Which of the following hormones peaks during ovulation in nonhuman mammals?

During ovulation in nonhuman mammals, estrogen specifically reaches its peak just before the release of the egg from the ovary. This surge in estrogen levels is crucial as it triggers the physiological changes necessary for ovulation. The increase in estrogen leads to several important effects, including the thickening of the uterine lining, which prepares the body for potential implantation of a fertilized egg, and positive feedback mechanisms that stimulate the release of luteinizing hormone (LH) from the pituitary gland, which is the hormone that ultimately induces ovulation.

While testosterone, progesterone, and cortisol have important roles in various reproductive and physiological processes, their peak levels do not align with ovulation in nonhuman mammals. Testosterone is often associated with male reproductive functions, progesterone levels increase after ovulation to maintain pregnancy, and cortisol primarily functions in stress response regulation. Thus, the peak of estrogen during the ovulatory phase is a critical event in the reproductive cycle of female mammals, highlighting its role in facilitating ovulation.