Threats and control of the brown necked ravens (Corvus ruflcollis) in Egypt [electronic resource].

Includes reference.

Most of the country of Egypt comprised of uninhabited land. The small fertile areas around Cairo are placed under enormous pressure of existing resources. In these areas, intensive agricultureal practices are performed in combination with high population densities. The described problem is that together with the agricultural practices and the urbanization, Brown necked ravens (Corvus ruflcollis) are in huge amounts attracted. The birds are very aggressive and showed to be a serious pest. They spread germs and diseases for human health and food production. Therefore, the birds need to be controlled. Our research focuses on identifying food preferences of raven and on the way raven control is most effective. Ravens are omnivorous birds. From our laboratory study it was seen that most preferable foods were, in descending order: fresh fishes, cow liver, crustacean, watermelons, tomatoes and yoghurt. Under field conditions, where stomach content was dissected, it animal matters were a more preferred food sourse than plant matters. Biological observations in the field on reproduction of ravens showed that raven females lay two to six eggs. Average number of babies per nest were from one to four, also average number of raven flock before sun rise was more than 100 birds, while it was less than 100 before sun set. The impact of mechanistic, biological and chemical control was investigated. Without control, approximately flock numbers of more than 100 ravens were recorded. The average number of raven nock was 60 before mechanical control operation (nests destroyed and using net), while it was 40 after mechanical control. Results for the biological control showed that kestrel (Falco tinnunculs rupicolaeformes) predated raven babies more effective than barn owls (Tyto alba). Within the chemical control experiments, klerat (0.0005%brodifacollm) \vas most effective against ravens, followed by Methomyl (90% carbomate con1pound) and Zink phosphide (19%).

Summary in Arabic.

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