In memory of the Christmas Island shrew

Summary

Once abundant on Christmas Island, the tiny, five-gram shrew (Crocidura trichura) filled the night forest with its high, thin cry before vanishing into silence.Introduced black rats and their parasites decimated the island’s native mammals, and by 1908 the shrew was thought extinct, its memory confined to museum drawers and field notes.Brief rediscoveries in 1958 and 1984 brought fleeting hope, but the last known individuals died in captivity, and no others have been found despite decades of searching.Its loss, now made official, adds to Australia’s grim record of extinctions—a quiet reminder of fragile lives erased by invasion, neglect, and the noise of human expansion.See All Key Ideas It never weighed more than a spoonful of sugar. Five or six grams of life, soft-furred and sharp-nosed, darting among the roots and leaf litter of a tiny island in the Indian Ocean. At night, its voice—a thin, high cry, part bat and part whisper—once filled the forest of Christmas Island. Now the forest is silent. Australia’s only shrew, Crocidura trichura, has been declared extinct. Few knew it lived, fewer still that it was Australian. The shrew was a stranger in a land of pouched mammals, a migrant that arrived tens of thousands of years ago, likely clinging to a raft of vegetation from what is now Indonesia. On this isolated outpost, it built a quiet lineage of survivors. When British naturalists arrived in the 1890s, they found the forest alive with its shrill chatter. “Extremely common,” they wrote. And then, almost at once, it vanished. The black rats came first, stowaways in bales of hay. With them came a parasite, Trypanosoma lewisi, that swept through the island’s naïve mammals like a plague. Within years, both native rats were gone. By 1908, the shrew was presumed lost too. Its name lingered only in museum drawers and in the footnotes of field reports. Yet it was not quite gone. Half a century later, in 1958, two shrews appeared as bulldozers tore into the forest for phos...