Date of Award

1997

Degree Type

Thesis

Degree Name

Bachelor of Science Honours

Faculty

Faculty of Science, Technology and Engineering

First Advisor

Prof Harry Recher

Abstract

The relatively recent and noticeable increase in abundance and distribution of the Australian Raven (Corvus coronoides) in the Perth metropolitan area, has led to an increase in the amount of problems associated with the bird resulting in a need to quantify its ecology in an urban context. This research documented the abundance and distribution of the raven, possible reasons for its increase, the basic nesting characteristics, peoples attitudes, basic morphology, food items and problems associated with the bird in Perth and Kings Park. These aims were achieved by using observational field data, culled birds, a newspaper questionnaire and Geographic Information Systems. Results showed that the population of the raven in Perth has increased significantly since 1977, and that the bird was found in higher densities where remnant vegetation had been cleared, and in older suburbs that had high numbers of tall trees. Ravens nest in tall trees between ten and twenty five metres in well covered canopies. Eucalypts were the most common nest tree, though many Norfolk Island Pines and Maritime Pines were also used. Morphology was found to be no different to that found in previous studies, while food items were in significantly different proportions to other research completed on the diet of ravens. 40% of respondants to the questionnaire found the raven to be a problem with the main causes being noise, scavenging and attacks on other birds. Main problem areas were inner suburban areas which correlated with the higher densities of the bird populations. An increase in the availability of food sources is ultimately the cause for the raven population increase and an escalation in the problems associated with the bird. Numbers should be controlled using a systematic culling program in areas where problems are severe, but mainly by the instigation of management techniques aimed at reducing access to and the number of food sources available to the bird.

Included in

Ornithology Commons

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