Amphibians

Introduction

The total number of amphibian species within the study area is still subject to distribution range confirmations, as many species are known to live in the neighborhood of the area, but so far have not been confirmed to exist inside it. The number will however very likely fall in between 40 – 50 species in total (C. Grünwald, personal communication, 2006). The Banderas Bay area is inhabited by several species of frogs and toads endemic to the Pacific Slope, such as the Dwarf Mexican Tree frog (Tlalocohyla smithii), the Sinaloa Toad (Incilius mazatlanensis) or the Cascade frog (Lithobates pustulosus). In total, up to 30% of local species may be endemic to West Mexico. Mexico, with more than 360 species of amphibians, ranks sixth among the world’s countries in terms of amphibian diversity (Santos, 2006). Mexican amphibian fauna is also highly valued if only because 60% of its species are endemic.

 Amphibians of streams and pools

All amphibians in the area are tied to habitats containing sources of fresh water. Therefore, all species in this guide are listed as present in fresh water environments. Any fresh water source, however, is typically surrounded by some kind of vegetation. While the vegetation certainly is an important element in the amphibian environment, it is the presence or absence of a fresh water source which rules amphibian life. Generally, amphibians are active during rainy season and aestivate during the dry season. Since amphibian skin is very permeable, by exposing themselves to the dry conditions of winter and spring, amphibians would run the risk of death caused by water loss in their bodies. Their inactivity during the dry season is also a response to lesser abundance of their primary food source—that is, insects.

How to find amphibians

All amphibian species of Banderas Bay are year-round residents. However, due to their dependence on fresh water availability, they are generally observed (with several exceptions) only during the wet season. The best way to find frogs and toads is by sound, or, more specifically, by their nocturnal call. The best time to look for amphibians is at night, after or during rains. flooded agricultural land or semi-permanent pools alongside the road are generally ideal places to look. While driving, slowly scan the road, as many species readily cross roads at night. Take care not to run over a crossing animal. Once on site, listen carefully and try to identify the exact location of the call. A sturdy, ergonomic, and preferably waterproof, flashlight is a must. Proper footwear is essential, and a light rain jacket and insect repellent are also important. finding amphibians in tropical forest streams is quite a bit more difficult, but the same rules apply. Carry a flashlight, use appropriate footwear and repellent, and listen carefully. Night walking in the tropical forest is recommended only under the supervision of an experienced guide.

Favorite frog and toad watching spots

Semi-permanent pools: pastures and plantations alongside the road throughout the bay area. Forest streams: streams in the area surrounded by forest.

Text excerpt from Viva Natura: Field Guide to the Amphibians, Reptiles, Birds and Mammals of Western Mexico

-Petr Myska, 2013-