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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Social and non-social influences on the behaviour of primates

Chamove, Arnold Shirek January 1998 (has links)
If a baby macaque monkey must be separated from its mother, it should be pre-fed formula before its separation at around day 5-6. If a milk bottle is always present and the infant routinely lifted to the bottle to feed, it will learn to feed itself in about 30 hours. Peer contact before the age of 5 months is desirable and as little as 1 hour per day produces socially adequate monkeys. A peer, adult male, unrelated adult female, or older juvenile can be used as a mother-substitute but if a peer is used, excessive clinging results from continuous contact with the same peer(s), and excessive aggression results if contact is with only one other animal. Self-injurious behaviour (similar to human stereotypy and not human SIB) results when young monkeys cannot direct aggressive play towards another monkey because one is not present during the day when the appropriate direction for such behaviour is practised. If the young monkey is subjected to altered levels of aggression, their subsequent aggressiveness will be similarly changed, even when there is no opportunity for modelling. It is as if there is some mechanism for copying those levels of aggression which they receive. During therapy of isolate monkeys, infants keep aggression levels low. Aggression levels are also determined by visual stimuli, animals that can never see other animals showing no aggression and those intermittently viewing them showing low levels when interacting with others in darkness. Interference with visual interaction by foliage or by visual screens also reduces aggression by at least half in animals such as monkeys and farmed bulls, deer, and chickens where aggression is problematic. Personality, is less able to predict behaviour in macaques than dominance rank. High dominance rank protects animals from stress during fights, while large changes in rank are stressful in new groupings.

Anti-predator behaviour in UK tit species : information encoding, predator recognition, and individual variation

Carlson, Nora January 2017 (has links)
To combat the ever-present threat of predation many species produce anti-predator vocalizations and behaviours (mobbing) designed to drive predators away. These vocalizations can encode a predator's threat level, and many species within a community will eavesdrop on this information. To determine how prey species produce, use, and respond to anti-predator information and how individual, social, and phylogenetic factors of different species may influence this behaviour, I conducted a series of robotic-predator presentation and anti-predator vocalization playback experiments in the wild and lab. I predicted that UK Paridae would encode information the same as previously studied species. I found that UK Paridae encode predator information in different ways, and that neither phylogeny nor ecology explained the patterns of similarity in how different species encode predator threat in their calls. Flock structure appeared to affect how species encoded predator threat and while multiple species may be sources of information for familiar flock mates, only blue and great tits met the criteria to be community informants. As blue and great tits need prior experience to recognize novel predators and juvenile great tits avoid novel predators only after seeing adults mob them, tits may use mobbing calls to learn about novel predators. While they responded to mobbing calls, juvenile blue and great tits did not engage in mobbing behaviour although they appear capable of doing so. Furthermore, while individuals varied in their responses to aerial alarm calls this variation was not explained by either their proximity to the call nor their personality. In this close examination of how anti-predator vocalizations are produced and used by UK Paridae, I found variation in these signals. This challenges previous assumptions about how Paridae encode information, raising questions as to the sources of this variation.

Studies of the searching behaviour and prey recognition of certain vertebrate predators

Smith, James N. M. January 1971 (has links)
No description available.

The effects of environmental complexity upon the aggressive behavior and growth of juvenile brown trout (Salmo trutta L.) and the carrying capacity of the environment

North, Eric January 1976 (has links)
Experiments were performed in stream tanks and aquaris to investigate the effects of environmental complexity upon the aggressive behaviour and growth of juvenile brown trout (Salmo trutta L.) and the carrying capacity of the environment. Natural materials and various structures were used to provide environmental complexity. Aggressive interactions were found to be significantly more frequent in simple environments than in complex ones. The different types of structures used to modify the complexity of the experimental environments had different effects upon the observed levels of aggressive behavioral structures providing overhead cover were associated with the lowest levels of aggression. Increasing fish density resulted in relatively greater increase in aggression in simple environment. The wigwag display of the fish was analysed and found to be a highly ritualised, defensive manoeuvre, the efficiency of which was determined by the social ranks of the fish involved. Carrying capacity of complex environments was significantly greater then that of simple environments. There was a significant inverse correlation between aggression and resident population size in the environment types used. In the growth experiment, different relationships between individual fish's specific growth rates and their size rank position were found in populations of fish kept in simple and complex environments. The differences were probably associated with the different levels of aggression observed in the two environment types and the effect of environmental complexity upon feeding behaviour.

Leadership, decision making and collective behaviour in animal groups

Dyer, John Robert January 2008 (has links)
No description available.

Cognitive bias as an indicator of emotional states in animals

Parker, Richard Munro Aubury January 2008 (has links)
An important objective of animal welfare science is the development of indicators of putative subjective emotional (affective) states. To this end, Paul et al (2005) have proposed devising animal-based measures sensitive to changes in certain cognitive processes found to be biased in characteristic ways across affective state in humans. This thesis investigates the application of this approach. The first three experimental chapters examine judgements of ambiguous stimuli in rodents. In the first two of these studies, it was hypothesised that a treatment designed to induce a positive, or negative, change in affect would be associated with a higher, or lower, probability (respectively) of responding to ambiguous stimuli in a manner in keeping with a bias towards optimism; such biases, across affect, have been found in humans. These hypotheses were not supported, at least not in simple terms, with the results revealing counter-intuitive treatment effects, and variation in response accuracy and efficiency. In the last of these three experimental chapters, we applied a treatment designed to induce a change in food motivation. This altered rats' operant responses in a manner suggesting their behaviour was a least partly goal-directed, and also suggesting that the possibility of motivation-related confounds, when studying responses to ambiguity, was real. The final experimental chapter investigated affect-related biases in the foraging behaviour of domestic chicks. We hypothesised that chicks undergoing a treatment designed to induce a negative change in affect would attack fewer red crumbs (a colour commonly associated with aposematism), and more green crumbs, than a control group. We found the opposite: i. e. the former treatment group attacked significantly more red crumbs. This curious finding was reconciled with reference to the functional architecture of the attentional processes implicated in foraging behaviour. In the final chapter, the implications of these, and related, findings are discussed

Vocal communication and the facilitation of social behaviour in the southern pied babbler (Turdoides bicolor)

Golabek, Krystyna Anna January 2010 (has links)
Animals use signals to facilitate the fundamental behaviours required for survival and reproduction. In social species, where many individuals interact and have to coordinate numerous behaviours, specialised signals are likely to arise. There are numerous costs and benefits to living in a group, and communication signals that minimise the costs and maximise the benefits of group-living are likely to be adaptive. In this thesis, I use a combination of behavioural observations, playback experiments and acoustic analyses to explore how vocal signals facilitate group-living in a cooperatively-breeding bird species, the pied babbler (Turdoides bicolor). Pied babblers forage together throughout the day, using their bills to find small invertebrates in the substrate, and emitting characteristic vocalisations whilst doing so. In chapter 3, I show that the acoustic structure of these chuck calls changes when a forager comes across certain food items and that the resulting `elevated chuck calls' attract other group-members to the foraging site. Calls are: not always given in situations suitable for sharing, sex-specific in structure, and (although dominant males gave elevated calls more often than expected by chance) males were less likely to be approached than females when giving these calls. These data suggest that elevated chuck calling is not an active signal to promote food sharing, but rather, I suggest, an asymmetry in calling among group members reflects the variation in the costs incurred by calling. Despite the fact that nutritional requirements and other incentives are likely to vary between group members, groups rarely split. In chapter 4, I explore the mechanisms that keep the group together whilst foraging and moving around the territory. I found that dominant individuals are more likely to initiate leading events and more likely to be followed by all other group members, initiating a `successful' lead that keeps the group together. The calls used whilst leading off do not appear to contain a dominant signature, and individuals that call and lead further are more likely to be followed, regardless of their dominance status. The most common patterns in leading and following are likely to reflect the most stable strategy for pied babblers, where dominant individuals hold the highest incentive to lead and subordinates pay thelowest costs of synchronizing movements with others. However, calling provides the opportunity for subordinates to successfully lead in situations where their own personal incentives are high, such as on days prior to dispersal. Pied babblers give a variety of loud calls in various contexts and these can be performed as either solos or group choruses. In chapter 5, I classify eight distinct call types, two of which are unique to males and one unique to females. Three additional calls types were used significantly more by the dominant male of the group, and another most often by dominant females. I discuss the possible functions and implications of the different calling patterns in this species. Group chorusing always occurs if another group is present, but also occurs in some intra-group contexts. In chapter 6, I investigate the function of group choruses, first looking at the patterns in which they occur, the difference in investment between individuals, and the significance of sex-specific call types. In common with other studies, my results suggest that choruses serve multiple functions, both in territory defence but also potentially acting as vocal billboards for the dominant pair to advertise their presence. In this way, choruses may aid in maintaining intra-group dominance hierarchies, and allow dominant females especially to deter opposite-sex competitors in order to retain their breeding position. Groups must defend their territory in order to retain access to resources such as food, breeding sites and sleeping sites, and all group members benefit from this behaviour. In pied babblers territorial signalling involves movement to territory boundaries and then long periods of group chorusing in combination with vigorous posturing displays. In chapter 7, I explore the seasonal patterns in territory defence and show that a reduction in territorial encounters and the strength of response to intruders in the nonbreeding season may be due to an energetic constraint, rather than being driven by breeding behaviours. Taken together, these results suggest that complex groups, where requirements and incentives are likely to be heterogeneous, can function successfully as a group by using signals to mediate the costs and benefits of group-living

A study of the social behaviour and ecology on the wild Barbary macaque, Macaca sylvanus

Deag, John Maxwell January 1975 (has links)
No description available.

The use of landscape features and habitats by the lesser horseshoe bat (Rhinolophus hipposideros)

Knight, Tessa January 2006 (has links)
This study examines the diet and foraging behaviour ofRhinolophus hipposideros from maternity colonies in three contrasting landscapes within Britain. Geographical and seasonal variations in diet and habitat selection exist. .Broadleaved woodlands, water, rural settlements and pastures with wooded edge or unmanaged hedges were generally most utilised and broad-leaved tree cover and edge habitats are likely to be of key importance. The presence of non-volant prey in the diet confirms gleaning, but the majority of prey is probably caught on. the wing during aerial hawking, within or close to the tree canopy. Feeding on swarming insects may play a major part in foraging, with dusk, and to a lesser extent dawn, being important foraging times. The first flying bout was significantly longer in the lowland implying feeding is more efficient in the high quality and upland landscapes. Bats flew for on average 57 % of the night but colder temperatures and increasing rainfall resulted in bats flying for longer. They may aim to reach a target of energy consumption, which takes longer in poorer conditions. An average of 2.1-4.5 night roosting bouts were recorded and R. hipposideros may deviate from the more typical bimodal pattern as their broad diet allows them to feed throughout the night. Night roosts were significantly nearer to core foraging areas than the maternity roost and may form an integral part of the core areas. Foraging density was estimated to be 0.09-0.50 batslha. The ranging behaviour was consistent across the three landscapes. Average home range was 147-177 ha and mean n:taximum distance from the maternity roost waS 2 Ian. It is likely that the bats were adopting an optimal behaviour that is constrained by the species' morphology. The implications of the findings for the species' conservation are discussed and management recommendations are made.

Factors influencing competition and mortality in barnacles

Barnett, B. E. January 1979 (has links)
Competition between Elminius modestus (Darwin) and Balanus balanoides (L) is considered to be an important issue in the invasion of British shores by E. modestus and in explaining the coexistence of both species in the intertidal barnacle niche. Competition is discussed by reference to the concept of ecological performance, which is a term describing all adaptations and physiological and behavioural attributes of each species. Much information on the biology of cirripedes already exists, but the importance of predation and settlement behaviour in relation to competition have not been examined satisfactorily. Consequently these two ecological features are investigated in the thesis. The tolerance of developing embryos to extremes of temperature, and the infection frequencies of the castrating parasite Hemioniscus balani (Spence Bate) are also examined to assess their importance in the ecology of each species. All the available information is then summarised. Comparative assessments of ecological performance are made for each species and for each single feature of their ecology. The assessments are then analysed in an attempt to identify factors which are especially important in regulating competition between the two species. It is acknowledged that the approach is necessarily an over-simplification, but it is broadly concluded that biological mechanisms are more important than actions of the physical environment. Settlement behaviour and susceptibility to predation may be especially significant in influencing competition both during the initial colonisation by E. modestus and in the contest of its coexistence with B. balanoides.

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