This thesis seeks to determine if juvenile birds preferentially select foraging information from their parents, by examining the acquisition of novel food-finding skills in juveniles of a flock-feeding species, the ringdove (Streptopelia risoria). / The first experimental examined the flock feeding behaviour of juvenile ringdoves foraging in a small aviary flock composed of kin and non-kin; frequencies of local enhancement, food begging and aggression were recorded, as well as the individuals that the juvenile associated with while searching for food. Juvenile ringdoves foraged significantly more often with their kin and were aggressed more by non-kin. The last three experiments tested juveniles on three components of foraging: novel food type, environmental colour cues associated with food and novel food-searching techniques. All three involved a choice-test where the juveniles had their father and an unrelated flock member as demonstrators. All three choice-tests showed there was no preference for selecting either demonstrator's solution. Juvenile doves in the field may appear to learn from their parents simply because they associate more with them. (Abstract shortened by UMI.)

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A seasonal change occurred in the type of food consumed by the birds studied. Plant food was more important in the winter than in the summer. Animal food, except in one species, was found to be more important during the summer months. The most important plant foods determined by frequency and listed in order of their abundance were: Helianthus annuus, Celtis sp., Quercus sp., Polygonum convolvulus, Amaranthus blitoides, Chenopodium album, and Amaranthus graecizans. The most important animal foods based on occurance in stomachs examined were: Coleoptera, Hymenoptera, Lepidoptera larvae, Orthoptera, Undetermined larvae, Diptera, Homoptera, Coleoptera larvae, Araneae, and Hemiptera. Seventeen species of birds were found to be common residents of the chaparral based upon number of times collected. Thirty nine species were found infrequently. Twenty different types of plant food was found among the species studied. Twenty three types of animal food was also recorded.

published_or_final_version / Ecology and Biodiversity / Master / Master of Philosophy

This thesis focuses on the relationship between innovation and social learning in the foraging context, across and within bird species, using two different sources of data: anecdotal reports from the literature, and experimental tests in the laboratory and the field. In chapter 1, I review the trends in innovation and social learning in the avian literature, and contrast them with trends in mammals, especially primates. In chapter 2, I use anecdotal reports of feeding innovation and social learning in the literature to assess taxonomic trends and to study the relationship between the two traits at the interspecific level. In chapter 3, I investigate the relationship between innovation and social learning at the intraspecific level in captive feral pigeons (Columba livia). Innovation is estimated from the ability to solve an innovative foraging problem, and social learning is measured as the number of trials required to learn a foraging task from a proficient demonstrator. (Abstract shortened by UMI.)

This project investigated the impact of bird predation on insect pest populations within two cornfields of Southwestern Quebec. Birds were excluded from portions of these fields through the use of bird-proof netting. Rhopalosiphum maidis, Ostrinia nubilalis, Agrotis spp. and Sphenophorus spp. were all found at greater densities in plots where birds were excluded as compared with the non covered plots. Only the adult Diabrotica longicornis population was not reduced by birds. Results significantly suggest that birds can reduce insect pest populations. Bird visits in cornfields with respect to distance from field edge, type of edge habitat and corn phenology were also studied. Red-winged Blackbird, Song and Chipping Sparrows and American Robin were the most frequently observed bird species inside cornfields. Early in the summer, birds tended to stay closer to the field edge, especially when composed of mature coniferous trees. Different bird species visited the cornfields at specific periods during corn development.

Part I of this study presents a procedure for standardization of pellet analysis methodologies which improves estimation of prey biomass and determines the number of pellets needed to estimate prey diversity indices. The procedure was developed to provide a simple, easily replicated methodology for the study of pellets which also retains maximal data recorded from pellet analysis. A sample size of ten Long-eared Owl pellets was found adequate to calculate diversity indices with no significant loss of accuracy when compared to total pellets recovered from beneath a roosting site. Analysis of the total sample of pellets from a specific roost provided information on intraspecies size selection by Long-eared Owls and also increased the probability of finding remains of rare prey in pellets from the areas studied. Part II of this study investigates the influences of seasonality and habitat differences on prey selection by Long-eared Owls in north-central Oregon. Differences in habitat where Long-eared Owls foraged were found to significantly influence prey species selection of Thomomys talpoides , Lagurus curtatus, Peromyscus maniculatus, Microtus montanus, and Perognathus parvus. Significant seasonal differences were also observed in the consumption of T. talpoides and M. montanus. Analysis of intraspecific size selection of northern pocket gophers by Long-eared Owls supports the observation that size of prey influences the foraging strategies of Long-eared Owls to a greater degree than does species composition.

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