Scat Collection and Processing
From 5 May–5 October 2019 and 13 June–22 September 2020, we collected all wolf scats encountered during fieldwork in IRNP. We collected fresh scats (e.g., strong smell, moist, tracks present) at wolf radio-collar GPS location clusters (Svoboda et al. , 2013) and on established hiking trails (Fig. 1). We placed each scat in a plastic bag, recorded the date and location (NAD83, UTM Zone 16N), and froze them for later processing. We considered the collection date as the date of deposit, although scats may have been up to 11 days old (Sanchez et al. , 2004).
We processed and identified scat contents following Chenaux–Ibrahim (2015). We placed frozen scats into nylon stockings, washed them in a washing machine to remove digestible material and then dried the contents in an oven. We spread the contents on a 21.5cm x 28cm plate, overlaid a 25-point grid, and randomly selected one hair from each point for microscopic identification (Ciucci et al ., 2004). We could determine moose age class (adult or calf) until 15 September, when the first molt occurs (Muller, 2006). After 15 September we identified all moose hair as adult. Wolf hair may be ingested due to grooming or cannibalistic activity, the latter resulting in a higher amount of hair in scats (James, 1983; Muller, 2006). Therefore, we did not consider wolf as a prey item unless we detected wolf hair at >10% of points in a sample. We pooled all other prey (birds, muskrats, small mammals, wolves, unidentifiable remains, and vegetation) into an “other” category.