Sanderling Diet and Size: Feeding Habits, Predators, and Measurements

Sanderlings are small robust waders with a straight black bill and black legs. They are almost all white in their winter plumage but they have brown backs in summer with white underbellies. They also have a distinctive black mark on their shoulders.

They are easy to identify because of the way they run along the tideline in an almost comical cartoonish way. Although Sanderlings don’t breed in the UK they are often spotted during the winter months and are also passage migrants which means you can often see them during spring and autumn.

In this article we’ll look into the diet, breeding habits and the size and weight of the Sanderling and much more besides. Keep reading to find out more.

The Dietary Habits Of The Sanderling

 The dietary habits of the Sanderling change with the seasons and it’s this adaptability that has helped them to survive as a species and spread all over the world in great numbers.

What Does A Sanderling Eat?

Sanderlings eat terrestrial and aquatic invertebrates found in their habitats. During the breeding season they mainly eat insects with most of their diet made up from mosquitoes, craneflies and midges.

During the winter and during their migration Sanderlings eat mainly small crustaceans, worms, snails, insects, fish and jellyfish. Sanderlings are also known to eat the occasional plant material like seeds, roots, shoots and plant buds to supplement their diets.

They feed by probing the soft ground with their bills, running along just ahead of or behind waves on soft sand probing for food as they run.

What To Feed A Baby Sanderling? 

Sanderling chicks are precocial which means they leave the nest around 24 hours after hatching. The parents will initially feed their chicks small invertebrates that are easy to catch and digest.

The parents will guide to chicks to the best feeding areas and show them how and what to forage for. As they grow and develop, the chicks will become more independent and find food for themselves.

Breeding Habits Of Sanderlings

Sanderlings breed in the high-Arctic across northern Canada, Greenland and parts of Siberia. Males perform aerial displays to attract females.

These displays include flying in large circles or a figure of eight pattern whilst calling.  They also make long rapid flutters of their wings whilst their heads turn from side to side. This is followed by a short glide.

They will also make courting displays on the ground which includes wing raising and calling. 

They nest on the ground with the female constructing a simple scrape nest lined with grass, moss and lichen. The female then lays 3 to 4 eggs which are a greenish-blue or olive-brown colour covered in brown spots or freckles.

Both parents undertake incubation duties and will lead the chicks to their feeding grounds soon after hatching.

Do Sanderlings Mate For Life?

In most cases, Sanderlings are monogamous and mate for life. However, this is not always the case with some females mating with a succession of males in the same breeding season.

Most pairs return to the same nesting site each year and pair up again on their return.

The Size & Weight Of Sanderlings

Now let’s take a look at the size and weight of the Sanderling. This will help in identifying these interesting birds when seen from a distance on the shoreline.

How Much Does A Sanderling Weigh?

The average weight of an adult Sanderling is around 50 to 60 grams. Which is roughly the same weight as a chicken’s egg.

These small lightweight birds are well adapted for their migratory lifestyle. They can travel the long distances between their Arctic breeding grounds and their wintering sites all across the world.

How Big Is A Sanderling?

An adult Sanderling is around 20 to 21 cm long with an average wingspan of around 36 to 39 cm. This is around the same size as the Redwing.

Are Sanderlings Under Threat?

Sanderlings are not currently considered to be under threat globally. They are listed as a bird of least concern on the International Union for Conservation of Nature (IUCN) Red List.

Having said that, there is some evidence that suggests that some Sanderling populations are in decline. The decline in numbers has been attributed to habitat loss due to coastal development as well as climate change which can cause rising sea levels and increased storms.

Of course there are other factors that can affect the numbers of Sanderlings including human activity on beaches, pollution and predators.

What Eats A Sanderling?

Sanderlings are most vulnerable during the breeding season when their nests are often invaded by Arctic Skuas, Glaucous Gulls, Snowy Owls, Arctic foxes and wolves. 

Where Can I See Sanderlings In The UK?

Sanderlings can be seen along large parts of the UK coastline especially during their non-breeding season. They can often be seen running along sandy beaches chasing after waves as they forage for food.

There are certain areas which are well known hotspots for Sanderling sightings. These areas include;

The East of England

• The Wash (Norfolk)
• The North Norfolk Coast

The South of England

• The Thames Estuary (Essex & Kent)
• Chichester Harbour (West Sussex)

South West England

• The Exe Estuary (Devon)
• The Hayle Estuary (Cornwall)

North West England

• Morecambe Bay (Lancashire/Cumbria)
• The Dee Estuary (Cheshire/Merseyside)

Wales

• Burry Inlet (Carmarthenshire)
• The Dyfi Estuary (Ceredigion/Powys)

Scotland

• Solway Firth (Dumfries and Galloway)
• Montrose Basin (Angus)

Northern Ireland

• Lough Foyle (County Londonderry/Donegal)

The best time to observe Sanderlings along UK coasts is at high tide when the birds are pushed closer to the shore where they congregate with other wading species. Or at low tide when they disperse across intertidal zones to feed.

SEE ALSO: Whooper Swan Life Cycle: Nest Building To Fledging (and everything in between)

Frequently Asked Questions