Elephants receiver response

Figure 3. Hypothetical responses of male elephants at different ages to pre-ovulatory urine that contains an estrous pheromone. The main response of signal detection is flehmen. Additional behaviors may reveai aspects of receiver condition, status, and experience. Behavior one might include "moves away , "vocalize", and "blow". Behavior two might include motionless with ears erect, dig, and suck. Ages are estimates and wouid vary with populations and their histories of human intrusion and poaching.

The interesting observations on the variety of discrete and different chemicals eliciting the low level, non-repetitive novel substance response reinforce the multiple receiver functionality of the VNO. Sets of molecules contained in the complex urine and single molecules are both capable of eliciting flehmen. The inactivity of chemicals such as phenols, especially 4-methylphenol, identified in urines of several species (Patterson, 1967 Hradecky, 1978 Brown et al., 1978) was expected because of both their volatility and their non-uniqueness in female elephant estrous urine. 

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