Hybrid teal?

A similar article will appear in OSNZ‘s Southern Bird shortly

Click here for the first article we wrote about this – with photos

Probable hybrid chestnut/grey teal breeding near Wanganui

On 16 Nov. 2002 Colin Ogle received a phone call from Neil Corballis of ‘Marangai’, Kaitoke, just south of Wanganui. Neil had seen a strange teal with very young ducklings on one of his farm ponds; and thought that it might be a native brown teal. He’d seen a similar bird in the same area two years previously. Colin visited the pond with Neil on 20 November and discovered the bird had four ducklings which were still quite small and fluffy. After hiding the ducklings in long grass bordering the pond, a single bird sat out on the water, giving excellent views. Realising the bird was not a brown teal, the closest match appeared to be chestnut teal, from Australia. Colin then contacted Sav Saville, and together with Brent Stephenson, and Nic Peet of Department of Conservation, headed back to the pond the next day (21 November), again with the assistance of Neil. This time there were two adult birds attending the ducklings. One bird headed over the paddock and sat about 150 m away, whilst the other called and paddled around the pond, allowing photos to be taken (see photo), before it took flight, returning a few minutes later.

From photographs taken and posted here, the general consensus was that we were dealing with hybrid teal of some description. This was supported by the lack of a breeding plumage (or moulting) male chestnut teal. Other possibilities for hybridisation were suggested following the photos appearing on the website, and included some of the North American ducks, grey duck and brown teal. However, we feel the most likely hybrid combination, due to general colouration and plumage characteristics, is between grey teal and chestnut teal.

The bird that sat out in the paddock had a very strange colouration, being very orangey-brown around the neck and head, and also had a strange ‘jizz’, being very long necked and round headed. Although the bird that stayed on the dam most of the time looked more like a chestnut teal, it was felt that this was also most likely to be a hybrid. This bird had very chestnut cheeks and throat, and there were also patches of chestnut on some of the upper breast feathering, but, as mentioned by some, the feathering on the closed wing appeared too much like a grey teal. It was felt that the chestnut colouration was unlikely to be some sort of staining, as it seemed too restricted and individual patterning on feathers could be distinguished from the photos.

The bird that initially stayed on the pond, and appeared more like a chestnut teal.

We all returned again on 4 December, hoping to catch the ducklings at a later stage, and Neil also thought he may have seen a bird resembling a male chestnut teal at the dam. Unfortunately this bird wasn’t around, but the ducklings had grown, with what appeared to be two broods evident. There was a larger duckling resembling a grey teal, and two almost fully grown ones, which were more like the chestnut-headed bird we had seen in the paddock on the previous visit. Several photos revealed little more than the first ones taken.

If we are in fact dealing with hybrid birds, it appears we have caught the story too late, and may now be dealing with second generation (or more) crosses. Hybrid birds will always present more questions than answers. Where have the birds come from in the first place? It was put forward that the apparent sedentary behaviour of the birds (they appear to have bred at the same pond for at least two of the last three summers), suggested a possible captive influence. It is possible that captive chestnut teal have been released or escaped. Or, could they have originated from wild Australian birds? Whichever, this does put into question many of the chestnut teal records for the Manawatu Estuary. Since 1991, 21 records of chestnut teal (representing at least 18 individuals) have been accepted for New Zealand, 18 of these reports from the Manawatu Estuary (with at least one bird being reported every winter since 1992, except 1997). Most of these birds have appeared to be immature drake plumaged birds, which could just as well have been hybrids. However, the most recent bird, seen first on 11 May 2002 (click here to go to this trip report), was almost certainly a full male chestnut teal. Its plumage was between eclipse and breeding plumage, and when seen several weeks later, its plumage appeared to have changed with the head having become more glossy. Hybrid birds are supposedly in a perpetual state of ‘eclipse’ with changes in plumage therefore unlikely.

Following discussion of the above events, reports of chestnut teal at Waiwera (just north of Auckland), at the local effluent ponds and the adjacent wetland were made. It was suspected that several of the birds were possible hybrids, with as many as 20 being seen there regularly. Hopefully someone will keep an eye out, and try and document/photograph these birds! Thanks to Neil Corballis for making the initial observations, and all those that replied to our requests for information and assistance in this perplexing matter.