Nhân khẩu học là nghiên cứu về kích thước và cấu trúc dân số và quá trình thay thế cá nhân tạo thành dân số. Nghiên cứu nhân khẩu học phát triển để dự báo dân số tăng trưởng. Tỷ lệ dân số tăng hoặc giảm phụ thuộc cơ bản vào khả năng sinh sản (số trứng đặt) và tử tuất của các cá nhân thuộc về dân số (Hình , phía dưới), nhưng cũng đến một mức độ thấp hơn (đặc biệt là đối với chim biển) về di cư. Bởi vì nhiều sinh vật, và đặc biệt là loài chim biển, giống nhiều. | Seabird Demography and Its Relationship with the Marine Environment Henri Weimerskirch CONTENTS Demography and Life History Seabirds and Other Demographic Parameters of Comparing the Demography of the Four Orders of Factors Responsible for Differences in Demographic Intraspecific Variations in Demographic Population Regulation and Environmental Perspectives .131 Literature DEMOGRAPHY AND LIFE HISTORY STRATEGIES Demography is the study of the size and structure of populations and of the process of replacing individuals constituting the population. The study of demography was developed to forecast population growth. The rate at which a population increases or decreases depends basically on the fecundity number of eggs laid and survivorship of the individuals that belong to the population Figure bottom but also to a lesser extent especially for seabirds on migration. Because many organisms and especially seabirds breed several times in their lives a population consists of cohorts of individuals of different ages born in different years. Moreover mortality and fecundity rates are generally age-specific life tables represent these birth and death probabilities. The relationship between the rate of increase or decrease and demographic parameters can be translated into more or less complex equations. The basic equation is the Euler-Lotka equation Euler 1760 Lotka 1907 that specifies the relationships of age at maturity age at last reproduction probability of survival to age classes and number of offspring produced for each age class to the rate of growth of the population r . The demography of organisms is a key to the evolution of life histories because it allows us to examine the strength of selection on life history traits. Although they can achieve similar population growth rates . being stable increasing or
