Birds are a vital part of ecosystems around the world. Their extinction can have major impacts on other species and the environment. Unfortunately, human activity has caused many bird species to go extinct. This article explores how many bird species have gone extinct due to humans.
What causes birds to go extinct?
There are several major threats that have led to bird extinctions caused by humans:
- Habitat loss and degradation – Deforestation, urbanization, agriculture and other human land uses remove or alter bird habitats.
- Invasive species – Non-native plants, animals and diseases introduced by humans can threaten native bird populations.
- Overexploitation – Unsustainable hunting and harvesting of birds for food, feathers and other uses has caused declines.
- Pollution – Pesticides, oil spills and other toxins have poisoned birds and their food sources.
- Climate change – Rising temperatures and extreme weather events disrupt bird habitats and food supplies.
These threats have grown substantially over the past few centuries as human populations and activities expand around the world. Their impacts often compound upon each other.
How many extinct bird species are there?
According to the International Union for Conservation of Nature (IUCN) Red List, there are 187 extinct bird species as of 2022. The IUCN tracks the conservation status of species worldwide. Birds are classified as extinct when there is no reasonable doubt they no longer exist in the wild.
The 187 extinct birds represent about 2% of the approximately 10,000 known bird species in the world. However, many researchers believe the actual number of extinctions may be significantly higher for a few key reasons:
- Some extinct species may not yet be classified as such on the IUCN Red List.
- Many island species extinctions following human colonization centuries ago are poorly documented.
- Some cryptic species may have gone extinct before scientists identified them.
Factors like these mean published extinction counts are often underestimates, especially for less studied groups like birds. The true number of human-caused bird extinctions could be hundreds higher than what is currently documented.
Extinct bird species by geographic location
Extinct birds are spread across the world, but island species make up a disproportionate amount of extinctions. Here is a breakdown of extinct species by major geographic region:
Region | Extinct Species |
---|---|
Oceania (Pacific islands) | 71 |
North America | 38 |
Asia | 28 |
South America | 15 |
Africa | 14 |
Europe | 12 |
Caribbean islands | 9 |
Island species make up over 50% of global bird extinctions, despite islands having a small fraction of the world’s birds. Islands often have high rates of endemism, meaning species are found nowhere else. Their small populations and habitats are highly vulnerable when humans arrive.
North America and Asia also have many extinct birds. Habitat loss from agriculture and development drove declines across these continents. Europe has fewer known extinctions, potentially because intensive hunting occurred before scientific documentation.
When did these extinctions occur?
The vast majority of human-caused bird extinctions occurred in the last few centuries:
Time Period | Extinct Species |
---|---|
1900 – 2023 (last 123 years) | 73 |
1800 – 1899 | 62 |
1500 – 1799 | 39 |
Before 1500 | 13 |
Just 13 birds are thought to have gone extinct prior to 1500, before European colonization and industrialization kicked extinction into high gear. Nearly 90% of known bird extinctions have occurred since the year 1800.
Extinction rates accelerated in the 20th century. Invasive species spread to new islands, while agricultural chemicals like DDT poisoned birds after World War II. Hunting for food and feathers also increased with growing human populations.
However, new conservation laws like the U.S. Endangered Species Act have helped reverse some extinction trends in recent decades. But many species remain at high risk from ongoing threats.
Recently extinct birds
Some birds have gone extinct extraordinarily recently, as humans rapidly modify environments:
- Poʻouli – This Hawaiian honeycreeper disappeared in 2004 due to habitat loss and invasive species.
- Spix’s Macaw – The last known wild member of this distinctive parrot died in Brazil in 2000.
- Pagan reed warbler – This Micronesian warbler was last seen in the 1970s after predators were introduced to its island.
- Bachman’s warbler – Habitat loss in the southern U.S. drove this warbler extinct in the early 1960s.
Dozens of bird extinctions have occurred in just the past century. Some extinct in the wild species like the California condor survive today only through captive breeding programs.
Most unique extinct bird species
While all extinctions represent a loss of biodiversity, some of the unique traits and behaviors of extinct birds are particularly notable:
- Elephant bird – This giant 1000 lb flightless bird went extinct about 1000 years ago in Madagascar.
- Passenger pigeon – This species exhibited remarkable nomadic migrations across North America until it was hunted to extinction by 1914.
- Carolina parakeet – This was the only parrot species native to the eastern U.S. before it went extinct by the early 1900s.
- Lyall’s wren – Known for its incredibly loud song, this tiny wren disappeared from New Zealand by the 1890s.
These examples and many other extinct birds represent huge losses of avian biodiversity. Their extinctions restrict our understanding of the natural world.
Effects of losing bird species
Why does bird extinction matter, beyond the loss of unique species? Extinctions can have many cascading effects on ecosystems:
- Plants lose essential pollinators and seed dispersers.
- Insects and rodents can irrupt without bird predation control.
- Nutrients are depleted from soil and water without bird guano.
- Scavengers lose food sources from carrion.
These ecosystem disruptions then reverberate up food chains. Entire habitats can become less resilient and face destabilization.
Beyond ecology, bird extinctions also matter due to cultural, economic and medical reasons. People often have strong personal connections to regional bird species. Bird-related recreation like birdwatching has major economic impacts. And scientists lose opportunities to study complex bird behaviors and physiology that could have human applications.
Preventing further bird extinctions
How can we prevent more bird extinctions in the future? Some key conservation approaches include:
- Habitat protection – Creating reserves and protecting land from development.
- Invasive species control – Removing non-native predators and competitors where possible.
- Wildlife-friendly practices – Promoting organic agriculture, reducing ocean pollution, and other sustainable practices.
- Captive breeding – Rearing small populations in controlled settings to reintroduce to the wild.
- Education – Teaching the public about threats birds face and how to help address them.
No single strategy will work everywhere. Combining techniques tailored to regional contexts offers the best opportunities for preserving species. But action is urgently needed to avoid losing more birds forever.
Conclusion
Human activities have already driven around 200 known bird species extinct, especially since the 19th century. The actual number may be much higher due to incomplete documentation. Most extinctions have occurred on islands, where birds evolved in isolation and are highly vulnerable to introduced threats.
However, extinctions are increasing around the world as human impacts expand. Habitat loss, invasive species, overhunting and pollution are all to blame. Resulting ecosystem changes can cause ecological instability and cascading effects.
Conservation efforts focused on habitat protection, reducing non-native threats, changing agricultural practices and other interventions can help prevent more irreversible bird extinctions. But action is needed quickly before unique and important avian biodiversity is lost forever.