Ornithology is the branch of zoology that deals with the study of birds. Various aspects in the study of ornithology are treated differently from other disciplines because of the aesthetic appeal and high visibility of birds. The study of birds has greatly aided the introduction and refinement of evolution, ecology, and behavioural instincts of avian species.
In early ornithology, the primary concern was the distribution and descriptions of avian species; however, ornithologists today try to answer various questions with the use of birds as models to test several predictions and hypotheses based on their theories. Because of the varied life of bird species, ornithologists use a wide range of equipment, tools, and new techniques to help them.
In observing migratory birds, ornithologists study the birds’ aspects of orientation, navigation, and physiology. The scientists are aided by the use of special tools. One of the tools that is used in ornithology is the Emlen funnel. It is a bird cage in a shape similar to an inverted triangle or cone. The Emlen funnel is used to have direct contact with birds and to study their behaviour. One of the common characteristic that is observed is the migratory instinct of birds. An ink pad is placed at the bottom of the funnel so that every time the bird flutters or hops onto the sloping walls it will leave a track before moving back down again. The view of the bird from the upper part of the cage can be easily manipulated.