Chestnut Teal, Marlborough

[FraserGurney]

Hi Russ, you raise some good points. I had assumed the consensus was that this bird was an immature male, having a look at HANZAB there are some features that support this and some that don't (GULP!). I certainly hope it isn't a hybrid...

On your head shape point it's interesting to note HANZAB state: "identical in structure, no difference in shape of head as sometimes stated." When I saw this bird I thought it had the faintest hint of green in the crown, although that may have been wishful thinking on my part.

I'd be interested to hear anything anyone else has to add.

[RussCannings]

Interesting note on the head shape Fraser. If that is correct I wonder if that is an element of the different facial patterning (creating an illusion of structural difference)? Either way, this bird's face seems atypical for Chestnut at the very least. I would think a younger bird might even be duskier-faced than a typical adult female? Individuals can vary of course and this is evident in Grey Teal as well (not to mention staining etc).

[Jake]

Just wondering if anyone thinks there's something a little 'off' about this bird?... the head/face to me looks like classic Grey Teal with very pale cheeks and throat, and a very round head. When I think about Chestnut Teal I've seen in Aussie, or look at images online--they appear to have more elongated head-shapes than Gray Teal and their faces are fairly consistently more dusky than Grey Teal, with less contrast between the darker brow and paler cheeks (and when there is contrast with Chestnuts, it's usually because their crowns can be more blackish or dark-greenish in males--this bird does not have a particularly dark crown to my eyes).

I highly doubt this can be an adult male Chestnut Teal (in eclipse) as the head should darker with more green tones--particularly in the crown. Perhaps I am ignoring an aspect of natural variation? If anyone has some examples of similar birds that would be appreciated. So could this be typical for an immature male? Or perhaps a post-menopause female (Yes that's a thing--I've seen female Mallards start to take on male phenotypical features in old age)?

I see what you're saying and suggest that there are many good photos of Chestnut Teal exhibiting "round heads" and many photos of Grey Teal that have their heads pointed; the head shape of individuals simply changes when they're moving/feeding/calling etc. I think we can exclude a Pateke hybrid too: the Chestnut on the Grovetown bird is a true orange, consistent with a Chestnut Teal, rather than a brown or intermediate (as we might expect) from Pateke Teal genes. The Grovetown bird's white areas, near tail, also seems to be bigger than that of Pateke. Looking at Pateke x Mallard F1 hybrids, an eye-ring is fairly obvious too.

As of yet, I don't think I've seen any really really high-quality photos of the Grovetown duck

Another Chestnut Teal feature, that the Grovetown bird has, which I'm not sure if we've noted yet, is the dark tail/undertail. I think the combined features, unique to Chestnut teal, are too many to write off. And features that we're "waiting for" i.e. darker back; dark green head, can more reasonably be explained away as shared juvenile features. Here's a good example of a juvenile Chestnut Teal in Australia. Granted, the face feathers, under the eye do look darker than our Grovetown one. Nevertheless, if we compare just this bird to our one, we can easily put the differences down to individual variation

Credit to Robby Nielsen (retreived from Facebook - Australian Bird Identification)

(154.8 KiB) Viewed 3758 times

[Jake]

He was still present tonight (16/04/2022), best viewed from the carpark. I've uploaded a few short clips to YouTube, which will hopefully show a bit of behaviour and angles/colourations to continue the debate
https://youtu.be/AQIjylSaKIU
https://youtu.be/v-WDYaizUkM
https://youtu.be/tS-4eouwrQs
https://youtu.be/5RPtheKIYRc
https://youtu.be/UptIBESmScY

[RussCannings]

Thanks for the follow up Jake. It seems most agree that the head shape indeed is not a legitimate feature to use (however I still feel like it exists to some extent, though my eyes may very well deceive me.

To be clear I agree that Chestnut Teal is likely the best explanation but I am always leery when the lone vagrant just happens to be at the extreme end of an important diagnostic feature--ie facial pattern/colouring). As you say, the photo you shared is noticeably darker cheeked and crowned (apparently) than the Grovetown bird. I have far less experience of Chestnut Teal than Grey Teal of course but I still haven't seen a confirmed Chestnut with a face/throat that pale. If anyone has found any I would be very appreciative. Hopefully this bird sticks around to complete another pre-basic molt and we can see what that noggin does!

Russ

[Sue D]

Hi,

I have been following the thread on this sighting and have made a couple of visits to Grovetown Lagoon to check it out. First visit 5.4. and 2 further visits on 11.4. and 12.4. On all 3 occasions the bird was present amongst a group of Greys during the afternoon located on the Lagoon just past the wooden over bridge.

I have attached 3 photos the first 1 taken on 11.4 and the other 2 on 5.4. I am not a Duck expert, but hope these pics may help with ID. More pics coming.

Cheers, Sue

Teal

(547.79 KiB) Viewed 3607 times

Teal

(538.79 KiB) Viewed 3607 times

Teal

(448.09 KiB) Viewed 3607 times

[Sue D]

Hi,

Some more pics of the Chestnut Teal taken 11.4.

Cheers, Sue

[Jake]

Beautiful photos, Sue!

Bird was present today, 01 May at 10:00. He was with the flock of Grey Teal but they were ~150m-200m down from the bridge/toilet area

[FraserGurney]

Nice photos Sue, it certainly looks like this bird has a dark throat coming nicely now. I know a couple of listers happy to see that...

[Sue D]

Hi,

Thanks Fraser and Jake.
Revisited Grovetown Lagoon afternoon of 4th May.
Teal still at same location out from Bridge/Toilet.
Pics attached.

Cheers, Sue