Christmas Island Frigatebirds breed biennially, nesting high in tall trees mainly on the coastal terraces along the north coast, sheltered from the prevailing south-eastern trade winds (Hill and Dunn 2004, James and McAllan 2014). During breeding, they forage over pelagic waters as well as Indonesian coastal areas for flying fish, squid and other marine species driven to the sea surface by large subsurface predators, such as tuna and dolphins (Hill and Dunn 2004, Hennicke et al. 2015). When not breeding they relocate to small uninhabited islands in Southeast Asia where they forage locally over shallower coastal waters with variable salinity and turbidity (James and McAllan 2014, Hennicke et al. 2015). It is assumed to be able to occupy all elevations on the island, up to the maximum elevation of 357 m, although most of the breeding colonies are at lower elevations. 

Conservation Actions Underway
CITES Appendix I. Listed as Vulnerable under the Environment Protection and Biodiversity Conservation Act 1999 (Hill and Dunn 2004). The Christmas Island National Park was established in 1980, and has since been extended to include two of the three current breeding colonies (90% of the population) (P. Green and D. O'Dowd in litt. 2003). A recovery plan has been completed (Hill and Dunn 2004) and a study using satellite telemetry and GPS loggers to study movements has been underway since 2005 (J. Hennicke in litt. 2008, 2010; Hennicke et al. 2015). A control programme for A. gracilipes was initiated after 2000 (P. Green and D. O'Dowd in litt. 2003), and plans have been established to control the scale bugs that the ants tend for their sugar secretions in order to reduce this food supply, but there remains no evidence that the ants are adversely affecting frigatebird colonies (Hennicke 2014, J. Hennicke in litt. 2010). A census of the breeding population on Christmas Island is currently being undertaken (J. Hennicke pers.comm. 2016). In 2014 and 2016, the Indonesian government had a conservation plan to assess seabird bycatch. Investigations under way in Jakarta Bay on trends in frigatebird weights.

Conservation Actions Proposed
Develop and implement appropriate techniques to monitor the total/breeding population size, population structure and rate of decline (Hill and Dunn 2004, Hennicke 2014). Undertake year-round monitoring in the Jakarta Bay area (Burung Laut Indonesia 2013). Understand importance of Sunda Straits as a migration corridor for the species (Burung Laut Indonesia 2013). Analyse existing data on breeding biology and success and investigate movements and habitat use. Continue tracking of adults and juveniles to identify foraging habitat and model population size and trend (Hennicke 2014, Hennicke et al. 2015). Assess threats to the species in both these areas and identify and protect important sites. Research the threats to the species off Christmas Island and the impact of mortality in Indonesian and Malaysian waters on the population size (Hennicke 2014, Tirtaningtyas and Hennicke 2015). Determine the extent of losses to hunting and bycatch. Develop and implement appropriate management in feeding habitat in South-East Asia to avoid bycatch and hunting. Undertake a biosecurity risk assessment to identify disease risk. Implement the species recovery plan.
Negotiate protection of all known and potential nesting habitat and appropriate buffers. Ensure no further habitat is lost. Continue to control the abundance and spread of A. gracilipes. Ensure breeding habitat is secure from weeds and disturbance. Maintain and strengthen biosecurity measures to prevent avian disease and invasive species incursions. Maintain a quarantine barrier between Christmas Island and other lands to minimise the risks of new avian diseases establishing (Hill and Dunn 2004). Lobby to prevent mining close to colonies. Collaborate with Indonesian authorities and non-government organisations to reduce losses from hunting.