Visual communication

Most observers agree that elephants have relatively poor vision. It is believed that elephants see the world in shades of gray under bright light, but may have very limited color vision under dull light. They possibly gain little information about their environment through sight except at very close distances. Nevertheless, several interactions among elephants involve visual signals, some of them very impressive to human observers (especially those directed toward the humans!).

Courtship between the sexes includes the characteristic "musth walk" by the male or the "estrous walk" by the female (see chapter 3). Visual signals are especially apparent in aggressive interactions. Several observers, including Iain Douglas-Hamilton and Joyce Poole for the African elephant and George McKay and M. Krishnan for the Asian species, have provided descriptions of such visual displays. Based on observations of captive African elephants, the ethologist Wolfdietrich Kuhme described body postures related to motivational states, in particular, several variations from the normal in the angle of the head, ears, and trunk.

While many of the descriptions in the literature pertain to displays toward humans or a predator, some of these or their variations are also seen when one elephant (usually a bull) approaches another with aggressive intent. A basic display described by George McKay for the elephant in Sri Lanka (Ceylon) is the approach with "the head raised somewhat and the ears extended forward or rather laterally" (1973, p. 66). A common variation of this is to extend the ears fully and approach the stimulus with the trunk raised. Another display is to extend the ears forward and at the same time "stand tall," sometimes by placing the front feet on a fallen log (fig. 4.10). Both African and Asian bulls indulge in these displays. For a species in which body size is an important determinant of social rank and dominance, such displays designed to exaggerate size are understandable. While these may have the maximum effect in the

Visual Communication Elephant

Figure 4.10

An impressive visual display by a bull African elephant at Tsavo National Park, Kenya.

Figure 4.10

An impressive visual display by a bull African elephant at Tsavo National Park, Kenya.

larger-eared African elephant, the twin domes on the Asian elephant's skull (or the single dome of the mammoth) may serve the same purpose.

Visual displays may be accompanied by behaviors such as swaying of the body or shaking of the head. Eventually, this may be followed by the classical forms of conflict behavior—displacement activity (kicking the ground with the front foot, throwing mud or leaves over its back, exaggerated feeding rate), redirected aggression (thrashing a bush, breaking a stem), attack (a mock charge or a full-blown attack), and retreat (with the tail held aloft). An elephant may not go through this entire sequence. A submissive animal may quickly flee with its tail held up. Visual displays may be accompanied by auditory sig-nals—a shrill trumpet or a series of short squeaks that indicate conflict. The Asian elephant is also known to produce a loud booming sound by rapping the trunk sharply on the ground, possibly through exhaling rapidly at the same time. Although many of these displays have been described in the context of male-male interactions, several of them may occur, although infrequently and subtly, during competition among females or family groups.

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