Island atlas · Landscapes & species
Gigantes Sur
2 species records name Gigantes Sur. Explore their natural history, taxonomic history and distribution sources.
Tangke saltwater lagoon, enclosed by limestone cliffs on Gigantes Sur.
Photo: Emman Asuncion Foronda · Original photograph · CC BY-SA 4.0. Displayed to fit the frame.
Beyond the species list
A sense of place.
Gigantes Sur is one of the two main islands of the Gigantes group, off northeastern Panay in the Visayan Sea. The group belongs to Carles in Iloilo. A narrow channel separates Gigantes Sur from Gigantes Norte.
Landscape & habitats
Tangke lagoon lies within the limestone scenery of Gigantes Sur. Its enclosed saltwater pool and steep rock walls illustrate how karst landforms can create sheltered aquatic environments beside the open sea.
Geographic sources
Geographic overview checked 7 October 2026. The photograph illustrates a landscape, not a snake observation.
Islands, barriers & evolution
Zoogeography
Small limestone islands with restricted-range fauna
Gigantes Sur shows that important centres of endemism need not be large islands. Brown and Alcala described the limestone frog Platymantis insulatus from South Gigante in 1970; later work places it in the Gigantes group and associates it with caves, crevices and fissures in limestone.
This example highlights the importance of very local habitat as well as island geography. It also shows why an original type locality should not be mistaken for the complete modern range of a species.
How to read the historical island groups
During Pleistocene glacial periods, lower sea levels exposed shallow seabeds and joined some present-day islands. Biogeographers call these reconstructed landmasses Pleistocene Aggregate Island Complexes (PAICs). Deep channels continued to separate others. This model helps explain regional similarities, but dispersal, older geology and habitat differences also shaped each fauna.
“Endemic” means restricted to a stated area; a Philippine endemic need not be confined to one island. The account above summarises published regional and local research. It does not add occurrences to the snake index below.
Regional framework: Meneses et al. (2024) ↗Zoogeographic sources · 2
- Brown & Alcala (1970) · A new Platymantis from South Gigante Island ↗Original description and locality evidence; historical record, not a modern range limit.
- Alcala et al. (2012) · Philippine limestone frog, FrogLog 104 ↗Gigantes-group distribution and limestone microhabitats.
Literature checked 7 October 2026. Survey results refer to the dates and areas studied.
Source-backed index
2 species
These are explicit source mentions, not a complete island richness estimate. Fine localities and habitat associations remain separate evidence claims.
A source naming Gigantes Sur does not establish occurrence in every municipality, protected area, or habitat on the island.