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中文Grazing the Kalahari Desert of Southern Africa, Meerkats (Suricata suricatta) are found to withstand extremes in temperature and predation. Subsisting on insects, Meerkats forage in large groups with females spending more hours foraging than their male counterparts when it is breeding season. Females forage more especially when they are pregnant or lactating young meerkats (Brotherton, P., et al., 2001; Scantelbury, M., et al., 2002). Forming intricate burrow networks, Merkaats gather in one chamber of the burrow in order to huddle together during nighttime when the African desert experiences very cold temperature. During the day when the heat is unbearable, Merkaats also seek shelter from these burrows (Russell, A., et al., 2002). Aside from extremes in temperature, these brown animals with patches of dark fur around their eyes also experience an elevated rate of predation. These predators range from jackals to aerial predators such as tawny and martial eagles (Clutton-Brock, T., et. al, 1999). To combat these predations, one or more of the meerkats guard the others while foraging, sounding alarm calls once a predator is in sight. This type of behavior is often referred to as sentry or vigilant behavior (Griffin, A.S. and West, S.A., 2002 & Griffin, A.S. and West, S.A.2003).
This particular ‘vigilant’ behavior is seen in meerkats either in captivity or in the wild. This paper will explore why this species exhibit such behavior and its significance. Next, odd behavior patters and evolutionary trends of this behavior will also be discussed together with the theoretical background of this behavior. The last part of this paper will provide a summary of the major points discussed in this paper.
Vigilant Behavior of Meerkats in the wild and in the Zoo
Almost all animals, when they forage- exhibit a certain level of vigilance as exemplified by such behavior as surveying their surroundings for potential predators (see for example Hochman, V. & Kotler, B., 2007; Lung, M. & Childress, M., 2007; Beauchamp, G. & Ruxton, G., 2007; Beauchamp, G. 2008 and Vasquez, R., et al., 2002). An elk, which is an example of a socially foraging animals, exhibit vigilance by scanning their surroundings for predators before and during devouring of vegetation (Lung, M. & Childress, M., 2007). Birds and other animals often disrupt their feeding sessions in order to look out for potential predators (Beauchamp, C., 2008). In Meerkats, this vigilant behavior is apparent when a large group of these species forage. While feeding, one or two more meerkats stand on their hind legs and scan the area (both aerial and land) for predators. Once a predator is identified, an alarm call is sounded to ensure that the group quickly returns to their burrows for protection. During this time, the young are also protected by kin recognition or the escorting of the young by their parents or adult carers of the group. Kin recognition is thought to play an important role in the survival of the young during feeding (Gilchrist, J., 2004; Manser, M.B., and Avey, G., 2000).
Vigilant behavior in animals, particularly in the meerkats, allows them to protect themselves against predation and to ensure their propagation and survival (Hochman, V. & Kotler, B., 2007; Lung, M. & Childress, M., 2007; Beauchamp, G. & Ruxton, G., 2007; Beauchamp, G. 2008 and Vasquez, R., et al., 2002). However, this vigilant behavior is half pronounced in meerkats who are placed in captivity or in the zoo. The environmental conditions in captivity or in a zoo are different compared to the real environment. Predation is absent and this allows the animals to adjust to their new environment and at the same time limit their vigilant behavior (Beauchamp, G., 2008).
Evolutionary Trends and Theoretical Background of Vigilant Behavior
Adaptation of this breed of mongoose results in the gradual change of the inherited traits of these species over a period of time. This change is a product of competition for scarce resources and natural selection (Cunningham, W. P and Saigo, B.W., 2001; Cunningham. W., 2004; Enger, E., 2002; Mayer, R., 2001). In animals whose social relationships is complex, “vigilance may be directed at conspecifics to reduce risks associated with proximity to conspecifics (conspecific risk)” (Lung, M. & Childress, M., 2007). A number of studies have suggested that the benefits of vigilance include predation risks although vigilance does vary with “predation pressure” (Wolff, J. and Horn, V., 2003). However, vigilance is not only limited to protection from predators but also in non-predator involvement. For example, both female and male adults in the reproductive stage have higher level of vigilance as compared to their non-reproductive counterparts and to their younger group (Lung, M. & Childress, M., 2007). Vigilance in reproductive females is geared towards the protection of its young (Beauchamp, G. & Ruxton, G., 2007). Whereas vigilance in males involves monitoring of conspecifics and ensuring mating success (Lung, M. & Childress, M., 2007). Another study also shows that when the herd population size is decreased along with the birth of offspring, the level of vigilance is increased (Stankowich, T., 2003). In female elk, its position in the herd serves as major predictor for its vigilance (Lung, M. & Childress, M., 2007).
Summary and Conclusion
The underlying mechanism of vigilance in animals such as the meerkats lie in at least two factors: protection of their species against predation; increasing the level of mating success in their group. The explanation of this animal behavior may be explained by the natural selection that this group of animals underwent during their evolutionary process (Cartwright, J., 2002). Aside from their natural protection against predation (i.e., the presence of dark furs around their eyes to protect their eyes against the sun when they scan the skies for predators), meerkats have developed some level of sophistication in their social group. This is exemplified by the time forage time of the group where one or more members of their group serve as sentinels of predators.
