Baer’s Pochard or Hybrid?

As the wild population of Baer’s Pochard (Aythya baeri, 青头潜鸭) has declined dramatically in the last few years, a new threat has emerged – that of hybridisation (see my article on Birding Frontiers here).  The only confirmed breeding site for Baer’s Pochard also hosts the closely related Ferruginous Duck (Aythya nyroca, 白眼潜鸭) and, this year, I have personally seen drake Baer’s displaying to females of Ferruginous Duck and Common Pochard.

This spring and summer I have been making regular visits to the breeding site in Hebei Province, south of Beijing, to monitor the Baer’s Pochards.  It’s a large site with many hidden ponds amongst the reeds, meaning that, in a short visit, it is not straightforward to count the birds present or to establish proof of breeding.  So far this year I am unaware of any confirmation that Baer’s has bred successfully.

My most recent visit, in early August with visiting British birder Richard Bonser, produced no definite sightings.  However, we did see the bird below, which we think *could be* a female Baer’s.  One of the problems with identification of ducks at this time of year is that adults are in ‘eclipse’ plumage, meaning that they look very different than when sporting their spring finery.  An additional complication is the spectre of hybrids.  I do not have knowledge of what Baer’s Pochard should look like in eclipse and I have been unable to find any images or literature to guide me.  Baer’s *ought* to be identifiable on structure but, with hybrids a very real possibility, this becomes less straightforward – we should expect at least some hybrids to exhibit Baer’s-like structure.

Clearly, given the “Critically Endangered” status of this bird, a priority must be to assemble images of known pure Baer’s in all plumages from private collections.  That will help birders seeing these birds in the wild to establish whether they are true Baer’s or hybrids which, in turn, will help conservationists to better establish the likely true population and the extent of the threat of hybridisation.

In the meantime, I would very much welcome views from anyone with experience of these birds as to whether the bird below is a pure Baer’s or a likely hybrid (in my view it is clearly not a pure Ferruginous on structure and plumage tones alone).

Possible Baer's Pochard (or hybrid), Hebei Province, 6 August 2013
Possible Baer’s Pochard (or hybrid), Hebei Province, 6 August 2013.  Note the robust, all dark bill and flattish head (inconsistent with pure Ferruginous but is there enough here to rule out a hybrid?).  The bird is an adult as it is in wing moult – a juvenile would look much ‘cleaner’.
Possible Baer's Pochard (or hybrid), Hebei Province, 6 August 2013
Possible Baer’s Pochard (or hybrid), Hebei Province, 6 August 2013
Possible Baer's Pochard (or hybrid), Hebei Province, 6 August 2013
Possible Baer’s Pochard (or hybrid), Hebei Province, 6 August 2013

 

 

6 thoughts on “Baer’s Pochard or Hybrid?”

  1. Thanks Ken. I have received some views, privately, from respected birders who think that there is nothing to suggest that this bird is not a pure Baer’s. However, it’s difficult to be certain at this time of year, in particular! Would very much welcome other views.

  2. Hi,Terry, I keep reading your blog for almost 3 years now, you are doing great becuase you keep writing after your bidding.
    Wonderful!

  3. Hi Terry, I visited the breeding site (I do not mention the name) on 22 and 23-04. we counterd at least 26 Bear’s. Many males where “paired” with males Ferruginous Duck. Maybe you can use this information. Greetings Max

  4. Hi Max. Thank you. That’s good and bad news! Good news that the Baer’s are back on site but bad news that hybridisation seems to be a major threat. I hope to visit next week and I am also working with the Beijing Birdwatching Society to develop a funding proposal to enable regular monitoring of this important site. Fingers crossed. Terry

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