76 Monitoring Threatened Species and Ecological Communities
Pseudemydura umbrina, for which monitoring has been conducted for more than
50 years: extraordinarily, at least one individual tortoise has been monitored over
the entire extent of this long-lasting program (Kuchling et al. 2018) (Fig. 6.2).
In contrast, no evidence of any monitoring activity could be located for 26
threatened reptile species (38% of Australia’s threatened reptiles). Terrestrial
squamate and freshwater turtle species, species without recovery plans, and species
of lower conservation status were most likely to have little or no monitoring (Table
6.2). Monitoring activity is limited in most of the metrics considered, but is
particularly weak for data availability and public reporting, demographic
parameters and design quality (Fig. 6.1).
The reason for the striking disparity in monitoring effort and adequacy
between marine turtles and almost all other threatened reptile species may be
because: (1) marine turtles are regarded as more charismatic than most terrestrial
squamates by researchers, the public and government agencies; (2) there has been a
long-standing global recognition of the decline of marine turtles, whereas
recognition of the threatened status of many endemic Australian snakes and
lizards is recent; (3) marine turtles are relatively easy to monitor (at least at
breeding sites); and (4) there may be more than usual incentive to monitor marine
turtles because their coastal habitats are subject to much development pressure that
invokes some regulatory interest.
Across the set of threatened species considered, monitoring activity was mostly
conducted by state agencies (for 29 species), university researchers (23 species), a
Commonwealth agency (Parks Australia) (nine species), and Indigenous ranger
groups (three species). Much of the monitoring effort conducted by university
researchers involved relatively short-term assessments of impacts of particular
threat factors.
Discussion
Given the limited extent and adequacy of monitoring programs for threatened
reptiles, it is difficult to draw generalisations. There are mixed results in the
monitoring data. In a few cases, the results from monitoring indicate some
increases in population size (or other relevant parameters) in response to
management actions (Chaloupka and Limpus 2005), and in some captive-breeding
populations (Andrew et al. in press). In a few cases, complementary monitoring
and survey effort has done much to progress knowledge of the status of individual
reptile species, and the impacts of threats, and has helped to focus management
responses that are increasingly effective (Bull and Hutchinson 2018; Kuchling et
al. 2018).
However, in many more cases, monitoring data indicate major declines in
population size (Smith et al. 2012), including at least one case of a failed