In collaboration with Drs J. Beehner and J.A. French, we are using levels of steroid hormones excreted in feces to study relationships among hormonal, ecological, and behavioral variables in wild and captive hyenas. Current & former students worked with Drs Beehner and French to develop suitable extraction protocols and assays with which to measure excreted corticosterone, estrogen, and androgens in hyena feces. After immunological validation of these assays had been completed, Drs S.E. Glickman and N. Place then used captive Berkeley hyenas to validate these assays in vivo, and they also examined effects of early treatment with anti-androgens on the hypothalamic-pituitary-gonadal axis in this species (Place et al 2002a). Dr Stephanie Dloniak has found that interacting with large aggressive females represents a significant “challenge” for male hyenas. Dr Dloniak has also found support for the hypothesis suggesting that concentrations of circulating and excreted androgens vary with maternal social rank during pregnancy, and that offspring behavioral phenotype varies with maternal androgen levels during pregnancy. Rates and intensities of aggressive acts emitted by female spotted hyenas appear to be affected by maternal androgens to which they are exposed in utero; these effects have now been documented in both juvenile (Dloniak et al. 2006) and adult hyenas (Holekamp et al. 2013). These data suggest that a special form of non- genetical "inheritance" might occur in mammals analogous to maternal deposition of androgens in the yolk of bird eggs (eg., Schwabl et al 1997). In a related analysis with Dr M. Spencer PhD student Nora Lewin has found that circulating levels of insulin-like growth factor (IGF-I) in young hyenas increase with maternal rank, suggesting yet another possible mechanism of non-genetical "inheritance." We have found no relationship between concentrations of excreted glucocorticoids (GCs) and social rank in hyenas, thus corroborating work by Goymann et al (2001), but male androgen levels increase dramatically when they disperse to a new clan (Holekamp & Smale 1998; Holekamp & Sisk 2003). Current graduate student Tracy Montgomery is also assessing how play behavior affects salivary hormone concentrations.