The other three members of the genus are red junglefowl ("G. gallus"), grey junglefowl ("G. sonneratii"), and green junglefowl ("G. varius"). The Sri Lankan junglefowl is most closely related to the grey junglefowl, though physically the male resembles the red junglefowl. Female Sri Lanka junglefowl are very similar to those of the grey junglefowl. Like the green junglefowl, Sri Lankan junglefowl are island species that have evolved side by side with their similarly stranded island predators and competitors. Uniquely complex anti-predator behaviors and foraging strategies are integral components in the long evolutionary story of the Sri Lankan junglefowl. As with other jungle fowl, Sri Lankan jungle fowl are primarily terrestrial. They spend most of their time foraging for food by scratching the ground for various seeds, fallen fruit, and insects. Females lay two to four eggs in a nest, either on the forest floor in steep hill country or in the abandoned nests of other birds and squirrels. Like the grey and green junglefowl, male Sri Lankan junglefowl play an active role in nest protection and chick rearing. The reproductive strategy of this species is best described as facultative polyandry, in that a single female is typically linked with two or three males that form a pride of sorts. These males are likely to be siblings. The female pairs with the alpha male of the pride and nests high off the ground. Her eggs are highly variable in colour, but generally are cream with a yellow or pink tint. Purple or brownish spots are common. Occasionally, a female produces red eggs or blotched eggs. The hen incubates her eggs, while the alpha male guards her nest from a nearby perch during the nesting season. The beta males remain in close proximity, and guard the nesting territory from intruders or potential predators, such as rival males, or snakes and mongooses. Sri Lankan junglefowl are unique amongst the junglefowl in the brevity of their incubation, which may be as short as 20 days as contrasted with the 21–26 days of the green junglefowl. The chicks require a constant diet of live food, usually insects and isopods such as sowbugs and pillbugs. In particular, the juveniles of land crabs are also highly important to the growth and survivability of the juvenile and subadult Sri Lankan junglefowl. In captivity, this species is particularly vulnerable to a poultry disease caused by the bacteria "Salmonella pullorum" and other bacterial diseases common in domestic poultry.