The critically endangered Manapany day gecko has long been known only from a small part of Réunion Island, a French territory in the Indian Ocean. A recent study finds the bright green lizard no longer appears in 28% of its previous habitat, but has cropped up in newer, more urban areas where it hasn’t been recorded before.

From 1995-2011, many subpopulations of the Manapany day gecko (Phelsuma inexpectata) disappeared or were close to extinction on the island, the researchers write. To find out where the gecko is now found, they first mapped areas where it had previously been recorded, working with grids of 20 by 20 meters (66 by 66 feet). From 2020-2022, they visited each grid cell up to three times during the gecko’s active hours.

The researchers write the species is brightly colored and doesn’t move away when people appear, which makes it easy to spot if it’s around.

The team found that between 2008 and 2020, the Manapany day gecko had been spotted within an area of 19.44 hectares (48 acres), equivalent to 486 grid cells. Of these, 320 cells contained human-modified habitats, such as housing, farmland and private gardens. Only 97 cell grids had natural habitats, while 69 had mixed natural and human-modified habitats.

During the 2020-2022 survey, the researchers also searched 459 of the previously occupied cells; they didn’t find the gecko in 128 of those — a decline of 28%.

The sharpest decline was in areas with natural habitats. However, the team did find the gecko in 268 new cells, or in about 10.72 hectares (26.5 acres), where it hadn’t been previously observed. Most of these areas contained human-influenced habitats like gardens.

With the species now occupying just 24 hectares (59.3 acres) along Réunion’s southern coast, it is likely “the rarest endemic terrestrial vertebrate on the island in terms of its distribution,” the researchers say.

They further speculate that the recent shift in its distribution to garden-like habitats could be because such areas contain diverse species of palm trees that are frequently watered. The gecko prefers to bask or hide in palm-like trees. Natural habitats, by contrast, support fewer palm species and are more exposed to heat and drought, the authors say. Additionally, gardens provide food sources all year round, including flowers and fruits that attract insect prey, while structures like pipes and buildings protect the geckos from predators and extreme weather. The invasive gold-dust day gecko (P. laticauda) is a rising competitor and threat to the Manapany day gecko.

The researchers recommend urban areas could be made more suitable for the Manapany day gecko by planting gecko host plants. Additionally, educating local people about the gecko,  and preserving the remaining 2.72 hectares (6.7 acres) of its natural habitat would safeguard the gecko’s survival in its historical range, they say.

Banner image of a Manapany day gecko by B.navez via Wikimedia Commons (CC BY-SA 3.0).