Behaviour · BEH·28

Raven Population and Conservation: Numbers, Trends, and Threats

[science] The Common Raven is classified Least Concern by the IUCN with an estimated 16 million individuals. Populations have expanded in many regions since mid-20th century legal protection and increased food availability from human infrastructure. Localised threats include lead poisoning, illegal persecution, and—in desert regions—over-expansion driven by human subsidy causing ecological cascades.

Global Population Estimates

[science] Precise global raven population estimates are complicated by the species' enormous range (spanning North America, Eurasia, North Africa, and the Middle East) and by variation in counting methodology across countries. Current consensus estimates:¹

Global: approximately 16 million mature individuals (BirdLife International); some estimates range to 20+ million.
North America: approximately 1.7–2 million individuals (North American Breeding Bird Survey data, extrapolated).
UK and Ireland: approximately 10,000–12,000 breeding pairs (UK BTO Bird Atlas data), concentrated in Wales, Scotland, and northern England.
IUCN status: Least Concern (Common Raven, Thick-billed Raven, Australian Raven, Forest Raven, White-necked Raven, Brown-necked Raven, Fan-tailed Raven, Chihuahuan Raven — all eight species assessed as Least Concern).

Historical Persecution and Recovery

[science] Ravens were systematically persecuted across Europe and North America from the medieval period through the 20th century, primarily on the grounds of:¹

Livestock predation: ravens were (and still are) accused of killing lambs and piglets, though evidence shows they primarily consume carrion rather than live prey; they will attack weakened or dying animals, which inflates perception of their predatory impact.
Game preservation: ravens were killed on grouse moors and shooting estates as perceived threats to game-bird eggs and chicks.
General "vermin" status: throughout Europe, corvids were classified as vermin to be killed; ravens shared this status with crows and magpies.

Legal protection came at different times in different countries: UK Wildlife and Countryside Act 1981 (with roots in earlier 1954 Protection of Birds Act); US Migratory Bird Treaty Act (covering ravens from 1972). Recovery in protected areas was rapid — raven populations in Wales and Scotland recovered significantly after persecution ended.

Regional Expansions: The Human Infrastructure Effect

[science] In several regions, raven populations have expanded well beyond historical levels due to human-provided food and water sources:¹²

Mojave Desert, California: raven densities near highways, rest stops, and human settlements in the Mojave have increased dramatically. These subsidised ravens have negative ecological effects — elevated raven predation on desert tortoise eggs and hatchlings is a documented conservation concern for the vulnerable Mojave population.
Western United States: raven densities near landfills, agricultural operations, and human settlements significantly exceed historical levels, with cascading effects on other ground-nesting birds.
UK: raven recolonisation of central and southern England (historically rare in these areas) has accelerated since the 1990s, with ravens now breeding in several English counties where they were absent for centuries.

Current Threats and Conservation Considerations

[science] While ravens are not globally threatened, localised threats remain:¹

Lead poisoning: ravens ingesting gut piles and shot animals (from hunting) accumulate lead, which can cause mortality and reproductive failure. Lead poisoning is documented as a significant mortality cause in scavenger birds in areas with heavy hunting pressure.
Illegal persecution: illegal killing on grouse moors and sheep farms continues in parts of the UK despite legal protection; convicted cases represent a fraction of actual illegal killing.
Vehicle collision: ravens feeding on road kills are struck by vehicles — a significant modern mortality source in areas with heavy traffic through raven territory.
Nest disturbance: recreational climbing and outdoor activities near raven nest sites can cause breeding failure; some nest sites are protected by seasonal restrictions.

Frequently Asked Questions

How many common ravens are there in the world?

Global Common Raven population estimates are difficult to make precisely due to the species' vast range, but BirdLife International estimates the population at approximately 16 million individuals (mature birds), with some estimates ranging higher. The species has a stable to expanding population trend in most of its range. It is classified as Least Concern by the IUCN — the lowest conservation concern category. Localized declines exist in some regions, but global population is robust.

Are ravens increasing or decreasing in population?

Common Ravens have been expanding in range and increasing in population in many parts of their range since the mid-20th century, primarily due to: legal protection (ravens were widely persecuted as livestock predators until the 20th century; legal protection in the UK came only in 1954); increasing food availability from human waste (landfills, refuse sites, tourism); and adaptation to suburban and urban environments. In some regions (Mojave Desert, California), raven populations have expanded dramatically due to human infrastructure providing water and food — with negative consequences for desert tortoises and other species through nest predation.

Are ravens endangered?

No — the Common Raven is not endangered. It is classified as Least Concern by the IUCN with an estimated population of approximately 16 million birds. Some other raven species have more restricted ranges: the Thick-billed Raven is endemic to the Ethiopian highlands; the Somali Crow has the most restricted range of any raven. However, none of the eight raven species are currently classified as threatened. The myth that ravens are endangered likely stems from their historical persecution and local rarity in some areas.

Sources

Boarman, W.I. & Heinrich, B. (1999). Common Raven (Corvus corax). In Poole, A. (ed.), The Birds of North America, No. 476. Cornell Lab of Ornithology. — population data, historical persecution, legal protection history, mortality causes.
Marzluff, J.M. & Angell, T. (2005). In the Company of Crows and Ravens. Yale University Press. — raven population expansion, human-subsidised populations, Mojave Desert ecological effects.

[science] peer-reviewed data