3.2 Seasonal activity of movements on the network
The average number of monthly movements was 26,212 (2017), 32,872
(2018), and 40,165 (2019). According to the Mann-Kendall seasonal test,
the overall time series of the monthly number of movements increased
over time (p<0.001). There was also a shift in the central
trend, detected by a change point (k) (Pettit’s test), which
corresponded to May 2018 (k=17, p<0.001) (Fig. 2A) (SI 2). The
monthly average seasonal activity of the movements was highest from May
to August and December and less frequent from January to April and from
September to November (Fig. 2B).
Figure 2. Seasonal plots of movements in the Ecuadorian pig network. (A)
Monthly number of movements in separate years, shift in central tendency
(k). (B) Graph of the subseries as a separate mini time series; the blue
line represents the mean of the observations within each season (month).