Patrick T. Gregory and Linda A. Gregory. 1998. Amphibians and Reptiles in Smith, I.M., and G.G.E. Scudder, eds. Assessment of species diversity in the Montane Cordillera Ecozone. Burlington: Ecological Monitoring and Assessment Network, 1998.

AMPHIBIANS AND REPTILES

Patrick T. Gregory¹ and Linda A. Gregory²
¹Department of Biology
University of Victoria
P.O. Box 3020 STN CSC
Victoria, B.C.
V8W 3N5
e-mail: VIPER@UVIC.CA
²1087 Briarwood Dr.
Cobble Hill, B.C.
V0R 1L0

INTRODUCTION

Although extant amphibians and reptiles are not closely related, they often are lumped together as “herptiles “ or “herps” (terms that we will eschew in the remainder of this chapter). Grouping these two kinds of organisms together is, for the most part, a marriage of convenience, based largely on their shared ancestral characteristics. Furthermore, amphibians and reptiles often (but by no means always) are found in the same habitats and by similar methods of searching. Thus, the science of herpetology was founded, and amphibians and reptiles (the "foul and loathsome creatures” of Linnaeus) are more-or-less permanently linked.

Amphibians and reptiles are ectotherms (the “cold-blooded” animals of popular, but misleading, press), which means that they regulate their body temperature mainly by behavioural means rather than metabolically (e.g. by basking in the sun, moving between warm and cold spots etc.). Ectothermy allows some species of amphibians and reptiles to be very small or to adopt thermally uneconomical (e.g. long and slender) body shapes (Pough, 1980) and this by itself accounts for considerable morphological diversity within these two groups of animals. This physiological trait also has important consequences for the role of these animals in ecosystems (Pough, 1980) and is a major factor influencing the geographic distribution and diversity of amphibians and reptiles.

Other factors that affect the pattern of diversity and distribution of amphibians and reptiles in the Montane Cordillera Ecozone include: geological history, especially glaciation; the proximity of potential source species, especially to the south, for recolonization following glaciation; present geography and topography; and local climate. Clearly, these factors are not mutually exclusive and interact to produce the patterns we see today.

Our aim in this chapter is to assess the species diversity of amphibians and reptiles in the Montane Cordillera and summarize our knowledge of these organisms, emphasizing unique or otherwise important aspects of their biology from the point-of-view of maintenance of biodiversity.

 

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