Unlike most other bats, the Christmas Island flying fox is active in the day (diurnal), likely due to a lack of major predators, observed to leave roosts as early as 1:00 p.m. local time, though uncommonly before 4:00 p.m., and peak time between 5:45 and 6:15 p.m.
Individuals forage across the island.
It primarily feeds on fruit (frugivory) and nectar (nectarivory), sourced from 35 native plants and 18 introduced, which increase productivity in the wet season from December to March.
Inferred from their commonness on the island, the most important trees to their diet are the powder-puff tree, C. timorensis, ivory mahogany, common fig, Polynesian chestnut, the parasol leaf tree, cockspur thorn, Planchonella duclitan, S. nervosum, beach almond, and Tristiropsis acutangula.
The introduced Muntingia calabura is also noted as a major component of its diet.

The Christmas Island flying fox and the Christmas imperial pigeon are the only major frugivores on the island.
Island-dwelling flying foxes, in general, may be the only animals on their island responsible for pollination and seed dispersal for local plants, acting as keystone species.

The Christmas Island goshawk has been seen attacking and eating the Christmas Island flying fox.
The Nankeen kestrel, which established itself on the island around 1950, has been observed harassing it.
Flying foxes are generally infested with spinturnicid mites, and the mite Meristaspis calcaratus was recorded on the Christmas Island flying fox, though in low density.
There is a report of a nonpathogenic coccidia protozoan infection, which is only recorded in 15 other bat species, and an unidentified ascaridid roundworm, possibly the deadly Toxocara pteropidis.
Unlike most other bats, the Christmas Island flying fox is active in the day (diurnal), likely due to a lack of major predators, observed to leave roosts as early as 1:00 p.m. local time, though uncommonly before 4:00 p.m., and peak time between 5:45 and 6:15 p.m.
Individuals forage across the island. It primarily feeds on fruit (frugivory) and nectar (nectarivory), sourced from 35 native plants and 18 introduced, which increase productivity in the wet season from December to March. Inferred from their commonness on the island, the most important trees to their diet are the powder-puff tree, C. timorensis, ivory mahogany, common fig, Polynesian chestnut, the parasol leaf tree, cockspur thorn, Planchonella duclitan, S. nervosum, beach almond, and Tristiropsis acutangula. The introduced Muntingia calabura is also noted as a major component of its diet.
The Christmas Island flying fox and the Christmas imperial pigeon are the only major frugivores on the island. Island-dwelling flying foxes, in general, may be the only animals on their island responsible for pollination and seed dispersal for local plants, acting as keystone species.
The Christmas Island goshawk has been seen attacking and eating the Christmas Island flying fox. The Nankeen kestrel, which established itself on the island around 1950, has been observed harassing it. Flying foxes are generally infested with spinturnicid mites, and the mite Meristaspis calcaratus was recorded on the Christmas Island flying fox, though in low density. There is a report of a nonpathogenic coccidia protozoan infection, which is only recorded in 15 other bat species, and an unidentified ascaridid roundworm, possibly the deadly Toxocara pteropidis.
Christmas Island flying fox