Species recoveries bring hope amidst biodiversity crisis

Conservation efforts have led to improvements in the status of ten species, according to update of The IUCN Red List of Threatened Species. This includes the recovery of the Guam Rail, a bird previously listed as Extinct in the Wild.

Despite these improvements, the IUCN Red List now includes 30,178 species threatened with extinction, and there is increasing evidence of the negative effects of climate change. There are now 112,432 species on the IUCN Red List.

“This IUCN Red List update offers a spark of hope in the midst of the biodiversity crisis. Though we have witnessed 73 genuine species declines, the stories behind the 10 genuine improvements prove that nature will recover if given half a chance. Climate change is adding to the multiple threats species face, and we need to act urgently and decisively to curb the crisis.

IUCN Acting Director General, Dr Grethel Aguilar

Conservation success stories

The latest IUCN Red List update reveals genuine improvements in the status of eight bird species and two freshwater fishes. Captive breeding, combined with careful management of wild populations, has been key to these conservation successes.

Among these improvements is the flightless, fast-running Guam Rail (Hypotaenidia owstoni) – the second bird in history to recover after being declared Extinct in the Wild, after the California Condor (Gymnogyps californianus). Once widespread on the Pacific island of Guam, its numbers declined after the Brown Tree Snake (Boiga irregularis) was accidentally introduced at the end of World War Two. In 1987, the last wild Guam Rail was killed by this invasive predator. Thanks to a 35-year captive breeding programme, the Guam Rail is now established on the neighbouring Cocos Island. However, the bird is still classified as Critically Endangered – one step away from extinction.

In Mauritius, the Echo Parakeet (Psittacula eques) continues its recovery thanks to conservation efforts, including a highly successful captive breeding programme. There are now more than 750 Echo Parakeets in the wild, and with this update the species has been reclassified as Vulnerable, following its improvement from Critically Endangered to Endangered in 2007.

Two freshwater fish species – the Australian Trout Cod (Maccullochella macquariensis) and Pedder Galaxias (Galaxias pedderensis) – have likewise improved, from Endangered to Vulnerable and Critically Endangered to Endangered respectively. Decades of conservation action have focused on establishing additional subpopulations through reintroductions and wild-to-wild translocations. Both species face threats from invasive species and habitat destruction and degradation.

Increasing evidence of the effects of climate change

Climate change has contributed to the declines of species including several freshwater fishes and the reef-dependent Shorttail Nurse Shark. Assessments in this update show climate change affects species by, for example, altering habitats and increasing the strength and frequency of extreme weather events.

This Red List update reveals that 37% of Australia’s freshwater fish species are threatened with extinction, of which at least 58% are directly impacted by climate change.

Fish are highly susceptible to extreme droughts caused by declining rainfall and increasing temperatures. Climate change also compounds the threat from invasive alien species, which can move into new areas as water temperature and flow change.

Native to the Western Indian Ocean, the Shorttail Nurse Shark (Pseudoginglymostoma brevicaudatum) has declined by approximately 80% over 30 years. Simultaneously affected by unmanaged fishing and climate change, it has moved from Vulnerable to Critically Endangered. Living only in shallow waters where it has no refuge from fishing, the shark is losing its habitat due to coral reef degradation caused in part by ocean warming.

Climate change is also threatening Dominica’s national bird, the Imperial Parrot (Amazona imperialis). While hurricanes naturally occur in the Caribbean, their increased frequency and intensity result in high bird mortality and habitat destruction, alongside devastating impacts on people. The species declined from Endangered to Critically Endangered after Hurricane Maria in 2017, the strongest hurricane on record to have struck the island. There are now estimated to be fewer than 50 mature individuals left in the wild.

Eucalypts assessed worldwide

All known eucalypt species worldwide have been assessed in this Red List update, revealing that almost 25% are threatened with extinction. Of the 826 eucalypts – comprising the Eucalyptus, Corymbia and Angophora species groups – 812 occur only in Australia. As keystone species, they define the landscape of the entire Australian continent, and are culturally significant to its First Nations People. Eucalypts including the Vulnerable Eucalyptus moluccana are the sole food source for the Koala (Phascolarctos cinereus), which has declined significantly due to loss of eucalypt habitat.

Elsewhere in the world eucalypts can be highly invasive, but in their native range in Australia they face threats from human use of land, especially agriculture and urbanisation. This has resulted in population declines of at least 30% for 134 eucalypts, such as the Endangered Rose Mallee (Eucalyptus rhodantha), which has declined by more than 50%. Mining also threatens some restricted range species, such as the Critically Endangered Eucalyptus purpurata.

Critical habitat for conservation now remains in the areas between rivers and land, on roadside patches and in paddocks where lone trees often remain.

“With 72% of the species added to the IUCN Red List in this update assessed with support from us, we are pleased to be contributing towards the achievement of the ambitious goal to have 160,000 species on the IUCN Red List by 2020. The IUCN Red List provides essential data that will inform decisions on the Post 2020 global biodiversity framework made next year, guiding progress towards the 2030 Sustainable Development Goals,” said Masako Yamato, General Manager, Environmental Affairs Division of Toyota Motor Corporation.

The IUCN Red List: The IUCN Red List of Threatened Species™ contributes to the achievement of Target 12 of the 2011– 2020 Strategic Plan for Biodiversity. Target 12: By 2020 the extinction of known threatened species has been prevented and their conservation status, particularly of those most in decline, has been improved and sustained.

The IUCN Red List

The figures presented above are only for those species that have been assessed for The IUCN Red List to date. Although not all of the world’s species have been assessed, The IUCN Red List provides a useful snapshot of what is happening to species today and highlights the urgent need for conservation action. Relative percentages for threatened species cannot be provided for many taxonomic groups on The IUCN Red List because they have not been comprehensively assessed. For many of these groups, assessment efforts have focused on threatened species; therefore, the percentage of threatened species for these groups would be heavily biased.

The IUCN Red List threat categories are as follows, in descending order of threat:

• Extinct or Extinct in the Wild
• Critically Endangered, Endangered and Vulnerable: species threatened with global extinction.
• Near Threatened: species close to the threatened thresholds or that would be threatened without ongoing conservation measures.
• Least Concern: species evaluated with a lower risk of extinction.
• Data Deficient: no assessment because of insufficient data.
• Critically Endangered (Possibly Extinct): this is not a new IUCN Red List Category, but is a flag developed to identify those Critically Endangered species that are in all probability already extinct but for which confirmation is required; for example, through more extensive surveys being carried out and failing to find any individuals