I used the great tit (<i>Parus major</i>) and zebra finch (<i>Taeniopygia guttata</i>) as model species to determine whether steroid hormones have effects on avian spatial learning and memory. To address this I took a four-pronged approach: First, as spatial ability is to some extent reliant on appropriate cue use, I examined cue preference in the great tit. In a one-trial associative memory task birds were trained to a compound stimulus where both colour and location cues could be used to locate a reward.  By dissociating the cues on probe trials I was able to determine which cues were controlling the birds’ food-finding behaviour. The overall distribution of choices was significantly different from random but did not differ between the sexes. Both sexes exhibited a preference for the location cue over the colour cue. Second, I exploited the existence of a well-characterised memory task that tests spatial and non-spatial memory. This was an operant conditioning delayed-non-matching-to-sample spatial memory task, presented on computer-controlled touch screen. I tested for sex differnces in performance in birds maintained under a breeding season (i.e. long-day) photoperiod. No sex differences in ability to perform either the spatial or visual memory task were found. Third, I used a non-invasive technique (oral administration) to manipulate hormone levels (testosterone (T), 5α-dihydrotesterone and oestradiol, the latter two being T metabolites) and determined their effect on learning and memory. Although T improved spatial learning and memory abilities in females in Experiment 1, no treatment effects were found in males or in Experiment 2. However, T increased response latencies (time taken to peck a touch screen image) in both sexes, suggesting a beneficial role of T on memory retention. My fourth approach was to use zebra finches selectively bred for differing peak (stress-induced) CORT levels to determine whether CORT affected avian spatial memory in a similar way to that seen in mammals.

Wild reindeer (Rangifer tarandus) were observed on mountain ranges in southern Norway from 1969 to 1971. Seasonal changes in herd distribution, movement, group size and activity were quantified. Traditional calving grounds were located on the Hardangorvidda plateau (60 N,7 E). Individual and social behaviour patterns were fully described including comfort grooming; eight antagonistic threat typos; courtship and displays by rutting males, including ritualised antler clashes and urine self-marking; parturition and the mother-infant bond. The mean gestation period was 227 days. Post-calving herds of up to 10,000 ranged widely. Gregariousness was related to an open habitat and social facilitation. Leadership and socially responsible roles were temporarily adopted by adult females at times of danger for the herd. Play by calves and adults occurred. Aspects of the social organisation of the population were influenced by seasonal environmental factors. The social hierarchy during winter grazing periods had the potential of reducing the physical condition of low-ranking animals; the presence and size of hard antlers was the main determinant of social rank. Winter winds over 30 km/h prevented grazing and provoked heat conservation and heat generation behaviour strategies. The effect of insect harassment on reindeer activity and social structure in summer was quantified and a close relationship with air temperature and wind speed established. Similar results were obtained for Alaskan barren-ground caribou on Arctic tundra in summer 1972. A provisional energy budget is constructed from observed activity times and estimated energy costs. Maximum energy was conserved at calving time (1.3 x BMR), and maximum energy expended in summer (2.5 x BMR) and in the autumn hunt (3.8 x BMR). Comparisons between populations on different mountain ranges revealed no basic behavioural differences. Mountain/tundra Rangifer form multi-male rutting groups while woodland Rangifer form single-male harems. Reindeer do not perform the caribou's particular alarm stance, excitation jump, head-high threat or headbobbing, but do exhibit multiple sucklings of one female by several calves. However the mass of behavioural evidence supports their taxonomic classification as one species.

The problems of defining territoriality and the functions of scent-parking were reviewed in mammals with particular reference to the Mongolian gerbil and the suggested territorial function of scent-marking. It was concluded, on the evidence presented to date, that it was unlikely that this gerbil displayed territorial behaviour in the strict sense of defending an exclusive area. It was also clear that there was insufficient evidence to associate scent-marking behaviour, in mammals in general and specifically in the gerbil, with the defence of a territory and that this behaviour could serve other functions. Experiments were then reported which investigated the links between the agonistic behaviour, territoriality and scent-marking in the gerbil. An ethogram of its agonistic behaviour, derived from laboratory experiments under a number of different conditions, was presented and the possible functions of the behavioural acts and postures observed were discussed. No evidence was found that pairs of gerbils would defend an exclusive territory under laboratory conditions and, although there was evidence of relative exclusivity of use of a home area, it was suggested that this was maintained by mutual avoidance. The rote of the scent-marking behaviour was discussed and experimental evidence presented which suggested that it could assist in the spacing of individuaLs in a natural population as a consequence of learning by association with the aversive stimuli of aggressive sngouqters with conspecifics.

No description available.

This is a study of sexual development and differentiation in the marmoset monkey, Callithrix acchus acchus. The effects of perinatal steroid treatments on the anatomy, physiology and behaviour of females of various mammalian species are reviewed. A summary of the literature on marmoset development is included. Detailed measurements of growth, plasma sex hormone levels and reproductive behaviour were obtained from captive marmosets at birth until 600-1000 days of age. Body weights and knee-to-heel lengths were similar for both sexes. Males had high levels of testosterone from 5-100 days of age and testosterone began to rise again, coincident with the pubertal growth of the testis, at about 250 days. Pre-ovulatory levels of oestradiol were found in females of 200 days old and over, but ovulations, as indicated by high progesterone levels (*N 20 ng/ml), did not occur for nearly another 200 days. The majority of males and females were copulating by 100-500 days old. Males of this age could ejaculate spermatozoa and females were able to conceive. However, first conceptions occurred more frequently when males and females were 500-600 days of age. Maternal age and experience was found more important than paternal for rearing offspring. In all captive groups only the dominant female reproduced. In families, sexual behaviour was virtually limited to the parents, but their maturing daughters ovulated and their sons could ejaculate spermatozoa. In newly-formed peer groups of unrelated animals, clear rank orders were achieved by fighting. The dominant male and female ranked over all the others, formed a pair bond, and attempted to prevent any other sexual relationship. Older and heavier males held high rank, but no such correlation was found with females. Subordinate females copulated but stopped ovulating. There was some evidence of accompanying elevated prolactin levels. The fertility of subordinate males was less affected because they copulated and could ejaculate spermatozoa. The mechanisms of reproductive inhibition and their possible roles in the marmoset's monogamous social system are discussed. Neonatally androgenized female marmosets displayed enhanced rough-and-tumble play and masculine sexual behaviour, but without the loss of feminine behaviour. There was no effect on aggression or fertility, but the clitoris of each animal was permanently hypertrophied. Other primates, such as the rhesus monkey and the human, may have a period of neonatal behavioural differentiation, but the function of high testosterone levels in newborn males remains to be determined. The differentiation of marmoset behaviour after birth may partly explain why females born co-twin to males are chimeric but are otherwise normal.

This thesis aims to identify appropriate methods for the modelling of animal behaviour data, and in the wider context, any time series of categorical data. We make extensive use of a large dataset of cow feeding behaviour, consisting of full feeding records for a number of cows over one month, the data taking the form of binary time series, i.e. feeding/non-feeding periods. After initial exploratory data analysis, we go on to investigate three classes of model: latent Gaussian, hidden Markov and semi-Markov. The latent Gaussian model assumes the binary data occur from the thresholding of an underlying continuous variable. We identify the one-to-one relationship between the autocorrelation of the observed and latent variables and consider techniques for parameter estimation. For a multivariate stationary Gaussian process we show the asymptotic equivalence of the likelihood written in its spectral and conventional forms, and provide a proof that for short-term memory processes such as ARMA models, a good approximation for the spectral form is obtained using Fourier transforms of correlations at only the first few lags. A simulation study highlights the saving in computing time that this offers, and also shows that, in contrast to the least squares methods considered, the number of lags to retain is not crucial for obtaining efficient parameter estimates. Hidden Markov models also directly model the underlying state of the animal, but the latent variable here is discrete and follows a Markov chain, observations being dependent only on the current state. However, this type of model constrains the durations between feeding events to follow a mixture of geometric distributions, which is seen to be inappropriate for the data considered. Semi-Markov models simply involve the animal moving between a set of feeding and non-feeding states according to a set of transition probabilities, the marginal distributions for durations in each state being specified directly.

The research presented in this Thesis investigated the relationship between hypothalamic gonadotrophin releasing hormone-I (GnRH-I) gene expression and the photoperiodic control of reproduction in the Japanese quail (<i>Coturnix c. japonica</i>). A cDNA encoding quail GnRH-I was cloned and used to develop a competitive RT-PCR assay for GnRH-I mRNA. The assay was validated and used to quantify levels of GnRH-I mRNA in the hypothalamus in a series of photoperiodic experiments. The first question addressed was whether a change in GnRH-I mRNA is involved in photoinduced luteinising hormone (LH) secretion, as inferred from an increase in blood plasma LH after transfer from short to long days. An increase in plasma LH was first seen 20h after dawn of the first long day and was found to be associated with an increase in hypothalamic GnRH-I mRNA. Exposure to one photostimulatory day followed by a return to short days, stimulated a surge of LH secretion which persisted for up to 10 days. This photo-induced carry “over effect” for LH secretion was not associated with a “carry over” effect for increased GnRH-I mRNA. The second question addressed was whether the development of relative photorefractoriness induced by prolonged exposure to long day lengths is associated with a change in hypothalamic GnRH-I mRNA. Relative photorefractoriness was demonstrated by showing that quail maintained on long days (18 hr light/day) for a prolonged period went out of breeding condition when transferred to 13 hr light/day, a photoperiod which is photo-stimulatory for fully photosensitive quail. The development of relative photorefractoriness in quail held on 18hr light/day was not associated with a decrease in plasma LH but was associated with a decrease in hypothalamic GnRH-I mRNA. Since the development of relative photorefractoriness is associated with increased prolactin secretion, a final series of experiments investigated the possibility that prolactin might exert an inhibitory effect on hypothalamic GnRH-I mRNA. Treatment of quail with ovine prolactin for 5 days after photostimulation suppressed the photo-induced increase in GnRH-1 mRNA.

No description available.

The thesis examined whether, when applied to behavioural sequences, fractal measures could have diagnostic value in assessments of stress in farm animals. The fractal analysis methodology of Detrended Fluctuation Analysis (DFA) was applied to continuous focal observations of hens and instantaneous scan-sample observations of growing pigs. In experiment one, the complexity of vigilance behaviour increased in young hens; both during the acute stress of open field exposure or following a five-minute period of restraint. The total duration of vigilance was increased in the open field but not following restraint. The DFA measures therefore revealed an alteration in behavioural organisation under stress not identified during standard analysis. In experiment two, a chronic intermittent stressor regime was applied to adult hens. This stressor regime caused alterations in food intake, body weight and egg production, which suggested the birds were transiently stressed. However, the behaviour of the treatment group did not differ from controls at any time point, either when using a standard analysis or a DFA. In the third experiment, a stressor regime involving repeated social defeats and additional mild stressors was applied to growing pigs. Following this regime the treatment group had higher levels of average 24hr cortisol than controls. The DFA did identify behavioural differnces between treatment and controls groups; however, it is unclear if these were directly related to the stressor treatment. The data sets generated in the experiments were used to further investigate the DFA method. Analyses showed that alterations in the duration of observation and the frequency of behavioural sampling can affect the end result. Although the analysis has some limitations it allowed novel dimensions of behavioural organization - not identified during standard analysis - to be measured. These dimensions were independent of total durations of behaviour and they were sensitive to stressful stimuli in some circumstances. In conclusion, fractal analysis of behaviour shows promise as a tool for measuring stress but further validation is required.

No description available.