Activity Patterns of Stenocercus iridescens in an Ecuadorian Coastal Agroecosystem: Is Temperature Important?

Abstract

Circadian rhythms of Neotropical lizards have been poorly studied, which represents a problem when designing ecological studies or monitoring such species based on direct observations. In this work, 1000 m-long transects were established in an agroecosystem area of the Ecuadorian coast region to study the activity patterns of Stenocercus iridescens. The number of individuals (as a response variable) was correlated with local weather conditions: temperature, precipitation, and heliophany (duration of the solar brightness). We carried out the study in both dry and rainy seasons, and during different time ranges. The time range in which the transects were performed was the most important predictor, and the activity peak was established between 16:00 h and 18:00 h. Heliophany negatively affected lizard activity, but only on the days with higher heliophany during the dry season, whereas temperature was not a significant predictor. Our results suggest that in an area where temperature is relatively constant and the solar radiation is high, particularly during the dry season, the heliophany (an indirect measure of solar radiation) can affect ectotherm activity patterns more than temperature, particularly in open habitats such as agroecosystems.

Species Composition and Ecology of Diurnal Herpetofauna in Agroecosystems of the Ecuadorian Chocó

“…We performed four herpetofauna censuses in each transect for 13 d during the dry season (September 2019) and 12 d in the rainy season (February 2020). Surveys were carried out at 14:00−18:00 by two observers focusing on diurnal species and based on peaks of the greatest reptile activity in the area (Zambrano et al, 2022), with each survey taking approximately 1.5 h to complete. Individuals were captured by hand or noose following Young et al (2001), Tessaro andGonzález (2012), andHeyer et al (2014).…”