13 – Insights from multi-species mammal monitoring programs in the Upper Warren^187important in gaining recognition of the existence and significance of the B. penicillata
declines, from which support for a timely and adequate response could be built.
A broader suite of species also can be monitored by the use of multiple
methods, because no single method is adequate for all species. Monitoring a
broader range of species provides greater contextual information relevant to
population changes of particular species of interest (e.g. intra-guild analogues,
competitors, predators, surrogates, possible indicator species). It also increases the
probability of detecting ecological surprises (i.e. unexpected findings about the
natural environment; Lindenmayer et al. 2010) that are likely because of our
incomplete understanding and the dynamism of ecological systems. Including
species that are not currently listed as threatened is also important in the longer
term because their conservation status may change (e.g. B. penicillata, Ps.
occidentalis, Ps. tapoatafa in UWR). Finally, having data when species are more
abundant will allow for more robust and detailed assessments of population change
and greater insights into the possible agents of change.
Baselines and covariate data
Having appropriate covariate data is important for understanding population
changes (e.g. Lindenmayer and Likens 2010). Having a conceptual model of how
the ecosystems work helps to identify priority covariates for inclusion. These may
include demographic characteristics and vital statistics (e.g. sex ratio, age structure,
survivorship, body condition) of the species of interest that help identify the
mechanics of population change (e.g. fecundity, mortality, immigration,
emigration), the species’ key threats (e.g. predators, resources, disease), and
potential processes or agents of change (e.g. climate, fire).
Although the initial years of monitoring may contribute to a baseline or
reference dataset, an additional deliberate effort to collect sufficient data to
constitute an adequate baseline is generally recommended. Inadequate baselines
substantially limit the capacity to identify or test the contributions of putative agents
of population change. For example, the belated but extensive collection of reference
blood samples during the rapid decline of B. penicillata led to the identification of a
putative agent of decline, the blood parasite Trypanosoma copemani (Botero et al.
2013). However, the limited number of baseline samples collected before the
declines at sites in UWR and elsewhere has hampered our understanding of the
significance of T. copemani infections on B. penicillata population changes. The
later analysis of other samples collected during B. penicillata monitoring also led to
the discovery of several new taxa (e.g. Bennett et al. 2010; Kaewmongkol et al. 2011;
Pan et al. 2012; Botero et al. 2013; Hobbs and Elliot 2016).
A strategic approach to adaptive monitoring
Resource constraints typically limit the capacity of monitoring programs. A
practical solution to this may be a strategic approach to adaptive monitoring.