cortisone has been analyzed from fecal samples using RIA, and I know some researchers working with CLIA on fecal, urine, saliva, hair and skin scrape samples

http://www.scielo.br/pdf/bjmbr/v37n12/5473.pdf

http://www.cwu.edu/~lixing/Zoo%20Biology%20paper.pdf

http://www.funakoshi.co.jp/data/datasheet/ARB/K017-C.pdf

Hi, you could contact Dr. Rupert Palme from University of Veterinary Medicine in Vienna, as he is the expert in this field. He may be able to offer you advice depending on your question.

Fecal glucocorticoid metabolites can be used to non-invasively assess HPA axis activity in these animals. There are two approaches: Rupert Palme and co-workers use EIAs with species-specific capture antibodies. The other approach is to use an RIA which has been used in a variety of animals. It appears that most mammals and some birds produce fecal glucocorticoid metabolites that have high affinity for an anti-body that was originally produced against rat corticosterone. Use of this assay within a species allows for accurate characterisation of HPA activity, which is able to identify the stress experienced during events such as capture and confinement and even seaonal variation. Validation of the assay though is essential and can be achieved with an ACTH challenge. I am busy completing validation studies for white rhinoceros, wildebeest and zebra and have found excellent results with this technique. The RIA kit is available from MP Biomedicals.

depending on which species you work with: hair is a very good non-invasive method to obtain long-term steroid hormone levels. In humans, we use scalp hair to determine e.g. cortisol levels (extraction with methanol, ELISA or LC-MS/MS ). In this way we obtain cumulative cortisol levels of the past weeks or months (to even years in retrospect, depending on the length of the hair). Stressful episodes (e.g. major life events) can be well detected in hair by creating timelines. In several other species cortisone and corticosterone can also be measured in hair.

A couple of comments to build on previous answers:

- I know some colleagues who have worked on measuring Fecal glucocorticoid metabolites in African buffalo dungs in Niger. The work is not yet published but I could give you their contacts if needed (Dr. Daniel Cornelis, Cirad; Dr. Serge Morand, Cirad/CNRS).

- From what I can remember, you can measure this variable and you will get data. However, the interpretation of this data is difficult: as mentioned previously, you need to have baseline data on glucorticoid production in your species of interest to know what is high and what is low; then you have also intra-species factors that will (should) influence glucocorticoide level in the feces (pregancy, male vs female, juvenile vs adult). If you want to measure absolute level of stress (descriptive approach), you can always interpret yuor data. If you want to measure relative level of stress (correlative approach) in relation to a variable (capture, mating season, migration etc.), the interpretation will be difficult as you don't know what other stressors can influence stress level (infections, pregnancy etc.).

I believe it is a very interesting area of research, and research is needed. But this is not a straight forward path!