This project is currently Active
Fowler’s Snouted Treefrog (Scinax quinquefasciatus) is a relatively recent invader of the Galapagos Islands, having been introduced from mainland Ecuador, most likely during the wet El Niño season of 1997/1998.
Little is known about the biology and ecology of this frog in Galapagos. To close this knowledge gap and to gain information for potential management, CDF is carrying out a study of the diet, distribution, habitat use and potential dispersal of this species.
The CDF works on this project in collaboration with the Galapagos National Park Directorate and the Escuela Superior Politecnica del Litoral (ESPOL).
Principal Investigator
Investigator
Investigator
Marcelo Loyola (Project Assistant).
The Fowler’s Snouted treefrog Scinax quinquefasciatus is a medium sized (33 – 38 mm) very adaptable frog species, native to western mainland Ecuador. It was probably introduced to the Galapagos Islands by means of cargo transfer in 1997/1998 during an exceptionally wet El Niño event. The unusual wet conditions during that period were thought to have facilitated the establishment of the species in the archipelago. The islands generally provide unfavorable environmental conditions for amphibians due to the lack of freshwater reservoirs or vast humid forest patches that are important for reproduction.
Presently, the treefrog has been reported from the islands of Santa Cruz and Isabela, and in the past, from San Cristóbal. While an attempt was made to control the species on Isabela, no updated information is available for Santa Cruz. It is important to know the distribution of this frog, its invasion potential and impact on native species in the islands to be able to formulate recommendations for management and quarantine decisions.
Our main goal is to improve the knowledge on the ecology and distribution of the invasive treefrog Scinax quinquefasciatus in an integrative approach, combining field-based assessments, lab-based dietary analyses and population genetic analyses.
Preliminary results show that the treefrog is widely distributed in the agricultural zone of Santa Cruz. Frog records outside the agricultural zone so far are located in Puerto Ayora and in transitional habitats towards the National Park are. The few records within the National Park area come from popular tourist sites, like Los Gemelos and Media Luna. Specimen obtained from the farm ‘Rancho Manzanillo’ were used for dietary analysis by means of gut content assessments. Preliminary results indicate that butterflies and moths (Lepidoptera) was the most frequently recorded insects. This is in line with field observations of frogs that aggregate at night around artificial light sources to feed on moths and other nocturnal insects attracted by the light.
The analysis is still in progress and is part of a thesis project linked to our collaborators from the ESPOL (Escuela Superior Politécnica del Litoral, Ecuador). Results about the dispersal risk between islands will be inform to quarantine efforts. We will also give management recommendations to the Galapagos National Park Directorate.
Keywords: Invasive frog, invasive species impacts, invasion potential, quarantine, dispersal potential