Are ruddy turnstones rare?

The ruddy turnstone (Arenaria interpres) is a small shorebird that breeds in the Arctic and subarctic regions and migrates long distances to spend the boreal winter on coastlines almost worldwide. As their name suggests, ruddy turnstones use their short, wedge-shaped bills to overturn stones, shells, seaweed and debris to find insects, crustaceans and other small invertebrate prey. They are highly gregarious, forming large flocks on their stopover sites during migration. Their characteristic feeding behavior and striking plumage make ruddy turnstones a favorite among birdwatchers. But are they actually rare?

Ruddy Turnstone Range and Population

Ruddy turnstones have an extremely large global range and population. According to the Cornell Lab of Ornithology, their breeding range spans across northern Alaska, Canada, Greenland, Iceland, Scandinavia and northern Russia. The species winters along coastlines nearly worldwide, as far north as England and as far south as Australia, Argentina and South Africa.

Population estimates for ruddy turnstones include:

With a global population likely exceeding 200,000 mature individuals, the ruddy turnstone is evaluated as Least Concern on the IUCN Red List of Threatened Species. Its population appears to be stable and may even be increasing in certain parts of its range.

Ruddy Turnstone Habitat

During the breeding season, ruddy turnstones inhabit tundra and boggy taiga habitats near wetlands and ponds in the Arctic and subarctic regions. They nest on open, relatively flat and dry ground, often on ridges and hummocks.

On migration and in their wintering range, ruddy turnstones occur exclusively along coastlines, favoring habitats that offer an abundance of small invertebrate prey such as:

• Sandy and cobble beaches
• Intertidal mudflats and sandflats
• Rocky shores
• Jetties and piers
• Estuaries and tidal lagoons
• Saltmarshes

They typically forage at the water’s edge or in the intertidal zone, but will also feed on wet sand, mud and open shorelines farther up the beach. Ruddy turnstones may also venture into adjoining grassy areas, flooded fields or algal meadows if food is available.

Ruddy Turnstone Diet

The ruddy turnstone has a varied omnivorous diet consisting predominantly of invertebrates supplemented by plant material and occasional carrion. Their main prey items include:

• Insects and larvae
• Spiders
• Crustaceans such as sandhoppers, shrimp and crabs
• Mollusks including snails, limpets and mussels
• Marine worms
• Small fish
• Eggs and chicks of other shorebirds
• Seeds
• Seaweed
• Algae
• Carrion from fish, birds and marine mammals

Ruddy turnstones forage both during the day and at night. They locate prey visually by walking along the shoreline or probing into crevices and mud. Their short, wedge-shaped bill allows them to flip over seaweed, stones, shells, debris and even clumps of sod in search of hidden invertebrates. They may also swim to pursue prey in shallow water.

Ruddy Turnstone Migration

The ruddy turnstone is one of the champion long-distance migrants in the bird world. The subspecies A. i. morinella undertakes an annual round trip migratory route of over 18,000 miles between breeding areas in Siberia and Alaska to wintering areas in Australia and Oceania.

Other ruddy turnstone populations also carry out epic migrations between the Arctic and destinations worldwide. Their migration includes long non-stop transoceanic flights as well as shorter stops to rest and refuel along the journey.

Some key facts about ruddy turnstone migration include:

• They migrate in large flocks of up to 2,000 birds.
• Most leave the Arctic by late July through August.
• They follow coastlines and make stopovers at sites with abundant food.
• Some fly non-stop for 4-6 days covering 4,000+ miles.
• Their flight speed averages 35-45 mph but can reach 65 mph.
• They arrive on wintering grounds August-November.
• Return migration begins March-May.

Ruddy turnstones have adapted to make these marathon migrations possible. They undergo physiological changes to support intense fat storage prior to long flights. They have a larger breast muscle mass relative to total body weight compared to related shorebirds. Their aerodynamic body profile and long, pointed wings maximize flight performance.

Ruddy Turnstone Nesting

Ruddy turnstones breed in the high Arctic tundra from early June to mid-July. They are generally socially monogamous but may occasionally practice polygamy. Pair bonds are established shortly after arrival on the breeding grounds.

The nest consists of a shallow scrape lined with lichen, leaves, feathers, pebbles or shells, often situated on a raised hummock or rocky outcrop. The female lays a clutch of 2-5 eggs that are variable in color from olive to brown, spotted and speckled with black.

Incubation duties are shared by both parents and lasts for 21-26 days. The precocial downy chicks leave the nest within a day after hatching. Both parents actively feed and brood the chicks, which fledge at around 18-20 days old. Most ruddy turnstones first breed when they are 2-3 years old. Their average lifespan in the wild is 7 years.

Ruddy Turnstone Conservation Status

With its large, global population, the ruddy turnstone is evaluated as Least Concern on the IUCN Red List. The species as a whole appears to be in good shape. However, local declines have been noted in some areas, such as the East Asian-Australasian Flyway population that migrates from Russia and Alaska to southeastern Australia and New Zealand.

Potential threats to ruddy turnstones include:

• Habitat degradation at migratory stopover sites
• Human disturbance
• Predation by invasive species
• Pollution
• Climate change affecting breeding and wintering grounds

Protecting crucial coastal wetland habitats and mitigating climate change impacts are important conservation priorities to ensure the long-term survival of these globetrotting shorebirds into the future.

Conclusion

In summary, ruddy turnstones are not considered rare globally. Key points supporting this conclusion include:

• Large breeding distribution across northern North America, Greenland, Europe and Russia
• Winter worldwide along coasts from temperate to tropical regions
• Global population estimate over 200,000 mature individuals
• Evaluated as Least Concern by the IUCN Red List
• Stable or increasing population trends in most regions

However, local declines in ruddy turnstone subpopulations highlights the need for continued conservation efforts, especially protecting migration stopover habitats and addressing climate change, to ensure these resilient Arctic shorebirds remain common well into the future. Their marathon migrations and characteristic feeding behaviors will hopefully continue to delight birders across the globe.