Christmas Island

Christmas Island is a territory of Australia and is part of the Christmas and Cocos Islands tropical forests ecoregion (EoE). Overviews of the natural history of the island are given in the "Christmas Island National Park Management Plan 2014-2024" (environment.gov.au) and at (Raffles Museum). A summary listing over 250 endemic species is at (BHL).

Mammals found nowhere else but Christmas Island include the Christmas Island White-toothed Shrew (WNS Stamps WM) (WA Museum), the recently extinct Christmas Island Pipistrelle Pipistrellus murrayi (Mongabay), and two extinct rats: Maclear’s Rat (Wikipedia) and the Bulldog Rat (Sixth Extinction WM). The Christmas Island Flying Fox Pteropus natalis (flickr) (iNaturalist) is sometimes recognized as distinct from the Black-eared Flying Fox Pteropus melanotus.

Landbirds unique to Christmas Island include the Christmas Imperial-pigeon (ARKive WM), the Christmas Boobook (Owl Pages), and the Christmas White-eye (eBird). Other birds sometimes considered full species are the Christmas Goshawk Accipiter natalis (Birdway) (iNaturalist), the Christmas Swiftlet Collocalia natali (eBird), and the Christmas Island Thrush Turdus erythropleurus (iNaturalist). Two seabirds breed exclusively on the island: Abbott’s Booby (eBird) and the Christmas Island Frigatebird eBird).

Reptiles endemic to Christmas Island include the Christmas Island Blind Snake Ramphotyphlops exocoeti (BHL), Lister’s Gecko Lepidodactylus listeri (IUCN) (Parks Australia), the Blue-tailed Snake-eyed Skink Cryptoblepharus egeriae (iNaturalist), Sadleir's Bow-fingered Gecko Cyrtodactylus sadleiri (AROD) (iNaturalist), and the now presumed extinct Christmas Island Forest Skink Emoia nativitatis (The Conversation) (IUCN).

Marine fish known only from Christmas Island include a sole Aseraggodes crypticus (Fishes of Australia), the Green Dottyback Pseudochromis viridis (Fishes of Australia), the Christmas Rockskipper Praealticus natalis (iNaturalist) (Fishes of Australia), the Christmas Viviparous Brotula Paradiancistrus christmasensis (FishBase), Anderson's Viviparous Brotula Microbrotula andersoni (Fishes of Australia), and the Christmas Dwarfgoby Eviota natalis (Fishes of Australia) (iNaturalist).

The Christmas Emperor Polyura andrewsi (ABC) (Google Books) is the sole endemic species of butterfly. A drosophilid fly Lissocephala powelli (Bishop Museum WM pdf) lives on red crabs and robber crabs. Other insects unique to the island include the Christmas Island Stick-insect Ramulus stilpnoides (iNaturalist), a wasp Polistes balder (iNaturalist), a robber fly Cophinopoda andrewsi (iNaturalist), a sweat bee Homalictus andrewsi (PaDIL WM), a hoverfly Syritta maritima (GBIF), a jewel beetle Chrysodema simplex (iNaturalist), a darkling beetle Bradymerus seminitidus (Southeast Asian Beetles WM), the longhorn beetles Ceresium quadrimaculatum (iNaturalist) and Pterolophia perplexa (iNaturalist) and Anomophysis coxalis (fig. 3 at BHL), a minute tree-fungus beetle Cis christmasensis (GBIF), a stag beetle Figulus rossi (GBIF), a rove beetle Cephennomicrus lawrencei (GBIF), a scarab Psammorpha lawrencei (ISEZ PAN WM pdf), a jewel weevil Rhyncholobus vittatus (fig. 6 at Internet Archive), the moths Bocula limbata (fig. 1 at BHL) and Nigilgia browni (figs. 24-25 at ResearchGate), the Christmas Island Cicada Oxypleura calypso (iNaturalist), a spittlebug Clovia eximia (flickr), the planthoppers Oliarus trispiralis (dpi.nsw.gov.au WM) and Distiana andrewsi (dpi.nsw.gov.au WM), a stink bug Plautia grossepunctata (fig. 2 at BHL), a raspy cricket Gryllacris rufovaria (iNaturalist), and the bush crickets Psyrana pomona (iNaturalist) and Paraphisis listeri (OSF).

The island's most famous endemic is the Christmas Island Red Crab Gecarcoidea natalis (ARKive WM) noted for its remarkable annual breeding migration of millions of individuals. Other endemic invertebrates include Garfunkel's Bright-eyed Crab Danarma garfunkel (GBIF), Jackson's Crab Karstarma jacksoni (iNaturalist), the Christmas Island Blue Crab Discoplax celeste (iNaturalist), a huntsman spider Heteropoda listeri (fig. 4 at Internet Archive), a crevice weaver spider Labahitha gibsonhilli (GBIF), a brushed trapdoor spider Idioctis xmas (p. 10 of AMNH WM pdf), a centipede Cryptops inermipes (BHL), an amphipod crustacean Curidia andreae (ResearchGate), a bioluminescent brittle star Ophiopsila xmasilluminans (p. 4 of Raffles Museum pdf), and several snails: Assiminea andrewsiana (fig. 23 at Internet Archive), Nesopupa proscripta (fig. 1 at Internet Archive), and Succinea solitaria (figs. 10 & 11 at Internet Archive). Endemic marine molluscs include Rissoina isolata (WoRMS), Schwartziella lata (WoRMS), and Peristernia venusta (Internet Archive).

There are at least a dozen unique species of cave-dwelling animals including the crabs Christmaplax mirabilis (ResearchGate) and Orcovita orchardorum (ResearchGate), a ground beetle Lymnastis brooksi (BHL), a cockroach Metanocticola christmasensis (Google Books), a scorpion Liocheles polisorum (ResearchGate), the shrimps Macrobrachium xmas (ResearchGate) and Procaris noelensis (ResearchGate), a whipscorpion Charon gervaisi (BHL), a millipede Lophoturus speophilus (MNHN WM pdf), and the ostracods Humphreysella baltanasi (WA Museum) and Microceratina martensi (ResearchGate).

Endemic lichens include Lithothelium quiescens (ANBG pdf) and Strigula elixii (ANBG pdf). Endemic fungi include Geastrum andrewsii (BHL) and Aecidium alchorneae-rugosae (ScienceDirect). Endemic non-vascular plants include the mosses Ectropothecium micronesiense (BHL) and Isopterygium jelinkii (BHL).

Christmas Island is the exclusive home of 19 species of vascular plants (environment.gov.au) including Abutilon listeri (WNS Stamps), Hoya aldrichii (Wikipedia), Asystasia alba (p. 57 of environment.gov.au pdf), a grass Ischaemum nativitatis (JSTOR), a pepper Peperomia rossii (POWO), a fern Asplenium listeri (iNaturalist), Dicliptera maclearii (GBIF), Illigera elegans (POWO), Zehneria alba (JSTOR),the recently rediscovered Ridley's Ground Orchid Zeuxine exilis (BHL), and several other orchids: Brachypeza archytas (iNaturalist) (IOSPE WM), Phreatia listeri (IOSPE WM), and Flickingeria (or Dendrobium) nativitatis (OrchidRoots) (iNaturalist).

Endemic trees include the Christmas Island Palm Arenga listeri (PACSOA WM), Pittosporum nativitatis (BHL) (ALA), Grewia insularis (p. 63 of environment.gov.au pdf), the screwpines Pandanus christmatensis (flickr) (iNaturalist) and Pandanus elatus (iNaturalist), and Colubrina pedunculata (ANBG).