Mosquito iDNA reveals landscape patterns of birds and mammals

Changes in fire regimes and the introduction of invasive species are
negatively impacting Northern Australia's biota, highlighting the
need for reliable biodiversity monitoring data. Here we used
mosquito‐ingested DNA (iDNA) to detect birds and mammals within Kakadu
National Park. Six sites were sampled on two occasions (wet and dry
season), with three traps deployed for two consecutive nights of sampling
at each site. Mosquitoes were processed in bulk samples per trap ranging
from 31 to 1987 mosquitoes. Extracted DNA was amplified using primers
targeting vertebrates (12SV5), mammals (16SMam1/2) and birds (Aves01) with
iDNA‐derived richness and composition measured. A total of 50 avian and 19
mammalian taxa were detected, including threatened species such as the
white‐throated grasswren (Amytornis woodwardi) and the ghost bat
(Macroderma gigas), along with difficult‐to‐monitor groups such as
small‐bodied and arboreal mammals. Community composition was shown to be
distinct between sampling events, and avian richness was higher during the
dry season. Importantly for the management of the park, our findings
suggest that fire regimes modified both bird and mammal communities during
the dry season, with vegetation structure being correlated with avian and
mammalian community composition during the wet season. This study
highlights the capacity for iDNA metabarcoding to provide fine‐scale
ecologically relevant information within a large, dynamic and
difficult‐to‐access landscape