Year to year activity and location data from a population of neighbouring Sleepy Lizards (Tiliqua rugosa)

Repository Content

This repository contains records of neighbouring lizard's activity data from 2008 - current. Sleepy lizards have an activity period concentrated from spring to late summer and therefore the data were collected, on a year to year basis, as follows:

- September 2008 - February 2009
- September 2009 - December 2009
- September 2010 - December 2010
- Proposed - September 2011 - December 2011
- Proposed - September 2012 - December 2012

Data for 40 lizards were collected from September 2008 - February 2009, while data for 60 lizards were collected in all other years. The records are uploaded to the repository each year after each field season is complete. Lizards are neighbouring within an approximate 1 x 1.5km study site. Data are collected from the same lizards, at the same study site each year, however, from year to year, some lizards are unable to be relocated and so the composition of the sampled lizards may vary within a given year. Each lizard is identified by a unique number, displayed in the file name. For example, GPS_12138_2009, represents the activity data for lizard 12138 over the 2009 field season.

Data Collection Methods and Details

Activity data are collected by attaching a 'lizard logger' to the lizard's tails with surgical adhesive tape. These lizard loggers record temperature and number of steps taken every 2 minutes and a GPS location (Easting, Northing) every 10 minutes, if the lizard had moved in the previous 10 minutes. Each lizard was relocated every 12-14 days. Then lizard activity data from the past 12 days were downloaded from the lizard logger.

GPS Data Quality

The precision of each GPS location varies according to the number of available satellite vehicles. In cases that included a GPS location, the lizard logger also recorded an estimated GPS location error, plus the date and time that the point was taken. Raw data in full GPS records consisted of: temperature (Celsius), step count, date (ddmm), Coordinated Universal Time (UTC) (hhmmss), Universal Transverse Mercator coordinate system (UTM) Easting (m), UTM Northing (m), Navigational Status (NF=No Fix, DR=Dead Reckoning, G2=Good fix 2D, G3=Good fix 3D), Horizontal Accuracy (m), 2D Horizontal Dilution of Precision, GPS Satellite Vehicle count. GPS locations were all taken in UTM zone 54.

Step Count Data Quality

Steps were counted by fastening a cylindrical magnet with superglue to the back of the lizards thigh, which connected to a reed switch on the corresponding place on the lizards tail. Occasionally the reed switch moved out of place under the surgical tape and therefore that unit did not accurately count steps at that time. As a consequence, sometimes lizard loggers may underestimate step counts. Each time a lizard was relocated every 12 days, we tested the number of steps the lizard logger recorded by connecting the reed switch to a multimeter while placing the lizard on the ground and encouraging it to take 30 steps. The number of steps that the reed switch counted per 30 real lizard steps was recorded and is included in the field notes for each time the lizard data were downloaded. If the reed switch was not accurately counting steps, it was repositioned and rechecked at the time
the lizard was released.

Additional information in Field Notes

Upon handling each 12 days, each lizard was measured (snout to vent length: SVL) weighed and assessed for the number of scales that were damaged on the head, and the torso. Lizards were also assessed for the number of ectoparasites (ticks), however ticks were added and removed in another experiment throughout different years of study and therefore may fluctuate accordingly. Information on SVL, weight, scale damage and parasite load is located in the field notes.

All methods were approved by the Flinders University Animal Welfare Committee.


Date coverage: 2008 - 2010
Location: Near Mount Mary, South Australia, Australia