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The Influence of Demonstrator Quality on The Social Transmission of Food Preference in the Norway Rat (Rattus norvegicus)
Get PDFAn observer rat that interacts with a conspecific, a demonstrator that has eaten a
flavoured food, is subsequently more likely to eat that food than an alternative, novel food
(Galef & Wigmore, 1983). In the first part of this thesis, four experiments were
undertaken to determine the influence of unreliable demonstrators on observer food
preference. In the first three experiments, observers were poisoned after interaction with
demonstrators; a demonstrator that demonstrated a food that led to poisoning was
considered an unreliable demonstrator. The first experiment compared the influence of an
unreliable demonstrator and an unfamiliar demonstrator on observers' food preferences.
Experiment 2 compared the influence of demonstration from an unreliable conspecific and
a familiar conspecific that had only provided irrelevant information. The third experiment
compared the influence of an unreliable and a reliable demonstrator. Experiment 4
compared the influence for protein-deficient observers of a demonstrator that had
previously demonstrated a protein-deficient diet and a demonstrator that was unfamiliar.
None of the first four experiments showed a significant difference in effectiveness of social
transmission due to demonstrator quality.
In the second part of the thesis I investigated the influence of familiarity on
demonstrator effectiveness. In Experiment 5, the influence of local sisters was compared with that of unfamiliar non-relatives as demonstrators. Sisters were not better
demonstrators than unfamiliar non-relatives.ThesisMaster of Science (MSc
Pup Cannibalism: A Description and Causal Analysis of One Aspect of Maternal Behaviour of the Golden Hamster (Mesocricetus auratus)
No full textFollowing parturition, the female golden hamster (Mesocricetus auratus, Waterhouse, 1839) exhibits a broad repertoire of maternal behaviours essential for the growth and protection of her developing offspring. In addition to engaging in obviously nurturent activities, the maternal hamster exhibits a behaviour infrequently observed in other species: she almost invariably cannibalizes some of her own live offspring. Hamster pup cannibalism has been characterized in the literature as a breakdown of normal maternal behaviour, resulting from a variety of possibly stressful conditions imposed upon the mother (for example, disturbance following parturition). The influence of such factors on frequency of pup destruction, however, has not been empirically examined, and, in fact, no systematic observation of hamster pup cannibalism has been reported in the literature. The major purposes of this thesis were to provide normative data on the frequency, extent, and time course of cannibalism by hamsters rearing their litters under standard laboratory conditions, and to determine the proximal stimulation controlling the onset, maintenance, and cessation of this behaviour. Systematic observations of 63 litters born to 21 mother indicated that there is a high probability (.75) of a mother exhibiting some cannibalism toward her young, but that each mother destroys only a few of her pups. Eighty percent of this destruction occurs within five days of parturition, and cannibalism is directed apparently randomly towards the pups present in the litter. While an individual hamster does not reliably cannibalize a certain number of pups, she does exhibit relative constancy in the number of pups she rears over successive litters. Experimental results indicated that the pup cannibalism normally exhibited by the hamster is not dependent upon the presence of the possibly stressful conditions suggested in the literature. Instead, the results provided evidence that the initiation of pup cannibalism is systematically controlled by a variety of stimuli which reflect the size of the litter, including olfactory stimulation and stimulation received during nursing. Each hamster apparently cannibalizes to regulate her litters at a particular size. If litter size is artificially reduced by removing pups from the litter, the mother reduces cannibalism proportionally. If litter size is increased on the day of parturition, by giving the mother newborn foster pups, she will exhibit a compensatory increase in cannibalism. The probability of observing this compensatory increase in cannibalism in response to artificial litter size increment decreases as a function of increasing time postpartum at which litter size is altered. The change in responsiveness to litter size was found to be a results of internal changes in the mother occurring as a function of time postpartum, rather than from changing stimuli received from pups increasing in age. Variations between individual mothers in the number of pups they rear per litter probably results from long-term constancies in their relative capacity to conceive, deliver, and/or successfully maintain young. The observation that hamster consistently gives birth to more pups than she will rear, and achieves a reduction in number of pups by an active culling of the litter, suggests that pup cannibalism enables the mother to alter the size of her litter to that size most compatible with her capacity to rear young under specific environmental conditions.Doctor of Philosophy (PhD
Conditioned Food Aversions: Illness-Induced Aversions to the Interaction of Gustatory and Nongustatory Cues
No full textLaboratory rats were habituated to drinking sucrose in one environment (the sucrose environment) and water in a second (the water environment). Subjects poisoned after drinking sucrose in the water environment subsequently exhibited a marked reduction in sucrose intake in the water environment. The same subjects did not exhibit depression of water consumption in the water environment and showed only a slight, nonsignificant reduction of sucrose intake in the sucrose environment. These results indicate that rates will form an aversion to a compound stimulus consisting of both gustatory and environmental components without forming an aversion to either the gustatory or environmental component in isolation.Master of Arts (MA
Social Feeding in Burmese Junglefowl (Gallus gallus spadiceus)
No full textThere is reason to believe that birds feeding in flocks enjoy several different types of advantage relative to birds that feed alone. Most relevant to this thesis, flocking can facilitate individual birds' discovery of potential foraging sites. In the present research, both the long-term consequences of social feeding socially were examined in Burmese junglefowl (Gallus gallus spadiceus). The results of experiments presented in Chapter 2 indicated that junglefowl can learn to select either a type of feeding site or a location in which to feed simply by observing feeding companions. Social interaction biased the foraging behaviour of fowl for at least two days after interaction occurred. In experiments described in Chapter 3, junglefowl used information acquired during the exposure to videotaped companions to orient their own subsequent feeding behaviour. Different aspects of the feeding behaviours of video-taped tutor fowl influenced different aspects of their observers' feeding behaviour. For example, during testing, observer birds' latencies to initiate pecking were reduced by pervious exposure to the sight of conspecifics feeding, while the orientation of observers' pecking was influenced only when observers had both seen and heard feeding companions. The final study, presented in Chapter 4, indicated that observer fowl, even while feeding, were themselves able to learn about foraging sites where videotaped companions fed.Doctor of Philosophy (PhD
Role of Attention in Exteroceptive-Cue-Aversion Learning
No full textExteroceptive-cue-toxicosis associations are usually difficult to produce and generally less robust than flavour-toxicosis associations. The following series of experiments investigates the paradoxical enhancement of aversion conditioning to exteroceptive cues induced by the presence of a novel flavour at the time of exteroceptive-cue-toxicosis conditioning. It was found that this flavour facilitation effect is due, in part, to the operation of a mechanism that directs subjects' attention to stimulus attributes of ingesta (Chapter 3). Further experiments suggested that the attentional mechanism is not robust enough to facilitate visual-cue-aversion conditioning over long delays (Chapter 4) and that, consistent with an attentional interpretation, only certain stimuli were subject to the operation of the attentional mechanism (Chapter 5). Apparently rats are more likely to treat certain stimuli as attributes of food objects and these stimuli are more readily associated with toxicosis. Adaptive-evolutionary accounts that dichotomize stimuli into those that are and those that are not associable with toxicosis or theories that suggest that all exteroceptive cues are contraprepared to be associated with toxicosis cannot account for the present finding of graded exteroceptive-cue-toxicosis conditioning with distance from the food object. The experiments of this thesis suggest that stimulus salience is not an inflexible characteristic of the stimulus itself. Rather, it is suggested that stimulus salience varies as a function of several factors amongst which the type of reinforcement and time of onset of reinforcement, the presence of other stimuli, the animal's past experience with the stimuli and the relation of the stimuli to the food object appear to play central roles.Doctor of Philosophy (PhD
Social Influences on Mate Choice
Get PDFClassical theories of how animals make mate choices have focused on each sex's
inherited preferences for the other sex's traits or behaviours. The present thesis
was undertaken to investigate how social factors play a role in determining an
animal's choice of mate. In the series of experiments reported here, 'focal' female
and male Japanese quail were given the opportunity to observe another quail (a
'model') of the same sex mating with a conspecific of the opposite sex (a
'target'). Results of experiments described in chapters 2 and 3 revealed that focal
females: (1) displayed an increased tendency to affiliate with male targets that
they had observed mating with model females, and (2) found a target male more
attractive if he had been observed just standing near another female. In Chapter 4,
social influences or male mate choice were investigated. Focal males: (1)
exhibited a decrease in their preference for female targets that they had observed
mating with model males, and (2) showed a decrease in preference for a female
target only if she had been seen mating with or being courted by a model male,
not simply standing near him. Finally, in chapter 5, it was determined that for
quail of both sexes, affiliation time was a reliable predictor of focal subjects'
actual choice of a mate. Taken together, these results are consistent with the
hypothesis that females gain benefits from attending to the mate choices of other
females, whereas for males there is a cost associated with mating with a female
that had recently muted with another male.ThesisDoctor of Philosophy (PhD
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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