Hormones are chemical messengers produced by specific organs in the body that travel in the blood to target tissues and influence behavior and physiology. The major hormone of interest to us is progesterone, a steroid hormone produced by the ovary and placenta in females. The body is constantly churning out new hormones, while destroying the old ones in the liver or eliminating them in urine and feces. Our interest lies in the reproductive endocrinology, or hormones related to reproduction, of female giraffes. Performing this study by investigating the contents of their excrement may be difficult for us, but it is exceedingly gentle on the animals. Such is the way of non-invasive research. How do we go from a lump of poop to a hormone profile, and what can it tell us about giraffe social relationships?
