New natural history note: “Nocturnal foraging and activity by diurnal lizards: Six species of day gecko (Phelsuma spp.) using the night‐light niche”.
A set of observations, recently published in Austral Ecology, noted six different species of day gecko (Phelsuma spp.) using artificial light at night (ALAN) to engage in nocturnal activity (e.g., foraging, courtship, and agonistic behavior). Lizards of this genus are widely believed to be primarily diurnal, however, their propensity to colonize both urban and highly-modified habitats, as well as establish invasive populations within novel landscapes, suggests they are a taxon that is quite flexible and adaptable.
A blue‐tailed day gecko, Phelsuma cepediana, foraging for insects under a fluorescent light in Mauritius. Photo credit J. L. Riley.
Remind you of any other small- to medium-sized adaptable and diverse group of lizards?
Keen readers of the Anole Annals will recall several posts about the effect ALAN can have on anoles, including its impact on physiological stress, metabolism, invasive potential, and reproductive output. With many accounts noting the costs and benefits of shifting diel cycles and daily activity period, but also the general impact light pollution may have. No doubt, there remains a lot of research potential to examine similar questions for the many Phelsuma species across their native and invasive ranges.
Reunion ornate day geckos, Phelsuma inexpectata, engaging in nocturnal activity under a fluorescent light inside a bathroom in Manapany-Les-Bains, Reunion (A,B), including courtship behavior (C). Photos credits C. Baider and F.B.V. Florens.
It is always worth keeping your eyes peeled in the field.
The observations that led to this note came from nine researchers working in various sites, locations, and projects across a number of archipelagos spanning the Indian Ocean and over several years. As with many natural history observations, most of these accounts began with a researcher – who was no doubt occupied with an entirely different task – seeing something out of the ordinary, snapping a picture and jotting down some quick details, and carrying on with their work. A great reminder to never leave home without your trusty notebook; digital or otherwise. Then later on, sometimes much later, this information regarding “something weird you saw” is shared between colleagues, sometimes met with an “oh ya, I saw that too, different species, different location, but the same thing,” and from there, patterns emerge and collaborations bear fruit.
Over the years, Anoles Annals has featured a number of posts related to day geckos, with some keener anolologists expressing the feeling that these colorful, charismatic, and adaptable geckos could be seen as “honorary anoles.” A compliment, surely, the geckos would appreciate and reciprocate toward anoles, if given the chance. Despite their stunning appearance, long history of public awareness, and ability to sell car insurance, there remains a lot of information we do not know about day gecko behavior, biology, and ecology. We hope this natural history note will prompt further research interest into this enigmatic group of lizards.