Asian elephant chemical signals female responses

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. 

---