I want to start by thanking Anole Annals for the offer to write a post not about anoles, but about a group of honorary anoles, Phelsuma geckos (Losos, pers. comm.). Our recent publication (Hagey et al. 2016) looked at how Phelsuma ornata, P. guimbeaui, and P. cepediana use their environment in Mauritius over the course of the day.
Understanding how species use their environments is a fundamental step to understanding how they’ve evolved and adapted. Extensive previous work has been collecting observations and quantifying the microhabitat use of anoles and other lizards. As we all know on this blog, Caribbean anoles can be organized into ecomorphs, species with convergent morphologies and microhabitat preferences. The microhabitat use patterns of these species are so critical that the names of the ecomorphs represent their habitat preferences. After quantifying the habitat preferences of a set of species, however, often little thought is then given to how this preference may vary seasonally or over the course of a day.
Back in 2002, Luke and Lisa Harmon collected observations of Phelsuma geckos on the island of Mauritius to investigate how these “pseudo-anoles” may be partitioning their microhabitat. They found that Phelsuma partition their habitat structurally, with species using palm or non-palm vegetation (Harmon et al. 2007). In addition, Luke and Lisa collected temporal information, observing the perches that Phelsuma use over the course of the day. With these data, we hypothesized that sympatric species would have complementary activity patterns, reducing the time in which species overlap using the same perches.
We did find that Phelsuma vary their microhabitats, moving to larger diameter and lower perches later in the day, but these changes don’t reduce microhabitat use overlap between sympatric species. Alternatively, species may be moving to track sunlight for thermoregulation, following prey, or avoiding predators. These temporal microhabitat changes are likely to be important for how Phelsuma interact with their environment. We therefore feel that temporal microhabitat and activity variation should be considered more often when quantifying a species’ microhabitat preferences, as it may be an important aspect of a species’ niche (see Pianka 1973; Schoener 1974).
Hagey, T. J., N. Cole, D. Davidson, A. Henricks, L. L. Harmon, and L. J. Harmon. 2016. Temporal Variation in Structural Microhabitat Use of Phelsuma Geckos in Mauritius. J Herpetol 50:102-107.
Harmon, L. J., L. L. Harmon, and C. G. Jones. 2007. Competition and community structure in diurnal arboreal geckos (genus Phelsuma) in the Indian Ocean. Oikos 116:1863-1878.
Pianka, E. R. 1973. The Structure of Lizard Communities. Annual Review of Ecology and Systematics 4:53-74.
Schoener, T. W. 1974. Resource Partitioning in Ecological Communities. Science 185:27-39.