Addo's male elephants prick up their ears when they get a trunk call from a strange female
Without dating sites‚ what’s a randy male elephant to do? The answer‚ it turns out‚ lies in listening to the nasal rumbles emitted by females.
Austrian researchers working in Addo Elephant National Park in the Eastern Cape have found that males respond much more eagerly to the sounds of unfamiliar females than those they know. By contrast‚ female elephants prefer familiar rumbles‚ according to an earlier study.
“Our results provide evidence that male elephants extract social information from vocalisations‚ yet with a different intention than females‚” say Angela Stoeger and Anton Baotic‚ from the mammal communication laboratory at the University of Vienna.
“Males might use social cues from vocalisations to assess mating opportunities‚ which may involve selection to identify individuals or kin to avoid inbreeding.”
Writing in the journal Nature‚ the researchers describe how they recorded rumbles from Addo‚ the Pilanesberg‚ Bela Bela‚ Hazyview and Vienna Zoo‚ and played them to 27 unsuspecting Addo males through a custom-built sub-woofer mounted on a 4x4 hidden behind bushes.
“We started playback trials only if a bull was browsing calmly or drinking at a waterhole‚ in each case facing the opposite direction of the speaker. This enabled reactions such as ‘turn to speaker’‚ ‘face speaker’ or ‘approach speaker’ to be best identified.”
Other reactions the researchers monitored included lifting the ears‚ head and trunk‚ and stopping feeding or drinking.
“(The males) generally displayed longer attentive reactions in response to the rumbles of unfamiliar females. These behaviours ... are suggested to indicate an intensive period of listening‚” they say.
“Though we cannot exclude that the ... responses were driven by novelty‚ the fact that females in similar experiments preferred the stimuli of more familiar females points to a preference.”
Stoeger and Baotic say previous studies had shown that low-frequency elephant rumbles transmit information about identity‚ reproductive state‚ arousal‚ age and size.