Activity area, movement patterns, and habitat use of the desert monitor, varanus griseus, in the zaranik protected area, north Sinai, Egypt

Abstract

A radio telemetry study of the desert monitor, Varanus griseus was conducted from July 1997 to June 1998 in the Zaranik Protected Area, North Sinai, Egypt. Five monitor lizards (SVL range 302 ‐ 360 mm) were equipped with SI‐2T temperature sensitive transmitters. Two individuals (male # 1 and female # 2) were residents of Fluseyyat Island in Zaranik, and three individuals (two males # 3 & # 4 and a female # 5) were translocated from sand dunes of similar habitat to Fluseyyat Island. I investigated differences between resident and translocated monitors in terms of their home range, movement and habitat selection. Four of the five lizards had home range sizes between 0.075 and 0.228 km2. A translocated male (# 4) exhibited homing behaviour, covering a total area of 2.11 km2. Lizards emerged from hibernacula in March and April and returned in October and November. Frequency of movement for lizards tracked year round ranged from 18 % ‐ 73.3 % of days. The mean distances travelled per day were 278.3 m and 182.7 m for males and females respectively, while the mean distances travelled per move were 173.9 m and 117.9 m. Translocated V. griseus travelled greater distances per day and per move than residents, for both males and females. Activity peaked in May and June. Daily patterns of activity occurred anytime between 07h00 to 20h00. Emergence normally began 2‐ 4h after sunrise, but earlier during the summer. Lizards retreated to burrows from 0.5 ‐ 1.5 h before sunset. Highest levels of activity were generally between 09h00 and 10h00, with basking being observed in the morning between 08h00 to 11h00 and again between 15h00 to 16h00. Bimodal activity patterns were most evident during the hottest months. The burrows most frequently used by monitors were located in areas with 20 ‐ 30 % vegetation cover.