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Varanus spenceri Print E-mail
Spencer's goanna, Plain goanna

Varanus spenceri    Lucas & Frost 1903

ImageSpencer's goanna is the least known of the large Australian monitor lizards. It appears to live only in grasslands on the clay plains of eastern Northern Territory and north-western Queensland (Cogger 1993). They usually reach lengths of 100cm TL (Schmida 1985) with a maximum of about 125cm TL. The tail is only slightly longer than the head and body (103-107% of SVL). This is a heavily built species that often has a very thick tail base and attains weights of over 2.25kg (Mertens 1958; Bustard 1970). Hatchlings measure about 22cm TL, 13cm SVL (Peters 1986). The short toes are equipped with long powerful claws which enable these lizards to burrow through clay. They are said to be most active between August and October (Schmida 1985). Pengilley (1981) found large numbers of females looking for nest sites among piles of red soil dumped at the side of a road in late September and early October. A wild caught female laid eggs at the beginning of November. Clutch size is large, with up to 31 eggs, each measuring about 5 X 3.5cm, recorded from large females (Pengilley 1981).

Spencer's goannas usually shelter in burrows or large cracks in the clay and often inhabit areas devoid of trees (Stammer 1970; Swanson 1976). In captivity they are able to climb quite well (McKeown pers comm.) and so may explore trees where they are present. The adult females examined by Pengilley (1981) had eaten mammals, large snakes, agamids, mammals and insects (mainly orthopterans). A specimen examined by Stammer (1970) contained large numbers of beetles. The stout bodies suggest that they are inactive throughout the winter, but there are no direct observations to substantiate this. Bipedal ritual combat in this species was first recorded by Waite (1929), who mistook them for perenties (Horn 1981). A burrow, probably intended as a nest is depicted by Pengilley (1981).

There are few references to the care of this species in captivity (e.g. Peters 1969a,c, 1970a, 1971, 1986). They require a spacious terrarium which provides plenty of opportunities to dig and would probably benefit from a seasonal reduction in activity. Eggs laid by a wild caught female hatched after 133-140 days at 29oC (Peters 1986). Juveniles are much more colourful than the adults, with bright yellow bands over a glossy brown back. They double in size within six weeks. In captivity, Spencer's goannas are said to be somewhat nervous but tolerant. They can live for at least 15 years (Snider & Bowler 1992).


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Bye Bye Butaan


Butaan start to visit fruiting trees before they are large enough to swallow the fruits. They make repeat journeys to trees, perhaps to reinforce memory of the position of the tree. If the youngster survives it may continue to use this tree for many decades. Fruiting trees like this are a vital resource for entire populations of butaan. Learn more >

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The Butaan Project
Butaan are Obligate Frugivores!
An obligate frugivore is an animal whose diet throughout its range consist largely of fruit. Other obligate frugivores in the Philippines include flying foxes, hornbills and other birds. The butaan is much larger than any other obligate frugivore in the Philippines and had a much more restricted diet; on Polillo the diet of adult butaan consists almost entirely of eight species of fruits and two species of snails.



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