Animal Adaptation
By Cecile Ashen-Young, CPDT-KA
Animals adapt both structurally and behaviourally to changes in their environment. From an evolutionary perspective, these adaptations have special functions that allow the animal to survive the challenges of novel environments. Structural adaptations occur over long periods of time and are exemplified by transgenerational adjustments in the animal’s genetic traits such as coat color, feathering, and limb characteristics. By contrast, behavioural adaptations can happen more quickly. They are exemplified by an individual’s responses to challenging environmental changes and they function to increase the individual’s chances of survival and reproduction. Behavioural adaptations may be learned and passed on to the next generation, or they may be passed on genetically over generations to become a characteristic behaviour for that species (Bauer, 2010).
Behavioural adaptations can benefit the group directly but may be detrimental to some individuals in the group. For example, migration is an action performed by individuals in a group that benefits the group as a whole because the environmental conditions of the destination increase the survival of the group: however, some individuals may die on the journey. Behavioural adaptations can also benefit the individual directly but at an immediate (though perhaps not long-term) cost to the group. For example, the subadult male lion that kills the offspring of a rival will benefit directly from his actions in that his genes have a better chance of propagation. The group will have lost one of its members, but the females of the pride will go into estrous and breed with this new male (Bauer, 2010; Bolhuis & Giraldeau, 2009).
Behavioural adaptations are seen in social carnivores, such as the wolf, in response to changes in social and foraging conditions. The wolf will use different behavioural tactics, such as territoriality, deferred reproduction, and dispersal mechanisms, depending on fluctuating cycles of population density and prey availability. The social environment will fluctuate within families (e.g. the death of a parent) and within the group (e.g. the dispersal and/or escalation of conflict among siblings). The hunting behaviour of adult wolves also varies with fluctuations in food resources. The wolf may follow migrating herds, hunt cooperatively when large game is involved, hunt smaller game individually, or scavenge from garbage dumps. This behavioural flexibility and the speed at which an animal adapts to changes in the environment are directly associated with the animal’s intelligence in terms of communicative skills, problem-solving skills, and learning (Packard, 2011).
There are a number of behavioural adaptations observed in animals undergoing domestication. These adaptations are characterized by quantitative changes in the nature of responses exhibited by domestic versus wild animals triggered by changes in key stimuli in the animal’s environment. An animal’s behaviour patterns may be reduced or exaggerated in response to novel stimuli, changes in intraspecific interactions, changes in nutrition and energy expenditure, and the presence of people. An example of a behaviour that has been adaptively reduced in the domestic animal is observational learning, a trait that is important for survival in the wild but loses its importance in a captive environment. The domestic dog differs from the wolf in this regard (Frank, 1980, as cited by Price, 1999): people serve as a buffer between the dog and the consequences of his actions and the actions of other animals, reducing the selective advantage associated with observational learning (Price, 1999).
Domestic and captive animals also exhibit reduced behavioural responsiveness in some contexts. A reduction in aggressiveness is correlated with increased tractability or handling by humans. For example, caged Norway rats are more likely to flee than become aggressive when compared to wild rats (Herre & Rohrs, n.d.). In many domestic animals, including South American llamas and alpacas, flight behaviour is almost completely eliminated (Herre et al., n.d.).
Behaviour may also be exaggerated or increased as a result of adaptation. Different feeding behaviour may be exaggerated in response to a captive or domestic environment. Wolves exhibit social behaviour at a feeding site, with juveniles and nursing mothers allowed priority access. By contrast, domestic dogs exhibit an increase in aggression when food is involved. Domestic cats may show an increase in certain aspects of the hunting sequence by repeatedly catching the same mouse without killing it (Herre et al., n.d.).
References
Bauer, M. (2010, July 7). What is the Meaning of Behavioral Adaptation? Retrieved July 9, 2011, from Livestrong.com: http://www.livestrong.com/article/188978-what-is-the-meaning-of-behavioral-adaptation/
Bolhuis, J. J. & Giraldeau, L. (2005). The Behavior of Animals. Mechanisms, Function, and Evolution. Oxford: Blackwell Publishing.
Herre, W. & Rohrs, M. (n.d.). Domestic Mammals. Retrieved July 8, 2011, from Animals in Captivity: http://www.primitivism.com/domestic.htm
Packard, J. M. (2011, February 29). Wolves. Retrieved July 9, 2011, from Encyclopedia of Behavior: http://wfsc.tamu.edu/jpackard/share/mypubs/packard09c.pdf
Pongracz, P. Molnar, C., & Miklosi, A. (2009). Barking in Family Dogs: An ethological approach. The Veterinary Journal .
Price, E. O. (1999). Behavioral development in animals
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