Management of Non-native Argentine Ants on Santa Cruz Island

©Tim Hauf,
Non-native Argentine ants have spread significantly since their accidental introduction to Santa Cruz Island, thought to have occurred in the 1960s. Since their initial discovery in two locations in 1996, the ants have established in two additional locations and increased the size of each colony. The infestation of Argentine ants is in four areas and covers approximately 1200 acres.

Argentine ants can have significant impacts on the functioning of an ecosystem, because of their strong competitive ability and broad diet. Argentine ants impact the native invertebrate community through direct predation, competition, interference, and egg predation. Native ants are particularly vulnerable and are largely eliminated in the presence of Argentine ants.

This impact has been observed on Santa Cruz Island. Santa Cruz Island is one of five islands within Channel Islands National Park. The National Park Service owns the eastern 24% of the island and TNC owns the western 76%. Argentine ants occur on both properties and the NPS and TNC are working together to achieve the elimination of the Argentine ants.

Project Objectives

  • Prevent additional introduction or human-assisted spread of Argentine ants on Santa Cruz Island.
  • Control or eliminate current infestations of Argentine ants.

Environmental Planning Process
The National Park Service has prepared an Environmental Assessment for the proposed project to control or eliminate Argentine ants from Santa Cruz Island. The Environmental Assessment can be downloaded at:

The park contact for this project is: Kate Faulkner (

Last updated: June 16, 2016

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