2.2.2 Bushpig relative abundance using the transects
Bushpigs are crepuscular and nocturnal and seldom observed. Therefore
the only realistic method of assessing bushpig abundance is the use of
indirect evidence provided by tracks, as well as photographs obtained by
static camera traps. Bushpig track transect counts, using the eight
transects used for warthogs, were conducted on a separate occasion (June
2018 to December 2018). In order to maximise statistical reliability,
each transect was walked 21 times recording bushpig tracks encountered.
The researcher was assisted by game scouts with experience in animal
tracking. Bushpigs tracks, when compared to those of warthog, have
broader hoofs and their claw mark show clearly on the tracks. To avoid
the risk of double-counting, tracks were erased using branches. For each
observation the following data were entered in MS Excel : date,
repetition, transect number, vegetation type, length of that particular
vegetation type in a transect, GPS coordinates of where the observation
was made, number of tracks and, number of events (an event is a discrete
cluster of tracks on a particular transect). Tracks indicated the total
count of tracks recorded per event. A linear mixed-effects regression
model was performed to predict the mean number of events and tracks
based upon habitat (Pinheiro & Bates,
2006), allowing an assessment of relative bushpig abundance indicators
(tracks an events) in each of the four habitat categories in NGR.