Urine African elephants, female

Our recent NSF-funded collaboration with Bets has yielded, for example, the first statistically significant evidence that male African elephants can distinguish conspecific female urine collected at the time of ovulation from urine obtained at the mid-luteal time of the estrous cycle (Bagley, Goodwin, Rasmussen and Schulte 2006). Additionally, we have published the first report of insect pheromones in the urine of female African elephants (Goodwin, Eggert, House, Weddell, Schulte and Rasmussen 2006). These findings bode well for the eventual discovery of the first African elephant pheromones. 

Abstract A relatively small number of mammalian pheromones has been identified, in contrast to a plethora of known insect pheromones, but two remarkable Asian elephant/insect pheromonal linkages have been elucidated, namely, (Z)-7-dodecen-1-yl acetate and frontalin. In addition, behavioral bioassays have demonstrated the presence of a chemical signal in the urine of female African elephants around the time of ovulation. Our search for possible ovulatory pheromones in the headspace over female African elephant urine has revealed for the first time the presence of a number of known insect pheromones. This search has been facilitated by the use of a powerful new analytical technique, automated solid phase dynamic extraction (SPDE)/GC-MS, as well as by novel macros for enhanced and rapid comparison of multiple mass spectral data files from Agilent ChemStation . This chapter will focus on our methodologies and results, as well as on a comparison of SPDE and the more established techniques of solid phase microextraction (SPME) and stir bar sorptive extraction (SBSE). 

Fig. 2.1 Compounds identified in female African elephant urine headspace that are known insect pheromones...

Use of automated headspace SPDE/GC-MS not only enabled the identification in female African elephant urine of a number of known insect pheromones (compounds 2-6, Fig. 2.1), but also revealed the presence of the beetle biochemical precursors to frontalin (2), exo-brevicomin (3) and ent/o-brevicomin (4), thus suggesting a common biosynthetic pathway (Goodwin et al. 2006). Extensive behavioral bioassays must be performed to determine whether any of these compounds is functioning as a pheromone among African elephants. 

The Asian elephant has farnesol, 4-ethylphenol and 4-methylphenol in its temporal gland secretion while the African elephant has only 4-methylphenol. Farnesol levels are inversely related to testosterone levels (Rasmussen and Perrin, 1999). Preovulatory female urine contains (Z)-7-dodecen-l-yl acetate (Rasmussen etal, 1996). 

CHEMICAL ANALYSIS OF PREOVULATORY FEMALE AFRICAN ELEPHANT URINE A SEARCH FOR PUTATIVE PHEROMONES... 

The edulans and dihydroedulans were first identified in passionfruit (Whitfield and Stanley, 1977 Prestwich et al., 1976). Subsequently, edulans were seen in human urine (Mills and Walker, 2001), while dihydroedulans have also been found in male scent organs of African butterflies (Schulz et al., 1993). The theaspiranes have been identified in green and black tea, as well as in a number of finits and berries (Schmidt et al., 1992). Later, a theaspirane was observed by SPME/GC-MS in urine from a female Asian elephant (Rasmussen, 2001). Recently, a dihydroedulan and a theaspirane were reported from giant panda urine (Dehnhard et al., 2003). 

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