postulated a mutually inhibitory relationship between sex and aggression such that any decrease in the level of one of these motivational states results in an increase in the level of the other. In order to test this hypothesized relationship between sex and aggression, male and female C. nigrofasciatum were exposed to either male or female stimulus fish for 24 consecutive hours. In the present investigation, performance of sexual behavior was found to inhibit performance of aggressive behavior and vice versa. A principle components statistical analysis was performed in order to reduce the number of dependent variables to a smaller number of underlying clusters of variables referred to as factors. The principle components analysis indicated that the data were characterized by two orthogonal factors, the first of which reflected qualitative differences between the sex and aggression variables, suggesting that a mutually inhibitory relationship exists between sex and aggression. Discriminant analyses indicated that females initiate courtship and perform more aggressive behaviors than males, males elicit more aggression than females, opposite sex dyads perform more sexual behaviors than same sex dyads, and same sex dyads perform more aggressive behaviors than opposite sex dyads. Habituation of aggression was demonstrated in all dyads. Significant decrements in sexual behaviors were not observed.

Pre-Copulatory and Copulatory Behaviour in Relation To Stages of the Oestrous Cycle in the Female Mongolian Gerbil

Abstract: 1. Most previous studies of sexual behaviour in female rodents have concentrated on "lordosis", and there have been few attempts to quantify pre-copulatory behaviour of the female. Conditions of testing commonly used in previous research into rodent sexual behaviour particularly seem to have focussed attention on copulatory behaviour of the female, leading to the neglect of female pre-copulatory behaviour. 2. The present study aimed to investigate both pre-copulatory and copulatory behaviour in the female Mongolian gerbil in relation to different stages of the oestrous cycle. 3. The experimental design of the present study was intended to provide an increased opportunity for females to display pre-copulatory behaviour. Daily observations were made of the behaviour of ten male/female pairs of Mongolian gerbils which were living together continuously over the four days of the oestrous cycle. Each female was paired with a test male on the day following the day of behavioural oestrus and the pair remained together until the end of the next day of behavioural oestrous. Experimental females and test males were all sexually experienced before use as subjects. 4. Under these conditions, females displayed a number of pre-copulatory behaviour patterns (piloerection posture, present posture, darting and foot-stomping) on the day of oestrus which did not appear on other days of the cycle. On the day of oestrus, females also showed pre-copulatory increases in rates of allogrooming initiated by the female and in rates of olfactory investigation of the male's head and anogenital regions compared to other days of the cycle. Oestrus females also approached and left the male more frequently than non-oestrous females. 5. Unlike lordosis behaviour, sequences of female pre-copulatory behaviour involving darting and the present or piloerection postures did not depend on tactile stimuli associated with male mounting. Sequences of female pre-copulatory behaviour always preceded instances of male pre-copulatory following and mounting. 6. During copulation, male sexual behaviour was organised into ejaculatory series of mounts and intromissions, separated by post-ejaculatory intervals. All males initiated a final "incomplete" series of mounts and intromissions which did not culminate in ejaculation. Female receptivity, as measured by the "lordosis ratio", remained high until the end of mating, and declined only in the final series of mounts and intromissions following the last ejaculation. However, the display of female "proceptive" behaviour patterns (darting, foot-stomping, present posture and piloerection posture) declined over successive ejaculatory series. 7. Sequence analysis showed that each mount or intromission was preceded by one of seven types of behaviour sequence, the most common sequence, "Type O", consisting of female darting, male follow, female present and male moult without intromission or male mount with intromission. At the beginning of mating, most "Type O" sequences were preceded by female behaviour patterns (approaching the male, investigating the male and foot-stomping). As mating proceeded, an increasing percentage of these sequences was preceded by male behaviour patterns (approaching the female and investigating the female's head). 8. It is concluded that, in the present study, oestrous female gerbils played an active role in the performance of sexual behaviour. Pre-copulatory activities of the female seemed to have a stimulatory effect on male sexual behaviour and probably made an important contribution to the initiation of mating. During copulation, females actively participated in the initiation of mounts and intromissions, and, in the earliest stages of mating, played an important role in the patterning of copulatory behaviour. In the later stages of mating, the male played an increasingly important role in the initiation of mounts and intromissions.

The Interpretation of Individual Differences in Rhesus Monkey Infants

Abstract: A varimax rotated solution of a Principal Components Analysis (PCA) was used to discover how in the rhesus monkey behavioural measures of interactions between mothers and infants and between infants and other members of the group clustered, in the sense that they were more strongly correlated with each other than with other measures. Eight week-old infants, living with their mothers in captive social groups, were the subjects, and the males and females were studied separately. A form of cluster analysis, the construction of Maximum Spanning Trees (MST), was used to display clusters of behaviours, corresponding to the PCA groupings, and to show how separate groups of measures could nevertheless be connected to each other. In both sexes, a group of measures called "Mother protects" proved to be separate from a group called "Infant social", and these groups were both separate from various measures reflecting maternal rejecting behaviour. Also separate was a single measure of the infants' tendency to show distress by squeaking, geckering and screaming, and a measure of the time the infants spent alone while out of contact with their mothers. The separation of these groups of measures means that, in working with the populations of male and female infants as wholes, it is not possible to predict an individual's score on a measure from one of the above-mentioned groups from the score of a measure from another group. The sexes differed in that the mother's act of moving away after her infant approached, possibly a rejecting or leading tactic, was associated with the other kinds of rejecting behaviour in female infants only. In males, mothers who groomed them for shorter times tended to restrain them more often, while in female infants maternal grooming was associated with other monkeys initiating contact with the infants. In females, but not males, the frequency with which others made contact was not associated with the frequency with which the infants played with others. We showed how "derived" measures can be interpreted in terms of the groupings of their component measures. Two derived measures, % Rejections and the Proximity Index, could (like a monkey's weight) be correlated with a variety of measures, themselves uncorrelated. We discussed the consequences of this, together with certain other complications that can arise when "derived" measures are used. Where we failed to find correlations between measures or groups of measures, we thought it possible that correlations might nevertheless be found in sub-populations of the infants. For example, only those infants whose mothers rejected them at above a certain frequency might show a correlation between the frequency of their distress and the frequency with which others make contact with them.

The imminence of behavioural change and startle responses of chicks

Abstract: The responses of chicks startled near the end of a bout of feeding or preening were different from, and measurably greater than, those of chicks startled at the beginning of bouts of these activities. This result provides evidence about changes in motivational state during a bout of activity. It is proposed that causal factors, which are changing during the bout, may initiate an attentional change as the point of transition to another activity approaches. Distractibility and information-processing rate may be increased near the end of an activity because the individual can then attend to a greater variety of inputs than it could earlier in the bout. This would maximise the efficiency of the ensuing behavioural change. In order to carry out these experiments, bouts of feeding and preening were measured using a criterion based on log survivor curves for inter-event gap-lengths. The effects on the response of the time during a bout at which interruption occurs, were shown by chicks of 2, 4 and 6 days of age. The method used in these experiments, the interruption of activities at previously defined instants whilst observing behaviour in detail, affords opportunities for studying the nature of behavioural sequences and their control.

Factors Affecting Flock Size Mean and Variance in a Winter Population of House Sparrows (Passer Domesticus L.)

Abstract: 1. In a field experiment with a winter population of house sparrows at a farm, flock size at a given feeding site appeared to be positively related to seed density. 2. The positive relationship between flock size and seed density resulted from individual birds spending longer in areas where seed density was high and from birds being recruited from elsewhere on the farm to experimental sites. 3. Mean flock size was positively related to and the variance of flock size negatively related to the time of day and both showed a tendency to be negatively correlated with the amount of human disturbance. Mean flock size was also positively related to ambient temperature and flock size variance negatively related to daylength. 4. The rate of fighting per bird increased with flock size and time of day but decreased with increasing ambient temperature. 5. The pattern of flock size distribution in house sparrows is compared to that in juncos and some differences between the two may be attributable to differences in the type of food supply and temperature range over winter.

An Investigation of Song-Based Species Recognition in the Red-Winged Blackbird (Agelaius Phoeniceus)

Abstract: To determine the aspect(s) of male red-winged blackbird (Agelaius phoeniceus) advertising song which function in the transmission of species identity, 74 territorial adult male redwings were exposed to 173 playback experiments of normal and experimentally altered red-wing song during the 1977, 1978 and 1979 breeding seasons. Unaltered red-wing song and altered song containing species-identifying information evoked aggressive behavior from territorial redwings when played through a loudspeaker placed in their territories. A list of red-wing aggressive behaviors was compiled and the males' responses to altered and unaltered song were scored on a "hybrid-index" scale according to the number of times they performed each of the aggressive behaviors during the playback experiment. The results of the study indicate that 1) the ordering of the three song "syllables" did not affect the intensity of the males' agonistic responses to playback song and therefore does not convey species information, 2) the initial two syllables of the red-wing song do not encode the species-identifying information, as these two syllables, alone or in conjunction, failed to elicit fully aggressive responses from the males, 3) the last syllable of the song, a "trill", when presented to the males alone or in conjunction with the other song syllables, evoked fully agonistic responses, suggesting that this trill syllable encodes the majority of species-specific information in the red-wing song, and 4) by playing back increasingly shorter (in duration) sections of the trill syllable to the territorial males, it was demonstrated that the trill must be somewhat longer in duration than 180 msec to function in species identification.

Naive Ducklings Show Different Cardiac Response To Hawk Than To Goose Models

Abstract: Naive mallard ducklings were exposed to overflights of a silhouette of either a hawk or a goose on one day and the other configuration on the next day. An audio record of the heart rate was recorded utilizing a small transducer. Most of the ducklings (14 of 20) showed a greater variance in heart rate in response to the hawk than to the goose (p<0.01 ). These results indicate that the ducklings without prior, specific experience can differentiate between a goose and a hawk and show a greater emotional response to the latter. This constitutes evidence for the recognition of configurational stimulus without prior, pertinent experience. The use of cardiac responses as a measure of emotionality or fear is discussed, as are the merits of various measures of changes in heart rate. We conclude that variance in heart rate is an excellent measure of emotional response to a stimulus.

Temporal Variation in Male Copulatory Behaviour in the Solitary Bee Nomadopsis Puellae (Hymenoptera: Andrenidae)

Abstract: 1. Females of the solitary bee, Nomadopsis puellae, foraging for pollen at flowers will copulate with any male that can reach them but the duration of copulation is not constant over the daily foraging-mating period (which lasts from about 0900-1300). Early on, copulations are brief (usually less than 1 min). As the morning progresses, males tend not to release their mates spontaneously but remain in copula for as long as it takes a female to collect a full pollen load and return to her nest. In addition, late in the mating period males that have not secured a single female may begin to assault pairs in attempts to usurp a female from a copulating male. 2. We propose that males control the duration of mating in ways that reflect a change in the genetic gains associated with brief versus prolonged copulations over the course of the morning. We assume that sperm precedence occurs in this species and that females are more likely to oviposit at the end of the foraging period than at the beginning. If these assumptions are correct, guarding a mate through prolonged copulation could become increasingly advantageous as the mating period draws to a close each day. Given a high degree of competition for mates, a male that secured a female on her last trip of the morning could greatly improve the chance that his mate would use his sperm for fertilization if he prevented other males from reaching her until she was safely back inside her nest burrow. 3. An alternative hypothesis that the variation in copulation length is due to changes in the readiness of females to receive sperm from a male over the mating period is considered. Limited data suggest that females do not signal degrees of sperm receptivity to males. Males probably determine how long they will copulate, switching from the tactic of securing many short (unguarded) copulations to a few lengthy (guarded) matings in the course of a morning.

Communication During Monocular and Binocular Looking in European Jays ( Garr Ul Us G. Glandarius)

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

Marking Behaviour and Olfactory Recognition in Genets (Genetta Genetta L., Carnivora-Viverridae)

Abstract: The functions of scent marking in individual, sex and physiological state recognition were studied in genets (G. genetta L.). Both males and females sniffed statistically more the scent marks (urine, secretion of the perineal glands, substances emitted by flank rubbing) of unknown conspecifics of the opposite sex than those of known conspecifics of the opposite sex. They also spent significantly more time in sniffing scent marks of strange conspecifics of the same sex than their own scent marks. The same results were found using fecal pellets. Concerning sex recognition, no significant differences in sniffing time were observed. The last experiment showed that males could recognize the physiological state of females by means of scent marks.