Using camera traps to estimate site occupancy of invasive Argentine black and white tegus (Salvator merianae) in South Florida

The introduction of nonnative species is a leading cause of biodiversity
loss. Many invasive species are cryptic or elusive in nature and therefore
often evade detection, complicating their management. Occupancy modeling
can reveal the presence and spread of invasive species over time and
therefore has important management implications. Camera traps can be used
to estimate occupancy, or the proportion of sites that are occupied by a
target species. During a 4-year study (2016–2020), we used camera traps
both with and without lures to detect the presence of invasive Argentine
Black and White Tegus (Salvator merianae) at sites in Miami-Dade County,
Florida. Our results from a multi-season occupancy model revealed that a
quadratic effect of ordinal day was the best predictor of detection, with
a peak in June, while occupancy was correlated with distance to landscape
features that may facilitate tegu movement.  We did not detect
any large-scale changes in occupancy over the course of our study. We also
discovered that the use of lures with camera traps did not impact
detection, which requires fewer resources from invasive species managers
for continued monitoring. Understanding the factors that impact occupancy
and detection probabilities can inform surveillance and removal efforts,
leading to more efficient management strategies.