Comparing biodiversity found with insect samplers and camera
traps
In total, iDNA and camera trapping methods revealed 90 vertebrate
species across the sampled landscape (Table 2). iDNA alone described 82
species with carrion fly data describing the most diversity of any
sampler with 62 species while sandfly data revealed 49 species and
mosquito data revealed 16 species. Camera trap data revealed 28
vertebrate species and added 8 species to the diversity already
described with iDNA.
Species accumulation curves show a statistically significant difference
in species richness gleaned from each iDNA source and camera trapping
(Fig. 2). Carrion fly data and mosquito data are extrapolated to match
the number of sandfly samples, and consequently the extrapolated curves
provide less certainty than the interpolated curves. However, the
confidence intervals show significant separation in the total species
richness from each iDNA source across both the interpolated and
extrapolated curves. Using carrion flies as a measure of biodiversity
reveals a significantly greater number of vertebrate species across the
landscape than both sandflies and mosquitos. Additionally, the total
number of carrion flies analyzed (n = 1,759) was lower than both the
total number of sandflies (n = 48,686) and mosquitos (n = 4,776)
analyzed. The species accumulation curve for camera trap data shows that
species richness plateaus after approximately 1,500 camera days meaning
that few to no new species are revealed by camera traps even with
continued camera days (Fig. 2). The species richness from camera traps
was most similar to the species richness from the extrapolated curve for
the pooled mosquito samples, which was the least efficient iDNA sampler
in describing vertebrate diversity (Fig. 2; Table 1).
Comparisons of species’ RAI from iDNA samplers and camera traps show
differences in diversity profiles across taxa groups (Fig. 3). As
expected, camera traps showed a high diversity of carnivore and ungulate
species and a low diversity of arboreal species or birds. Camera traps
also did not capture the occurrence or diversity of domestic species and
rodent species particularly when compared to the diversity of these
groups found using iDNA methods. Carrion fly data consistently showed a
high diversity of species in each taxa group. Sandfly data also showed
high diversity of species in most taxa groups with an especially high
diversity and relative abundance of armadillo species (Fig. 3; Table 2).
Lastly, mosquito data showed the lowest species diversity for many of
the taxa groups and only showed a high diversity of domestic species
when comparing mosquito data to the other datasets (although carrion fly
data still displayed greater diversity and relative abundance from
domestic species). When species incidence data was parsed at the site
level, camera traps showed the highest median species richness at sites
(Fig. 4) and a consistent diversity profile across sites (Appendix S1:
Fig. S3) indicating that camera trapping consistently samples the same
species across sites.