The matching-to-sample (MTS) task, as pointed out by Ginsberg (1957), is a "special case" of a conditional discrimination problem. It is "special" in that the conditional stimulus is identical to the stimulus the subject is to choose. Thus, in the MTS task, the subject can use either the physical properties of the sample (ST) stimulus directly, or employ some mediating event as the discriminative stimulus. The present study is an attempt to isolate the functional discriminative stimulus in the MTS task. The study varied the response requirements to the STs, and hypothesized the information (i.e. resnonse produced cues or stimuli) induced by these requirements provides the basis for correct matching behavior. Before proceeding to the proposed method of testing this hypothesis a description of the MTS task will be given, along with a brief review of the theories and data leading to this research.

The purpose of this work was to determine the manner of inheritance of serum alkaline phosphatase in the racing pigeon, (Columba livia). The evidence indicates that the electrophoretic patterns of serum alkaline phosphatase in the pigeon are inherited as codominant genes.

A methodological study was performed in order to derive a suitable procedure for the study of the Muller—Lyer illusion in the pigeon. Pigeons were trained to peck at one key when the middle wing in a Muller-Lyer figure was displaced towards one of the outside wings, and at the other key when it was displaced towards the other outside wing. The subjects were then presented with varied settings of the middle wing in order to determine the setting at which they would switch from one key to the other. It was found that, in a two-key situation, the pigeon developed a "preference" for one key over the other and that this tendency, carried over into the testing situation, influenced the "switchover point in a direction determined by the key preference. This evidence enabled the derivation of a more suitable method, which is suggest for use in further research on the Muller-Lyer illusion in the pigeon. / Thesis / Master of Arts (MA)

Pigeonpea (Cajanus cajan (L.) Millsp.) is cultivated by many farmers in the semi-arid areas of Kenya as a source of food and cash. However, the yields have remained low, ranging between 500 to 800 kg haˉ¹. Apart from drought, fusarium wilt is reported to affect yield. Breeding pigeonpea hybrids, using cytoplasmic male sterile (CMS) lines, hybridized with the local improved germplasm, have the potential for increasing yield and improve income for smallholder farmers. The objectives of the study were to: 1) examine the various stakeholders of the pigeonpea value chain and their core functions and identify characteristics of the pigeonpea varieties preferred by the market to be considered in the hybrid breeding programme, 2) evaluate cytoplasmic male sterile lines of Indian origin for stability across several environments in Kenya, 3) screen pigeonpea genotypes for general resistance to Fusarim udum Butler and 4) evaluate pigeonpea hybrids for grain yield and earliness across sites and seasons in Kenya. The stakeholder analysis established that the main players in the pigeonpea value chain were farmers, traders/processors, International Crops Research Institute for the Semi-Arid Tropics, Kenya Agricultural Research Institute, Kenya Plant Health Inspectorate Services, and Ministry of Agriculture. White seed, large seed size and medium maturity were the preferred traits by farmers and processors/exporters for both domestic and export markets. The unavailability of quality seed in sufficient quantities of high yielding varieties was cited as the main factor negatively affecting pigeonpea production. The stakeholder analysis approach, used for the first time in a breeding programme, demonstrated that it can be an important tool that can be used to diagnose crop production constraints, and define opportunities available for setting up a breeding programme that is highly client-oriented. Two CMS lines, ICPA2043 and ICPA2039 were the most stable across sites with 100% and 99% pollen sterility respectively. Screening for the presence of physiologic races of F. udum based on morphological and cultural characteristics on PDA identified three distinct isolate groups named ISO-A, ISO-B, and ISO-C. Studies under controlled conditions using the three isolates identified seven pigeonpea genotypes (ICPB2043, ICP12012, ICP13092, ICPA2039xICP13092, ICPA2043xICP12012, ICPA2043xICP13092, ICPA2043xICP9135) resistant to the three F. udum isolates. In the field evaluation, seven genotypes (ICPA2039xICP13092, ICPA2039xAsha, ICPA2043x12012, ICPA2043xICP13092, ICPA2043xICEAP557, ICPB2043 and Maruti) were found to be moderately resistant. The variances due to GCA and SCA were significant, showing that both additive and non-additive gene actions were important. The resistant hybrid, ICPA2043xICP12012 had the highest negative SCA that was highly significant for all the isolates and in the field indicating general resistance. The CMS (A) line ICPA2043 was found stable across environments and highly resistant to the three F. udum isolates. Therefore, it can be evaluated further for commercial hybrid seed production in Kenya. Evaluation of the pigeonpea genotypes across environments indicated that the highest yielding environment was Kiboko, with average and maximum yield of 2,249 kg haˉ¹ and 4,234 kg haˉ¹ respectively. Most hybrids were in the medium duration maturity group with days to maturity ranging from 147 to 186. Overall, the highest yielding hybrids were A2043xTZ26 and ICPA2039xTZ24 with mean yields 2,803 kg haˉ¹ and 2,527 kg haˉ¹ respectively. Mean yields for the best performing parents were 2,036 kg haˉ¹ for ICP12012 and 1,629 kg haˉ¹ for Asha. For specific sites, the highest yielding hybrids in Kabete, Kiboko and Leldet were A2039xTZ24 (2,057 kg haˉ¹), A2043xTZ26 (2,803 kg haˉ¹), and A2043xUG8 (1,708 kg haˉ¹) respectively. Mean heterosis for yield varied from -35% (A2039xA2043) to 50% (A2043xUG8). In Kenya, the potential for production and commercialization of hybrid pigeonpea is feasible due to high hybrid vigour recorded, and the stability of the CMS lines. Hybrids also have greater uniformity in grain size a factor which is important for the market. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

Thesis (M.S.)--Oregon State University, 2004. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.

Understanding how organisms learn perceptual categories on the basis of experience has been an important goal for researchers in a number of subdisciplines of psychology, including behavior analysis, experimental psychology, and comparative cognition. The primary aim of this thesis is to investigate how nonhumans (pigeons) and humans learn to make visual category judgments when stimuli vary quantitatively along two dimensions, particularly when accurate responding requires integration of information from both dimensions. The thesis consists of four chapters and a technical appendix. Chapter 1 is a literature review which provides a broad overview of studies on categorization by nonhumans and humans, as well as specific background for the current research. Chapters 2 and 3 constitute the empirical portion of this thesis. Four experiments are described, using a category task based on the ‘randomization’ procedure developed originally by Ashby and Gott (1988) with human participants and employed in subsequent research by Ashby, Maddox and their colleagues (see Ashby & Maddox, 2005; Maddox & Ashby, 2004, for review). Stimuli were Gabor patches that varied in frequency and orientation. Our primary goals were to determine whether pigeons could respond accurately in an information integration task with dimensionally-separable stimuli, and to compare performances of pigeons and humans. Chapter 2 reports two experiments with pigeons. Experiment 1 compared performance in two conditions which varied in terms of whether accurate performance required control by both dimensions (“information integration; II) or by a single dimension (“rule based”; RB). Results showed that pigeons learned both category tasks,with an average percentage of correct responses of 85.5% and 82% in the II and RB conditions, respectively. Although perfect performance was possible, responding for all pigeons fell short of optimality. Model comparison analyses showed that the General Linear Classifier (GLC; Ashby, 1992), which has been proposed to account for category learning in similar tasks with humans, provided a better account of responding in the II conditions, but a unidimensional model that assumed control only by frequency provided a better account of results from the RB condition. Thus results show that pigeons can respond accurately in an information integration task based on dimensionally-separable stimuli. However, analysis of residuals showed that systematic deviations of GLC predictions from the obtained data were present in both II and RB conditions. Specifically, accuracy for one category (A) was an inverted-U shaped function of orientation, whereas accuracy for the other category (B) did not vary systematically with orientation. Results from the RB condition showed evidence of an interaction between frequency and orientation, such that accuracy was higher for orientation values that were relatively low (i.e. close to horizontal) than high (i.e., close to vertical). Experiment 2 compared responding in two RB conditions which differed in terms of whether frequency or orientation was the relevant dimension. Pigeons again responded accurately in the task. Results from the frequency-relevant condition replicated the interaction obtained in Experiment 1, whereas results from the orientation-relevant condition gave no evidence of an interaction. Chapter 3 reports two experiments which compare performances of pigeons (Experiment 1) and humans (Experiment 2) in category tasks using identical stimuli. In each experiment there were two conditions, both based on the information-integration task in which the range of orientation values was wide or narrow. There were two primary goals. First, we wanted to test whether the inverted-U shaped pattern for Category A accuracy as a function of orientation would be replicated with different pigeons and stimulus values. Second, we wanted to compare responding of pigeons and humans. A secondary aim was to test whether restriction of range would affect control by orientation. Results from the condition with a wide orientation range were similar to those from Chapter 2, and showed that the inverted-U shaped pattern was replicated for both pigeons and humans. When the range of orientation values was narrow, responding for both pigeons and humans was exclusively controlled by orientation. Overall, results for pigeons and humans were similar and suggest that a common process may underlie information-integration category learning in both species. Chapter 4 provides a summary of the empirical results from Chapters 2 and 3, and shows that the inverted-U shaped pattern of accuracy for Category A as a function of orientation is unanticipated by current models for category learning, such as the GLC, prototype theory, and exemplar theory. A new ‘fuzzy prototype’ model is described which provides a good account of the results and predicts the inverted-U shaped pattern. According to the new model, subjects associate a linear segment in the stimulus space (‘fuzzy prototype’) with one of the category responses. When a stimulus is presented on a trial, subjects are assumed to use an ‘A/Not-A’ decision rule, with the probability of a Category A response determined as a function of the minimum distance of the stimulus from the fuzzy prototype. Possible directions for future research are considered. The thesis concludes with a technical appendix which describes the experimental chambers, interface hardware, and computer software developed to conduct the research,and a detailed user’s manual for the software. The system allows the same control procedure for both human and pigeon experiments, and should be useful for future research on categorization

Pigeonpea (Cajanus cajan (L.) Millsp.) is a drought tolerant legume of the Fabaceae family in the order Fabales and the only cultivated species in the genus Cajanus. It is mainly cultivated in the semi-arid tropics of Asia and Oceania, Africa and America. In Malawi, one of the top producers of pigeonpea in Africa, it is grown by small scale farmers as a source of food and income and for soil improvement in intercropping systems. However, varietal contamination due to natural outcrossing causes significant yield losses for farmers. In this study, 48 polymorphic SSR markers were used to assess diversity in all pigeonpea varieties cultivated in Malawi with the aim of developing a genetic fingerprint to distinguish the released varieties. SSR alleles were separated by capillary electrophoresis on an ABI 3700 automated sequencer and allele sizes determined using GeneMapper 4.0 software. Allelic data was analysed with PowerMarker. A total of 212 alleles were revealed averaging 5.58 alleles per marker with a maximum number of 14 alleles produced by CCttc019 (Marker 40). Polymorphic information content (PIC) ranged from 0.03 to 0.89 with an average of 0.30. DARwin software was used to generate a neighbour-joining tree that displayed three major clusters with two sub clusters in Cluster I. The released varieties were scattered across all the clusters observed, indicating that they generally represent the genetic diversity available in Malawi, although it was observed that there is substantial variation that can still be exploited through further breeding. Screening of the allelic data associated with five popular pigeonpea varieties for which a DNA fingerprint was to be developed, revealed 6 markers – CCB1 (Marker 1), CCB7 (Marker 2), Ccac035 (Marker 7), CCttc003 (Marker 15), Ccac026 (Marker 37) and CCttc019 (Marker 40)– which gave unique allelic profiles for each of the five varieties. With further tests needed for its robustness, this genetic fingerprint can be used for seed certification to ensure only genetically pure seeds are delivered to Malawi farmers. / Agriculture and  Animal Health / M. Sc. (Agriculture)

Walking pigeons display a characteristic behaviour: head-bobbing. Head-bobbing consists of two phases, the hold phase during which the head is kept stable in space, and the thrust phase during which the head is quickly moved forward. But why do pigeons and so many other birds head-bob? Two theories have been developed to answer this question. First, head-bobbing may have a visual function, namely object detection during the hold phase and depth perception during the thrust phase. Second, head-bobbing may have the biomechanical function of increasing the stability. The present study aimed to gain further insight into why pigeons head-bob. A gait cycle analysis of walking pigeons revealed that the hold phase starts at a specific point in the gait cycle and is not dependent on the walking speed. The point in the gait cycle at which the hold phase starts indicates a potential increase in stability during the single stance phase, as it leads to a longer period of time during which the center of mass is above the base of support. The end of the hold phase, however, is dependent on the walking speed, specifically the step length for a given walking speed. I found that the thrust phase duration is constant for all walking speeds and the distance the head travels during that time is equal to the step length. With increasing walking speed the head moves faster during the thrust phase and the hold phase duration is decreased leading to a higher head-bobbing frequency. With fast enough walking speed the hold phase is eventually eliminated, marking the transition point from walking with head-bobbing to fast walking without head-bobbing. The exact velocity of this transition point was predicted for each individual and was dependent on the maximal step length of each pigeon. All head-bobbing parameters could be described with the step-frequency, the thrust phase duration, and the maximal step length, indicating that head-bobbing behavior is individual for every pigeon and depends on its body size. / Thesis (Master, Biology) -- Queen's University, 2013-07-22 23:11:41.557

A persistent challenge for behaviorally-based accounts of learning has been providing an account of learning that occurs in the absence of systematically programmed contingencies of reinforcement. Symmetry, one type of emergent behavior, has been repeatedly demonstrated with humans, but has been considerably more difficult to demonstrate with non-humans. In this study, pigeons were exposed to a go/no-go procedure in which hue stimuli were presented full screen on a touchscreen monitor. Pigeons learned 12 baseline relations in less than 30 days. Traditional measures used to evaluate symmetry indicated that, during tests, three of the four birds responded more to the reverse of relations that were reinforced in training than to the reverse of relations that were not reinforced in training. However, additional analyses of these data suggests that these differences were driven by one of two trial types and that symmetry was only observed for one of the two predicted relations. These data systematically replicate and extend work by Urcuioli and colleagues and point to areas where further research is needed.

"A Telemetric monitoring of the feral pigeon ( Columba livia f. domestica) population at the Karlovo náměstí square in Prague" This thesis deals with both the monitoring of numbers in the pigeon (Columba livia f. domestica, "the Pigeon") sites in question and also the spatial definition of the daily activities of individual specimens using a telemetric system. Previous researches gathered data on population density and food routes usually obtained by observation. Therefore we believe it's important to supplement this data with spatial movement maps of individuals that cannot be obtained by observation but the telemetry system allows us to do so in certain time period. The data obtained from GPS trackers will be processed into daily spatial activity maps of the specimen. These data will hopefully help us to gain insight into the life of not just specific individuals, but will also allow us to derive spatial activity of the entire population living in the locality in question. The results will be compared with the results from the previous pigeon count. This knowledge can be useful to population control, or serve in other studies. Keywords: pigeon, abundance, telemetry