A preliminary account of a regular fluctuation in California quail in Central Otago

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Over the last eleven years California quail (Lophortyx califamicus) in Central Otago have exhibited a very regular annual fluctuation in winter age-ratios as calculated from records of the sex and age of birds shot during the open season. Sexing and aging are simple but accurate operations-the former depending upon a strong sexual dimorphism, the latter upon the possession of mottled primary coverts by birds of the year. The sample obtained by the diary scheme is broken down by the sportsmen co-operators into four classes :-adult males and females and immature males and females. The annual age-ratios are calculated as the total number of immature birds per hundred adult females, and the result of the eleven-year study is shown in Fig. 1.