Skip to main content
Dryad

A next-generation sequencing study of arthropods in the diet of Laysan Teal (Anas laysanensis)

Data files

Jun 07, 2023 version files 20.22 KB

Abstract

The critically endangered Laysan Teal Anas laysanensis (known as koloa pōhaka in the Hawaiian language) in the Northwestern Hawaiian Islands has wild populations on Kamole (Laysan Island), Kuaihelani (Midway Atoll NWR), and Hōlanikū (Kure Atoll). The Laysan Teal faces a new risk on Sand Island, Kuaihelani: non-target poisoning via a pending House Mouse Mus musculus eradication. After mice were observed attacking and depredating Laysan Albatross Phoebastria immutabilis (mōlī) in 2015, plans to eradicate mice were developed to protect this seabird species. However, this approach risks poisoning the Laysan Teal. To reduce exposure, teal will be translocated during mouse eradication. Even so, there is a potential risk of secondary poisoning for teal by ingesting arthropods that feed on mouse bait. We therefore used next-generation sequencing (NGS) to identify which arthropods teal consume. From August 2019 to February 2020, we collected 71 fresh teal faecal samples on Sand Island, and successfully extracted DNA from 21 samples. Via NGS, we found that teal most frequently consume cockroaches (order: Blattodea), freshwater ostracods (Cyprididae), midges (Chironomidae), and isopods (Porcellionidae). To a lesser degree, teal also eat spiders (Araneae), moths (Lepidoptera), beetles (Coleoptera), springtails (Entomobryomorpha), thrips (Thysanoptera), and crabs (Decapoda). Notably, Sand Island’s teal consume entirely different arthropods from teal on Kamole, which mainly eat flies (Diptera) and brine shrimp (Anostraca, Artemia sp.). Our study serves as a model for risk mitigation during invasive rodent eradications.