Showing papers in "Behaviour in 1969"

Flight Behaviour and Avoidance of Predators in Thomson's Gazelle (Gazella Thomsoni Guenther 1884)

Abstract: [As a suhsidiary result of a study on social behaviour of Thomson's gazelle in Serengeti National Park (Tanzania) there are given informations on flight behaviour and avoidance of predators. Alert posture, flight in galloping and stotting, and especially the relatively soft alarm call are more or less contagious and can release alertness or flight in conspecifics. Shaking of the flank (BROOKS, 1961) does not initiate flight only but galloping in general. It is the last link in a chain of actions which appears completed only in intraspecific situations. In perception of enemies the tommy reacts to optical stimuli from silhouettes and movements. The senses of smell and hearing are not so important in this context. If the tommies have recognized an enemy in time they try to keep it under control (behaviour of fascination). The territorial ♂♂ are especially important in this context. Bachelor herds are found predominantly at the periphery of an area inhabited by a gazelle population. Thus predators often encounter them first. Gaits and behaviour patterns in flight are described with special regard to stotting display. The young fawns stay put (Abliegen, WALTHER, 1059/60) and so are difficult to be seen. The way in which the mother manages her fawn especially during the first days of its life lead to the view that the fawn and the place where it rests are kept from contamination with odors attractive to predators. In rare cases even adult gazelles try to evade predators by lying down. Tommies do not fight against predators when hunted. The mother defends her fawn against jackals and tries to divert hyenas which hunt for her fawn. Factors which influence the flight distance are discussed. The flight distance varies with the different predators according to their danger for gazelles. Experiments showed that adult ♂♂ in herds (bachelors) have a lesser flight distance than ♀♀ in herds, adult ♂♂ have a lower one than subadult ♂ ♂ , territorial ♂♂ have a lower one than adult bachelors, but solitary wandering ♂♂ show the greatest flight distance of all gazelles. Thus age, sex and social status are all significant factors influencing flight distance. By observations of the behaviour in response to predators, human beings, cars and especially by the study of the mistakes in flights from animals which are not predators of gazelles, it was possible to find a few flight releasing factors, most of them similar to or identical with sign stimuli : sudden appearance, direct course (toward the gazelles), size, good perceptibility (contrast), large number of enemies, high speed, proximity, strangeness, and experience. In concrete cases usually several of these factors operate concomitantly. A remarkable number of them are also known as factors which release the following reaction in young ungulates (WALTHER, 1964a, 1966). This may explain certain cases of ambivalent behaviour, especially of gazelle fawns in regard to predators. A few observations on kills of predators lead me to the view that the age, sex and social groups are preyed upon by various predators at different rates. There are relationships between the differences in flight distances, and the spatial distribution according to the social grouping of gazelles on the one hand, and the different hunting methods of the predators on the other hand. The ecological importance of each predatory species depends on its specialization and preference for gazelles as prey animals, its number, and its preferred biotype. Implications for the management of national parks and game cropping outside the protected areas are discussed. Thomson's gazelles show very few behaviour patterns of alertness, alarm, flight and hiding that are restricted to predators only; most patterns are also seen in intraspecific situations. Certain observations lead to the view that these behaviour patterns are adapted primarily to special conditions of the intraspecific realm and work better in it., As a suhsidiary result of a study on social behaviour of Thomson's gazelle in Serengeti National Park (Tanzania) there are given informations on flight behaviour and avoidance of predators. Alert posture, flight in galloping and stotting, and especially the relatively soft alarm call are more or less contagious and can release alertness or flight in conspecifics. Shaking of the flank (BROOKS, 1961) does not initiate flight only but galloping in general. It is the last link in a chain of actions which appears completed only in intraspecific situations. In perception of enemies the tommy reacts to optical stimuli from silhouettes and movements. The senses of smell and hearing are not so important in this context. If the tommies have recognized an enemy in time they try to keep it under control (behaviour of fascination). The territorial ♂♂ are especially important in this context. Bachelor herds are found predominantly at the periphery of an area inhabited by a gazelle population. Thus predators often encounter them first. Gaits and behaviour patterns in flight are described with special regard to stotting display. The young fawns stay put (Abliegen, WALTHER, 1059/60) and so are difficult to be seen. The way in which the mother manages her fawn especially during the first days of its life lead to the view that the fawn and the place where it rests are kept from contamination with odors attractive to predators. In rare cases even adult gazelles try to evade predators by lying down. Tommies do not fight against predators when hunted. The mother defends her fawn against jackals and tries to divert hyenas which hunt for her fawn. Factors which influence the flight distance are discussed. The flight distance varies with the different predators according to their danger for gazelles. Experiments showed that adult ♂♂ in herds (bachelors) have a lesser flight distance than ♀♀ in herds, adult ♂♂ have a lower one than subadult ♂ ♂ , territorial ♂♂ have a lower one than adult bachelors, but solitary wandering ♂♂ show the greatest flight distance of all gazelles. Thus age, sex and social status are all significant factors influencing flight distance. By observations of the behaviour in response to predators, human beings, cars and especially by the study of the mistakes in flights from animals which are not predators of gazelles, it was possible to find a few flight releasing factors, most of them similar to or identical with sign stimuli : sudden appearance, direct course (toward the gazelles), size, good perceptibility (contrast), large number of enemies, high speed, proximity, strangeness, and experience. In concrete cases usually several of these factors operate concomitantly. A remarkable number of them are also known as factors which release the following reaction in young ungulates (WALTHER, 1964a, 1966). This may explain certain cases of ambivalent behaviour, especially of gazelle fawns in regard to predators. A few observations on kills of predators lead me to the view that the age, sex and social groups are preyed upon by various predators at different rates. There are relationships between the differences in flight distances, and the spatial distribution according to the social grouping of gazelles on the one hand, and the different hunting methods of the predators on the other hand. The ecological importance of each predatory species depends on its specialization and preference for gazelles as prey animals, its number, and its preferred biotype. Implications for the management of national parks and game cropping outside the protected areas are discussed. Thomson's gazelles show very few behaviour patterns of alertness, alarm, flight and hiding that are restricted to predators only; most patterns are also seen in intraspecific situations. Certain observations lead to the view that these behaviour patterns are adapted primarily to special conditions of the intraspecific realm and work better in it.]

The Effect of Experience and Novelty On Avian Feeding Behavior With Reference To the Evolution of Warning Coloration in Butterflies Part I: Reactions of Wild-Caught Adult Blue Jays To Novel Insects

Abstract: Several neo-tropical butterfly species were presented to 171 wild-caught adult Blue Jays to determine if insects of unfamiliar color pattern would elicit an attack response from an avian predator regardless of the visual characteristics of the prey. It was found that unfamiliar insects do not always elicit an attack response. Four aspects of the birds' behaviors were noted: 1) the initial responses to various training diets were different; 2) the training diets had a direct effect on the reactions of the birds to new insects; 3) there was a difference in the attack responses of the birds to different novel insects ; 4) there was an interaction between training diets and novel insects. Four aspects of avian feeding behavior were discussed as possible explanations of the results : preference for familiar food, generalization from previous experience, innate avoidance of specific stimuli, and innate avoidance of novel stimuli.

Comparative Prey-Attack Studies in Newborn Snakes of the Genus Thamnophis

Abstract: Garter snakes (Thamnophis) from five species (including three subspecies of one form) were tested several days after birth with water extracts of at least 12 small animals (1.5 g animal to 10 ccm warm distilled water). The 12 prey animals included three species of earthworms and three of fish, a salamander and its larva, a frog, a leech, a slug and a baby mouse. A distilled water swab elicited tongue flicking only, while certain extract swabs resulted in actual prey-attack behavior after at least one tongue flick. A score was given to each extract test using a simple formula based upon tongue flick frequency and attack latency. Differences and similarities between the species were found and are discussed in relation to the actual feeding preferences in nature and captivity. For example, the aquatic Thamnophis elegans aquaticus attacked only the extracts made from the salamander larva, the frog, and the three fish; Thamnophis sirtalis also attacked the leech and the three earthworm extracts. It is suggested that the perceptual selectivity shown by naive snakes is an evolutionary response to present and past ecological conditions. The ability of newborn snakes to rapidly acquire a food avoidance response was also demonstrated.

Zur Vergleichenden Ethologie Verschiedener Mollienesia-Arten Einschliesslich Einer Höhlenform Von M. Sphenops

Abstract: [1) Auf Grund von Grose und Differenzierungsgeschwindigkeit wird bei M. velifera und M. latipinna zwischen Fruh- und Spat-♂ ♂ unterschieden. Die Spat-♂ ♂ von M. velifera bilden eine Dorsale aus, die meist hoher als der Korper ist. Auf einige Faktoren fur die Ausbildung der hohen Dorsale wird eingegangen. Die ♂♂ des zur Verfugung stehenden Stammes von M. latipinna bildeten dagegen keine hohe Dorsale aus2) Alle ♂♂ der beiden "hochflossigen" Arten M. velifera und M. latipinna (ausgenommen die Fruh- ♂♂ von M. latipinna) zeigen eine Schaubalz vor dem ♀ (Balzschwimmen), bei der die aufgestellte Dorsale dem ♀ in auffallender Weise dargeboten wird. Bei der "niedrigflossigen" Art M. sphenops fehlt dagegen eine solche optisch wirksame Balz. Andererseits sind Anschwimmen, Folgen und Nippen in ihrer Intensitat deutlich gesteigert. Die Einzelelemente des Rivalenverhaltens stimmen in qualitativer Hinsicht bei "hoch"und "niedrigflossigen" Arten recht gut uberein. 3) Von M. sphenops wurde eine Hohlenform untersucht, die sich von der oberirdischen Form durch fast vollstandiges Fehlen von aggressiven Reaktionen unterscheidet. Als Ursache der fehlenden Aggressivitat wird eine genetisch bedingte Degeneration des Rivalenverhaltens angenommen. Die Reduktion des Aggressionsverhaltens ist unter den Bedingungen des Hohenlebens vermutlich selektionistisch begunstigt. Da die Wirkung aggressiver Verhaltensweisen auf den Gegner im Dunkeln stark vermindert ist, durfte es fur das ♂ vorteilhafter sein, moglichst lange mit dem ♀ in Kontakt zu bleiben. Die aggressive Auseinandersetzung mit dem Rivalen aber wurde im allgemeinen dazu fuhren, das die Verbindung zum ♀ fur langere Zeit verloren geht. Das Fehlen einer Schaubalz beim oberirdischen M. sphenops, die deutlich gesteigerte sexuelle Aktivitat und vor allem die Fahigkeit der ♂ ♂ , auch sehr schnell schwimmenden ♀♀ nippend zu folgen, lassen die Annahme zu, das der oberirdisch lebende M. sphenops fur ein erfolgreiches Leben im Dunkeln pradisponiert ist. 4) Bei allen drei Arten wurde das zeitliche Auftreten der einzelnen Verhaltensweisen wahrend der Ontogenese registriert. Die Jungtiere der drei untersuchten Arten verfugen schon einige Tage nach der Geburt uber das vollstandige Rivalenverhalten. Die Einzelelemente des Sexualverhaltens erscheinen dagegen erst kurz vor oder mit beginnender geschlechtlicher Differenzierung. Die Form der Einzelelemente des Sexual- und Rivalenverhaltens unterscheidet sich nicht von derjenigen erwachsener Tiere. Auffallend ist aber die auserordentliche Haufigkeit aggressiver Verhaltensweisen bei Jungfischen. Die Einzelelemente folgten nicht in rein zufalliger und beliebiger Reihenfolge aufeinander, sondern es waren schon die gleichen Verhaltensfolgen zu beobachten wie bei erwachsenen Tieren. 5) Es wurden Kaspar-Hauser- ♂♂ aller drei Arten beobachtet. Die Entwicklung fast aller beschriebenen Elemente des Sexual- und Rivalenverhaltens ist von der Erfahrung mit Artgenossen unabhangig. 6) Ein Vergleich der bisher ethologisch untersuchten Arten der Gattung Poecilia i.w.S., d.h. im Sinne von ROSEN & BAILEY (1963), ergibt zum Teil erhebliche Unterschiede in der Balz. Zwei der bisher untersuchten Arten zeigen uberhaupt keine Anzeichen einer Schaubalz. Die Zuruckfuhrung der Balz auf einen Grundtypus scheint im Gegensatz zu den Verhaltnissen innerhalb der Gattung Xiphophorus nach den bisherigen Untersuchungen nicht moglich zu sein.., 1) Auf Grund von Grose und Differenzierungsgeschwindigkeit wird bei M. velifera und M. latipinna zwischen Fruh- und Spat-♂ ♂ unterschieden. Die Spat-♂ ♂ von M. velifera bilden eine Dorsale aus, die meist hoher als der Korper ist. Auf einige Faktoren fur die Ausbildung der hohen Dorsale wird eingegangen. Die ♂♂ des zur Verfugung stehenden Stammes von M. latipinna bildeten dagegen keine hohe Dorsale aus2) Alle ♂♂ der beiden "hochflossigen" Arten M. velifera und M. latipinna (ausgenommen die Fruh- ♂♂ von M. latipinna) zeigen eine Schaubalz vor dem ♀ (Balzschwimmen), bei der die aufgestellte Dorsale dem ♀ in auffallender Weise dargeboten wird. Bei der "niedrigflossigen" Art M. sphenops fehlt dagegen eine solche optisch wirksame Balz. Andererseits sind Anschwimmen, Folgen und Nippen in ihrer Intensitat deutlich gesteigert. Die Einzelelemente des Rivalenverhaltens stimmen in qualitativer Hinsicht bei "hoch"und "niedrigflossigen" Arten recht gut uberein. 3) Von M. sphenops wurde eine Hohlenform untersucht, die sich von der oberirdischen Form durch fast vollstandiges Fehlen von aggressiven Reaktionen unterscheidet. Als Ursache der fehlenden Aggressivitat wird eine genetisch bedingte Degeneration des Rivalenverhaltens angenommen. Die Reduktion des Aggressionsverhaltens ist unter den Bedingungen des Hohenlebens vermutlich selektionistisch begunstigt. Da die Wirkung aggressiver Verhaltensweisen auf den Gegner im Dunkeln stark vermindert ist, durfte es fur das ♂ vorteilhafter sein, moglichst lange mit dem ♀ in Kontakt zu bleiben. Die aggressive Auseinandersetzung mit dem Rivalen aber wurde im allgemeinen dazu fuhren, das die Verbindung zum ♀ fur langere Zeit verloren geht. Das Fehlen einer Schaubalz beim oberirdischen M. sphenops, die deutlich gesteigerte sexuelle Aktivitat und vor allem die Fahigkeit der ♂ ♂ , auch sehr schnell schwimmenden ♀♀ nippend zu folgen, lassen die Annahme zu, das der oberirdisch lebende M. sphenops fur ein erfolgreiches Leben im Dunkeln pradisponiert ist. 4) Bei allen drei Arten wurde das zeitliche Auftreten der einzelnen Verhaltensweisen wahrend der Ontogenese registriert. Die Jungtiere der drei untersuchten Arten verfugen schon einige Tage nach der Geburt uber das vollstandige Rivalenverhalten. Die Einzelelemente des Sexualverhaltens erscheinen dagegen erst kurz vor oder mit beginnender geschlechtlicher Differenzierung. Die Form der Einzelelemente des Sexual- und Rivalenverhaltens unterscheidet sich nicht von derjenigen erwachsener Tiere. Auffallend ist aber die auserordentliche Haufigkeit aggressiver Verhaltensweisen bei Jungfischen. Die Einzelelemente folgten nicht in rein zufalliger und beliebiger Reihenfolge aufeinander, sondern es waren schon die gleichen Verhaltensfolgen zu beobachten wie bei erwachsenen Tieren. 5) Es wurden Kaspar-Hauser- ♂♂ aller drei Arten beobachtet. Die Entwicklung fast aller beschriebenen Elemente des Sexual- und Rivalenverhaltens ist von der Erfahrung mit Artgenossen unabhangig. 6) Ein Vergleich der bisher ethologisch untersuchten Arten der Gattung Poecilia i.w.S., d.h. im Sinne von ROSEN & BAILEY (1963), ergibt zum Teil erhebliche Unterschiede in der Balz. Zwei der bisher untersuchten Arten zeigen uberhaupt keine Anzeichen einer Schaubalz. Die Zuruckfuhrung der Balz auf einen Grundtypus scheint im Gegensatz zu den Verhaltnissen innerhalb der Gattung Xiphophorus nach den bisherigen Untersuchungen nicht moglich zu sein..]

The Aggressive and Territorial Behaviour of the Mantis Shrimp Gonodactylus Bredini Manning (Crustacea: Stomatopoda)

Abstract: In the stomatopod Gonodactylus bredini when two individuals of the same sex encounter each other, they exhibit marked aggressive interaction. One animal usually becomes dominant over the other in approximately 10-20 minutes, and the frequency of aggressive acts declines steadily during the course of an hour. Dominance is influenced, although not necessarily determined, by size, stage in the reproductive cycle (females), stage in the moult cycle, and individual differences in level of aggressiveness. Aggressive behaviour involves a variety of fixed motor actions including spreading of the raptorial meri, antennular flicking, lunging with the meri spread, coiling of the body, and attacking and striking with the raptorial second maxillipeds. The meral expansion reveals conspicuous white spots on the inner surfaces of the raptorial meri and also silver streaks along the borders of the small first maxillipeds while the remaining maxillipeds are extended to form a rosette. This posture seems to serve as a threat. Because of structural modifications of the cuticle, especially on the dorsal surface of the telson, and of the frequent assumption of a coiled position during aggression, the strikes of attacking animals are seldom severely injurious. In nature G. bredini occupies cavities in rocks in shallow water from just below low tide line, and the aggressive behaviour is well suited to the defence of these cavities. The meral spread, for example, effectively fills the entrance and hence blocks encroachment by an intruder. The occupant may leave briefly to strike another animal or attack prey, but quickly returns to its home. The behaviour with respect to cavities thus seems to be territorial with the territory including the occupied rock plus a small area surrounding it. A resident animal undertakes several "housekeeping" activities including cleaning its chamber and closing the entrances at night with small bits of debris and reopening them the following morning. Only a particularly aggressive and dominant animal is capable of dislodging a cavity occupant, but eviction takes place rapidly when it does ocrur. Aggressive displays from outside alone seem insufficient to cause a def ender to leave a chamber ; takeover occurs when the attacker enters the cavity and drives the defender out.

Ontogeny of Prey-Killing Behavior in Canidae

Abstract: The development of prey-killing behavior in naive hand-raised wolves, coyotes and grey foxes was studied. Action patterns and sequences of prey-killing and play with prey were also determined in these species and also in the red and Arctic fox and domesticated dog. Movement of the prey was a strong stimulus to all canids, eliciting orientation, approach and attack. These reactions occurred earliest in ontogeny, followed by seizure of the prey and carrying to a safe or quiet place. Consummatory eating in the wolf and grey fox appeared to be triggered by blood. The ontogeny of temporal sequences of prey killing behavior are detailed, and the action patterns which are species-specific and family-specific are compared. Temporal cycles of play with prey are described in the coyote and grey fox. The question of intraspecific and interspecies aggression in relation to prey killing patterns is discussed and the socio-ecological aspects of hunting, which have not been studied in this investigation, are considered.

The Anatomy of Aggression and Its Ritualization in Canidae: a Developmental and Comparative Study

Abstract: The postnatal development of agonistic behavior patterns in the wolf, coyote and grey fox are described, and in the red and Arctic fox which were first observed at a later age. Piloerection and back arching were present in all species, the latter behavior being especially well developed in the grey fox. The orientation of attack was almost exclusively directed at the cheek in the grey fox, but in other canids the shoulder hackle area, throat and muzzle area were also attacked; prolonged bouts of jaw-muzzle wrestling occurred in the wolf, scruff-wrestling in wolf and coyote and dog, and cheek-wrestling in the grey fox during agonistic play (play-fighting). Orientation of attack was correlated with distinctive body markings in various species. The contribution of social experience in the ontogeny of scruff-oriented attack was demonstrated in hand-raised isolated dogs and visually deprived group-raised dogs. The significance of head-turning, looking away and avoidance of eye contact in the wolf and dog is discussed.

Seed Selection By Pigeons

Abstract: The food preferences of 59 captive Pigeons Columbia livia were tested in a series of experiments in which each bird was given a 25 g. seed mixture. This consisted of 5 g. each of Maize, Millet, "Grain" (Wheat, Oats and Barley), and two varieties of Field Pea ("Big Peas" and "Small Peas"). There was a wide range of individual variation. Most birds preferred Peas, and took little Maize; however, others actually preferred "minority" seeds such as Maize. These individual preferences were stable over short periods, though there were gradual, long-term changes in birds tested repeatedly over a period of four months. There were also individual differences in feeding technique, though these could not be correlated with the differences in seed preference. The origins of these individual variations are discussed. It was not possible to relate them to individual differences in bill size, nor to the proportions of the seeds in the birds' normal feed. When the total quantity of the experimental seed mixture was increased from 25 g. to 50 g., the birds increased their total intake while keeping constant the proportions of the different seeds in it. Since the seeds differ in nutritional composition, it is suggested that the birds were maintaining a nutritionally balanced diet. It is possible that the variations in seed preference may reflect individual differences in metabolism. Individual birds also maintained a constant ratio of "Big Peas" to "Small Peas" in their seed intake, even though these differ little, if at all, in nutritional content. It is suggested that such apparently "arbitrary" food choices might increase the efficiency of the birds' food-finding tactics. Some ecological implications are briefly outlined. If feeding is controlled by the quality as well as the quantity of available food, this could influence the extent to which the birds exploit their environment, and the degree to which their numbers are limited by the food supply.

A Stochastic Analysis of the Maintenance Behaviour of Skylarks

Abstract: The paper attempts to describe the maintenance behaviour of Skylarks Alauda arvensis using conventional qualitative and quantitative descriptive frameworks and, as a new technique, random event series analysis. It is based on behaviour records of individually marked birds which were observed in the field for extended periods. Starting from frequency analysis and using random signal analysis as a stepping stone the rationale of random event analysis is briefly explained. Some of the problems involved in considering behaviour sequences as signals and the implications of viewing animals as black box systems, particularly when only the output i.e. behaviour, is available, are reviewed. The limitations of random event analysis for dealing with non-stationarity and non-linearity are considered. A qualitative description of the maintenance behaviour follows. Some information is given on the behavioural responses to environmental stimuli, particularly to the arrival of the observer. The sequential organisation of the behaviour in terms of transition probabilities is presented next. Deviations from a null order model are found when the behaviour events are separated by less than a minute and some of the implications are briefly mentioned. In a special subsection the sequential organisation of preening is similarly treated but on the basis of too few data to give any conclusive result. Then the distribution of intervals between the various behaviour patterns are given in a matrix form and some indications of deviations of random occurrence are found and discussed. A matrix of inter-behaviour correlations based on the frequency of behavioural events per various time units is presented and the finding that the duration of time units affects the correlations is discussed. In this context some correlation coefficients with non-maintenance behaviour are given and they support the idea that the comfort patterns may be related to a sleep syndrome. Matrices of auto-and cross-correlation functions and the related intensity functions support the view that frequency correlation matrices are not capable of imparting information on an important characteristic of interbehaviour relationships, the time dependent dynamic responses. Lastly, the transformation of the correlation function, the auto- and cross-spectra, are presented for comfort behaviour and flying. These support the notion that comfort behaviour is affected by rhythmical processes while flying is shown in an essentially random fashion. Little systematic relationship was found between comfort behaviour and flying as reflected by the transfer and coherence functions. In the discussion the various quantitative descriptive formats are briefly discussed and some of the objections to the use of advanced analytical techniques are dealt with. The implications of these techniques for models of behaviour are discussed and the complexity of interactions between the causal processes leading to behaviour are stressed. Finally some suggestions for future work are offered.

The Organisation, Control and Development of Parental Feeding in the Oystercatcher (Haematopus Ostralegus)

Abstract: I. The transport and presentation of food to the young Oystercatcher is described. The parents will present food to the young either on their own initiative or in response to the approach of the young. 2. The auditory and tactile interactions between the hatching eggs and the incubating parents are described. As hatching proceeds both the parents and young become more responsive to each other, and both show marked selective responsiveness. These pre-hatch interactions lead to the transition from incubation behaviour to brooding behaviour and to the onset of parental feeding. It is suggested that the young may learn to respond to the call of the parent before hatching. 3. Both non-breeding and breeding birds show the same cyclical pattern of total feeding activities and it is suggested that self-feeding and parental feeding are part of the same motivational system. Once the food has been presented to the young, the subsequent behaviour of the parent is dependent upon the speed with which the young seizes and eats the food. If the young reacts within a certain time (the Waiting-Time Threshold) then the parent will present more food, and will continue to do so for as long as the young reacts within the threshold time. In this way feeding trains are initiated and maintained. The feeding train is broken off once the young fails to react within the threshold time. As the young grows older the parent plays an increasingly minor part in the initiation of feeding trains, the role of the young becoming more important. This leads to the eventual breakdown of parental feeding which is closely correlated in time with how long it takes the young to learn to feed itself. A model of the motivation and control of parental feeding is described. 4. It is suggested that parental feeding evolved in the Oystercatcher subsequent to the evolution of a specialised feeding behaviour which very small young were unable to

Social Attachment in Rats By Odor and Age

Abstract: The odor of rat litter-mates was experimentally modified from 3-10, 11-18, or 22-29 days of age. Acetophenone or ethyl benzoate were used during the experimental period and the natural odor was present during the other two periods. After living in the natural odor colony for another 2 weeks, Ss were compared on duration of time near each olfactory stimulus animal in an eight hour test. Ss preferred the stimulus animal characterized by the experimental odor with which they were reared. Age of exposure was not a significant factor. These results indicate that the odor of the species is learned, that the intensity of the odor is important, but that age is not a critical variable in the early learning of the species odor in the rat.

Electrical Stimulation of Agonistic Behavior in the Mallard

Abstract: Electrical stimulation of the brain of unanesthetized, freely moving adult Mallard ducks (Anas platyrhynchos) produced response patterns characteristic of the aggressive and escape behaviors of this species. Aggressive reactions were classified into three categories: (a) directed attacks on a companion; (b) defensive threat display automatisms characteristic of a cornered bird but lacking attack behaviors; and (c) the rabrab and inciting vocalizations associated with aggressive encounters but unaccompanied by other responses associated with attack or escape. Five categories of fear-like reactions were distinguished: (a) sneak-into-cover reactions characterized by attempts to hide under objects and a strong preference for shelter; (b) crouch-flat reactions in which the birds would stretch out flat on the floor or surface of the water; (c) directed escape reactions characterized by a variety of response topographies but all oriented toward the window or shelter; (d) undirected escape reactions characterized by rushing or flying responses but lacking orientation; and (e) alarm vocalizations unaccompanied by other fear-like responses. Testing of the stimulation-produced reactions under a variety of environmental conditions indicated that many of the reactions (e.g., directed attack, sneak-into-cover) were dependent on specific stimuli for their performance, while other reactions (e.g., threat display automatisms) showed consistent thresholds and response topographies in a variety of situations. Aggressive reactions were elicited from the archistriatum and from wide areas in the diencephalon. Sites producing escape reactions were located primarily in diencephalic and midbrain regions. Evidence was presented suggesting that the different patterns of escape behaviors have different neuroanatomical distributions.

Waning of the Aggressive Response in the Three-Spined Stickleback Upon Constant Exposure To a Conspecific. I, a Preliminary Analysis of the Phenomenon

Abstract: Stickleback males, which are held solitary under experimental conditions described above, give a more or less constant aggressive response toward a test-male (aggression test) when tested once or twice daily during a 4-day period following nest-construction. A distinct waning of this response is found in such males that have a continuous view of another male in a neighbouring territory behind a glass partition ('rival situation') : the frequency of biting decreases and becomes nil or fluctuates about a low level. Rival males and controls do not differ in the response toward a test-female (sex test). Therefore, rival males are said to have attained to a 'hypo-aggressive' condition. The stimulus situation that produces the waning of aggressiveness appears to have some specific properties, e.g. a goldfish neighbour does not lead to the same results. Waning of aggressiveness is also found toward the neighbour if it is used as a test-male. Waning is qualitatively independent of the presence of the glass partition, it occurs also in situations where neighbours can interact freely. Neighbours need not have a continuous view of one another to become hypo-aggressive, a (frequent) intermittent view leads to the same results. We conclude from our experiments that a recovery of aggressiveness, if present, takes place slowly (as a matter of days). A further analysis of the rival responses leads to the separation of three types: I, an unmodified response (similar to controls) ; II, a hypo-aggressive response without an increase of sexual activities toward the test-male; III, a hypo-aggressive response with an increase of sexual activities in addition. A large part of the type III males do not seem to discriminate a test-male and a test-female, the numbers of bites and zigzags in both test situations being nearly equal. Nest-building, or perhaps the presence of a complete nest, is a relevant factor for the occurrence of hypo-aggressiveness and the increase of sexual activities toward a test-male. The interaction of the aggressive and sexual tendencies is found to be entirely consistent with SEVENSTER'S (1961) results. In controls, biting and zigzagging result from the same aggressive and sexual tendencies irrespective of whether they are shown in aggression or in sex tests, and both tendencies are mutually inhibitive. The same conclusion is drawn for the interaction of aggressive and sexual tendencies in rivals. Though the interactions take place on quantitatively different levels, the relations of the tendencies remain qualitatively similar.

Quantitative Analyse Der Reiz-Reaktionsbeziehungen Bei Visuellem Auslösen Des Fluchtverhaltens Der Wechselkröte (Bufo Viridis Laur.)

Abstract: [An Wechselkroten (Bufo viridis Laur.) wurde die Abhangigkeit der Fluchtaktivitat von folgenden Reizparametern einer Feindattrappe quantitativ untersucht: 1. Ort der Feindattrappe (schwarze Kreisscheibe von ca 50° ∅) im Gesichtsfeld: "Bodenfeinde" (Abb. 2b) haben eine sehr viel geringere Auslosewirkung als "Luftfeinde" (Abb. 2a); 2. Betrag und Vorzeichen des Reiz-Hintergrund-Kontrastes: die Fluchtaktivitat nimmt zu, je starker sich die Feindattrappe gegen den Hintergrund abhebt; bei maximalem Absolutbetrag des Reiz-Hintergrund-Kontrastes lost eine dunkle, vor hellem Hintergrund bewegte Feindattrappe starker aus als eine helle vor dunklem Hintergrund bewegte Attrappe; 3. Sehwinkelgeschwindigkeit : bei einer Sehwinkelgeschwindigkeit der Feindattrappe von v = I [grad x sec -1 ] ist die Fluchtaktivitat sehr gering, sie steigt mit zunehmenden Werten von v an, hat bei v = 30 [grad x sec- 1 ] ein Maximum und sinkt fur v>30 [grad x sec -1 ] wieder ab (Abb. 3) : 4. Grose: von unterschiedlich grosen, schwarzen Kreisscheiben, die als "Luftfeind" im dorsalen Gesichtsfeld uber die Krote hinweg bewegt werden, lost eine Kreisscheibe von ca 50° ∅ maximale Fluchtaktivitat aus (Abb. 4). Kreisscheiben, deren ∅≷50° ist, haben fur das Fluchtverhalten geringere Reizwirksamkeit. Die Reizflache der optimalen 50°-Scheibe (Abb. 13a) lies sich schrittweise reduzieren, so das verschiedene geschlossene und aus Einzelflachen zusammengesetzte Muster mit gleich hoher Reizwirksamkeit entstanden: 10° breiter Kreisring von ca 50° ∅ (Abb. 13b), Doppelstreifen mit 10° Streifenbreite und ca 50° Abstand der Streifen-ausenkanten (Abb. 13c), Vier-Punkt-Muster mit 10° Punktdurchmesser ca 50° Abstand benachbarter Punkte (Abb. 13d). Durch flachenmasige Veranderungen dieser Muster lies sich die Fluchtaktivitat nicht weiter steigern, wohl aber verringern (Abb. 5 bis 12). - Kreisscheibe, Ring, Doppelstreifen und Vier-Punkt-Muster haben eine gemeinsame Reizkomponente; sie bildet das Merkmal "Grose" des Feindschlusselreizes : visuelle Ereignisse, die auf der Retina in sowie quer zur Bewegungsrichtung der Feindattrappe simultan mit einer raumlichen Distanz von ca. 50° erfolgen. Dei Reiz-Reaktionsbeziehungen fur das Beutefang- und Fluchtverhalten werden miteinander verglichen. Die Befunde werden im Rahmen unserer bisherigen neurophysiologischen Kenntnisse des visuellen Systems der Krote diskutiert., An Wechselkroten (Bufo viridis Laur.) wurde die Abhangigkeit der Fluchtaktivitat von folgenden Reizparametern einer Feindattrappe quantitativ untersucht: 1. Ort der Feindattrappe (schwarze Kreisscheibe von ca 50° ∅) im Gesichtsfeld: "Bodenfeinde" (Abb. 2b) haben eine sehr viel geringere Auslosewirkung als "Luftfeinde" (Abb. 2a); 2. Betrag und Vorzeichen des Reiz-Hintergrund-Kontrastes: die Fluchtaktivitat nimmt zu, je starker sich die Feindattrappe gegen den Hintergrund abhebt; bei maximalem Absolutbetrag des Reiz-Hintergrund-Kontrastes lost eine dunkle, vor hellem Hintergrund bewegte Feindattrappe starker aus als eine helle vor dunklem Hintergrund bewegte Attrappe; 3. Sehwinkelgeschwindigkeit : bei einer Sehwinkelgeschwindigkeit der Feindattrappe von v = I [grad x sec -1 ] ist die Fluchtaktivitat sehr gering, sie steigt mit zunehmenden Werten von v an, hat bei v = 30 [grad x sec- 1 ] ein Maximum und sinkt fur v>30 [grad x sec -1 ] wieder ab (Abb. 3) : 4. Grose: von unterschiedlich grosen, schwarzen Kreisscheiben, die als "Luftfeind" im dorsalen Gesichtsfeld uber die Krote hinweg bewegt werden, lost eine Kreisscheibe von ca 50° ∅ maximale Fluchtaktivitat aus (Abb. 4). Kreisscheiben, deren ∅≷50° ist, haben fur das Fluchtverhalten geringere Reizwirksamkeit. Die Reizflache der optimalen 50°-Scheibe (Abb. 13a) lies sich schrittweise reduzieren, so das verschiedene geschlossene und aus Einzelflachen zusammengesetzte Muster mit gleich hoher Reizwirksamkeit entstanden: 10° breiter Kreisring von ca 50° ∅ (Abb. 13b), Doppelstreifen mit 10° Streifenbreite und ca 50° Abstand der Streifen-ausenkanten (Abb. 13c), Vier-Punkt-Muster mit 10° Punktdurchmesser ca 50° Abstand benachbarter Punkte (Abb. 13d). Durch flachenmasige Veranderungen dieser Muster lies sich die Fluchtaktivitat nicht weiter steigern, wohl aber verringern (Abb. 5 bis 12). - Kreisscheibe, Ring, Doppelstreifen und Vier-Punkt-Muster haben eine gemeinsame Reizkomponente; sie bildet das Merkmal "Grose" des Feindschlusselreizes : visuelle Ereignisse, die auf der Retina in sowie quer zur Bewegungsrichtung der Feindattrappe simultan mit einer raumlichen Distanz von ca. 50° erfolgen. Dei Reiz-Reaktionsbeziehungen fur das Beutefang- und Fluchtverhalten werden miteinander verglichen. Die Befunde werden im Rahmen unserer bisherigen neurophysiologischen Kenntnisse des visuellen Systems der Krote diskutiert.]

The role of experience in the development and retention of seed preferences in zebra finches.

Abstract: The role of experience in the development of individual food preferences was tested in Zebra Finches using seeds of canary grass, white millet and red millet. Natural preferences, determined in birds reared from hatching on a mixture of equal parts of the three seeds was: red millet = white millet> > canary seed at five weeks of age, and red millet> white millet> > canary seed at 21 weeks. Birds reared exclusively on one of the millets invariably selected a millet over canary seed when tested at five weeks of age or at 21 weeks of age. Choice between the two millets in these tests was irregular with a slight tendency to select the familiar type. Birds reared exclusively on canary seed selected canary seed over a millet in 19 of 22 cases at five weeks of age and in 8 of 10 cases at 21 weeks of age. Selection in the 5 exceptions was statistically random. Birds reared exclusively on one of the millets for five weeks and then changed to the mixed ration for 16 weeks showed preference for a millet in 16 of 10 cases; the remaining 3 showed no definite preference. Birds similarly reared on canary seed and then given the mixed rations before testing selected canary seed in two cases, a millet in 7 and showed no definite preference in 3. Birds reared exclusively on canary seed for 21 weeks and then given only millets for 8 weeks selected canary seed in 2 cases, a millet in one and showed no clear preference in two. Birds reared on one seed type through the nesting period and then on a second seed through the fledgling period all selected the second, fledgling period, seed when tested immediately. When a two weeks period on a third seed, one of the naturally preferred millets, was inserted before testing 3 birds fledged on canary seed retained a preference for canary seed, 4 selected a millet and 2 showed no clear preference. Birds reared on the mixed ration to 21 weeks of age and then given only canary seed for 8 weeks showed a preference for canary seed in 2 cases, for a millet in 3 cases and for neither type in one. It is concluded that restriction to a non-preferred seed during the first 5 weeks of life induces a preference for that seed in Zebra Finches. This learned preference declines gradually with open or forced experience with naturally preferred seeds but persists in some individuals for at least 2 to 4 months. The 2-3 week period after fledgling is important in the establishment of these induced seed preferences, but some birds are postively influenced by imposed food experiences after 5 months of age.

Homing Ability and Orientation in the Painted Turtle Chrysemys Picta Marginata

Abstract: The homing abilities of 45 painted turtles, Chrysemys picta marginata, were examined by observing their behavior when transported to release sites varying distances from their home pond. The turtles displayed a marked tendency to orient homeward when released 100 meters to the north, south, or east. This ability disappeared entirely, however, when the distance of displacement was increased to one mile. Studies of possible orientational cues used during these short homing trips indicated the following: (1) Turtles did not tend to orient by simple, positive geotaxis although such downhill movements could have partially explained the homing results. (2) Homeward orientation did not correlate with wind direction at the time of release. Consequently, olfactory cues emanating from the home pond probably are not essential guiding stimuli. (3) Turtles released under conditions of complete overcast continued to display accurate homeward orientation, thereby arguing against the importance of celestial cues. The use of a form of bicoordinate celestial navigation for homing over short distances is further dispelled by a consideration of the extraordinary sensory capabilities required by such hypotheses. (4) When turtles were blindfolded prior to their release, there was a pronounced deterioration both in homeward orientation (random) and in the straightness of the paths traversed. These results, together with analyses of the actual paths followed by individual turtles, suggest that visual recognition of local topographic landmarks may play an important role in enabling Chrysemys to return to their home ponds. The possession of such a simple, short-distance, homing ability would seem well adapted to the needs of a relatively sedentary species such as the painted turtle.

Maternal Behavior in the Rat: an Investigation and Quantification of Nest Building

Abstract: A technique has been developed to quantify nest building in rats. Small wooden dowels are provided as nest material. Rats shred the dowels, and the degree of nest building is determined by the amount shredded daily. Pregnant females show a marked increase in dowel shredding at or just prior to the time of parturition; shredding falls precipitously after parturition. Males and nonpregnant females show no such pattern over an equivalent period of time; their dowel shredding, in fact, decreases over time. A series of experiments were carried out involving hormone manipulations of pregnant and nonpregnant females. The only significant finding was that progesterone reduced the percentage of females which shredded dowels and also delayed the time of onset of this behavior. When nonpregnant females and males were exposed to cool ambient temperatures, dowel shredding increased markedly. On the other hand, exposing females to a warm temperature blocked dowel shredding behavior. Some similarities and differences between these findings and findings for the rabbit and mouse are discussed.

Nest-Building Behavior in Three Species of Deer Mice, Peromyscus

Abstract: Nest-building behavior of Peromyscus floridanus, P. gossypinus, and P. leucopus was studied. The three species were compared on the basis of amount of cotton removed daily from a dispenser and the type of nest built, and floridanus and gossypinus were also tested for their tendency of shred paper strips. Floridanus removed less cotton and built poorer nests than the other species, which did not differ significantly in these measures. First generation laboratory conceived and reared subjects of floridanus and gossypinus performed more poorly and more variably in these tests than wild-caught individuals, although the relative differences between species persisted. Floridanus did less shredding than gossypinus. In contrast to the cotton-removal experiments, laboratory subjects of both species tended to do more shredding than field animals and had lower coefficients of variation. The differences between field and laboratory subjects in both kinds of tests are attributed mainly to non-genetic differences in activity or temperament produced by conditions of captivity. The poor nest-building behavior of floridanus apparently reflects evolution of burrow nesting habits, with consequent reduction in selection for nest-building behavior, under the influence of warm, xeric climatic conditions. The higher level of nest-building activity in gossypinus and leucopus correlates with their greater habitat and nest-site diversity. The differences in nest-building behavior of these three species are believed to provide at least a partial explanation of their present patterns of ecologic and geographic distribution. Intraspecific variation in nest-building activities was greater in two floridanus populations than in gossypinus from the same areas. The more pronounced difference in the floridanus stocks is correlated with their greater genetic isolation and ecological divergence and appears to be related to the types of burrows available in the two habitats. It is concluded that evolution of nest-building behavior of these three species, although influenced by gross climatic conditions, has been more closely associated with more proximate ecological factors such as habitat and nest site preferences which in turn help to determine the specific microclimates under which each species lives.

Significance of Antiphonal Song in the Eastern Whipbird, Psophodes Olivaceus

Abstract: A spectrographic analysis of the antiphonal song of the Eastern Whipbird, Psophodes olivaceus was carried out. Preliminary results show an overall constancy of male song and a marked geographical variation in female song. Male song is shown to consist of two components: the introduction, which is individually variable; and the whip-crack, which is rigidly species specific. Individual male birds use a series of up to four distinct frequency bands in their introduction. The female antiphonal component shows an individual variation but a constant pattern in any one area. There is a slow development of antiphonal song in juvenile pairs. Both sexes have specialised non-directional nest approach calls. Tentative conclusions indicate a threefold function of antiphony in this species: maintainance of contact; maintainance of the pair bond; and territorial advertisement and display. The song of P. olivaceus is discussed in relation to P. nigrogularis and other Passerine antiphonal species. There is a discussion of the possible origin, evolution and adaptive significance of antiphony in P. olivaceus.

Habituation of Conspecific Aggression in the Three-Spined Stickleback (Gasterosteus Aculeatus L.)

Abstract: 1) Male three-spined sticklebacks which were clearly in the sexual phase of their reproductive cycle, were presented with aggression eliciting stimuli for a period of fifteen minutes each day for ten days. One group was stimulated with a live, nuptially colored male stickleback in a clear plastic tube each day. Another group was presented with a wooden model of a male stickleback each day. The third group received no aggression eliciting stimulation. Both groups which received stimuli showed a decrement in responding to the stimuli over the ten days; the more dramatic decrement was found with the group presented with a live stimulus since this stimulus elicited the greatest aggression initially. 2) Aggressive responses did not all wane at the same rate, but rather one, charges at the stimulus, dropped out first, followed by bites. Orientations toward the stimulus decreased over the ten days but never reached a low level. 3) All three groups were presented with a gravid female stimulus for five minutes each day. The group presented with a model of a male stickleback and the group presented with no male stimulus both showed no change in the level of sexual response directed toward the female stimulus. The group presented with the live male stimulus demonstrated an increasing number of sexual responses directed at the gravid female.

Innate visual form preferences in the pecking behavior of young chicks.

Abstract: 1. Young chicks from the age of 1 to 91/2 days were tested daily for unrewarded two-dimensional form preferences in pecking behavior. 2. Forms having a 049 square inch area were found to be preferred, from high to low, as follows: serrated circle, oval, circle, hexagon, star, pentagon, square, rectangle, and diamond. 3. Chicks that were shown the same forms in a smaller size, .012 square inches in area, preferred them in the same order except that star shifted to last place. The smaller forms elicited a higher level of pecking behavior than did the large ones. 4. There were found increases in pecking behavior as a function of age up to the age of 5 days, after which there was a plateau. Up to (but not including) and after the age of 6-61/2 days the order of preferences for the forms was the same. 5. The disruption of the preference hierarchy at the age of 6-61/2 days is discussed in relation to the food imprinting that HESS (1962, 1964) has demonstrated to occur in chicks.

Behavioral Effects of Rearing Dogs With Cats During the 'Critical Period of Socialization'

Abstract: Social behavior of dogs raised singly with cats from 25 days to 16 weeks of age was studied. A series of tests evaluated the effects of such restricted social experience and later recovery and comparisons were made between cats and dogs that had or had not prior social experience with an alien species. Dogs raised with cats showed a marked intra-species avoidance and lack of species or self-identity. The intra-specifically directed greeting was absent but reappeared following intra-species socialization, together with species or self-identity. Only cats with prior experience with a dog interacted socially with dog raised dogs while the latter always solicited play from cats.

Experimental Analysis of Sexual Behavior of the Deermouse Peromyscus Maniculatus Gambeli

Abstract: Ejaculation in the deermouse Peromyscus maniculatus gambeli was preceded by a sequence of brief penile penetrations (intromissions). In the sexually rested male the number of intromissions preceding the first ejaculation averaged 7 to 8. Each intromission was preceded by a short "bout" of running in which the male pursued the female. Following ejaculation the male failed to mount or investigate the female for the next 6 or 7 minutes. This "refractory period" was terminated when the male achieved another sequence of intromissions and ejaculated again. Males were considered sexually satiated after 30 minutes elapsed without any more ejaculations. Using this criterion it was found that from 3 to 6 ejaculations precede sexual satiation. The refractory periods became progressively longer following each successive ejaculation. If, following satiation, the female was removed and a different female was placed in the test area, all the males achieved additional intromissions and 8 out of 10 ejaculated. When the original mating partner was removed and then returned none of the males achieved ejaculation. This failure to achieve ejaculation with the original female was not due to changes in the condition of the female as a result of copulatory stimulation. Satiated males achieved additional ejaculations with females that had copulated with a different male just prior to the test just as frequently as they did with fresh females that had not copulated for 14 days. The condition of the female as affected by copulatory stimulation did influence other measures of the male's mating performance. These effects were seen most clearly in sexually rested males. The number of intromissions achieved prior to the first and the second ejaculation was greater with females that had received copulatory stimulation just prior to the test than it was with fresh females that had not copulated for 14 days. The time delay between intromissions was longer with fresh females. When males were allowed to achieve their first ejaculation with a fresh female and their second with the same female, there was no change in the number of intromissions from the first to the second ejaculation. This is in contrast to findings with the rat and hamster, in which species a decrease in intromission frequency occurs after the first ejaculation. The current study of the deermouse indicated that if the condition of the female was held constant by testing a male with a fresh female for the first ejaculation and another fresh female for the second ejaculation, a decrease in intromission frequency occurred. On the basis of these results it was concluded that: (i) sexual satiation in the male deermouse is, in part at least, specific to the particular female mating partner, and (2) changes in the condition of the female as a result of copulatory stimulation can have major effects on the "measure of male sexual performance".

Preoptic activation of mating call orientation in female anurans.

Abstract: Techniques are described for inducing ovulation in tree frogs (Hyla cinerea) and toads (Bufo woodhousei fowleri) and for testing the ability of these gravid females to orient to homospecific mating calls. A few preliminary tests were also made with heterospecific mating calls. Several responses to calls are described. Of special interest is an escape response made by Bufo to heterospecific calls. This may serve as an isolating mechanism by effecting avoidance of heterospecific calling males. Males of the same species could not be induced to move toward mating calls. Testing of females with forebrain lesions showed that the telencephalon and the dorsal part of the preoptic area are not necessary for orientation behavior, but that the region of the ventral magnocellular preoptic nucleus is essential.

The Communicative Function of Pelvic Fin-Flickering in Etroplus Maculatus (Pisces, Cichlidae)

Abstract: 1. Fin-flickering (calling) is exhibited only by adult fish when they are caring for the young. This behavior is especially frequent when the parents are alarmed. The calling frequency of the parents was as much as 17 times greater during disturbed conditions than during undisturbed conditions. 2. During disturbed conditions the duration and frequency of calling were significantly greater on the third day that the fry were free-swimming than on any of the other test days. This increase in calling is discussed in connection with other behavioral and histological changes that have been deported to occur on day 3. 3. The parents alternate in the care of the school. The times spent with the school by each parent are not significantly different whether observed during disturbed or undisturbed conditions. 4. On each test day the vertical and horizontal dispersion of the school decreased as calling increased, causing the school to become more compact. The distance from the center of the school to the parent changed significantly only on day 6 of free-swimming, decreasing as calling increased. 5. During the free-swimming stage of development the fry make continual physical contact with the body of the parents, a behavior termed glancing. Glancing rates were unaffected by changes in calling frequency on days 1 and 3 of free-swimming. However, on day 6 and on subsequent days glancing decreased as the calling frequency increased. 6. The changes in school activity as a function of increased calling, which were seen on day 6 but not on day 3, are discussed in light of their adaptive significance.

The Egg-Eating Behaviour of Bomb Us Lapidari Us L

Abstract: When B. lapidarius workers built egg cells and laid eggs, their queen ate the eggs and appropriated the egg cells for her own eggs, whereupon the workers tried to eat her eggs. There was a positive general correlation between the tendency of workers to behave aggressively, to demolish and build cells, to lay and eat eggs, and the degree of their ovary development.

Aggressive Behaviors of Paired Rodents in an Avoidance Context

Abstract: Although the number of rodents of different species and sexes was somewhat small, the consistency of the results enables a reasonably confident description of the effect of pairing rodents in an avoidance context. Considering first the situation in which both rodents were required to make the same manipulatory response to avoid or escape from electric shock: I. Naive rodents paired in this situation do not learn to avoid the shock by responding after the onset of a warning signal and before the shock. In the same situation, the rodents avoid 75-90 percent of the shocks if trained singly. This deficit is not the result of failing to notice the warning signal nor detecting its significance; the incidence of crouching, squealing and anticipatory foot-stomping indicate that the warning signal had acquired secondary aversive properties. 2. The presence of two rodents in the same avoidance situation does not materially affect their escape behavior when viewed at the molar level of the latency of escape responses. At a more molecular level, however, the escape response was almost invariably executed by the rat judged to be submissive when paired outside the avoidance context. When the shock was not quickly terminated, the dominant rat made distinct threat and aggressive responses such as foot-stomping and aborted attack until the submissive rat turned the wheel. 3. After the termination of the shock, the rodents engaged in various forms of interaction of an aggressive nature, including sparring, muzzling, over-and-under, and actual fighting. The most dramatic form observed was mounting with pelvic thrusting by the dominant rodent, even if it was a sexually naive female in the presence of another non-receptive female. 4. Essentially the same pattern of behavior was observed if either or both of the rodents had been pretrained singly in the apparatus either to escape or to avoid the shock. In the case of laboratory rats, which were observed to remain in close proximity to each other, the disappearance of avoidance behavior was more gradual than in their wild counterparts. In the case of the Florida packrats, which were observed to remain very far apart in the apparatus, avoidance behavior gradually reappeared. 5. The pairing of rodents in an avoidance situation had a dramatic effect upon their subsequent behavior when introduced into the situation singly. Even if they had previously learned the avoidance response individually, very little avoidance behavior was observed after a few sessions paired with another rodent. 6. All of the above observations are specific to the situation in which the same manipulatory response is required of both rodents. If a shuttle avoidance situation is employed,in which the necessity for confrontation in making the response is obviated, then avoidance behavior by both rodents continues when paired essentially at the same level as when run singly.

Aggressive Communication By Larus Gla Ucescens Part Ii. Visual Communication

Abstract: Pairs of complete models or wooden block models with adjustable stuffed heads of Larus glaucescens were placed in gull territories. Choice of attack on the models revealed that the head and neck of L. glaucescens are the parts of the body that release aggressive display in territorial behavior. When using models with the head and neck mounted in a normal posture, the upright threat model received a significantly greater number of attacks than the oblique model. The oblique model received a significantly greater number of attacks than the choking model. When comparing the reactions caused by the abnormal postured head at levels identical to those of the normal aggressive postures upright threat, oblique and choking, there were similar results. It was apparent that visual communication was accomplished by head level. A higher head level portrayed lower level of aggressiveness, whereas a lower head level portrayed greater level of aggressiveness and inhibited attack on the model. Secondary aggressive stimuli, such as squinted eyes and muscle tension, are probably not significant in evoking or prohibiting an attack.

Contact and Social Attachment in Domestic Chicks

Abstract: Reasons are given for the possible importance of contact stimulation in imprinting or in the development of social attachments in chicks. This possibility was examined in 2 experiments. In the first experiment chicks were reared for 8 days in isolation cages with coloured balls hanging inside and/or outside the cages. The outside balls were connected with, and moved with, the inside ones. All the chicks made social responses to, and spent time alongside, the balls during rearing and a majority chose their familiar colour ball in a two-choice discrimination test. Chicks with only a ball outside the cage showed significantly less responding during rearing than did chicks with a ball inside the cage. There was also a tendency for fewer of them to respond in the discrimination test. In a second experiment chicks were reared singly with either a ball or a ball covered with a wire-mesh jacket. Responding was equally strong in the 2 groups both during rearing and in 10-trial discrimination tests. Chicks reared with both these objects in their cages directed all their responses to the unprotected ball. If reared with the unprotected ball fixed, they directed all their responses to the protected ball. If both objects were fixed to the cage wall there was less responding but it was directed to the 2 objects equally. The results show that contact with the object is not important for social attachment or imprinting in the chick. They also confirm that movement of the imprinting object strongly affects the degree of responding and the preferences in responding but is probably not essential for attachment to occur.

Tests of Behavioural Characteristics for Rhesus Monkeys

Abstract: A series of tests were designed to assess differences in behavioural characteristics between immature rhesus monkeys. The tests mostly involved responses to strange objects or behaviour in mildly disturbing or frustrating situations. They were administered when the infants were 6, 12, 18 and 30 months of age. Rank order correlations between the same measure in replicated tests, between different measures in one test, between measures from different tests, and between measures from the tests and data from routine observations on mother-infant interaction and on infant activity, were calculated: these were used to assess the reliability and relations between the measures used. The tests were used to assess differences between groups of monkeys differing in previous experience such as presence or not of companions other than the mother, or having been separated from their mother or not. Despite the small group sizes, some significant differences appeared.