The ruddy turnstone diet varies seasonally between wintering and breeding habitats. They eat primarily invertebrates, mostly insects during the breeding season and crustaceans, mollusks, and other marine invertebrates during migration and winter. In the breeding season, ruddy turnstones use their stout bills to turn over rocks, probe through tundra vegetation or soils, and chase down mostly insect prey. Early in the season they may rely on carrion and plant materials, until insect prey becomes more abundant. Dominant prey in summer are flies and their larvae (Diptera), especially midges (Chironomidae), but also crane flies (Tipulidae), dance flies (Empididae), syrphid flies (Syrphidae), muscid flies (Muscidae), and blow flies (Calliphoridae). They also take spiders (Dictynidae, Lycosidae, Linyphiidae, Thomisidae), moth and butterfly larvae (Lymantriidae, Liparidae, Noctuidae, Nymphalidae), and beetles (Coleoptera). They may also take the eggs of colonial nesting birds (Larus, Sterna) in summer if they are nesting nearby. Once the young have hatched, families hunt together mostly along the margins of ponds and wetlands, where dipteran prey is most abundant.
In winter and during migration, ruddy turnstones take prey found on or just under the surface in their sandy, coastal habitats, especially crustaceans, mollusks, and polychaete worms. Diet varies with local and temporal availability of prey. During migration they will take advantage of highly abundant, but temporary, food resources, such as horseshoe crab eggs (Limulus polyphemus) on the mid-Atlantic coast during May and blowfly larvae (Calliphoridae) along the coasts of Alaska during August. Ruddy turnstones are opportunistic and will take carrion, the eggs of other birds, fish, and plant material as available. Dominant prey items in winter habitats include barnacles (Balanus), amphipods (Gammarus, Caprella), copepods (Calanus), shrimp and crabs (Crago, Cancer, Hippa, Emerita, Carcinus, Eupagurus, Pagurus), polychaete worms (Nereis), chitons (Chaetopleura, Chiten), periwinkles (Littorina), and bivalves (Mytilus, Cardium, Mya). They include other aquatic invertebrates in their diet as well.
Ruddy turnstones are aggressive birds, actively hunting down and efficiently manipulating prey. They use their stout bills to turn over rocks and other objects and probe into substrates to find prey. They are skilled at opening and dislodging bivalves and barnacles.
Animal Foods: fish; eggs; carrion ; insects; terrestrial non-insect arthropods; mollusks; terrestrial worms; aquatic or marine worms; aquatic crustaceans; echinoderms; other marine invertebrates
Plant Foods: fruit
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods, Molluscivore )
Most predation on ruddy turnstones is on eggs and hatchlings. Known predators are long-tailed jaegers (Stercorarius longicaudus), parasitic jaegers (Stercorarius parasiticus), glaucous gulls (Larus hyperboreus), common ravens (Corvus corax), arctic foxes (Vulpes lagopus), and red foxes (Vulpes vulpes). Jaegers may be the primary predators, they will continue to visit nests that they discover until all eggs or young are taken. Predation pressure on ruddy turnstones and other shorebirds nesting in tundra is highest when population numbers of collared lemmings (Dicrostonyx groenlandicus) are lowest. Ruddy turnstones have dispersed nesting territories, even in habitats with dense populations, to make it more difficult for predators to discover nests. Males actively patrol the nesting territory and warn the female when there is a predator nearby. In response, females sneak away from the nest to disguise its location from the predator. When predators are detected by pairs with hatchlings, their warning calls cause the hatchlings to freeze and the parents may perform a distraction display, pretending to be injured. Adults are only occasionally preyed on, reported predators of adults are Eurasian sparrow-hawks (Accipiter nisus), peregrine falcons (Falco peregrinus), merlins (Falco columbarius), and owls (Strigiformes).
Known Predators:
Anti-predator Adaptations: cryptic
Ruddy turnstones are small, robust sandpipers with stout, black, slightly upturned bills. They are 21 to 26 cm long, weighing from 84 and 190 g, and a wingspan of 50 to 57 cm. Plumage in breeding and non-breeding seasons are similar, slightly darker overall in the non-breeding season. Males and females are also similar in appearance. Ruddy turnstones have rufous feathers on their back and dorsal surface of their wings. They have black and brown plumage on the head and interspersed with the rufous areas overall. The belly is white and the legs are bright orange. They have a dark, black band that stretches across the neck and chest, like a bib. In flight they have distinctive white wing stripes and black on the trailing edge of the wing. There are two white stripes along the back and a broad, white rump patch.
Range mass: 84 to 190 g.
Range length: 21 to 26 cm.
Range wingspan: 50 to 57 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
The longest lifespan for ruddy turnstones in the wild is an individual that lived to 19.7 years. Average lifespan in Finland was estimated at 6 to 7 years. Survival rates in the first year are estimated at 45 to 58% in some areas. Annual survival of adults is estimated at 66 to 85% in some areas. Eggs and hatchlings are vulnerable to cold weather, damage to eggs during incubation, and predation.
Range lifespan
Status: wild: 19.75 (high) years.
Ruddy turnstones are found in arctic tundra and rocky coastal areas during the breeding season and along coastlines during winter and migration. Preferred habitats in winter are sandy coastlines and mudflats, but ruddy turnstones are also found on rocky beaches, wetlands, and other intertidal areas.
Habitat Regions: temperate ; tropical ; polar ; terrestrial
Terrestrial Biomes: desert or dune
Aquatic Biomes: coastal
Other Habitat Features: estuarine
Ruddy turnstones are one of the northernmost breeding shorebirds. They breed in arctic tundra from Alaska, across Canada, Greenland, Scandinavia, the Baltic Islands, and across northern Siberia to the Bering Sea. In winter they are found along coastlines from northern Massachusetts and northern California throughout the Antilles, Central and South America to Tierra del Fuego and along coastlines throughout Europe, Africa, Australia, New Zealand, Southeast Asia, and the Pacific Islands.
Biogeographic Regions: nearctic (Native ); palearctic (Native ); oriental (Native ); ethiopian (Native ); neotropical (Native ); australian (Native ); oceanic islands (Native )
Other Geographic Terms: holarctic ; cosmopolitan
Ruddy turnstones are important predators of insects and other invertebrates in their tundra breeding habitats and crustaceans and mollusks in coastal habitats at other times of the year. There are few parasites recorded in ruddy turnstones, only some records of nematode infections.
Mutualist Species:
Commensal/Parasitic Species:
Ruddy turnstones are interesting and charismatic members of coastal faunas throughout the world.
There are no adverse effects of ruddy turnstones on humans.
Ruddy turnstones are not considered threatened because of their large geographic range and population sizes. They are protected under the U.S. Migratory Bird Act. However, populations are threatened by many of the things that threaten shorebirds worldwide: alteration, destruction, and contamination of coastal habitats. Their breeding grounds may be influenced increasingly by global climate changes. Especially critical is the impact of coastal disturbance on ruddy turnstones during migration, especially important staging areas where historically superabundant food resources, such as horseshoe crab eggs (Limulus polyphemus) or herring eggs (Clupea pallasii pallasii), were critical to body condition during the spring migration.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Ruddy turnstones use vocalizations and visual displays extensively in communicating with conspecifics. They use displays, both on the ground and in the air, to attract mates and reinforce pair bonds. Males vocalize more than females, but both sexes do produce a variety of calls in different contexts. Ruddy turnstones have been described as "noisy." Variations on a call that sounds like "kitititit" are contact and alarm calls. "Pri pri pri" type calls are used to call young. Clicking calls and sounds are used when distracting or attacking predators and high pitched "i i i" sounds are distress calls.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Ruddy turnstones are one of 2 species in the distinctive genus Arenaria, along with black turnstones (Arenaria melanocephala). Their relationships with other sandpipers are poorly understood. There are two recognized subspecies: A. i. interpres, which occurs throughout the range of ruddy turnstones, and A. i. morinella, which is found breeding in southeastern Alaska, across the Canadian arctic to Greenland, and winters in coastal South America and the Antilles.
Ruddy turnstones are monogamous. Pairs form on the breeding territory, meeting again in the same territory used the previous year. In one study 16 turnstones kept the same mate each year over a 5 year period. Ruddy turnstones are aggressive, mated pairs initially are aggressive towards each other, even when one or the other returns to the nest. Pair bonds are renewed through courtship displays on the ground and in the air. Displays can be initiated by either females or males. Once the pair bond is established, males and females remain within sight of each other until egg-laying begins.
Mating System: monogamous
Ruddy turnstones arrive on the breeding grounds in late May and early June and establish pair bonds within 7 to 10 days of their arrival and create a nest scrape lined with leaves and lichen and begin laying eggs within a few days after that, usually by mid-June. Egg laying is influenced by the availability of prey and may be delayed if there isn't enough animal foods. Females lay 1 egg each day for the first 3 eggs, with other eggs laid at 1 to 2 day intervals. Locally, females are highly synchronous in egg-laying. Clutches are completed by late June and incubation begins at the 3rd egg laid. Clutches are from 2 to 5, but usually 4, dark brown or olive splotched eggs and incubation is 21 to 24 days long. Young hatch within a day or two of each other. Fledging occurs at 19 to 21 days old, at which point the young are independent. Ruddy turnstone young remain on their wintering grounds throughout their first year after hatching. Young begin to breed in their 2nd year, although breeding may be delayed until 3 or 4 years old.
Breeding interval: Ruddy turnstones breed once yearly.
Breeding season: Ruddy turnstones breed in May and June.
Range eggs per season: 2 to 5.
Average eggs per season: 4.
Range time to hatching: 21 to 24 days.
Range fledging age: 19 to 21 days.
Range time to independence: 19 to 21 days.
Range age at sexual or reproductive maturity (female): 4 (high) years.
Average age at sexual or reproductive maturity (female): 2 years.
Range age at sexual or reproductive maturity (male): 4 (high) years.
Average age at sexual or reproductive maturity (male): 2 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Females and males incubate the eggs, but females do most of the incubation and caring for the eggs and nest. Males patrol the nest area and warn the female of the presence of predators, at which point she will move from the nest to distract attention from the eggs. Young ruddy turnstones hatch with downy feathers and are able to walk and begin to find food within a few hours after hatching and the nest is abandoned within a day of hatching. Males and females protect the hatchlings, but the female abandons the brood mid-way through the hatchling period and the male remains to protect the young until they fledge, at 19 to 21 days old. Parents aggressively guard their young and lead them to areas with lots of prey, especially midges, so they can feed themselves. A few days after fledging, usually at 21 to 23 days old, the young are almost at adult sizes and begin their first migration to the wintering grounds.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Protecting: Male, Female)
Regular passage visitor and winter visitor.
A medium-sized (8-10 inches) plover, the Ruddy Turnstone in summer is most easily identified by its orange back and legs, pale breast, white head with black patches on the face and throat. In winter, this species becomes dull brown above and white below. Birds in summer plumage are unmistakable, while winter birds may be separated from other dull shorebirds by this species’ short, upturned bill. Male and female Ruddy Turnstones are similar to one another in all seasons. The Ruddy Turnstone occurs throughout much of the world. In the New World, this species breeds in the high arctic of Canada, Alaska, and Greenland, wintering along the coasts of the Americas from mid-latitude North America south to southern South America. In the Old World, this species breeds along the edge of the Arctic Ocean, wintering from Europe south to South Africa and from South Asia south to Australasia and the islands of the Pacific Ocean. Ruddy Turnstones breed in wet areas on the arctic tundra. In winter, this species may be found along the coast on sandy or rocky beaches. Ruddy Turnstones primarily eat small insects during the summer months, switching to crustaceans and small fish during the winter. Due to this species’ remote breeding grounds, most birdwatchers are only familiar with Ruddy Turnstones during the winter. At that time, this species is most easily seen while walking or running along the shoreline, turning over stones while foraging for food (a behavior which gave this species its name). Ruddy Turnstones are most active during the day.
A medium-sized (8-10 inches) plover, the Ruddy Turnstone in summer is most easily identified by its orange back and legs, pale breast, white head with black patches on the face and throat. In winter, this species becomes dull brown above and white below. Birds in summer plumage are unmistakable, while winter birds may be separated from other dull shorebirds by this species’ short, upturned bill. Male and female Ruddy Turnstones are similar to one another in all seasons. The Ruddy Turnstone occurs throughout much of the world. In the New World, this species breeds in the high arctic of Canada, Alaska, and Greenland, wintering along the coasts of the Americas from mid-latitude North America south to southern South America. In the Old World, this species breeds along the edge of the Arctic Ocean, wintering from Europe south to South Africa and from South Asia south to Australasia and the islands of the Pacific Ocean. Ruddy Turnstones breed in wet areas on the arctic tundra. In winter, this species may be found along the coast on sandy or rocky beaches. Ruddy Turnstones primarily eat small insects during the summer months, switching to crustaceans and small fish during the winter. Due to this species’ remote breeding grounds, most birdwatchers are only familiar with Ruddy Turnstones during the winter. At that time, this species is most easily seen while walking or running along the shoreline, turning over stones while foraging for food (a behavior which gave this species its name). Ruddy Turnstones are most active during the day.
The ruddy turnstone (Arenaria interpres) is a small cosmopolitan wading bird, one of two species of turnstone in the genus Arenaria.
It is now classified in the sandpiper family Scolopacidae but was formerly sometimes placed in the plover family Charadriidae. It is a highly migratory bird, breeding in northern parts of Eurasia and North America and flying south to winter on coastlines almost worldwide. It is the only species of turnstone in much of its range and is often known simply as turnstone.
The ruddy turnstone was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Tringa interpres.[2] The species is now placed together with the black turnstone in the genus Arenaria that was introduced by the French zoologist Mathurin Jacques Brisson in 1760 with the ruddy turnstone as the type species.[3][4] The genus name arenaria is from Latin arenarius, "inhabiting sand", from arena, "sand". The specific interpres means "messenger"; when visiting Gotland in 1741, Linnaeus thought that the Swedish word Tolk, meaning "interpreter" applied to this species, but in the local dialect the word means "legs" and is used for the redshank.[5]
Two subspecies are recognised:[4]
It is a fairly small and stocky bird, 22–24 cm (8.7–9.4 in) long with a wingspan of 50–57 cm (20–22 in) and a weight of 85–150 g (3.0–5.3 oz). The dark, wedge-shaped bill is 2–2.5 cm (0.79–0.98 in) long and slightly upturned. The legs are fairly short at 3.5 cm (1.4 in) and are bright orange.[6]
In all seasons, the plumage is dominated by a harlequin-like pattern of black and white. Breeding birds have reddish-brown upper parts with black markings. The head is mainly white with black streaks on the crown and a black pattern on the face. The breast is mainly black apart from a white patch on the sides. The rest of the underparts are white. In flight it reveals a white wingbar, white patch near the base of the wing and white lower back, rump and tail with dark bands on the uppertail-coverts and near the tip of the tail. The female is slightly duller than the male and has a browner head with more streaking.[6]
Non-breeding adults are duller than breeding birds and have dark grey-brown upperparts with black mottling and a dark head with little white. Juvenile birds have a pale brown head and pale fringes to the upperpart feathers creating a scaly impression.[6]
Birds of the subspecies morinella are smaller with darker upperparts and less streaking on the crown.[6]
The ruddy turnstone has a staccato, rattling call and also a chattering alarm-call which is mainly given during the breeding season.[6]
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On Heligoland, North Sea
Non-breeding plumage
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A. i. morinella on Tobago
on Bald Head Island, North Carolina
in India
Ruddy Turnstone, Vasai, Maharashtra, India in December
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in flight, non-breeding plumage, Madagascar
The ruddy turnstone breeds in northern latitudes, usually no more than a few kilometres from the sea. The subspecies A. i. morinella occurs in northern Alaska and in Arctic Canada as far east as Baffin Island. A. i. interpres breeds in western Alaska, Ellesmere Island, Greenland, Norway, Denmark, Sweden, Finland, Estonia and northern Russia. It formerly bred on the Baltic coast of Germany and has possibly bred in Scotland and the Faroe Islands.[1]
In the Americas, the species winters on coastlines from Washington and Massachusetts southwards to the southern tip of South America although it is scarce in southern parts of Chile and Argentina and is only an unconfirmed vagrant in the Falkland Islands. In Europe, it winters in western regions from Iceland, Norway and Denmark southwards. Only small numbers are found on Mediterranean coasts. In Africa, it is common all the way down to South Africa with good numbers on many offshore islands. In Asia, it is widespread in the south with birds wintering as far north as southern China and Japan (mainly in the Ryukyu Islands). It occurs south to Tasmania and New Zealand and is present on many Pacific islands.[1] Some non-breeding birds remain year round in many parts of the wintering range, with some of those birds still taking on breeding plumage in the spring and summer.
The ruddy turnstone has a varied diet including carrion, eggs, fish[7] and plant material but it feeds mainly on invertebrates. Insects and their larvae[7] are particularly important in the breeding season. At other times it also takes crustaceans, spiders,[7] molluscs and worms. It often flips over stones and other objects to get at prey items hiding underneath; this behaviour is the origin of the name "turnstone". It usually forages in flocks.[8]
They have also been observed preying on the eggs of other bird species such as gulls, terns, ducks, and even other turnstones, though this behaviour is uncommon. In the majority of observed cases, turnstones typically go after undefended or unattended nests, puncturing the shells with their beaks to get at the contents within.[9]
Ruddy turnstones engage in a variety of behaviours to locate and capture prey. These behaviours can be placed into six general categories:[10]
There is evidence that turnstones vary between these feeding behaviours based on individual preference, sex, and even social status with respect to other turnstones. In one studied population, dominant individuals tended to engage in routing while preventing subordinates from doing the same. When these dominant individuals were temporarily removed, some of the subordinates started to rout, while others enacted no change in foraging strategy.
When foraging, turnstones adopt different postures indicative of their level of dominance. A lowered tail and a hunched stance is associated with chasing and aggression, and thus a dominant individual. Dominance in aggression is age-related, with juveniles assuming the subordinate role a disproportionate amount of the time.[12]
The plumage patterns of ruddy turnstones exhibit an unusual amount of variation in comparison with other shorebirds. Turnstones use these unique plumage patterns to recognize individuals and discriminate intruders in their territory from neighbours occupying an adjacent territory. When a fake fiberglass turnstone model is placed in a turnstone's territory, the occupant is less likely to respond aggressively if the model is painted to have the plumage pattern of a neighbouring turnstone.[13]
Ruddy turnstones can survive in a wide range of habitats and climatic conditions from Arctic to tropical. The typical breeding habitat is open tundra with water nearby. Outside the breeding season, it is found along coasts, particularly on rocky or stony shores. It is often found on man-made structures such as breakwaters and jetties. It may venture onto open grassy areas near the coast. Small numbers sometimes turn up on inland wetlands, especially during the spring and autumn migrations.[8]
In terms of wintering sites, ruddy turnstones are particularly faithful to specific locations. A study published in 2009 examined turnstones wintering along a stretch of coastline in the Firth of Clyde. It found that 95% of birds resident to the area at the end of winter returned the following autumn. The same study also confirmed ruddy turnstones as one of the longest lived wader species, with annual adult mortality rates of under 15%.[11] Their average lifespan is 9 years with 19 years and 2 months being the longest recorded.
It is a monogamous bird and pairs may remain together for more than one breeding season. The nest is a shallow scrape, often with a lining of leaves. It is about 11 cm (4.3 in) across and 3 cm (1.2 in) deep. It may be built amongst vegetation or on bare stony or rocky ground. Several pairs may nest close together.[8]
A single clutch of two to five eggs is laid with four being most common. The eggs measure about 41 mm × 29 mm (1.6 in × 1.1 in) and weigh around 17.9 g (0.63 oz). They are smooth, slightly glossy and oval to pear-shaped. They are variable in colour but are commonly pale green-brown with dark brown markings, densest at the larger end. Incubation begins when the first egg is laid and lasts for about 22–24 days. The female is mainly responsible for incubating the eggs but the male may help towards the end.[8]
The young birds are precocial and are able to leave the nest soon after hatching. They are buff above with dark grey markings and are white below. They are able to feed themselves but are protected by the parents, particularly the male. They fledge after 19–21 days.[8]
According to the International Union for Conservation of Nature (IUCN), the ruddy turnstone population is currently very stable. Environment Canada surveys suggest that they have in fact decreased in abundance relative to the 1970s (up to 50% by one estimate) and face a variety of threats during migration and winter.[14] They estimate that the Canadian population is 100,000–500,000 adults. The Canadian Wildlife Service estimates that the worldwide population of ruddy turnstones is 449,000, and that 235,000 are breeding in North America while the rest are breeding throughout the Arctic regions. They are very common and widespread. Their remote breeding range and widespread winter range should help them remain a common species.[1][8]
The ruddy turnstone (Arenaria interpres) is a small cosmopolitan wading bird, one of two species of turnstone in the genus Arenaria.
It is now classified in the sandpiper family Scolopacidae but was formerly sometimes placed in the plover family Charadriidae. It is a highly migratory bird, breeding in northern parts of Eurasia and North America and flying south to winter on coastlines almost worldwide. It is the only species of turnstone in much of its range and is often known simply as turnstone.
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