04 June 2011

Colour Change of Arabian Spiny-tailed Lizard

02/06/2011 - Dhahran Hills

Early in the morning (02-06-2011) I saw this Arabian Spiny-Tailed Lizard at its burrow entrance at the edge of the spray fields. They tend to establish themselves in hilly, rocky areas with good shelter and accessible vegetation. They are diurnal and emerge early in the morning with ambient temperatures around 30°C (86 °F) and spend the highest percent of daylight hours above ground basking (13.8%) followed by foraging (4.6%) and den clearing (0.4%). Individuals retreat underground for most of the day (81.2%) when ambient temperatures reach around 40°C (104 °F). They are active throughout the year except during the colder months (November-February) when the temperature is about 20°C (68 °F) or less, when they hibernate. Like many reptiles, these lizards' change body colouration throughout the day, according to the temperature, initially at low temperatures the animals are dark grey (such as the top photograph) to nearly black, normally directly after emergence from their burrows and change to a light greenish or yellow colour (bottom photograph) with a black throat and small black dots on the neck and upper side, whilst basking during the heat of day. Basking generally occurs in areas with surface temperatures of over 48.9 °C (120 °F) and the darker pigmentation allows their skin to absorb sunlight more effectively. They bask at the burrow entrance, and once warm, they may take circular walks from their burrow to nearby shrubs to browse. They are seasonal with respect to their activity and visibility outside of their burrows, with three quarters of the yearly activity observed in spring and summer.
Arabian Spiny-tailed Lizard (Blue colour 05:50 hrs) – Dhahran Hills 02/06/2011

Arabian Spiny-tailed Lizard (Yellow colour 14:35 hrs) – Dhahran Hills 12/05/2011