Asian elephant chemical signals responses

To begin the assessment of possible chemical messages between male Asian elephants, responses of captive males to conspecific musth and nonmusth urine were measured. Some obvious disadvantages of captive studies are substantially offret by some real advantages (1) close, accurate behavioral observations in a limited-size enclosure, (2) precise placement of test samples on substrate free of conflicting signals, (3) safe collection of test samples of elephant origin from males whose hormonal status can subsequently be determined. 

Our standard control in these studies is vanilla extract in water. The control generally elicits a low level of interest, mainly sniffs and checks. We interpret this as interest in an odor source but not one with a meaningful signal (i.e., with evolutionarily evolved meaning). Female Asian elephants often show about the same interest in luteal urine as our control. However, luteal urine does evoke place and flehmen response on occasion, whereas, the control does not (Slade et al., 2003). Luteal urine probably contains cues on sender identity, but chemicals either specific to or more abundant in follicular urine reveal reproductive readiness. 

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