However, other scientists maintained that this would not be likely, as the monitors would compete with humans for food, grow slowly, and yield little meat.

[2] Phylogenetic analysis has also affirmed monitors being native to Micronesia, having colonized the islands and diverged from the V. indicus species complex during the Late Pleistocene.

[8] The USDA's Animal and Plant Inspection Service announced that it intends to use a combination of two poisons, diphacinone and brodifacoum, to kill-off the invasive rodents on Cocos Island (Guam), thus negatively affecting monitor populations, either by directly consuming the poisoned rodents, dead or alive, or by lowering their overall prey availability leading to starvation.

The USDA has also expressed an interest in lowering (or eliminating) the introduced mangrove monitor (Varanus indicus) population on Cocos Island by at least 80%, with several trapping methods proposed by herpetologist Seamus Ehrhard; this is deemed as vital, as the monitors are believed to prey upon the critically endangered, ground-nesting Guam rail (Gallirallus owstoni) and its eggs.

This stance has been further supported by more recent and detailed genetic analyses, which have shown the monitors to be native to Guam and other adjacent islands, having arrived there during the Pleistocene epoch.