Full length paper

Seven-year relative abundance in two syntopic neotropical lizards, Liolaemus quilmes and L. ramirezae (Liolaemidae), from Northwestern Argentina

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Cuadernos de Herpetología 22 (2): 73-79, 2008 mhalloy@webmail.unt.edu.ar

Abstract

Studies on the relative abundance of sympatric lizard populations can give insight into their life histories and, if longterm, can help estimate potential conservation problems. Through the years, patterns of coexistence between two or more species may emerge, such as the effect of one species over the other, or the effect of factors such as precipitation and temperature, or prey abundance and predator pressure. Here we report a sevenyear study on the relative abundance of two Neotropical species from Northwestern Argentina, Liolaemus quilmes and L. ramirezae. These two species are found in syntopy at a site called Los Cardones. We monitored an area of 60 x 60 m, two to five days, every one or two months, throughout theactivity period of the lizards, from 2000 to 2007. During that time, the relative abundance of L. quilmes, taken as the average number of adults sighted per survey per month, remained stableduring the sevenyear study whereas that of L. ramirezae increased in the last two years. The relative abundance of one population did not affect the other over the years nor did that of maleand female L. quilmes. Although the amount of precipitation varied significantly over the years, it was not associated to the relative abundance of each population. The two species show differences in their habitat use and in prey preferences which may facilitate coexistence. However, besides taking into account these ecological parameters, historical constraints must also be considered in order to explain the patterns observed today.

Key words:

Abundancia relativa; lagartos; Liolaemus; Noroeste Argentino

Received: Oct. 24, 2007 ▪ Accepted: Sep. 09, 2008

Associate Editor: F. Lobo
Robles, C.I. & Halloy, M. 2008. Seven-year relative abundance in two syntopic neotropical lizards, Liolaemus quilmes and L. ramirezae (Liolaemidae), from Northwestern Argentina. Cuadernos de Herpetología 22: 73-79.