White-throated monitor
| White-throated monitor | ||||||||||||
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White-throated monitor ( Varanus albigularis ) |
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| Varanus albigularis | ||||||||||||
| ( Daudin , 1802) |
The white-throated monitor ( Varanus albigularis ), sometimes also called Cape monitor , is a species of scale crawfish (Squamata) from the genus of monitor lizards ( Varanus ).
features
The white-throated monitor reaches a maximum length of 1 to 1.5 m, depending on the location. Males grow slightly larger than females. The head-torso length makes up about 45% of the total length. Sexually mature males weigh 5 to 8 kg, sexually mature females 4.5 to 6.5 kg. In captivity, extremely obese specimens can weigh up to 20 kg. The snout of the white-throated monitor is blunt and clearly thickened above the nostrils. The claws are strong and curved. The white-throated monitor is strongly built.
The head is gray to brown, the throat is noticeably lighter. A clear temporal strip begins behind the eye and continues to the shoulder where it branches. The basic color of the trunk is gray to brown. The trunk and the tail show a variable, cream-colored pattern.
distribution
The white-throated monitor lives in South and East Africa. He mainly inhabits dry steppes and savannas. However, it is absent in deserts, as well as in forests. The species has been recorded in the following countries (from north to south): Sudan , Djibouti , Ethiopia , Somalia , Democratic Republic of the Congo , Uganda , Rwanda , Burundi , Kenya , Tanzania , Angola , Zambia , Malawi , Zimbabwe , Mozambique , Namibia , Botswana , South Africa .
Way of life
General
Like all monitor lizards, the white-throated monitor is a diurnal loner. During the summer, the white-throated monitor hides in a burrow or other hiding place around noon; the rest of the day he is active. During the winter the animals stay in their den and are largely inactive due to the lack of food. After winter, males weigh 60% of their weight during summer; in females it is 50%. This weight loss will be compensated for within 2 months of the beginning of summer.
The white-throated monitor is primarily a ground dweller, and climbs trees to hunt and to escape from predators.
The movements of the white-throated monitor have been studied in southwest Africa. Males have action areas of an average of 18.3 km², females of an average of 6.1 km². White-throated monitor lizards cover up to 5 km a day in search of food.
nutrition
The white-throated monitor is an active predator, the lambent looking for food. Invertebrates such as snails, centipedes, grasshoppers, beetles and crickets make up the majority of the diet. In addition, white-throated monitors also attack small to medium-sized snakes including cobras (e.g. Naja nigricollis ). The white-throated monitor also prey on eggs and chicks from ground- and tree-breeding birds. Small mammals apparently only make up an insignificant proportion of the diet.
Reproduction
Both sexes reach sexual maturity with a head-trunk length of about 50 cm, probably after about 4 to 5 years. In southwest Africa, the mating season falls in early spring (August & September), i.e. 3 months before the onset of rain. Males are particularly active at this time and travel long distances in search of females. They follow certain pheromones of the females ready to mate. Mating occurs 1 to 2 days after the female is found. Males are polygamous . The eggs are laid about 35 days after mating. The clutch can contain up to 50 eggs. The young hatch after about 135 days. So the hatch falls at the height of the rainy season when most of the food is available.
Systematics
The white-throated monitor was first described in 1802 by François Marie Daudin under the scientific name Tupinambis albigularis . He was later assigned to the genus Varanus . The species belongs to the subgenus Polydaedalus , which contains all African monitor lizards. There the white-throated monitor is assigned to the V. exanthematicus group based on its hemipenis morphology .
Currently three subspecies of V. albigularis are recognized. These are difficult to differentiate because the subspecies themselves are highly variable. The validity of the subspecies V. a. ionidesi (Laurent, 1964) is questioned.
- V. a. angolensis : Angola, Democratic Republic of the Congo.
- V. a. microstictus : East Africa (South Sudan and Ethiopia south to Zimbabwe and Mozambique).
- V. a. albigularis : Remaining distribution area.
supporting documents
- ↑ a b c d D. Bennett: Monitor lizards of the world. World of monitor lizards. Edition Chimaira, Frankfurt am Main 1996, ISBN 3-930612-05-4 , pp. 114-118.
- ↑ a b c d e f g h J. Phillips: Varanus albigularis. In: ER Pianka & DR King (Eds.): Varanoid Lizards of the World. Indiana University Press, Bloomington / Indianapolis, 2004, ISBN 0-253-34366-6 , pp. 91-94.
- ↑ W. Böhme: Checklist of the living monitor lizards of the world (family Varanidae). In: Zoologische Verhandelingen. Volume 341, 2003, pp. 3-43.
- ↑ Varanus albigularis in The Reptile Database ; Retrieved March 5, 2011.
