The challenges of identifying an intermediate stint

To: Birding Aus <>
Subject: The challenges of identifying an intermediate stint
From: L&L Knight <>
Date: Wed, 9 Apr 2008 20:58:43 +1000
As I mentioned in a previous posting, I came across a pair of contrasting stints at the Manly Wader Roost [SEQ] a week and a half ago. I have learnt a bit in the process of determining whether the bird is a Little or Red-necked Stint. If the bird were in full breeding plumage, the identification process would be fairly straightforward. However, the bird is in transition and has many characteristics that are indeterminate.

I have forwarded the images to a number of birders - the responses are evenly split between Little and Red-necked. Interestingly, two commentators who are linked to the HANZAB section on Little Stints have come up with differing conclusions.

Tom Tarrant has kindly set up "Mystery Stint" in the Ciconiiformes> Scolopacidae section of ABID for the three photos I took. I have reduced the size of the first shot so people can see the stint standing beside a much larger stint. The other two images are full size. The images will be available for viewing after Tom loads them onto the website.

To the pertinent characteristics of the stint in question.

I compared the size of the two stints using the first two shots - the two stints adopt comparable stances in the separate shots, and since neither they nor I moved in the intervening time, it is possible to compare their measurements. According to HANZAB, the size range for Little Stints is 12-14cm, while the size range for Red-necked Stints is 13-16cm.

Measuring on the screen, I found that size ratio between the stints was 1.22 [you can't do this with the ABID photos as I had to reduce the size of the first shot]. By way of reference 16:13 is 1.23. So if the larger stint is 16 cm, then the smaller stint would be 13.1 cm. If the larger stint is 15 cm, the smaller stint would be 12.3 cm. This means that if the stint is a RNS, then it is at the very small end of the spectrum, while the other stint is at the very large end of the spectrum. If it is a LS, then it is in the middle to small section of the spectrum.

The bill shape would be at the finer end of the spectrum for a RNS. As far as I can see, there is no apparent swelling at the tip of the bill - RNS often have a bulbous tip.

The stint has a relatively smooth shaped head. Many of the RNS I have photographed could be described as blockheads with noticeable cranial ridges above their eyes. In contrast, the bulk of the LS photos I have looked at are relatively smooth shaped. [That may be a subjective assessment, but it is one feature that I can make out.]

As for the plumage, the bird has a mantle stripe consistent with a LS, but it is not bright, so is not an ID clincher. More importantly, for a bird with coloured "cheeks", its chin and throat are white. If it is a RNS, then the colour change on its throat is significantly lagging its cheeks.

Working on the assumption that the bird is 13 cm long, the chestnut fringing on the tertials is 2.5 mm. HANZAB gives a figure of 1 mm for the fringing on a RNS [p. 265 If there is a figure for LS in HANZAB, I didn't find it.]

The scapulars have large dark centres, broad chestnut fringing and white tips.

The lesser wing coverts are a dull grey-brown - presumably this would be retained non-breeding plumage if the bird is a LS.

People are welcome to view the photos and post their conclusions on BAus. I am particularly interested in the opinions of people who are familiar with Little Stints in the field.

On a concluding note, based on photos taken in the UK I have come to realise that the white wingbar often diffuses into the primaries of Little Stints - contrary to the text in P&K [7th ed]. I had been working on the understanding that I would be able to ID a LS in flight based on the colour of its primaries, but I can see that is not case.

That's a classic lesson - I suspect that like myself, many birders look for key plumage markers to make their IDs. However, for some birds, plumage is an unreliable feature.

Regards, Laurie.

To unsubscribe from this mailing list, send the message: unsubscribe (in the body of the message, with no Subject line)

<Prev in Thread] Current Thread [Next in Thread>
  • The challenges of identifying an intermediate stint, L&L Knight <=

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the birding-aus mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU