Interaction between the Hawaiian dark-rumped petrel and the Argentine ant in Haleakala National Park, Maui, Hawaii

The endemic biota of the Hawaiian islands is believed to have evolved in the absence of ant predation. However, it was suspected that this endemic biota is highly vulnerable to the effect of immigrant ants especially with regard to an aggressive predator known as the Argentine ant (Linepithema humile). First recorded in the Haleakala National Park on the island of Maui in 1967, this ant was believed to have reduced populations of native arthropods in high-elevation subalpine shrublands. In addition, concerns were raised that this immigrant ant may have also reduced the breeding success of the endangered Hawaiian Dark-rumped Petrel (Pterodroma phaeopygia sandwichensis), a native seabird. If so, then it was believe that this ant could become another major threat to the survival of this endangered seabird in addition to the threat that was caused by the introduction of introduced mammals, the advent of hunting by the Polynesians, and a loss of breeding habitat. As a result, the purpose of this study was to determine if the Argentine ant affects the nesting success of this native Hawaiian seabird.