Ornithology is the scientific study of birds. Ecology is the study of organisms and their environment. Vexillology is the study of flags. Geology is the study of the Earth's physical structure.

Demography is the study of statistics such as births, deaths, income, or the incidence of disease, which illustrate the changing structure of human populations. Geology is the study of the Earth's physical structure. Psephology is the study of elections. Ecology is the study of organisms and their environment.