Species Groups

Vidal et al. 2012 separated Odatria into two species groups; the V. acanthurus group included V. acanthurus, V. baritji, V. brevicauda, V. bushi, V. caudolineatus, V. eremius, V. gilleni, V. kingorum, V. primordius, and V. storri, while the V. tristis group included V. auffenbergi, V. glauerti, V. glebopalma, V. mitchelli, V. pilbarensis, V. scalaris, V. semiremex, V. similis, V. timorensis, and V. tristis. ^[4]

To maintain monophyly in light of Brennan et al. 2020, V. glebopalma would be excluded from the V. tristis group, and more species would be included as in the following:

V. acanthurus group - (V. acanthurus, V. baritji, V. brevicauda, V. bushi, V. caudolineatus, V. eremius, V. gilleni, V. kingorum, V. primordius, V. sparnus and V. storri)

V. tristis group - (V. auffenbergi, V. glauerti, V. hamersleyensis, V. mitchelli, V. pilbarensis, V. scalaris, V. semiremex, V. similis, V. timorensis, and V. tristis)

Behaviour

The genus is diverse in terms of behaviour, and includes terrestrial, arboreal, and semiaquatic species. Many are saxicolous, i.e., they are strongly associated with rocky habitats, while some others prefer forests. ^[2]

Ritualized fighting sometimes occurs between males. Unlike many larger monitors which grapple with each other while standing on their hind legs, some dwarf monitor species instead grapple each other with all 4 limbs, belly to belly, and roll around on the ground trying to force the other onto its back. Biting may also occur.^[6]

Diet

Orthopteran insects and other species of lizards make up the mainstay of the diet for most species. One species, the rusty desert monitor, consumes a particularly large amount of lizard prey with lizards such as various species of Ctenotus accounting for up to 70% of their diet by weight. ^[7] Larger species such as black-palmed rock monitors are also known to prey on other dwarf monitors. ^[2]

Reproduction

Like all other monitors, all species within Odatria are oviparous. As parthenogenesis is well known in monitor lizards in some other subgenera, it is possible that dwarf monitors are also capable of parthenogenesis; there is a report of a suspected case of parthenogenesis in peacock monitors. ^[2]

Parasites

Physalopterid nematodes of the genus Abbreviata are major gastrointestinal parasites in many species of reptiles. Those that parasitize dwarf monitors include A. hastaspicula and A. levicauda; the former may specialize in Australian monitors. Depending on the species, more than half of all individuals collected from the wild may be infected, but in most cases the parasites do minimal harm. Various other parasites are also known, but in comparatively much low numbers. ^[1][8] In captivity, wild caught individuals may suffer more from the effects of parasites due to the stressful process of being taken from the wild and being shipped elsewhere.