Social, state-dependent and environmental modulation of faecal corticosteroid levels in free-ranging female spotted hyenas.
W Goymann, M L East, B Wachter, O P Höner, E Möstl, T J Van't Hof, and H Hofer
Proc Biol Sci. 2001 December 7; 268(1484): 2453–2459. doi: 10.1098/rspb.2001.1828.PMCID: PMC1088899