Abstract # 5881 Poster # 60:

Scheduled for Saturday, September 13, 2014 07:00 PM-09:00 PM: Session 11 (Decatur B) Poster Presentation


THE EFFECTS OF EXTRACTION METHOD AND FREEZE/THAW CYCLES ON FECAL CORTISOL METABOLITES MEASUREMENTS IN SULAWESI CRESTED BLACK MACAQUES AT THE BUFFALO ZOO

D. A. Bertrand2,3, M. Heistermann3, S. W. Margulis1 and C. M. Berman2
1University at Buffalo - SUNY, 380 MFAC, Ellicott Complex, North Campus, Buffalo, NY 14261, USA, 2University at Buffalo - SUNY, 3Endocrinology Laboratory, German Primate Center
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Collecting feces is the least invasive way to measure average daily stress responses in wild primates. Fecal steroid metabolites can degrade quickly; freezing samples immediately and keeping them frozen until extraction slows this process. However, this can be difficult at field sites without reliable electricity. Currently validated methods for extracting Macaca nigra samples involve freezing at the field station followed by lyophilizing. This study aimed to test a method to extract fecal glucocorticoid metabolites directly in the field using ethanol. We asked whether metabolite levels in a captive group of M. nigra at the Buffalo Zoo differ 1) between samples extracted after lyophilizing vs. extracted directly via 80% denatured ethanol or via 80% pure ethanol and 2) after being subjected to multiple freeze/thaw cycles. An ANOVA indicated a significant difference between lyophilized samples and both ethanol samples (F(2,14)=6.48,p<.005). However, all extraction methods produced concordant results (Kendall's W=.937,p<.006). Thus while ethanol extraction methods may not be suitable for measurement of absolute hormone concentrations, they are suitable to measure concentrations at an ordinal level. Additionally, an ANOVA indicated no overall significant difference between immediately lyophilized samples and freeze/thaw cycle samples. However there was a significant contrast between the control and one cycle (F(1,14)=17.49,p=.001), suggesting caution. These results argue for the use of ethanol extraction when conditions in the field may result in frequent inadvertent thawing of samples.