Environmental DNA (eDNA) and invertebrate‐derived DNA (iDNA) have been increasingly recognized as powerful tools for biodiversity assessment and conservation management. However, eDNA/iDNA efficiency for vertebrate diversity assessment remains uncertain, and comparisons to conventional methods are still rare. Through a meta‐analysis of previously published vertebrate diversity surveys, we compared the efficiency of eDNA/iDNA against conventional methods across several types of samplers, vertebrate groups, and locations (tropical vs. temperate zones). We also assess eDNA/iDNA efficiency to estimate relative abundance or biomass over different molecular methods (qPCR and metabarcoding) and type of experiment (in the laboratory or in the field). We showed that for water sampler, fish as a target species, and studies achieved in temperate zones, eDNA presents lower risk of not detecting a species or a site with a target species than conventional methods. These results show that eDNA is an efficient tool to assess fish diversity. Moreover, eDNA data presents positive correlation with fish abundance or biomass. However, such correlation was higher in laboratory experiments than in the field. For the other samplers, vertebrate groups, and in tropical zones we were not able to draw general conclusion, highlighting the urgency of conducting more comparative studies.

Ingested‐derived DNA (iDNA) from insects represents a powerful tool for assessing vertebrate diversity because insects are easy to sample, have a diverse diet and are widely distributed. Because of these advantages, the use of iDNA for detecting mammals has gained increasing attention. Here we aimed to compare the effectiveness of mosquitoes and flies to detect mammals with a small sampling effort in a semi‐controlled area, a zoo that houses native and non‐native species. We compared mosquitoes and flies regarding the number of mammal species detected, the amount of mammal sequence reads recovered, and the flight distance range for detecting mammals. We also verified if the combination of two mini‐barcodes (12SrRNA and 16SrRNA) would perform better than either mini‐barcode alone to inform local mammal biodiversity from iDNA. To capture mosquitoes and flies, we distributed insect traps in eight sampling points during 5 days. We identified 43 Operational Taxonomic Units from 10 orders, from the iDNA of 17 mosquitoes and 46 flies. There was no difference in the number of species recovered per individual insect between mosquitoes and flies, but the number of flies captured was higher, resulting in more mammal species recovered by flies. Eight species were recorded exclusively by mosquitoes and 20 by flies, suggesting that using both samplers would allow a more comprehensive screening of the biodiversity. The maximum distance recorded was 337 m for flies and 289 m for mosquitoes, but the average range distance did not differ between insect groups. Our assay proved to be efficient for mammal detection, considering the high number of species detected with a reduced sampling effort.

Ingested-derived DNA (iDNA) from insects can represent a powerful tool for assessing vertebrate diversity because insects are easy to sample, have a varied diet, and are widely distributed. Despite these advantages, the use of iDNA for mammalian detection is still little explored, especially in the neotropical region. Here we aimed to compare the effectiveness of mosquitoes and flies to detect mammals in a semi-controlled area of a Zoo that houses native and non-native species. We evaluated the number of mammal species detected by the iDNA samplers and verified the distance range of each sampler group for detecting the mammal species. To capture mosquitoes and flies we used CDC (Center for Disease Control) and fish-baited plastic bottle traps, respectively, distributed in eight sampling points during five days. Using two mini-barcodes (12SrRNA and 16SrRNA) and the metabarcoding approach, we identified 45 Operational Taxonomic Units from 10 orders. There was no difference between the number of species recovered per individual insect, although the number of flies captured was higher, resulting in more mammal species recovered by this insect group. Eight species were recorded exclusively by mosquitoes and 20 by flies, suggesting that using both samplers allowed a more comprehensive screening of the biodiversity. The maximum distance recorded was 337 m for flies and 289 m for mosquitoes, but the average range distance did not differ between insect groups. Our essay proved to be quite efficient for the mammal detection, considering the high number of species detected with a reduced sampling effort. Thus, combining iDNA from different samplers and metabarcoding can be a powerful tool for mammal survey and monitoring in the neotropics.