Determinants of pup emergence date:
The window of mean temperature and mean snowpack that had the strongest
association with pup emergence date was between mid-April to early-May
(Figure S2). Using these results, mean spring temperature and snowpack
were defined as between April 15th and May
5th.
Average spring snowpack was positively related to pup emergence date,
but average spring temperature was not (Table 2, Figure 2). Pup
emergence date was also affected by valley with pups emerging later in
the up-valley compared to the down-valley (Table 2).
Table 2. Univariate animal model
(number of females = 184; number of litters = 425, mean number of
observations per female = 2.3, range of observations per female = 1-9)
to analyze the association of changing average spring snowpack and
temperature with pup emergence date. Reference category is down-valley
for valley. Pup emergence date was scaled and mean-centered.