Cover image: Ruddy Turnstone by John and Anne Todd, 9 April, at St Helena Bay in the Western Cape, South Africa. Most of the turnstones in this photograph are almost in complete breeding plumage and will leave soon on migration to Siberia (BirdPix 164625). The two birds at the left hand end of the group are juveniles, and will remain behind. See the text below for details!
Identification
Most of the waders/shorebirds are tricky to identify. The Ruddy Turnstone is an exception. Firstly, as we will see from the distribution map below, it is almost exclusively found on the coastline. Although it does sometimes occur inland, most birders will never see one at a freshwater wetland! Secondly, it has an unusual size and shape, and it is conspicuously marked.
In flight, Ruddy Turnstones have a distinct pattern of dark-brown and white. This makes them easy to identify.
Even though Ruddy Turnstones are distinct from all other species, their plumage is variable, depending on their age and whether they are getting into or out of breeding plumage. The series of photographs below indicate some of the range (and take a special look at the last image in this section).
The image below comes from a paper published in the journal Auk. The paper is called “Individual differences in the head and neck plumage of Ruddy Turnstones (Arenaria interpres) during the breeding season” and you can download it here.
The take home message is that not only do Ruddy Turnstones have a breeding plumage and non-breeding plumage, individual birds, both female and male, have distinct black and white patterns on their heads and necks during the breeding season.The paper was written by Peter Ferns, and is based on observations made in northeastern Greenland during an expedition in 1974. I am grateful to Harry Green for telling me about this paper.
Distribution
The distribution of the Ruddy Turnstone is almost exclusively coastal:
There are scattered records across the interior. You need to search quite hard in the distribution map to see the yellow-shaded pentads where they have been recorded. The yellow indicates that the reporting rates in these pentads are small; in other words, Ruddy Turnstones are rarely recorded in them. These inland records are mostly young birds on their first southwards migration, and are mostly made in September, October and November, having left the breeding grounds on the tundra mostly in August.
Migration of Ruddy Turnstones
In this map, the lines join the place where the bird was ringed (circle) with the place where the bird was recovered. The birds did not fly along the lines! The map is contained in a report which summarized recoveries of all species of waterbirds which had been ringed with SAFRING rings (Underhill LG, Tree AJ, Oschadleus HD, Parker V 1999. Review of ring recoveries of waterbirds in southern Africa. Cape Town: Avian Demography Unit: 1–119). You can download the report.
The longest recovery on the map is an exceptional record of a Ruddy Turnstone colour-ringed on Ellesmere Island, Canada, which was observed for eight successive years on the same beach in Namibia. You can read the full story of this bird here. In a nutshell, a turnstone with four colour rings was spotted at a beach north of Swakopmund in March 1999. Detective work by SAFRING revealed that the bird had been ringed at Alert on Ellesmere Island in 1996. This bird was seen again at the same beach in each successive summer up to 2005. The turnstones which breed in this part of Canada mostly migrate to West Africa, and many make a stop-over in Iceland en route.
The table below presents 13 of the most interesting recoveries in the SAFRING database up to 1999.
Number 1 is a recovery from Mauritius (country code Mu) to India (In). Number 12 also involves Mauritius. An adult ringed in Mauritius in February would have migrated to breed on the Siberian tundra. It was recorded back in Mauritius in September, seven months later, having navigated back to a small island in the Indian Ocean. The longest elapsed time is 16 years for Number 5; it was ringed as a first year bird in January 1977 near Swakopmund, Namibia, and was found in February 1993, 11 km from its ringing site. The straight line distance from Swakopmund to the breeding grounds in Siberia is about 12,500 km. It would have covered about 400,000 km in migration flights alone, which is a bit more than the distance from the Earth to the Moon! The records in the table are interesting, and repay careful study!
In broad brush terms, we understand that the Ruddy Turnstones that migrate to southern Africa breed in the Siberian tundra.
Breeding
Turnstones are circumpolar breeders. That means they breed in suitable habitat, mainly Arctic tundra, in both North America, and Eurasia, without any big gaps in distribution. The photographs here were made during an expedition to the Taimyr Peninsula in Siberia in 1991.
This nest was placed in the centre of some frost-heaved tundra, a patch of mud about 40 cm wide. The nest lining is critical, because it insulates the eggs from the freezing cold surface below; it is only a handful of centimetres down to the permafrost. This nest has a lining consisting of tiny dry leaves and a lichen of the genus Thamnolia; these are popularly called “whiteworm lichens”. Beyond the mud, is moss. There are almost always four eggs; that is the standard clutch size for most of the waders that breed on the tundra.
This is the kind of landscape in which to search for the nests of Ruddy Turnstones (and most of the other waders which breed in Arctic tundra).
The foreground consists mainly of the mud of frost-heaved tundra, and some moss. In the middle distance is Lake Pronchishcheva (75.3N, 112.5E), still frozen, except along the edges, and in the distance, to the north, are the Byrranga mountains of the interior of the Taimyr Peninsula.
Finally, and on a personal and sad note … This Ruddy Turnstone is being examined by Dr Evgeny Syroechkovskiy (1968-2022). Zhenya, as we all knew him, was leader of our International Arctic Expedition to Lake Pronchishcheva in 1991; it is hard to believe that he was only 23 years old when he took on this massive responsibility. He went on to accomplish a wide variety of achievements in ornithology and bird conservation. At the time of his passing in February 2022, he was chair of the Spoon-billed Sandpiper Task Force. Their News Bulletin 26 of March 2022 is dedicated in its entirety to Zhenya, with many people paying tribute; download it here. This trip to the tundra in 1991 was pivotal in giving a new direction to my life, and I have extremely good memories of Zhenya’s outstanding leadership of that expedition.
Further resources for the Ruddy Turnstone
Species text in the First Southern African Bird Atlas Project.
Recommended citation format: Underhill LG 2024. Ruddy Turnstone Arenaria interpres. Biodiversity and Development Institute. Available online at https://thebdi.org/2024/04/04/ruddy-turnstone-arenaria-interpres/
