Checklist and Images Documenting the Biodiversity of Johnston Atoll National Wildlife Refuge




Rash, Ryan

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Included are five pdf files documenting biodiversity on Johnston Atoll National Wildlife Refuge in the Pacific Ocean from June of 2019 through December of 2019. Most images are taken by Ryan Rash, but some were provided to him by others there cohabitating the island at the time. He, and a crew of 4 others were employed to work on the island by the United States Fish and Wildlife Service in an effort to control and document the spread/containment of invasive yellow crazy ants (Anoplolepis gracilipes) and document their effects on native wildlife. The images here were taken by him during his off-time, as a side-project while working on the island. They were compiled and produced into the files provided here in the months after his deployment. The project aimed to record every species of animal and plant, preferably with a photograph sufficient for species determination, but in some cases, as indicated in the included checklist, species were noted without a photograph. In addition to the checklist, images were organized into a collection of four taxonomic presentations: (1) Fish; (2) Birds; (3) Plants; and (4) Herps, Inverts, and Mammals. Within each file, species are sorted alphabetically within their higher taxa, which are also sorted alphabetically for easy perusing.

Johnston has a lengthy military history beginning in the early 1930s. Nuclear radiation and harmful chemicals like agent orange were stored there and have leaked out into the environment. These have since been remediated, but sometime in the early 2000s after the military left in 2004, yellow crazy ants infiltrated the island via driftwood—or more likely as incidental passengers on personal vessels hopping between the Pacific remote islands. The crazy ants quickly took over the island, proving especially detrimental for the resident red-tailed tropicbirds (Phaethon rubricauda) that nest on the ground. The ants began swarming the nesting tropicbirds and their chicks, spraying them with formic acid expelled through their acidopores. Tropicbirds, after being sprayed repeatedly in the eyes, were blinded and eventually perished only to be consumed by the ants.

In 2010, U.S. Fish and Wildlife Service researchers visited Johnston and discovered the infestation. They ended up creating a treatment plan later that year and sent out the first Crazy Ant Strike Team (CAST), and ever since there has been a crew of ~5 people on the island at all times (apart from hurricane evacuations). Thankfully, the pesticide treatment worked and yellow crazy ants haven’t been detected since December of 2017, but extensive monitoring has continued in order to be completely sure of their eradication. The last step in deeming the island free from crazy ants is bringing scent dogs out to survey for the formic acid scent trail, as the ants could have possibly taken up residence in underground plumbing and electrical conduit. This will hopefully occur at the end of this year. If everything goes to plan, the dogs won’t find anything and our confidence in eradication will be more well-founded.

Johnston Atoll at the time of the infestation was home to the largest red-tailed tropicbird colony in the world with over 5,000 active nests. The entire island was just surveyed a month ago and that number has increased to over 10,800 active nests! It was important to save this atoll from the infestation, as it’s the only landmass for over 800,000 square miles of ocean and is one of the, if not the most, isolated landmasses in the world, and a key nesting/stopover point for many bird species.


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