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| Describe in relation to Whimbler and Curlew Image source Google |
Identifying bird species in the field can be a delightful yet challenging endeavor, especially when it comes to distinguishing between similar-looking species such as the Whimbrel ( Numenius phaeopus ) and various species of Curlews ( Numenius spp.). Both belong to the same genus and share many physical traits, making it essential to pay close attention to specific characteristics such as body size, bill shape, plumage, and behavioral cues. This guide aims to help new birdwatchers confidently differentiate between Whimbrels and Curlews.
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| Image source Google |
Physical Characteristics
1. Size and Structure:
- Whimbrel:
The Whimbrel is a medium-sized shorebird, typically measuring around 37-47 cm in length with a wingspan of 76-89 cm. They have a relatively slender body and long legs, which aid in their distinctive feeding style along shorelines.
- Curlew:
Curlews, particularly the Eurasian Curlew (Numenius arquata), are larger than Whimbrels, with lengths ranging from 50-60 cm and wingspans between 89-106 cm. They are robust birds with a more substantial body and longer legs compared to Whimbrels.
2. Bill Shape and Size:
- Whimbrel:
Whimbrels have a long, down-curved bill that is relatively shorter and less pronounced compared to that of Curlews. Their bill length averages between 6-9 cm. A distinctive feature is the slight kink or curve at the midpoint of the bill, which is less dramatic than that of a Curlew.
- Curlew:
Curlews possess an extremely long, down-curved bill, which can range from 9-15 cm depending on the species. The bill is a key distinguishing feature, often significantly longer and more uniformly curved than that of a Whimbrel. In species like the Long-billed Curlew ( Numenius americanus ), the bill length can be quite striking, making identification easier.
Plumage and Coloration
Whimbrel:
Whimbrels exhibit a streaked brown and gray plumage, which provides excellent camouflage in their coastal and marshy habitats. They have a distinctive crown stripe, which is typically darker with a central pale stripe running from the base of the bill to the nape of the neck. This "striped cap" is one of the key identifiers.
Curlew :
Curlews generally have a more uniform brown and buff coloration, with less pronounced streaking compared to Whimbrels. Their plumage is mottled and blends seamlessly with their environment. While some Curlews may have a faint crown stripe, it is not as well-defined or prominent as in Whimbrels.
Behavioral Observations
1. Feeding Habits:
- Whimbrel:
Whimbrels are often seen foraging in coastal areas, mudflats, and estuaries. They use their shorter bills to probe into the mud and sand for invertebrates, crabs, and small mollusks. Their feeding is more focused on the upper layers of the substrate.
- Curlew:
Curlews, with their longer bills, are adapted to probing deeper into the mud and sand. They frequent similar habitats but can access deeper-living prey. Their feeding behavior includes using their long bills to reach prey that Whimbrels cannot.
2. Vocalizations:
- Whimbrel:
The Whimbrel's call is a rapid, piping series of notes, often described as a "pip-pip-pip" or "tyu-tyu-tyu" sound. This call is typically higher pitched compared to that of Curlews and can be heard during flight or while foraging.
- Curlew:
Curlews have a more melodious and haunting call, often characterized by a drawn-out "cur-lee" sound, from which their name is derived. The call of the Eurasian Curlew, in particular, is distinctive and can carry over long distances, making it a useful auditory clue for identification.
Habitat and Range
Whimbrel:
Whimbrels are widely distributed across coastal regions during migration and breeding seasons. They breed in sub-Arctic and Arctic regions, migrating to temperate and tropical coasts worldwide during the non-breeding season. They are commonly found along shorelines, mudflats, and estuaries.
Curlew:
Curlews, depending on the species, have varied ranges. The Eurasian Curlew breeds across temperate Europe and Asia and winters in Africa and South Asia. The Long-billed Curlew, native to North America, breeds in the central plains and winters along the southern coasts. Their preferred habitats are similar to those of Whimbrels but often include inland marshes and grasslands.
Key Identification Tips
1. Focus on the Bill:
The length and curvature of the bill are the most reliable differentiators. Whimbrels have shorter, slightly kinked bills, while Curlews boast longer, smoothly curved bills.
2. Check the Crown:
Look for the distinctive crown stripe on Whimbrels, a feature less prominent in Curlews.
3. Size Matters:
Remember that Curlews are generally larger and more robust than Whimbrels.
4. Listen Carefully:
Familiarize yourself with their calls, as vocalizations can be a strong clue, especially in mixed flocks.
5. Observe Behavior:
Note the depth and style of their probing when foraging; Curlews dig deeper with their longer bills.
By focusing on these key aspects—bill shape and size, plumage details, vocalizations, and behavior—new birdwatchers can more accurately identify Whimbrels and Curlews in the field.
Bibliography
- Hayman, P., Marchant, J., & Prater, T. (1986). *Shorebirds: An Identification Guide to the Waders of the World*. Houghton Mifflin Harcourt.
- O'Brien, M., Crossley, R., & Karlson, K. (2006). *The Shorebird Guide*. Houghton Mifflin Harcourt.
- Chandler, R. J. (2009). *Shorebirds of North America, Europe, and Asia: A Photographic Guide*. Princeton University Press.
- Sibley, D. A. (2014). *The Sibley Guide to Birds*. Knopf.
- Svensson, L., Mullarney, K., & Zetterström, D. (2010). *Collins Bird Guide: The Most Complete Guide to the Birds of Britain and Europe*. HarperCollins Publishers
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