The three major naturally occurring estrogens in women are estrone (E1), estradiol (E2), and estriol (E3). Estradiol is the predominant estrogen during reproductive years both in terms of absolute serum levels as well as in terms of estrogenic activity.strogen may also refer to any substance, natural or synthetic that mimics the effects of the natural hormone. The steroid 17Î²-estradiol is the most potent and prevalent endogenous estrogen, but several metabolites of estradiol also have estrogenic hormonal activity.
The study of animal behavior begins with a library of behaviors, called an ethogram. An ethogram is a list of species-specific behaviors describing the elements and function of each behavior. Normally, the best ethograms are functional; they are organized into categories that reflect meaningful distinctions to the animal.
The Ethogram: quantifying behavior and testing hypotheses. Basic questions about animal behavior come initially from observations. Observation leads to questions, which lead to hypotheses, which lead to predictions, which lead to experimentation.