Curlew Sandpiper Vs Dunlin: Key Differences Explained
While Curlew Sandpipers and Dunlins might be found in the same habitats, there are clear differences between them. From the plumage they display during the breeding season to their distinctive calls and habitats, these birds create an interesting contrast.
In this article, we will compare their physical characteristics, breeding patterns, and the sounds they make. Continue reading to learn what sets each species apart.
Table of Contents
Key Takeaways
- Both male Curlew Sandpipers and Dunlins are more colourful during breeding, with Dunlin males having a darker belly than females.
- Post-breeding, Dunlins migrate to coastal marshes, estuaries, and mudflats to find food and milder temperatures.
- Curlew Sandpipers lay four eggs that blend with the tundra, characterised by their dark spots and yellow, cream, or olive hues.
- Dunlins make a soft ‘peep’ and a distinctive trill during breeding.
- Curlew Sandpipers are a little larger and heavier than Dunlins.
What Is The Difference Between A Curlew Sandpiper And A Dunlin?
Let’s take a look at the differences between Curlew Sandpipers and Dunlins, from their appearances and habitats to the sounds they make and how much they weigh.
Visual Differences
Curlew Sandpipers have longer bills that curve downward, while Dunlins have slightly down-curved beaks. The white rump of the Curlew Sandpiper is another distinctive feature when flying, which is not seen in Dunlins.
In the autumn, Curlew Sandpipers appear lighter, with a pale, clean look and a striking white eyestripe. In the breeding season, their plumage turns rich chestnut. Meanwhile, Dunlins feature a black belly patch during the breeding season.
Both species see their males become more colourful during the breeding season, with male Dunlins showing a darker belly than the females.
Differences In Habitat
Dunlins are known to breed in wet coastal tundra regions across the Arctic and subarctic zones, including parts of North America, Europe, and Asia. These areas provide undisturbed landscapes, where they find plenty of insects and small invertebrates to feed on.
After the breeding season, they make their way to coastal regions such as marshes, estuaries, mudflats, and sandy beaches, where they rely on abundant food supplies and milder temperatures to survive.
Curlew Sandpipers breed in the Arctic as well, although they are typically found in Siberia’s lowland tundra. Their nests are near marshes or pools, built on dry patches of tundra.
After breeding, they migrate to various regions, including Australia, Africa, Southern Asia, and South-east Asia, where they are often found on intertidal mudflats, lagoons, estuaries, mangroves, and rocky shores. While their habitats have similarities to those of Dunlins, Curlew Sandpipers also thrive in more tropical environments.
Nests & Eggs
Nests of Curlew Sandpipers are simple, usually consisting of shallow scrapes in the ground lined with bits of vegetation. These nests are built quickly, taking anywhere from a few hours to a couple of days.
The eggs, typically laid between mid-June and late August, are yellow, cream, or olive, marked with dark spots that help them blend into the tundra. A clutch usually has four eggs, and the incubation period lasts around 19 to 20 days, during which the female keeps the eggs warm and the male watches over the nest.
The nesting process for Dunlins is also quick, usually taking just a few days. Several shallow scrapes are made by the male, which are lined with grass, sedge, and willow leaves. One of these scrapes is chosen by the female, who adds the finishing touches.
Dunlin eggs are generally pale, either buff or olive in colour, with dark spots for camouflage. The eggs are laid between late May and mid-July, and the typical clutch size is three to four eggs.
The incubation period lasts about 20 to 22 days, with both parents sharing the responsibility of keeping the eggs warm.
Bird Calls
A soft ‘peep’ is the primary call of the Dunlin, a subtle noise that is typically heard in their habitat. However, during the breeding season, they produce a more prominent trill as part of their display song, which stands out in the breeding grounds, adding to the lively sounds of the area.
As for Curlew Sandpipers, their call is a soft, rolling ‘chirrup’. This subtle sound fits naturally into the coastal and wetland environments they inhabit, offering a soothing and more peaceful tone in contrast to the sharper trill of the Dunlin.
Size & Weight
Typically measuring between 18 and 23 cm in length, Curlew Sandpipers are small to medium-sized waders, with a wingspan of 38 to 41 cm. Their weight generally falls between 45 and 90 grams, with females tending to be heavier, which helps in egg production and incubation.
Slightly smaller, Dunlins usually measure 16 to 20 cm in length, with a wingspan ranging from 35 to 40 cm. They weigh between 40 and 50 grams, making them lighter than Curlew Sandpipers, although they gain weight before migration to prepare for long flights and winter conditions.
SEE ALSO: Curlew Sandpiper Cycle: Nest Building To Fledging (and everything in between)
Frequently Asked Questions
The difference between a Curlew Sandpiper and a Dunlin lies in their bill shape, size, plumage, and preferred habitats. Curlew Sandpipers have longer, more curved bills and tend to be slightly larger and heavier, while Dunlins display a distinct black belly patch during breeding.
You can identify a Curlew Sandpiper by its downward-curved bill, pale rump visible in flight, and chestnut-coloured breeding plumage. In non-breeding seasons, they are lighter with a clean white eyestripe.
The characteristics of a Dunlin include a slightly down-curved beak, a black belly patch in the breeding season, and a soft ‘peep’ call. They are also known for their migration to coastal marshes, mudflats, and estuaries.
Curlew Sandpipers are typically between 18 and 23 cm in length with a wingspan of 38 to 41 cm, weighing around 45 to 90 grams. Females are usually heavier than males, aiding in egg production and incubation.
