Final answer:
The unusual behavior observed in about 20% of gerbils is known as barbering, a behavior where gerbils chew or pluck their own or another's fur, often due to stress or lack of stimulation.
Step-by-step explanation:
An unusual behavior that may be noticed in approximately 20% of gerbils is D) Barbering.It is important to monitor the gerbils closely and provide appropriate veterinary care if any injuries or complications arise from barbering.
Barbering is a term used to describe a behavior where animals, including gerbils, chew or pluck their own fur or the fur of other gerbils. This behavior can sometimes be seen in environments where gerbils are kept in captivity and may be triggered by factors such as stress, boredom, or dominance hierarchy. Gerbils are social creatures and need environmental enrichment to stay mentally and physically healthy. If not given sufficient space or stimulation, they might engage in barbering as a displacement activity. Preventative measures like providing ample space, social interaction with other gerbils, and environmental enrichment can help to decrease the incidence of this behavior.