The effect of visibility on territory size and shape

Abstract

Although several authors have suggested that visibility affects territorial behavior, there have been few systematic studies of this phenomenon. Here we review five ways that visibility might influence the use and defense of space in territorial animals, and then we discuss a laboratory study on the effect of visibility on territory size and shape. Juvenile lizards were allowed to establish territories in two habitats identical except for a visual obstacle that bisected one of the two habitats. Lizards in the habitat with good visibility defended compact territories of a size comparable to those in the field. In contrast, those in the low-visibility situation avoided territories that included the visibility barrier and instead chose either very small or highly elongated territories. Territories with good visibility probably cost less to defend than those with poor visibility; territory owners may also prefer high-visibility territories because they reduce predation risk or increase foraging success.