How rare are Green-winged Teal?

The Green-winged Teal (Anas crecca) is a small dabbling duck that breeds across the Northern Hemisphere. They are highly migratory and some populations undertake remarkably long migrations. Green-winged Teal are considered common in parts of their breeding range but are scarce or rare elsewhere. Their global population is estimated to be between 3.8 and 4.6 million birds.

What is a Green-winged Teal?

The Green-winged Teal is a small, compact duck with a short neck and bill. Males have grey heads with bold green and white stripes behind the eyes. Their breast is pinkish-buff with thick dark vertical barring. The rest of the body is mostly mottled brown with a conspicuous vertical white bar along the flanks. Females are mostly mottled brown like Eclipse males. Both sexes have iridescent green speculum feathers framed with thin white margins on the wings. The Green-winged Teal gets its name from the striking green patches on the wings of the male. There are no major subspecies.

Where are Green-winged Teal found?

Green-winged Teal have an extremely large breeding range across northern North America, Europe, and Asia. Their breeding range extends throughout Alaska, Canada, the northern United States, Iceland, the UK, Scandinavia, and northern Russia. They winter as far south as northern Africa, the Middle East, India, South-east Asia, southern Japan, and northern South America.

During the breeding season, Green-winged Teal inhabit small wetlands, ponds, marshes, and the edges of lakes. They nest on the ground, concealed in dense vegetation near water. During winter and migration, they occur on both freshwater and marine habitats like estuaries, rivers, lakes, flooded fields, and coastal mudflats.

How many Green-winged Teal are there?

The global population of Green-winged Teal is estimated at 3.8 to 4.6 million birds:

This species has an extremely large range and population, and is not currently at risk of extinction. The global population appears to be stable and is not believed to approach the threshold for vulnerability under population decline criteria.

Is the Green-winged Teal endangered?

No, the Green-winged Teal is evaluated as Least Concern on the IUCN Red List of Threatened Species. This means they are not currently considered threatened with extinction at the global level. Their populations appear stable and they remain widespread and common over much of their breeding and wintering range.

Threats and conservation

There are no major threats to Green-winged Teal across their range. They are hunted recreationally and for food in some regions, but harvest levels are not believed to be negatively impacting populations. As a common, resilient species, they are able to withstand moderate levels of hunting pressure and habitat loss.

Wetland drainage, degradation, and destruction remains a concern across parts of their range, however they are somewhat flexible in using both freshwater and coastal habitats. Their early breeding season and ability to nest over a scattered area make them less vulnerable than other waterfowl to localized habitat loss.

Green-winged Teal occur in many protected areas across their range. There are no targeted conservation actions in place for this species currently, and none are urgently required given their large, stable population.

Is the Green-winged Teal rare in any regions?

While Green-winged Teal remain common and widespread over much of their range, they are considered rare, scarce or uncommon in parts of the world, including:

United Kingdom

Green-winged Teal are very rare breeding birds in the UK with only around 50-100 pairs. They are red-listed as a Species of High Conservation Concern. The small breeding population is scattered across northern Scotland, mainly in the Outer Hebrides and Orkney Islands. However, Green-winged Teal are more common winter visitors throughout the UK, arriving between September and November from their breeding grounds further north. Still, maximum winter counts only range from 1,000 to 6,000 birds across the UK.

Western Europe

Green-winged Teal are scarce breeding birds across most of Western Europe including France, Belgium, the Netherlands, Germany, Switzerland, Italy, and Spain. The breeding population in France is estimated at only 110-220 pairs. They are considered rare or occasional breeders in many European countries. However, larger numbers migrate through Western Europe in winter, arriving from northern breeding areas.

Southern Africa

In Southern Africa, Green-winged Teal are considered rare non-breeding visitors. They are seldom recorded south of Zambia and Zimbabwe. A small population winters in East Africa, especially in Ethiopia. There are very occasional records from South Africa and Namibia despite the extensive wetlands there. It is unclear why they are generally scarce across Southern Africa during winter compared to other dabbling ducks.

South America

Green-winged Teal are also rare over much of South America. The small southern populations that winter in northern South America are estimated at fewer than 10,000 birds. They are seldom recorded across extensive wetland areas further south in Brazil, Paraguay, Uruguay, Chile, and Argentina despite the presence of apparently suitable habitat.

Japan

In Japan, Green-winged Teal are considered nationally threatened and endangered. The breeding population is estimated at only 100-300 pairs restricted to a few sites on Hokkaido. However, larger numbers of wintering birds arrive from the north in Japan from October to December, boosting winter populations to around 12,500 birds.

Hawaii

Green-winged Teal are also rare vagrants to Hawaii. Despite Hawaii falling within their winter range, only around 60 records of this species exist from the Hawaiian Islands since the 1950s, mostly involving single birds. They are considered an uncommon winter visitor and transitory migrant to Hawaii.

Why are Green-winged Teal rare in some areas?

The reasons why Green-winged Teal are scarce or rare in certain parts of their range are not fully understood. Possible explanations include:

• Their breeding and wintering ranges don’t fully overlap in places like South America and Southern Africa. Their migration routes may bypass suitable habitat here.
• They appear to be less adaptable to colonizing new habitat or expanding their breeding and wintering range compared to some other dabbling ducks.
• They may be subject to competition with or predation by other duck species in parts of their winter range.
• Their populations can fluctuate naturally, leading to occasional lower numbers in some regions.
• Habitat loss or hunting pressure may have caused declines from historical levels in some areas.
• Vagaries of migration routes can cause fewer numbers to reach certain wintering regions in some years.

Further research is needed to fully explain their rarity and determine whether their scarce numbers in these regions constitute the natural state, or a decline from previously higher levels.

Conclusion

In conclusion, Green-winged Teal remain a common and widespread duck species across much of their breeding and wintering range in the Northern Hemisphere. However, they are considered rare, scarce or endangered in a few isolated parts of their range, including the UK, Western Europe, Southern Africa, South America, and Japan. The reasons for their scarcity in these areas is not fully understood, but could relate to gaps between their migratory flyways, lower adaptability, competition, fluctuating populations, habitat loss, and other factors. Their global population remains healthy and stable, however localized declines and rarity in some regions highlights the need for continued monitoring and conservation of wetland habitats across their range.