Salamanders and newts are members of the order Urodela, also known as Caudata, and are amphibians with a lizard-like appearance. This is a diverse group of animals with variable ecology, thus the behaviors of individual species are likely to vary considerably. Certain species such as the red-backed salamander and the small-mouthed salamander have been extensively studied, whereas others are yet to be researched – little is known about them.
This article examines some of the social behaviors displayed by these creatures, in an attempt to determine if they are actually social, or if they are happier in their own company.
Territoriality
Some salamander species are highly territorial. For example, the red-backed salamander, Plethodon cinereus, establishes its territory and begins to defend it once it has grown to a sufficient size – prior to this, it wanders between areas as it matures. These territories are maintained both by males and females, during and outside of breeding season, and are also used as feeding areas for individuals. This act of driving other conspecifics away gives the impression that this species is not particularly social.
Courtship
The red-backed salamander, Plethodon cinereus, has been found to engage in social monogamy, with males and females forming pairs throughout summer and autumn. Individuals have also been observed making attempts to reduce the likelihood of matings taking place outside of their pair, driving conspecifics of the same sex away from the territory. This is the first instance of social monogamy to be reported in salamanders.
Various social behaviors are shown during the courtship routine of many salamander species. The male nudges the female with his head, and they walk together with the female straddling the male’s tail, resting her head at the base of it. Some species, such as the small-mouthed salamander, Ambystoma texanum, also undergo amplexus, where the male grasps the female. These behaviors are specific to courtship and are not shown at any other time.
Communication
Salamanders and newts communicate with each other using a variety of sensory cues. Visual signals such as arching the back and elevating the tail are used in territorial displays, whereas olfactory cues such as pheromones are used to identify members of the same species, mark territories, and find potential mates. Some salamander species will also communicate using auditory cues, such as the small-mouthed salamander, Ambystoma texanum, which produces sounds in response to threats, as well as during courtship. Despite this array of methods of communication, they are only used either in reproduction or agonistic encounters, which suggests that salamanders are not especially social beings.
Other Social Interactions
Group living is rarely seen in salamanders. However, in extreme environments it can present benefits – for example, Luschan’s salamander, a species found in the Mediterranean, resides in arid habitats, and groups of this species have been reported to aggregate in shelters. This strategy is thought to reduce the chances of dehydration, as well as protect against predators.
Similar trends can be observed in larval salamanders, such as larval ringed salamanders (Ambystoma annulatum), which may be present in large groups and respond to visual cues from their conspecifics in a phenomenon called social facilitation, where individuals copy behavior shown by others. This can keep larval salamanders safe from detection by predators.
Most ‘social’ behaviors reported in salamanders take place out of necessity, such as mating and territorial displays, which are required for the survival of the species. These animals show little inclination to spend time with one another unless there is a serious risk of predation, but even then, they are not especially gregarious. We can conclude that salamanders and newts are not a social species.
