August 13, 2014
Over the past several months, Galapagos National Park (GNP) rangers have been monitoring the presence of introduced fire ants in Marchena, Rábida, Baltra, North Seymour, and Plazas Islands, as well as on the sites of Cousins, Bainbridge, and Chinese Hat. Monitoring activities allow researchers to identify which of the four existing introduced ant species is present on each island and track its territorial expansion in order to implement appropriate management measures. In the coming days, the team will continue to several sites east of the archipelago.
The methodology for this project, developed by scientists at the Charles Darwin Foundation, involves dividing each monitoring site into transects 200 meters apart from each other and placing sticks with peanut butter as bait every 50 meters. After one hour, the rangers collect the bait, take samples of ants found, and record the points of discovery with GPS.
The four introduced fire ant species in Galapagos — some of which have been registered in the archipelago since 1960 — include Solenopsis geminata, Wasmannia auropunctata, Monomorium destructor, and Pheidole megacephala. The ants negatively impact Galapagos ecosystems by preying upon the eggs and young of reptiles and birds that are endemic to the islands.
On several sites, including giant tortoise nesting areas on Santa Cruz Island, park rangers are conducting control activities by using a product specifically made for fire ants that is collected by worker ants and taken up into the nest where the whole colony is fed. Efforts to monitor and control fire ants takes place 3 times a year in areas of high ecological value and in nesting colonies of native and endemic Galapagos species.
Read more about managing invasive ants in Galapagos.
Translated with permission from the Galapagos National Park Directorate. Please contact Galapagos Conservancy with inquiries.