Methods of communication exhibited by captive slender mongooses Herpestes sanguineus

Abstract

Slender mongooses are solitary, diurnal viverrids. No detailed studies on communication in this species have been reported. Smithers (1971) and Taylor (1975) record the production of a distress call, and Taylor (1975) describes a hissing sound produced by alarmed mongooses. In the present study (348 h of observation) vocal and non-vocal displays of captive mongooses were examined. Six pairs of mongooses were maintained in outdoor enclosures for up to 20 months (for details concerning housing, see Baker 1981). Vocalizations were recorded on a Uher 4200 L tape recorder at speeds of 9,5 or 4,7 cm/s using a Uher M517 microphone. The sounds were analysed using a Kay sonagraph 7030A following Kiley (1972). A male and a female mongoose were asphyxiated and all large skin glands were located and dissected out. The method, frequency and site of glandular marking, micturition and defaecation were recorded. Vocalizations Five different vocalizations were identified. 1) Spit. This sound is loud and sharp. The duration varies from 0,2 to 0,4 s. Repetition within a 2-s interval is infrequent. The sound is produced with the mouth open. Sound energy is distributed over a wide range (Figure 1). The fundamental frequency varies from 2 kHz to 3 kHz and usually drops 1 kHz from start to finish. The amplitude of the sound is greater at the beginning of the vocalization, which corresponds to the initial burst of energy that is characteristic of spitting. 2) Growl. Sound energy is distributed over a wide range (up to 6 kHz). The growl is often repeated three times within a 2-s interval. The fundamental frequency occurs at 0,5 kHz, with overtones at 1,3 kHz, 2,7 kHz, 5,5 kHz and 6,0 kHz. The amplitude is usually greatest in the middle of the growl. When the sound is produced, the mouth is opened very slightly. Call duration varies from 1,05 s (Figure 2) to 6,30 s (Figure 3) with a mean of 2,55 s. 3) Snarl. No recording was made. This vocalization lasts for approximately 0,8 s (measured with a stopwatch) and is produced with the mouth slightly open and the upper lip retracted. Repetition within a 2-s interval is infrequent. 143 6 4 Figure 1 Sonagraph (narrow band filter) of a spit. Figure 2 Sonagraph (narrow band filter) of a growl. SECONDS Figure 3 Sonagraph (narrow band filter) of a growl. 4) Buzz. No recording was made of this soft call. It is not repeated within a 2-s interval. These four vocalizations are used in agonistic encounters. Growling and spitting were produced when threatening a conspecific or warding off potential attackers. Snarling was used only when two animals approached each other in attack. Growling, spitting and snarling were produced equally by both male and female mongooses. A female mongoose buzzed when she intercepted her mate