Most species-specific conservation efforts require estimates of population size to establish priorities and to
monitor management activities. Yet obtaining reliable estimates of animal populations is often difficult, especially
given time and funding limitations experienced by
many research programmes. Consequently, there is a
great need for practical methods to provide indices of
animal density. Ideally, accurate estimates of populations
would be obtained through mark-recapture data
collected from recognizable individuals over multiple
censuses that cover the entire population range. Such
data are rarely available, so conservation biologists have
no alternative but to resort to analyses of less perfect
data, ranging from permanent-point censuses from cameras
through to transect data on sightings and spoor
encounters. The importance of census and monitoring
data makes the development, and validation, of new
techniques a priority. Because we do not live in a perfect
world, there is a need to develop methods that can
give an estimate of population sizes. It would be naïve
to assume that these will give hugely accurate estimates
of population size, but these techniques can prove useful
in identifying areas that are likely to benefit from
conservation action.