AMPHIBIANS

Amphibians were the first vertebrates to colonise land. There are three classes of amphibians, anura (frogs and toads), caudata (salamanders and newts), and caecilian (legless worm like amphibians). Amphibians still required moist environments to be active and reproduce. In dry weather they may bury themselves in soil, litter, or mud, cling tightly to the face of leaves, or live under bark or in leaf axials.

Balam Ja Way is in the driest area of Corozal District, and of Belize, and consequently some amphibian species recorded for Corozal District may not be in Sarteneja. However, other species are found in dry areas of the Yucatan Peninsula, or because the region around Sarteneja is the driest in Belize and isolated from the Yucatan Peninsula there may be new species to be discovered.

Amphibian species expected in Sarteneja District and at Balam Ja Way.

The forest type found around Sarteneja is the most threatened type in Central America. A central theme of our project is to expand our knowledge of the biodiversity in the region, to study the effects of habitat fragmentation, and habitat enhancement.

On Balam Ja Way there is a cenote of about one acre that floods during the wet season. The cenote has a red mongrove forest of very large trees. In 2011 when our project began the cenote edges were choked with weed species, and partially surrounded by recently cleared and burnt land. We have been creating habitat for frogs and other small vertebrates by clearing the invasive tree and vine species. We have been placing the branches around the cenote edge and on the surrounding land, and leaving open areas of water. Cenote - vegetation clearance and regrowth.

The calling of the frogs in the B'alam Ja Way area follows a seasonal pattern. The dry season extends from about March to June and no frogs move. In mid-May the wet season begins with breaks of thunderstorms and rain. Often this is followed by a period of a few weeks of dry then the wet really begins with days of heavy rain. This is when the cenote floods and stays flooded until the end of the wet in early March.

Frogs begin calling with the first rains when the cenote stays dry. These frogs consist of tree dwelling species, particularly small frogs that can spawn in the water or moist areas of tree hollows. A few larger tree frogs that spawn in pools begin to call. If there is a pronounced few weeks of dry calling almost ceases. Then over the few days of the beginning of the wet before the cenote floods, first many individuals and then large chorus' of frogs call. Chorus' are particularly impressive as their emphasis moves across the landscape in waves. The noise can be almost deafening. When the cenote floods the frogs move toward it to spawn.

In 2011 half of the area was recently burnt. About 75% of the edge of the cenote was free of shelter and vegetation. The fires had burnt into the cenote in parts. Relative to later years there were few frogs calling and few species.

In 2012 new habitat consisting of cut branches of weed tree and brush species on at the edges of the cenote provided additional habitat for frogs. However, other habitats within 0.5 km had more frogs.

In 2013 shelter had been provided around much of the edges, larger areas with the cenote cleared, and some small permanently ponded areas excavated, and the number of frogs was exceptional with many species some not previously heard. Rainfall in 2013 was 3x normal for the region.

In 2014 there was a poor start to the wet season and then an 8 week drought. Rainfall really began in September and continued with seasonally early exceptionally cold fronts from November.

References:

Herpetofauna of Shipstern Nature Reserve Nathalie Nguyen Quang Minh, Zoological Institute, University of Neuchâtel, rue Emile-Argand 11, 2007 Neuchâtel, Switzerland, for the obtention of a master degree in biology 2004-2005. 26p.

Shipstern Nature Reserve Species Inventory  Jan Meerman, 1993. Checklist of the Reptiles and Amphibians of the Shipstern Nature Reserve, Jan C. Meerman. In "Occasional Papers Of The Belize Natural History Society. A journal of Belizean Natural History". 2(1-11): 1-84. Also has a checklist of flora, insects, birds, and mammals and some valuable biogeographical information.