The IUCN Red List is an objective and authoritative system for evaluating the global conservation status of species and categorising them according to their risk of extinction. To date, over 91,000 species of plants, animals and fungi have been assessed and their status determined (see figure). Their 2017 evaluation lists 28% of these as threatened. BirdLife International is the official Red List Authority for birds, tasked with evaluating the status of the world’s entire avifauna and keeping these data up to date. As of 2017, BirdLife has established that worldwide 1,469 bird species (13.4% of the total, or roughly one in eight) are threatened with extinction (). These species have small, fragmented or dwindling ranges (), tiny populations (), or are declining rapidly (). Of these, 222 species are considered Critically Endangered and face an extremely high risk of extinction in the immediate future.

Structure of IUCN Red List categories   The IUCN Red List provides a scientifically objective way of assessing species in terms of their extinction risk. Information on a taxon's population size, population trend and range size are applied to standard quantitative criteria to determine its Red List Category (Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, Near Threatened or Least Concern). Species for which there is insufficient information to apply the criteria are assessed as Data Deficient.

Although threatened bird species are found across the globe, the greatest concentrations occur in the forested tropics (). Some regions hold particularly high numbers of threatened species, for example, the tropical Andes, Atlantic Forests of Brazil, eastern Madagascar, and the archipelagos of South-East Asia (, ). A disproportionately high number of threatened species, almost half, occur on islands, particularly oceanic islands far from land (). For seabirds, the greatest concentrations of threatened species are found in the southern oceans, notably around New Zealand ().

Despite global conservation efforts, the overall status of the world’s birds continues to worsen. Of the world’s threatened species, over 80% have populations that are currently in decline () and there have been some truly catastrophic recent population collapses (, ). For long-lived, slow-breeding species, such as albatrosses, however, even relatively slow population declines can have alarming consequences ().

The IUCN Red List Index (RLI) for birds tracks the movement of species through categories of extinction risk. It reveals a steady and ongoing deterioration in the status of the world’s species since the first comprehensive global assessment in 1988 (). The IUCN categories, however, are relatively broad and species often have to undergo substantial changes in order to cross the thresholds between categories. In 2004, BirdLife conducted a ‘snapshot’ survey of over 100 experts in order to get a more complete picture. It revealed that just 11% of threatened species could be judged to be improving in status ().

The RLI for birds can be broken down biogeographically. The results show that although species have deteriorated in all major ecosystems and regions, these changes have not occurred evenly across the globe. Birds associated with Pacific islands, the open ocean and the lowland forests of Asia have undergone particularly sharp declines (, , ).

Birds are impacted by a range of threats—mostly human-derived—with the conversion of natural habitats to agricultural land the most significant (). The pressures associated with farming seem set to intensify as the human population grows and demand for animal protein and biofuels increases ().

Over the last five hundred years, invasive alien species have been partly or wholly responsible for the extinction of at least 65 bird species, making this the most common contributory factor in recent losses to the world’s avifauna (). Invasive species affect around half of currently threatened bird species. Island species are particularly susceptible, with three-quarters of threatened birds on oceanic islands affected by invasive species (). Rats and cats have had far and away the greatest impact, threatening the survival of hundreds of different bird species worldwide, but other species have also had devastating impacts (, , , ).

Hunting and trapping (, , , ), logging (), urbanisation (), pollution (, ) and fisheries () are also major threats, with climate change becoming increasingly significant (, , ).

In 2010, BirdLife confirmed the extinction of Alaotra Grebe Tachybaptus rufolavatus—the latest in a long line of tragic demises attributable to humankind. The coming years will almost certainly bring other sad losses, however, there remains cause for optimism. Given sufficient resources and political will, species can be saved from extinction. The Herculean efforts of conservationists have brought numerous species back from the brink. A recent study showed that at least 33 bird species would have disappeared in the last century, including 16 during 1994–2004 without dedicated conservation action (, ). These include Mauritius Parakeet Psittacula eques, which had been reduced to fewer than a dozen birds in 1986 before targeted intervention led to its spectacular recovery (). California Condor Gymnogyps californianus and Asian Crested Ibis Nipponia nippon reached similarly perilous numbers before intensive reintroduction programmes pulled them back from the edge (, ). Successful conservation interventions such as these can involve a variety of actions, from raising public awareness () to providing supplementary food () and translocating birds (, ).

BirdLife has identified the priority conservation actions needed for all Critically Endangered species and launched a ‘Preventing Extinctions Programme’ in order to ensure they are implemented. To date, the initiative has appointed ‘Species Guardians’—local organisations or individuals responsible for leading initiatives to reverse the fortunes for almost 60 the world’s most imperilled species (). For example, in the Azores, SPEA (BirdLife in Portugal)—the Species Guardian for the archipelago’s endemic Bullfinch Pyrrhula murina—has had huge success in reversing the species’ decline through habitat management and restoration ().

To access more case studies on threatened birds and BirdLife's work to save them, please click on the following links.

• Important Bird Areas for globally threatened species: Blue Swallow
• Bird Conservation Nepal is establishing safe ‘diclofenac free’ feeding sites for vultures
• Important Bird Areas including habitat fragments and the surrounding matrix: an example from Kenya
• One in eight of all bird species is threatened with global extinction
• Most threatened birds have small ranges
• Most threatened birds have small populations
• Most threatened birds are declining, some catastrophically
• Threatened birds occur in all habitats, but the majority are found in forest
• Threatened birds occur in nearly all countries and territories
• Some countries are particularly important for threatened birds
• Many threatened birds are restricted to small islands
• The southern oceans are important for threatened seabirds
• Most threatened birds are in decline
• Asian vulture populations have declined precipitously in less than a decade
• Titicaca Grebe is being driven rapidly towards extinction owing to the unregulated use of gill nets
• Many albatross species are in alarming slow decline
• The status of the worlds birds has deteriorated over the last 20 years
• Most threatened birds are deteriorating in status
• Birds have deteriorated in status in all major ecosystems, particularly marine
• Birds in some regions, notably Oceania and Asia, have deteriorated in status faster than others
• Birds in some families, notably seabirds, have deteriorated in status faster than others
• In Australia, the extinction of birds since 1750 can be linked to human impacts
• A range of threats drives declines in bird populations
• Agricultural expansion is a major threat to birds, and appears to be increasing in importance
• Farming is destroying the Brazilian cerrado, one of the worlds richest savannas
• Invasive alien species have been implicated in nearly half of recent bird extinctions
• Small island birds are most at risk from invasive alien species
• Native birds on Gough Island are being devastated by house mice
• Native forest birds in the Hawaiian Islands are limited by introduced avian diseases
• Endemic birds on Christmas Island are being devastated by introduced ants
• Bird populations in the Northern Mariana Islands are being decimated by brown tree snakes
• Avian diseases are spreading to impact hitherto unaffected populations
• The Red List Index for utilised bird species illustrates their deterioration in status
• Overexploitation is a threat to many large and conspicuous bird species
• Sought-after species face rapid declines
• The Red List Index for internationally traded bird species shows their deterioration in status
• The illegal parrot trade remains a problem in Latin America
• In Papua New Guinea, deforestation for oil palm plantations is causing declines in endemic birds
• Threatened birds indicate the consequences of unchecked infrastructure development
• Collisions and electrocutions pose real threats for young and migrating birds
• Mountaintop mining in the Appalachians is causing a decline in Cerulean Warblers
• Pollution from agriculture, forestry and industry has significant impacts on birds
• Vultures are under threat from the veterinary drug diclofenac
• In Australia, fires are linked to habitat changes and the decline of many bird species
• Longline fishing effort overlaps with foraging hotspots for seabirds
• Trawl fisheries cause significant mortality to albatrosses along the west coast of southern Africa
• Climate change may make habitats become unsuitable in large parts of the range of Worthen's Sparrow
• The biological traits of some bird species render them particularly vulnerable to climate change
• In Hawaii, climate change will increase the impact of disease
• The number of montane endemic birds that go extinct in Australia depends on the degree of warming
• More bird species are threatened in the developing than the developed world
• Species lists form a key part of several conventions and need to be reviewed and updated regularly
• Without conservation action, 16 bird species would have gone extinct over the last ten years
• Back from the brink: four Critically Endangered species saved from extinction
• Are we doing enough to save the world's birds?
• In Europe, many essential nationally based actions have been undertaken but more must be addressed
• Stable isotope analysis reveals the wintering grounds of the Aquatic Warbler
• Nest protection and brood manipulation has helped the Mauritius Parakeet to recover
• Captive breeding plays a crucial part in bringing the Californian Condor back from the brink
• Captive breeding and release of Asian Crested Ibis: linking Japan and China
• Supplementary feeding for vultures in Nepal
• Translocating Rimatara Lorikeets to Atiu, Cook Islands
• Bermuda Petrel is being conserved through translocation and provision of artificial nest-sites
• Working together to conserve flamingos at a network of sites in the High Andes
• Raising public awareness to save the Yellow-eared Parrot
• Species Guardians and Species Champions: taking and funding action for the most threatened species
• Habitat restoration has led to the recovery of the Azores Bullfinch
• Local knowledge surveys can help track threatened species: the example of Horned Curassow
• Trade in Africa’s Grey Parrots and Timneh Parrots is currently not sustainable
• Predator control is helping to secure the future of New Zealand's Kokako
• 'Colony Guardians' are working with local communities to protect Hooded Grebe nesting sites
• Surveys suggest that Puerto Rican Nightjar is more widely distributed than previously thought
• BirdLife Partners are taking action for Spoon-billed Sandpiper along its entire migration route
• The habitat of Araripe Manakin is being formally protected
• A State Park of 10,000 hectares has been established to protect Restinga Antwren
• BirdLife South Africa supported by a Species Champion is researching the threats to African Penguin
• BirdLife is working with local communities to safeguard the Liben Plain for people and larks
• Habitats for Carnaby’s Black-cockatoo are being restored through work with private landowners

   

Links
BirdLife's species work
Globally Threatened Bird Forums
BirdLife news story: 2017 IUCN Red List update—Seabirds starving, songbirds trapped, hope for pelican and kiwis
BirdLife news story: 2016 IUCN Red List update—6 things you might have missed from the 2016 Red List
BirdLife news story: 2016 IUCN Red List update—Great news for island endemics, disaster for cagebirds
BirdLife news story: 2015 IUCN Red List update—vultures, shorebirds and other iconic species
BirdLife news story: 2014 IUCN Red List update—One tenth of bird species flying under the conservation radar
BirdLife news story: 2013 IUCN Red List update—Red List for Birds 2013: Number of Critically Endangered birds hits new high
BirdLife news story: 2012 IUCN Red List update—Threat to the Amazon’s birds greater than ever, Red List update reveals
BirdLife news story: 2011 IUCN Red List update—big birds lose out in a crowded world
IUCN Red List

Compiled 2011, updated 2012, 2013, 2014, 2015, 2017

Recommended citation
BirdLife International (2017) Spotlight on threatened birds. Presented as part of the BirdLife State of the World's Birds website. Available from: https://datazone.birdlife.org/sowb/spotthreatbirds

BirdLife acknowledges and thanks its Founder Patrons, the A. G. Leventis Foundation, the Aage V. Jensen Charity Foundation, the Tasso Leventis Foundation, Zeiss, Ryuzo Kosugi and all BirdLife Species Champions for supporting its Red List assessments and the taxonomic work that underpins them. Thanks also to Lynx Edicions/HBW and to everyone who contributes information to the Red List assessments, including via the Globally Threatened Bird Forums (https://forums.birdlife.org/).