The IUCN has officially declared the once-widespread migratory bird known as the slim-billed curlew extinct.

There are now even more animals on the list of those driven to extinction. A charismatic bird, Australian marsupials, and a few plants are among the species that the International Union for Conservation of Nature (IUCN) has formally declared extinct in its most recent report.

The update monitors the conservation status of over 172,000 species globally and is a component of the IUCN's Red List of Threatened Species. One of the most thorough indicators of the health of animals worldwide, the results this year are, at best, conflicting.

The following species have recently been declared extinct:

The curlew with thin bills (Numenius tenuirostris)

The Crocidura trichura, or Christmas Island shrew

Cone snail species (Conus lugubris)

The marl, sometimes known as the Shark Bay bandicoot (Perameles myosuros),

The striped bandicoot from the southeast (Perameles notina)

The Perameles papillon, or Nullarbor barred bandicoot

Some plants are also included, such as Delissea sinuata, a plant indigenous to the Hawaiian Islands, and Diospyros angulata, a species in the same genus as ebony trees that was last known to exist in the early 1850s.

Goodbye to the thin-billed curlew

The slender-billed curlew, which was once common throughout Europe, North Africa, and West Asia, has not been formally observed since February 25, 1995, when it was seen on a tidal lagoon on the Atlantic coast of Morocco. Although it was not verified, birdwatchers in Hungary's Kiskunsag National Park reported seeing it again in 2001.

Although the exact reason of its extinction is still unknown, scientists believe that habitat loss and irresponsible hunting are major contributing causes.

This is the first time the IUCN Red List of Threatened Species, one of the most reputable sources on conservation, has recognised the bird as extinct, despite some organisations having already done so in recent years due to its glaring lack of observations.

For the conservation of migratory birds, the Slender-billed Curlew's extinction is a tragic and sombre event. It emphasises how urgent it is to put in place efficient conservation measures in order to guarantee migratory species' survival. In a statement, Amy Fraenkel, Executive Secretary of the Convention on the Conservation of Migratory Species of Wild Animals, expressed hope that the extinction of this species will inspire action to save other endangered migratory species.

The disappearance of Australian marsupials

Three extinct marsupials—the Nullarbor barred bandicoot, the south-eastern striped bandicoot, and the marl—represent yet another setback to Australia's distinctive fauna. The decline of these small mammals has been driven largely by introduced predators such as foxes, feral cats, and dogs, alongside habitat destruction and changing land use.

Additional information from the IUCN

However, it wasn't all bad news. One encouraging development in the most recent IUCN report is the green sea turtle's (Chelonia mydas) ascent from Endangered to Least Concern. Thanks to decades of conservation efforts, the once-problematic species' global population is thought to have grown by about 28% since the 1970s.

But the bigger picture is still really alarming. The bearded seal (Erignathus barbatus) and harp seal (Pagophilus groenlandicus) have gone from Least Concern to Near Threatened, while the hooded seal (Cystophora cristata) has decreased from Vulnerable to Endangered.

Birds are also suffering, with up to 61 percent of bird species seeing diminishing populations, up from 44 percent in 2016.

Launched at the IUCN Congress in Abu Dhabi, today's Red List update highlights both the pressing issues and the enormous opportunities that lie ahead. In a statement, IUCN Director General Dr. Grethel Aguilar said, "The recovery of the green turtle reminds us that conservation works when we act with determination and unity, even though species like Arctic seals and many birds face growing threats."