Black-winged Stilt

Habitat:

Mostly a freshwater species, preferring paddyfields and shallow pools on open land. Occasionaly in brackish water environments and even (rarely) on intertidal mudflats.

Status in Malaysia:

A scarce but increasingly widespread breeding bird in Peninsular Malaysia, with breeding records from at least Perlis, Kedah, Pulau Pinang, Perak and Kelantan. The first breeding record for Malaysia was in 1998 (Jeyarajasingam 2012). Not known to breed in East Malaysia. Numbers are greatly augmented during the northern winter months by migrants and overwintering birds.

Annual peak counts

Source: Bird I* Witness Malaysia. http://birdlaa5.memset.net/worldbirds/malaysia.php

The table above shows the maximum count per year since 1988. Even allowing for vastly increased observer coverage, numbers do seem to be increasing.

Monthly peak counts

Source: Bird I* Witness Malaysia. http://birdlaa5.memset.net/worldbirds/malaysia.php

Peak counts per month in the years 1988 – 2012 suggest that birds from more northerly populations move south through Malaysia in Sep – Nov, and northwards again in Jan – Feb, with significant numbers choosing to winter in the country in some years.

I’ve observed adults copulating in March, downy chicks in May, and well developed but still dependent juveniles in July and August. It may be that breeding timing is sometimes determined by suitable conditions becoming available rather than being at fixed times of year.

July

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Presumed first summer/breeding, Pulau Burung, Penang, 10 July 2010.

Stilts are remarkably tolerant of extreme pollution! The grey mantle, inner greater coverts and extremely worn upper tertial make this likely to be a first breeding plumaged bird.

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Adult female, Pulau Burung, Penang. 10 July 2011

A heavily worn adult accompanying a juvenile. The brown mantle indicates that this is a female.

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Juvenile, Pulau Burung, Penang. 10 July 2011.

A still dependent juvenile. The tarsi are noticeably swollen at this age and the legs are yellowish-pink. The base of the lower mandible is pale pinkish, unlike that of adults. The primaries are not yet full-grown, making them look oddly round-winged in flight.

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Juvenile, Pulau Burung, Penang. 10 July 2011.

Juvenile secondaries and inner primaries are tipped white, unlike those of adults.

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Adult, Pulau Burung, Penang. 7 July 2010,

The lack of white tips to the secondaries indicate this is an adult. The bird is in mid wing moult – most of the secondaries and the inner primaries are fresh, while the outermost primaries, innermost secondaries and tail feathers are old.

August

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Juvenile, Pulau Burung, Penang. 5 August 2007

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Juvenile, Pulau Burung, Penang. 5 August 2007

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Juvenile, Pulau Burung, Penang. 5 August 2007

Judging by the primary growth, a slightly older bird than the one photographed in July 2011. It is also markedly browner, with strikingly white lower ear coverts. I’m not sure if this is just random individual variation, or indicates a difference in gender.

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Adult female, Pulau Burung, Penang. 20 August 2007.

The brown mantle and unglossy wing coverts indicate a female.

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Adult, Pulau Burung, Penang. 20 August 2007.

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Adult male, Pulau Burung, Penang. 20 August 2007.

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Adult, Pulau Burung, Penang. 12 August 2010.

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Adult male, Pulau Burung, Penang. 12 August 2010.

Black scapulars and mantle and glossy wing coverts indicate males. All birds photographed in July and August seem remarkably consistent in being midway through wing and tail moult. There is considerable variability in the amount and extent of dark markings on the head and neck. Both males and females can show a completely white head and neck, or variable amounts of blackish at the base of the nape.

September

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Juvenile, Malim Nawar, Perak. 1 September 2013.

Yet another variation of head pattern in this still-dependent juvenile.

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Juvenile, Pulau Burung, Penang. 2 September 2008.

This bird has just begun its moult into first non-breeding plumage (one or two plain grey scapulars). The legs are still yellowish and swollen at the top of the tarsus, the bill base is pink and the upperpart feathers are still mostly juvenile. The body feathers are extremely worn, only about a month after they were grown. This illustrates how comparatively weak the first set of feathers is, relative to later plumages.

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Juvenile and adult male, Pulau Burung, Penang. 2 September 2008.

Juveniles still stay close to their parents at this stage.

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First non-breeding, Kampung Selarong Gajah, Penang. 2 September 2013.

This must be a bird hatched early in the year. It has already completed a full head and body moult, replacing all the coverts and tertials as well – the latter have not yet grown.

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First non-breeding, Kampung Selarong Gajah, Penang. 2 September 2013.

The same bird as above, showing the extent of moult. The tertials are missing, but all the coverts, except for a few inner median coverts, appear to be new feathers.

The majority of adults at this time are white headed. Most males show no dark marking on the neck, while a few females have a more noticeably dark nape.

There are some photos of birds in Tawau, Sabah, on 26 September 2009 here

October

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First non-breeding, Kubang Semang, Penang. 30 October 2009

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First non-breeding, Kubang Semang, Penang. 30 October 2009

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First non-breeding, Kubang Semang, Penang. 30 October 2009

A young bird in fresh first non-breeding plumage. The pale-based bill and pale legs are signs of immaturity. Most of the wing and tail are still juvenile feathers – you can just make out the white tips to the secondaries on the top picture. The body, mantle, scapulars and upper tertials are all fresh first non-breeding feathers. The lower scapulars and tertials are much greyer than on an adult.

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Adult female, Pulau Burung, Penang. 25 October 2007.

After the end of the breeeding season an increasing number of birds exhibit a black hindneck and whitish head, and look superficially like White-headed Stilt. I’m not sure if this variation of non-breeding plumage occurs randomly or is associated with a population originating from a particular area.

November

No photos from Peninsular Malaysia yet…

There are some from Penampang, Sabah on 21 November 2009 here and here. This is a first non-breeding plumaged bird.

December

No photos yet…

January

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Female (left) and male, Pulau Burung, Penang. 14 January 2011.

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Adult female, Pulau Burung, Penang. 14 January 2011.

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Adult male, Pulau Burung, Penang. 14 January 2011.

The difference between the brown mantle of the female and the glossy black upperparts of the male is evident in strong light. This male has a prominent black nuchal mane, but also fine dark markings on the rear crown (unlike White-headed Stilt).

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Adult male, Pulau Burung, Penang. 14 January 2011

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Adult male, Pulau Burung, Penang. 14 January 2011

Judging from this and earlier photos, it appears that adult Black-winged Stilts in Malaysia undertake a complete moult after breeding, starting in July and finishing probably by the end of the calendar year. In fresh plumage a green gloss is visible on the upperwing of males. The tail appears to be pale grey on the upperside in all plumages.

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First non-breeding, Sejingkat, Sarawak. 23 January 2011

East Malaysia. The hint of pink at the base of the lower mandible may indicate that this is a subadult. Also, the tertials are greyer than the primaries. My guess is that this is a first non-breeding female (by the brown mantle).

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Adult male, Sejingkat, Sarawak. 23 January 2011

East Malaysia. Evidently a male by the blackness of the upperparts. A very different head pattern to that commonly seen on birds in Peninsular Malaysia.

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Adult male and first non-breeding female, Sejingkat, Sarawak. 23 January 2011

East Malaysia. The same male but a different female to those above.

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Adult male (centre) and 2 first non-breeding females, Sejingkat, Sarawak. 23 January 2011

East Malaysia. All three birds together. There’s not much difference in the brightness of the legs between the adult and the first years.

February

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Kampung Permatang Pauh, Penang. 14 February 2012.

A flock of stilts with a Common Greenshank. This gives an idea of the variability of head and neck colouration in non-breeding plumage. Some birds have a pinkish base to the lower mandible, which may be a pointer to immaturity. Some of these birds look very similar to those in Sarawak. .

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Adult female, Pulau Burung, Penang. 25 February 2010.

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Adult male, Pulau Burung, Penang. 25 February 2010.

This male has very bright legs. I wonder if this is connected to coming into breeding condition (as in egrets and herons)?

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Adult male, Malim Nawar, Perak. 13 February 2012.

Another “White-headed” type. Again, there is fine streaking on the rear crown.

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First non-breeding, Sejingkat, Sarawak. 21 February 2011.

East Malaysia. Probably the same individual as the upper of the three Sarawak birds taken in January 2011.

March

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Adult male, Pulau Burung, Penang. 18 March 2008.

Another striking “White-headed” type male, again with dark crown streaking. Bright pink legs…

March_Pulau Burung_180309_DSCN1847A less well-marked male. My guess is that both these birds are migrant visitors. It seems that resident breeding males show fewer dark head and neck markings.

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Adult female, Pulau Burung, Penang. 18 March 2008.

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Adult, Pulau Burung, Penang. 18 March 2008.

The flight feathers all look fresh, although on the lower bird, the primaries are browner than the secondaries – this probably doesn’t mean they’re older. Bright legs.

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Adult female (left) first breeding (right and in flight), Pulau Burung, Penang. 18 March 2008.

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First breeding, Pulau Burung, Penang. 24 March 2008.

I’m assuming that the white head is a feature of first breeding plumage (first non-breeding plumage has greyish markings on the head and neck). The varying amounts of wear affecting the trailing edge of the wings are perhaps due to the actual age of the birds (early vs late hatchers last breeding season). The legs are bright pink and may be a sign of sexual condition. Chandler (2009) mentions that a few breed in their second calendar year.

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First breeding female, Pulau Burung, Penang. 24 March 2008.

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First breeding female, Pulau Burung, Penang. 24 March 2008.

I’m not certain of the age of this bird, but the very worn coverts and tertials at this time of year suggest a first year rather than an adult bird. The tertials are greyish.

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Adult breeding female, Pulau Burung, Penang. 24 March 2008.

Despite the very worn outer tail feather visible beneath the near wing, I think the freshness of most of the plumage makes this more likely to be an adult than a first year.

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Adult breeding male, Pulau Burung, Penang. 24 March 2008.

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Adult breeding male, Pulau Burung, Penang. 24 March 2008.

I suspect that dark head and neck markings are less common in breeeding than in  non-breeding plumage for males.

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Adult breeding male and female, Pulau Burung, Penang. 24 March 2008.

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Adult breeding male and female, Pulau Burung, Penang. 24 March 2008.

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Adult breeding male (left) and female, Pulau Burung, Penang. 24 March 2008.

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Adult breeding male (left) and female, Pulau Burung, Penang. 24 March 2008.

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Adult breeding male (left) and female, Pulau Burung, Penang. 24 March 2008.

During copulation, the pupils constrict and the iris and legs show intense colour. Moments afterwards, the leg colour is more muted. It’s impossible not be entranced by the balletic movements during and post-coitus!

April

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First non-breeding (left) and adult male, Kuala Sungai Abdul, Penang. 22 April 2013.

A rare sighting of stilts on intertidal mudflats. These birds were presumably migrants.

May

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Adult breeding female, Pulau Burung, Penang. 21 May 2008.

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Adult breeding male, Pulau Burung, Penang. 21 May 2008.

June

No photos yet…

Summary

Adults can be sexed by the colour of the mantle, scapulars and tertials – brown in females and black in males.

Black markings on the hindneck can occur in both sexes, but seem commoner and more prominent on non-breeding plumaged birds.

First year birds have greyish tertials, inner greater coverts, and a variable number of rear scapulars, as well as white tips to the secondaries and inner primaries. Younger birds show a pink base to the lower mandible and muted leg colour.

Moult. (Timing for these are best guesses for now)

Juvenile – first non-breeding: Body only – August – October

First non-breeeding – first breeding: Body only – March onwards

Adult breeding – non-breeding: Complete – July – October

Adult non-breeding – breeding: Body only – February – April

Similar Species:

White-headed Stilt is a potential non-breeding visitor, especially to Sabah.White-headed (of both sexes) has a clearly demarcated, thick black ‘mane’ up the rear of the neck, and a pure white head. It also has proportionately shorter legs and longer bill, and is smaller than Black-winged. The call is of critical imporatnce in distinguishing the two species, being significantly lower-pitched and briefer than typical calls of Black-winged.

Obtaining photographs (of all birds present if there is more than one) and recordings of calls are important when faced with a possible White-headed.

References:

Bakewell, D.N. 2012. What is the status of White-headed Stilt Himantopus (himantopus) leucocephalus in the Oriental region? BirdingASIA 17:14-16

Chandler, R. 2009. Shorebirds of the Northern Hemisphere.  London: Christopher Helm

Jeyarajasingam, A. 2012. A Field Guide to the Birds of Peninsular Malaysia and Singapore. Oxford: Oxford University Press

Mann, C.F. 2008. The Birds of Borneo: An Annotated Checklist. BOU Checklist No. 23. Peterborough: BOU

This is a community resource! If you’d like to contribute photos or suggest amendments, please contact me. Photos should have been taken in Malaysia or Singapore, and be accompanied by the date and location details. Minimum resoluition = 900 pixels along the horizontal edge.

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3 thoughts on “Black-winged Stilt

  1. Pingback: Ask The Experts: Stilt Identification | e-BON

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