General News
15 August, 2022
Native animals tangled in invasive songs
JAMES Cook University researchers say the noises made by invasive species may interfere with the behaviour of native species and could have stronger effects than human-made noise.
Professor Lin Schwarzkopf, Head of Zoology and Ecology at JCU, was part of the study.
She said the transmission and reception of sound, both between members of the same species and among individuals of different species, plays a crucial role in survival.
“Correct interpretation of acoustic signals enables important behaviours, such as predator avoidance, successful foraging, and mate location and identification,” Prof Schwarzkopf said.
“Male frogs, for example, call to attract females, and as calls are species-specific, individuals of the same species can find each other for breeding.
“For that system to work properly, females must hear and recognise the calls of males.”
She said when a new noise made by an invasive species is introduced to a species’ habitat, animals may not hear as well or can become confused.
Professor Schwarzkopf said the public is generally aware of possible adverse effects of urban noise on animals, such as traffic, planes and machinery.
“Although invasive species’ calls and anthropogenic (human-made) noises such as traffic share some features, the noises made by animals are also different in important ways and have different effects,” she said.
“Animal noises are concentrated in particular frequencies, and they call or sing notes.
“They also employ frequency modulation and vary the time of their noises – all of this makes animal noises different from many human-made noises.”
She said because of the timing and lack of modulation of urban noise, animals may habituate and cease to react to it.
“But if native species can better detect or pay more attention to the sounds of other animals than to anthropogenic noise, then invasive species’ calls may have even greater effects on ecology than anthropogenic noise,” Prof Schwarzkopf said.
She said invasive species with loud, long calls and with similar ecology and evolutionary background to native species seem the most likely to impact natives negatively.
“Determining the native species most likely to be impacted and what these impacts are likely to be should constitute the goal of future research,” Prof Schwarzkopf said.
“Answering these questions will help us to determine the degree to which soundscape intrusion by invasive species should be considered in future conservation initiatives.”
