Beaver-tailed agama (Xenagama batilifera (sensu lato))
Keeping and breeding at BION Terrarium Center
DESCRIPTION, DISTRIBUTION AND BIOLOGY
Important note. In this article we will talk about our experience of Xenagama batilifera sensu lato keeping and breeding experience at BION Terrarium Center. We use term “sensu lato” as some of our animals may refer to another species – Xenagama wilmsi. This species was separated from X. batilifera in 2013 (Wagner et al., 2013). According to the article “morphological and mitochondrial (16S) DNA sequence data revealed that Xenagama batillifera is a complex of two cryptic species”. We are deeply thankful to Thomas Mazuch who explained as the difference between X. batilifera and X. wilmsi. The most difficult thing is that X. wilmsi has very wide morphological variability of the tail and head shape and it is extremely hard to distinguish it from X. batilifera if you’re not an expert on Xenagamas or without making molecular analysis. This info is also mentioned in COMMENTS section in retile database: “Similar species: All “X. batillifera” in captivity are actually X. wilmsi. Since the revision of WAGNER et al. 2013 X. batillifera is the rarest species of the genus.” (http://reptile-database.reptarium.cz/species?genus=Xenagama&species=batillifera). Anyway our breeding and keeping success is a fact and in this article we will focus on X. batilifera sensu lato in order to be fair with our subscribers and everybody who will read this text.
Beaver-tailed agama (Xenagama batilifera Léon Vaillant, 1882) is a large Xenagama species with males probably shorter than females. Total length is about 145 mm. Males (SVL is 78–97 mm (3.07 – 3.81 in) seem to be somewhat smaller than females (SVL is 89–101 mm (3.5 – 3.97 in). Total length is 103–137 mm (4.05 – 5.39 in) in males, and 130–145 mm (5.11 – 5.7 in) in females. The tail is always shorter than the body, 25–42 mm (0.98 – 1.65 in). Head is longer than broad. Occipital scale is not larger than other head scales and the nasal scale is situated on the canthus rostralis. Ear hole is surrounded in front and above by single short conical scales. No neck crest is presented. Body scalation is heterogeneous, with smooth matrix scales, intermixed smooth to keeled enlarged scales and the ‘annectens scale type’ presented. Gular and ventral scales are smooth. Tail is shorter than the body and head, discoidal part is developed, but not as strongly as in X. taylori, longer than broad, gradually merging into the terminal filament. Discoidal part of the tail is arranged in whorls with one scale ring each. Filament is not arranged in distinct whorls (Boulenger, 1895; Barts, 2001; Wagner et al., 2013).
Different Xenagama species’ natural range (Wagner et al., 2013).
This Xenagama species is only known from Somalia (found mainly near Somaliland) (Parker, 1942). They are even found up to 2000 m (mainly between 1300 and 1800 m) above sea level. They inhabit grasslands, savannas, deserts and volcanic areas with their habitat including massive rocks, steep cliffs and deep canyons (https://www.exotic-pets.co.uk/beaver-tailed-agama.html).
This diurnal species has been found in flat semi-desert and savannah. Within these habitats, they are found on sandy to clayey soils, without rocky surfaces, and burrows were found hidden under low bushes. Outside the breeding season they live solitary in self-dug burrows of about 80–120 cm (31.49 – 47.24 in) in length, about 50–80 cm (19.68 – 31.49 in) in depth and with a mouth diameter of about 3.5–5 cm (1.37 – 1.96 in). Burrows of adult specimens are longer and deeper than burrows of juveniles or subadults. Usually, burrows were found as close to each other as about 1.5 m (59.05 in). An estimated population density of about 20 specimens in a square of 50x50 m (19.68 x 19.68 in) (Largen, Spawls, 2010; Wagner et al., 2013).
KEEPING AT BION TERRARIUM CENTER
Keeping. We keep adult X. batilifera in horizontal terrariums that should be long enough to provide temperature gradient. We use terrariums of 90*60*60 cm (35 *23*23 in) for a breeding group (1.1; 1.2 or 1.3). We provide a layer of loam mixed with clay (depth 10-12 cm) as a substrate. These lizards like to dig so even if kept without substrate a box with appropriate substrate layer should be provided. Decoration includes stones and plates for basking and potsherds as hiding places.
Lighting. Since these lizards are arid and diurnal, high light intensity is needed. UV-light is necessary. We use full spectrum Zoo Med lamp “Reptisun UV.10” for up to 14 hours in summer and 5-6 hours in winter. A 60 watt spot incandescent lamp is used as a heat source for the same period of time as UV lamp.
Temperature. Ambient temperature should be around +28 °C (82.4 F) at the day and not lower than +22 - +24 °C (71.6 – 75.2 F) at night. At basking place the temperature is about +40 - +45 °C (104 – 113 F). A flat stone/ceramic plate is placed under the basking lamp.
Humidity. Humidity level is 50-60%. It should be sufficiently dry in the terrarium. But it is necessary to keep moist down the substrate level as these lizards are good diggers.
Water. Water bowl is placed inside a terrarium.
Diet. Diet for adults consists of crickets, roaches, mealworms, sometimes butterflies of the Pyralidae family of appropriate size. Food is provided every other day by 3-5 insects per head. Also, we offer salad on a daily basis. Summer mix includes: dandelion, nettle, hemp, clover, plantain, leaves of cultivated grapes, - winter version: Chinese cabbage, different kinds of green salads, parsley, celery, carrot. For babies we offer crickets, roaches, sometimes butterflies of the Pyralidae family. The size of the insects is 0.3-0.5 cm. Food is provided daily by 3-5 insects per head. Salad is given in small quantities on a daily basis. We dust insects with calcium (especially it’s important for babies and pregnant females). We use Reptical + D3. Mineral all from Repashi for babies and adults once a week. We provide Reptivit with D3 to all babies starting from 2 months of age. Food can be put inside a dish or just on the plate at basking place.
It is strictly recommended not to use wild caught insects. Sometimes if an animal is still hungry we can offer one or two additional feeding items. All insects should be gut loaded and dusted with vitamin-mineral supplementation every other feeding.
BREEDING AND RAISING AT BION TERRARIUM CENTER
Males and females of beaver-tailed agamas reach their sexual maturity at 15-18 months. Females achieve their best reproduction level at the age of 2 years. Sexual dimorphism is evident at the age of 5-7 months. Males differ from females by a slightly smaller size, more intensive turquoise color of the chin and neck while stressing as well as the presence of distinct femoral pores above the hole, covered with waxy yellow grease.
To stimulate reproduction, we provide hibernation (soft conditions). We arrange hibernation from the beginning of November till the beginning of February. We arrange hibernation in the same terrariums where the lizards are kept. The temperature at that time is 22-24°C, the day length of 5-6 hours. Fresh water is available all the time, humidity is low, of 50-60% (just sprinkling the soil at the basking place). We didn’t observe mating, but presumably, it occurs after hibernation, subjected to a gradual increase in the day length to 14 hours. Duration of gestation period is still unknown.
The female lays eggs in a wet burrow that she digs in the sand hill in the cool end or makes it inside a shelter under the basking point. After oviposition, the female loses weight and feels very weak. In 2020 we got a clutch of 9 eggs. The eggs are transferred to the incubator without changing polarity. A small recess is made in vermiculite and each egg is placed in such a recess individually at no more than 2/3 eggs’ height depth.
X. batilifera hatchlings.
Substrate for incubation is wet vermiculite. Incubation temperature is around +29,5 °C (85.1 F). Hatchlings appear after about 40 days of such incubation. Hatchlings’ total length is about 3,5 - 4 cm (1.4 - 1.6 in) with average weight of 0,26 g. All babies start foraging and eating small crickets on the 2nd day of life.
40 * 60 cm (15.7 – 23.6 in) is an optimal space required per 4 juveniles. Decoration, substrate and other keeping conditions are identical to those for adults. For babies we sometimes use carton egg trays that provide a lot of shelters.
X. batilifera hatchling in a decorated terrarium on a coarse sand and a hatchling on a hand of adult human.
1.. Barts, M. (2001) Xenagama batilifera (Vaillant), Sauria 23 (3): 2.
2.. Boulenger, G.A. (1895) An account of the reptiles and batrachians collected by Dr. A. Donaldson Smith in western Somaliland and the Galla Country., Proc. zool. Soc. Lond.: 530-540.
4.. Wagner Philipp, Tomas Mazuch and Aaron M. Bauer 2013. An extraordinary tail – integrative review of the agamid genus Xenagama. J Zoolog Syst Evol Res doi: 10.1111/jzs.12016.
5.. Parker, H. W. 1942. The lizards of British Somaliland. Bull. Mus. Comp. Zool. Harvard 91: 1—101.
6.. Largen, M. J., Spawls, S. 2010. Amphibians and Reptiles of Ethiopia and Eritrea. Edition Chimaira, Frankfurt, 694 pp.