XIX-B8, 2012 
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012 
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia 
MAPPING THERMAL HABITAT OF ECTOTHERMS BASED ON BEHAVIORAL 
THERMOREGULATION IN A CONTROLLED THERMAL ENVIRONMENT 
Teng Fei *°, Andrew Skidmore °, Yaolin Liu * 
? School of Resource and Environmental Science, Wuhan University, 129 LuoYuRoad, Wuhan, 430079, P.R. China 
? Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, P.O. Box 217, 7500 AE, Enschede, The 
Netherlands. 
feiteng@whu.edu.cn 
Working Group, Theme or Special Session: VIII/6: Agriculture, Ecosystems and Bio-Diversity 
KEY WORDS: thermal habitat, lizard, behavioural thermoregulation, ectotherm 
ABSTRACT: 
Thermal environment is especially important to ectotherm because a lot of physiological functions rely on the body temperature such 
as thermoregulation. The so-called behavioural thermoregulation function made use of the heterogeneity of the thermal properties 
within an individual's habitat to sustain the animal's physiological processes. This function links the spatial utilization and 
distribution of individual ectotherm with the thermal properties of habitat (thermal habitat). In this study we modelled the 
relationship between the two by a spatial explicit model that simulates the movements of a lizard in a controlled environment. The 
model incorporates a lizard's transient body temperatures with a cellular automaton algorithm as a way to link the physiology 
knowledge of the animal with the spatial utilization of its microhabitat. On a larger spatial scale, ‘thermal roughness’ of the habitat 
was defined and used to predict the habitat occupancy of the target species. The results showed the habitat occupancy can be 
modelled by the cellular automaton based algorithm at a smaller scale, and can be modelled by the thermal roughness index at a 
larger scale. 
1. INTRODUCTION 
Among different environmental factors, thermal properties have 
been used as an important indicator either for the terrestrial 
animal or for the aquatic animal. Thermal environment is 
especially important to ectotherm because a lot of physiological 
functions rely on the body temperature such as 
thermoregulation (Waldschmidt and Tracy, 1983). 
To cope with the wide diversity of thermal qualities of habitat, 
ectotherms are able to maintain body temperature by 
continuously shifting their location. The so-called behavioural 
thermoregulation function made use of the heterogeneity of the 
thermal properties within an individual’s habitat to sustain the 
animal’s physiological processes. This function links the spatial 
utilization and distribution of individual ectotherm with the 
thermal properties of habitat (thermal habitat). 
Several studies had been focused on the relationship between 
the thermal properties of land surface and reptile distribution: 
On scale of microhabitat, we have evidences that the thermal 
properties of rocks (Schlesinger and Shine, 1994) or shrubs 
(Kerr et al, 2003) may influence whether reptiles use them as 
shelters. Reptiles are also sensitive to thermal environment at 
much larger scales: at continental and global scale, the richness 
of reptile families is highest at low latitudes (Barnosky et al., 
2001). Spellerberg (Spellerberg, 1972) discussed in general the 
Significant relationship between reptile thermoregulatory 
behavior and distribution. However, Past researches were 
mainly limited to reptiles’ habitat at very large scales, and 
relatively little is known about how reptiles respond to 
environmental temperatures at the micro and landscape scales 
(Fischer and Lindenmayer, 2005). 
In this study, we propose to develop an innovative method to 
map and understand the thermal habitat use of a reptile. The 
method is based on a spatially explicit dynamic model, which 
simulate the changing thermal environment and the response of 
the reptile at the same time. 
2. METHODS 
2.1 Data collection 
2.1.1 Thermal Environment 
An experiment was carried out at a reptile zoo “Dierenpark De 
Oliemeulen” during September, 2008 in Tilburg, the 
Netherlands. A glass terrarium of size 245cm x 120cm x 115cm 
was constructed. At the bottom of the terrarium, at least 10 cm 
of gravel and sand were mixed to form a flat substrate surface. 
Photoperiod was maintained at 14L:10D with a 100-Watt heat 
lamp. An infrared heat lamp of 100W provided additional heat 
input for 5 h during the middle of the photophase. Temperature 
sensors (HoboTM temperature and relative humidity smart 
sensors, Onset Computer Co.) were placed at a height of 10 cm 
above the ground surface to record the air temperature inside 
the terrarium. A 4-year-old male Timon lepidus was kept in the 
terrarium for 10 days before the experiment started, in order that 
the lizard could acclimatize to the new environment. The lizard 
was fed on vegetables, crickets, newly born mice, and some 
fruits such as apple and banana. 
2.1.2 Animal Responses 
Three IRISYS 1011 thermal imagers (each with a resolution of 
16 x 16 pixels) were mounted in a row at 2m above the ground 
surface of the terrarium, pointing down with a field-of-view