2.3 | Sample collection and storage
Since 2013, freshly voided feces have been routinely collected and archived. Samples are collected using sterile nitrile gloves which are inverted, sealed, and kept in insulated bags containing icepacks until returning to the laboratory on the same day (max ~6 hrs). Subsamples (~1–2 grams each) are stored in cryotubes at −20oC while on the island before transfer to long-term storage at −80oC on the mainland at the end of each field season. For the present study we selected 86 fecal samples collected in 2014 between mid-July and early-September from 86 different adult females (mares) spanning 52 social bands (1–4 samples/band) which ranged from 3–12 horses in size. Each mare represented in the dataset was only sampled once. Ages ranged from 3–9+; 9-year-old mares might be over 9 years of age, as they were adults before the inaugural field season of the long-term study.