Elephants 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. 

Most noteworthy is the high intensity response of the Asian bull elephant to female estrous urine. This intense response is higher than to any other substance and of higher intensity than exhibited by males of any other species to estrous females. The intensity, expressed as flehmen frequency (flehmens per unit time) of the Asian bull elephant response at estrus is at least 10-fold the response at anestrus. In the wild horse, estrous females were preferred (Turner, 1981). And in the cat, the response differential was 2-fold (x = 5.6, duration, 8.4 seconds toward estrous urine, and X = 2.8, duration, 3.3 seconds toward non-estrous urine Verberne, 1976). Flehmen duration in the elephant exhibited no measurable difference between... 

In rabbits, the as yet unidentified maternal signal during lactation has analogous properties in guiding the reliable orientation of suckling, mainly via MOS input (Hudson and Distel, 1986 Schaal et al., unpubl.). Minor fractions may still function as flag contributors, exemplified by the attractiveness of proestrous elephant urine. Male responses show that intact urine is conspicuously more attractive in comparison with the pure insect mammal pheromone (9.) presented in water (Rasmussen et al., 1996). 

Perrin T. and Rasmussen L.E.L. (1994). Chemosensory responses of female Asian elephants (Elephas maximus) to cyclohexanone. J Chern Ecol 20, 2953-2958. 

Rasmussen L.E.L., Schmidt M.J. and Daves G. (1982). Asian bull elephants Flehmen-like responses to extractable components of female elephant estrus urine. Science 217, 159-162. 

Fig. 7.2 Comparison of the proportion of elephants responding with chemosensory behaviors to the general substrate (environment) and to urine/feces for pre- and post-pubescent males and females, (a) Ndarakwai Ranch, Tanzania sample size of different elephants from left to right for environment and to urine/feces 40, 44, 46 and 40. The same animals were observed for response to urine/feces as to the environment, (b) Addo Elephant National Park South Africa sample size from left to right for environment 59, 43, 53 and 48. Many of the same animals were observed for response to urine/feces as to the environment. Sample sizes to urine/feces from left to right 49, 32, 44 and 44...

Loizi, H. (2004) The development of chemosensory behaviors in African elephants (Loxodonta africana) and male responses to female urinary compounds. M.Sc. thesis, Georgia Southern University. 

Even adults can still develop olfactory preferences that contravene those acquired before sexual maturity. Female laboratory mice imprinted by the odor of one mouse strain will prefer this odor even more if they are exposed to males of this strain as adults. However, if they are exposed to males of a different strain when sexually mature, their original odor preference will be reversed (Albonetti and D Udine, 1986). Naturally occurring sex or body odors may assume their sexual significance after association with sexual activity male mice were aroused by a perfume that they had experienced earlier on scented females they had interacted with (Nyby etal., 1978). Practitioners have known that adult mammals can acquire responses after exposure to certain animals. For instance, bulls of the Asian elephant that had been housed near African elephant bulls respond to temporal gland secretion and its three components phenol, 4-methylphenol, and (E)-farnesol from the latter species. Asian bulls thathad not been associated with African bulls did not respond (Rasmussen, 1988). 

Rasmussen, L. E. L. (1988). Chemosensory responses in two species of elephants to constituents of temporal gland secretion and musth unrvt. Journal of Chemical Ecology 14, 1687-1711. 

Thornton, S.J. (2000). Investigations into the diving response of northern elephant seals (Mironnga angustirostris) using Magnetic Resonance... 

Pheromones are also important in mammals, although many fewer have been identified. As one example, (Z)-7-dodecen-l-yl acetate has recently been identified in the urine of female elephants when they are in heat. This ester elicits a specific sexual response in male elephants. Interestingly, this same ester is part of the pheromone mixture that many insects, especially moths, use as a sexual attractant. 

Fresh urine was collected from Asian elephant females that were at the height of estrus.150 Urine was extracted with an immiscible organic solvent and concentrated. Bioassay involved reconstitution of the extract concentrate in acetone, addition of the acetone solution to (in active) urine samples from females that were not in estrus, and application to concrete slabs or logs. Observers, who were unaware of the sites where samples had been placed, recorded the flehmening responses of test bull elephants. These studies convincingly demonstrated that in Asian elephants the estrous state, and probably the receptivity of the female, is revealed by a substance or substances that can be extracted from the urine 150 of females in estrus. 

Figure 5 Chemosensory inspection behaviors by male and female elephants to frontalin (52), demonstrating specific and varying responses to this male pheromone during different life history stages.155...

First identified in Asian elephants during a headspace analysis of volatiles collected from secretions of the musth temporal gland of adult males,156 frontalin (52) is a bicyclic ketal, which is structurally reminiscent of the male mouse priming pheromone component 3,4-dehydro-ara-brevicomin (37). Frontalin (52), Z-7-dodecen-l-yl acetate (51), was already known because of its chemosensory role in the insect world it is an aggregation pheromone in bark beetles.157 Interestingly, the ratio of the two enantiomers of frontalin (52) changes with age and stage of musth and elicits different behavioral responses.158... 

The structural similarities between the putative mammalian chemosignals and the pheromones identified previously in the insect world are quite striking. The farnesenes [257, 258] (entries 66, 67) and 2-heptanone [259] (entry 68) have been implicated previously as insect pheromones. There is only one double bond distinguishing the male mouse pheromone 3,4-dehydro-exo-brevicomin (entry 65) from a bark beetle pheromone [260], brevicomin. In addition, the elephant pheromone (Z)-7-dodecen-l-yl acetate (entry 69) is also known to be an insect pheromone [259]. While the potency may not compare to the insect system, investigators are beginning to find evidence that many mammals ranging from pigs to elephants can have a pheromone-type response to a sniff of secretions even humans appear to respond [261],... 

The isolated boar ketones, 5a-androst-16-en-3a-ol (androstenol) and androst-16-en-3-one (androstenone) secreted by the sub-maxillary gland, have a direct effect on the sexual receptivity of the sow and are used commercially to assist in artificial insemination (14). The fact that estrus can be determined in the sow by her response to these compounds suggests that there is a heightened acuity for these compounds at the time of ovulation. This is similar to the increase in olfactory acuity for certain compounds noted in human females prior to ovulation (15). A somewhat unique but analogous situation is the elephant temporal gland which is an apocrine gland that is active under stress and possesses an elephanty odor (16). Table III summarizes some of the mammalian communication systems that have been studied and the chemicals which have been found to have behavioral effects. 

Figure 2 Mean flehmen responses per approach to musth and nonmusth urine by two age classes of male elephants...

---