The Earth officially lost at least six species this year, according to the IUCN Red List of Threatened Species.

The list — an inventory of the global conservation status and extinction risk of biological species maintained by the International Union for Conservation of Nature — declared the species as officially extinct by moving the creatures to the Extinct category on the list, a move not made unless a species has not been observed alive in the wild for years.

The species that made the move to the Extinct category includes: the Christmas Island shrew (Crocidura trichura), a species of cone snail (Conus lugubris), the slender-billed curlew, and three Australian mammals — the marl (Perameles myosuros), the south-eastern striped bandicoot (Perameles notina), and the Nullarbor barred bandicoot (Perameles papillon).

While the species were declared extinct in 2025, they have long been missing from the wild. According to the IUCN, the Christmas Island Shrew and Conus lugubris snail were last observed in the wild in the 1980s. For the slender-billed curlew, the last sighting was in 1995, when someone took a photo of a migratory waterbird in Morocco.

The absence of these species may not be new to conservationists, but seeing the animals move to the extinct list is difficult for experts.

“The extinction of the slender-billed curlew is a tragic and sobering moment for migratory bird conservation,” Amy Fraenkel, the executive secretary of the Convention on the Conservation of Migratory Species of Wild Animals, told USA Today in 2025.

Fraenkel added to the outlet that she is hopeful these losses will galvanize animal lovers to protect the Earth’s most threatened species by advocating for “effective conservation measures.”

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Mongabay noted that animals weren’t the only species declared extinct this year; Diospyros angulata, a tree native to Mauritius, and Delissea sinuata, a plant only found in the Waianae Mountains of O’ahu, Hawai’i, both moved to IUCN’s Extinct list in 2025.