Using an on-site laboratory for fecal steroid analysis in wild white-faced capuchins.

• We introduce an "on-site laboratory", the Taboga Field Laboratory, established outside the Taboga Forest Reserve in Costa Rica. • This manuscript is the first collaboration across three long-term field sites on the behavior and biology of wild white-faced capuchins (Cebus imitator). • We validate six steroid hormone assays for use on wild capuchin fecal samples (glucocorticoids, androgens, estrogens, and progestogens). Hormone laboratories located "on-site" where field studies are being conducted have a number of advantages. On-site laboratories allow hormone analyses to proceed in near-real-time, minimize logistics of sample permits/shipping, contribute to in-country capacity-building, and (our focus here) facilitate cross-site collaboration through shared methods and a shared laboratory. Here we provide proof-of-concept that an on-site hormone laboratory (the Taboga Field Laboratory, located in the Taboga Forest Reserve, Costa Rica) can successfully run endocrine analyses in a remote location. Using fecal samples from wild white-faced capuchins (Cebus imitator) from three Costa Rican forests, we validate the extraction and analysis of four steroid hormones (glucocorticoids, testosterone, estradiol, progesterone) across six assays (DetectX® and ISWE, all from Arbor Assays). Additionally, as the first collaboration across three long-term, wild capuchin field sites (Lomas Barbudal, Santa Rosa, Taboga) involving local Costa Rican collaborators, this laboratory can serve as a future hub for collaborative exchange. [ABSTRACT FROM AUTHOR]