Most turtles are territorial however some are more aggressive than others; it really just depends upon the species. Red-eared sliders for instance are notorious for being aggressive and territorial creatures. It is for this reason that many suggest only putting them in tanks by themselves unless you have a very large tank where they can stay away from one another.
Other species such as the snapping turtle are solitary creatures that prefer to live alone. Even though many turtles may be found in a small area, their social interactions are often limited to aggression between individuals. Males are especially prone to this type of behavior. Snapping turtles are known for being quite vicious and also kill other turtles by biting off their heads. It is suggested that this behavior might be a means to protect their territory from other turtles.
Many pet owners have learned the hard way that male turtles do not often like each other’s company. Typically after a male turtle becomes larger than 4 inches and is more mature it is nearly impossible to get them to get along with the other males in the tank. In this case, they should almost always be separated from one another or kept in a very large tank so they might be less likely to fight.
Aquatic turtles are especially territorial, and male turtles that are housed in an environment that is too small to live in together peacefully, will often be found fighting and trying to force the other turtles away. Mating can also turn into a territorial and sparring process as the males show off to try and impress a female turtle to mate with during this time.
In most cases male turtles attempt to establish dominance when it comes to territory, mates, and/or food. It is common for turtles to become very aggressive towards one another and they may even begin biting or “clawing” at one another when this happens.
cathy rogers says
my son had 1 red ear slider for approx 5yrs. one of my coworkers purchased two sliders for her grandchildren which she had for 9yrs, however, they wanted to get rid of them. my son adopted them. they’ve been in the same tank (40 gal) as ours for a few months, but recently our turtle has begun snapping at the smaller of the
two ones. why would the turtle wait so long to become territorial and how do we tell if they are male or female?