Monitoring populations of threatened, endangered, and at-risk species (TES) on Department of Defense (DoD) installations is challenging, expensive, and time consuming. Yet, population monitoring itself is only one component of TES management. Critically needed for monitoring are tools that assess the factors directly affecting these populations, specifically assessing habitat quality and how habitat changes affect TES populations. This project has three primary objectives to aid population monitoring of TES bird species on DoD lands: 1) demonstrate the utility of metabarcoding of environmental DNA of arthropods (from bird feces and vegetation sampling) to assess habitat quality of TES birds on military lands; 2) validate the approach and compare to conventional methods of diet and food availability; and 3) provide user-friendly guidance to military land managers to employ and interpret this technology for future monitoring of a broad range of TES species on military installations.

The golden-cheeked warbler: an endangered bird species of interest for population monitoring.

This project will use metabarcoding of environmental DNA (eDNA) from fecal samples, as well as conventional sampling through collections of arthropods from vegetation, to assess the diets of five TES bird species and arthropods in their habitats. This will be the most in-depth analysis of diet attempted from insectivorous birds on military installations and should provide species-level identification of prey items. The project team will then use diet and arthropods as a measure of habitat quality at four DoD installations: Fort Hood, Texas; Camp Pendleton, California; Fort McCoy, Wisconsin; and Schofield Barracks, Hawaii. This breadth of sites and species will enable the project team to assess the suitability of this technology across diverse systems that are representative of TES bird populations managed by DoD. SERDP has funded several recent basic science projects that have used eDNA to develop technologies that assess various organisms in the environment. This project enables the application of these technologies for meaningful monitoring and resource management.

The approach provides a cost-effective assessment of prey consumption by avian insectivores and will also generate critical baseline data to understand the potential role of insect declines on TES bird populations. This will allow DoD installations to focus on habitat management that most effectively bolsters TES bird populations. Moreover, the metabarcoding approach can be applied to assessing detailed diets of a broad range of taxa other than birds, including amphibians, reptiles, and mammals, as well as to assess endangered or invasive arthropod populations. This project will provide DoD natural resource managers with the tools to be able to assess potential partner labs, the types of available analyses, and how to interpret molecular results.