Image of a veiled chameleon by Geoff (CC BY-SA 3.0).

It is a well-known fact that people need constant interaction with others in order to grow up to become normal, healthy adults. But do all types of animals require group contact with other members of their species as we do? Ballen and colleagues were interested in the behavioral differences caused by raising a particular type of lizard, the veiled chameleon, in a group or in isolation. The findings of their paper were further brought to public attention by the science writer, Mary Bates, in her news article titled “Lizards Need Social Lives, Too.” Although the main message from these two pieces of literature is the same, Ballen and colleagues wrote for the scientific community and Bates wrote for a more general and wider audience.

Ballen and colleagues knew from previous studies that birds and mammals raised in isolation had problems with “social behavior, mental performance, and foraging behavior” (Ballen 2014). However, they were curious if reptiles were also negatively affected by being raised alone. Ballen found a type of lizard known to grow up with its siblings in its early life: the veiled chameleon. Ballen decided to test if isolation early in life affected the chameleon’s ability to forage for food and interact with members of its species later in life. To do this, Ballen incubated chameleon eggs until they hatched and then raised some of these hatchlings in groups and others in isolated enclosures. The chameleons’ foraging ability was then tested by measuring the amount of time an individual took to catch a cricket. The scientists tested social behavior by placing two chameleons of the same size and sex together and observing aggressiveness and submissiveness in social interactions. (more…)