Hormone Sampling Protocol

In recent years the non-invasive measurement of adrenal and gonadal steroid hormones excreted in feces and urine of wild animals has become increasingly important for behavioral studies and for conservation. This method will allow orangutan researcher to monitor physiology non-invasively and to examine the relationship between endocrine function and social factors in the wild.

Here follows a description of collection and storage methods for orangutan fecal samples intended for hormone analysis.

Materials Required

Feces tube 76x20mm , 14ml (Sarstedt 80.734.311). The collection spoon is integral to the closure cap allowing feces samples to be collected safely and cleanly.


Only 2-3g feces are needed, therefore only one third of the tube needs to be filled. The fecal material should be mixed before collection (in contrast to genetic sampling where the outer layer of the fecal material is needed). Therefore, if possible, mix the fecal material beforehand with the spoon, or collect both from the inside and outside of the material. Place 2-3g of feces into the tube with the attached collection spoon. The fecal material should not have gotten into contact with urine on the ground. Samples should be preferentially collected early in the morning but for certain study questions several samples per day can be useful. Always write time of defection on the tube, together with date, animal ID and observer name.


Because the steroids can further degrade under ambient temperature the collected samples need to be frozen as soon as possible, at the latest on the end of the day of collection. The temperature of the freezer in camp needs to be checked regularly and temperature noted in book next to the freezer. The freezer should run at temperature of at least -10°C. Keep track in an Excel file or sample book how long samples were stored in the freezer before taken (cooled) to hormone taken to a hormone lab for analysis.