Alien invasive species can disrupt ecosystems directly by outcompeting native species for resources. Effects of invasions, however, can be also indirect and less predictable. Among animals that rely on sound for attracting mates, alien intruders may cause noise and reduce mating success.
In a study of invasive amphibians in Brazil, researchers used a combination of field studies, literature and GBIF-mediated species occurrences of six species with invasive populations to analyze current habitats and future distributions. The generated models revealed large increases in potential ranges for two species–E. johnstonei and R. jimi.
Through spectral analysis, the researchers compared vocalizations and found high overlaps between calls of invader P. luteolus and native Ischnocnema sp. For domestic invader L. labyrinthicus, they found spectral overlaps with locals L. knudseni and–even more pronounced–L. pentadactylus.
Determining whether these overlaps causes actual acoustic interference–or even mistaken recognition and potential hybridization– will require further studies, however, this paper highlights the potential effects of invasions, which, combined with projected range expansions, suggests a need for increased monitoring and control.