Wandering Tattlers at Ocean Beach, Whangarei Heads

[BerndHuss]

I was booked on Scott's pelagic out of Tutukaka last weekend, but unfortunately the sea conditions didn't allow us to go out. To make the best of the situation I went to Whangarei Heads in the hope to catch a glimpse of the Wandering Tattlers known to have been present there for some time. And I got lucky with both birds showing wonderfully, allowing me to get within a few meters of them. Lifers for me, I couldn't have been happier. Thanks to Scott to recommend this little trip to compensate for missing out on a day out at sea!

[paradoxdinokipi]

Has there been any discussion over whether the one in breeding pIumage couId be a Grey-TaiIed TattIer? (As Iack of barring on the vent is typicaI for Grey-taiIed compared to Wandering which wouId normaIIy have barring cover the entirety of the underparts)
UnIess of course both of these: https://ebird.org/atlasnz/checklist/S160839231, birds had nasaI grooves up to ~3/4 of their biII, as they're aImost definiteIy the same pair.

[bradley_birdsnz]

Here's close ups of both birds back in Feb.

Both birds appear to have long nasal grooves

[BerndHuss]

Close-ups of the birds from last Saturday, which shows the grooves nicely. Opinions?

[BerndHuss]

According to the Australian Bird Guide, the groove of the Grey-tailed is 1/2 of the bill length, which matches the bird with non-breeding plumage, whereas the groove on the Wandering is 3/4 of the bill length, which is a match with the other bird. Going by just that Id marker, these should be two different species.

[BerndHuss]

One more with both birds in the same shot with identical side view.

[Oscar Thomas]

Per BOTW: Gray-tailed Tattler has nasal groove (linear depression on upper mandible containing nostril) ending at least 17 mm from bill tip (Wandering has wing usually >170 mm and nasal groove extending to within 15 mm of bill-tip; Prater et al. 1977). In the field, difference in nasal groove length rarely discernible, with Wandering appearing to have groove running from base of bill to two-thirds its length and with Gray-tailed having groove extending only to about half the length of the bill.

What makes these birds both Wandering tattlers to me is the shade and extent of grey while in basic plumage, and the fact they have been living on the rocky shore as opposed to in an estuary/harbour. I also believe the extent of barring on the breeding bird is more than can be seen on GT tattler. The supercilium on the basic bird is not very pronounced which also suits Wandering, and the angle of the head in Bernd's close up could distort the length of the nasal groove (but I still think it looks longer than 1/2 the bill length).

[pauljacques]

Hi all
I agree with others, these are certainly both Wandering Tattlers, but this species pair are tricky and an ID discussion is always worthy. I have been lucky to travel a lot for work in Polynesia, Melanesia and Micronesia the past few years where I have seen many Wandering Tattlers and a few Grey-tailed, and I have just once seen one of each standing side-by-side. Here are some of my observations with some photos for illustration.

Habitat
A Tattler on the rocks is very, very likely to be a Wandering, but a tattler on the sand or estuarine mud is not necessarily a Grey-tailed! Wanderings are usually found on wave platforms and coastal rocks, but I have also seen them on freshwater rivers (Tahiti), muddy pond edges, tidal flats (Wallis and Futuna) and sewage ponds (Hawaii). I have generally seen Grey-tailed on sandy beaches, estuaries and tidal flats. I have also seen them roosting on shingle at Awarua Bay in Southland and perched on tree trunks above sandy beaches in the Marshall Islands (see photo

WT at sunset.

WTattlerFP.jpg (120.19 KiB) Viewed 236 times

GTT, back-lit so darker than field impression.

GTTattlerRMI2.jpg (99.61 KiB) Viewed 236 times

).

Plumage tone
As Oscar states, this is a crucial ID feature, & though it sounds subjective it is reliable once you have seen a couple of each. Wanderings are dark - depending on the light they can look slate-grey, sooty or deep maroon-brown in morning or evening light (see photo). The breast and flanks are similar tone to the upper parts and this make the white throat really stand out. Grey-tailed are paler, (some are much paler), varying with light and wear from mid-grey/brown to pearl grey. When I saw both together (on a tidal flat in the Marshall Islands) the difference in plumage tone was really striking, so much so that at distance I thought the GTT was a Terek.

Call
The call can be relied on to clinch the ID of a tricky tattler. Their calls are completely different and fortunately they call a lot, particularly in flight or when disturbed. You can usually make them call by approaching them a little way. The wanderings staccato, shrill whistle is a characteristic sound of Pacific Islands. The Grey-tailed makes a two-note "too-whee" call that sounds to my ears similar to a Pacific golden plover.

Nasal groove
This is no doubt handy if you have a bird in the hand but I don't think it is useful in the field unless you can get ridiculously close. I have found both species to be wary and inclined to fly away to a safe distance when you get too close, calling loudly as they depart!

Cheers
Paul