Action: Remove or control invasive Cuban tree frogs
- One before-and-after study in the USA found that the abundance of squirrel tree frogs and green tree frogs increased after removal of invasive Cuban tree frogs.
Invasive amphibians such as Cuban tree frogs Osteopilus septentrionalis can have significant impacts on native amphibian species if they compete for resources. For example, a study found that survival and growth rates of tadpoles of the dominant native species, southern toad Bufo terrestris, decreased significantly in the presence of Cuban tree frog tadpoles and that the invasive tadpoles became dominant (Smith 2006). The same study found that the effects of Cuban tree frogs on southern toads were reduced if predatory eastern newts were also present.
Smith K.G. (2006) Keystone predators (eastern newts, Notopthalmus viridescens) reduce the impacts of an aquatic invasive species. Oecologia, 148, 342–349.
Supporting evidence from individual studies
A before-and-after study in 2001–2003 in Florida, USA (Rice et al. 2011) found that the abundance of squirrel tree frogs Hyla squirella and green tree frogs Hyla cinerea increased after removal of Cuban tree frogs Osteopilus septentrionalis. Squirrel tree frog abundance in the wet season doubled following Cuban tree frog removal at one site (20 removed; abundance: 109 vs 200). However, survival rates did not differ (0.9). Green tree frogs also increased at one site where 589 Cuban tree frogs were removed (7 vs 24). Other species and sites were not compared due to small sample sizes. A total of 693 Cuban tree frogs were removed (10–589/site). Tree frogs were captured in 84–99 refuges/site, which were checked each week or month. Refuges were 1 m long, 5 cm diameter polyvinyl chloride pipes hung 1 m from the ground and with a cap at the bottom to retain water. Tree frogs were marked and from 2002 all Cuban tree frogs captured were removed.