About This Project

The lizard, Aspidoscelis costatus costatus, emits vocalizations when captured. This project seeks to determine whether these calls differ between sexes due to seasonality. We will capture 25 individuals from either sex which vocalize during the wet and dry seasons. The spectro-temporal variables and rate of emission of the calls will be subjected to a statistical analysis. As these factors affect bird and mammal calls, we want to see if this is true for the species.

Ask the Scientists

What is the context of this research?

The Balsas Basin Whiptail (Aspidoscelis costatus costatus) is a moderately large, oviparous lizard native to the Mexican West (Gómez-Benítez et al. 2016). It currently is protected under Mexican laws (SEMARNAT 2010) and has a medium EVS (Wilson et al. 2013). A preliminary study in the species determined that vocal production was present after the lizards were seized or grasped (De La Rosa-Silva et al. 2023). As several factors could affect the vocalizations, most of which are unknown to us, we decided to explore whether sex and/or seasonality may impact them. For this purpose, the project will analyze the spectro-temporal variables (components of the vocalization) and rate of emission of the call, subjecting the data to a statistical analysis.

What is the significance of this project?

Historically, vocal sound production has been mainly studied in birds, mammals, and anurans (Köhler et al. 2017; Lewis et al. 2021), as it was believed that reptiles were a silent group. Nowadays, we know that all orders within make use of sound production (Colafrancesco and Gridi-Papp 2016; Capshaw et al. 2021). Still, many gaps in the knowledge of vocal production remain, especially within Order Squamata. While many investigations have been undertaken when it comes to the main vocal taxon of Squamata, Gekkota (Capshaw et al. 2021), few have focused on other lizard families (Russell and Bauer 2020). We think that our study will be an important step in better understanding lizard vocal production and behavior, as well as determining where vocalizations come from.

What are the goals of the project?

Our main goals are to determine if the components that constitute the call, as well as the number of vocalizations in Aspidoscelis costatus costatus, differ due to sex and/or seasonality. We also want to classify the calls with a larger pool of individuals. Our study will begin in September 2024. We will collect 25 individuals from either sex who vocalize in the field, and then stimulate them to call (as detailed by De La Rosa-Silva et al. 2023). The vocalizations will be taped by using a TASCAM Digital Recorder. Afterward, they will be explored through the program Raven Pro 1.6, to obtain its components. The data will be subjected to a statistical analysis to determine any statistical differences.