Bird Hybrids: Anas undulata

Yellow-billed Duck x Indian Spot-billed Duck hybrid, Hannover Zoo (Germany), 24th October 2012 - copyright Joern Lehmhus

(photo ID: 0587)

Here's Joern's commentary on this bird:

At a first glance, this bird looks close to a Yellowbill, but there are some differences. Yellowbill does not show any facial pattern, but this bird has a weak facial pattern. Indian Spotbill on the other hand has a marked facial pattern. The uppertail coverts are all black in this hybrid, similar to a Spotbill. Yellowbill would have pale fringed uppertail coverts.

Note the orange legs of this hybrid, with some dark areas on the toes. Indian Spotbill has bright orange legs. Yellowbill legs are dark brownish or blackish with an orange hue, but not bright orange as in this hybrid.

The speculum looks a bit closer to Yellowbill, being too blue for Indian Spotbill, but the white line in font is broader than normal and the white line ending the speculum is fairly thin. This also seems to indicate Spotbill influence; see the speculum of Indian Spotbill here:

arunachalabirds.blogspot.de/2011/05/indian-spot-billed-du...
The bill pattern is close to Yellowbill, but the upper edge of the upper mandible is yellow-orange, not yellow. This also points to Indian Spotbill as the second parent, as this has a red upper edge of the upper mandible and a yellow tip on a mainly black bill. The tertials of the hybrid are again closer to Yellowbill in colour and pattern, as they are partly white in Indian Spotbill.

There were two very similar free-flying hybrids so it is not certain whether the photos involve one or both birds.

Yellow-billed Duck x Indian Spot-billed Duck hybrid, Hannover Zoo (Germany), 24th October 2012 - copyright Joern Lehmhus

(photo IDs: 0585-0586)

In the next photo the hybrid is on the left side in the middle ground; in the foreground left is a Yellow-billed Duck and on the right are Indian Spot-billed Duck and Red-crested Pochard.

Yellow-billed Duck x Indian Spot-billed Duck hybrid (with Mallards, Yellow-billed Duck, Indian Spot-billed Duck and Red-crested Pochard), Hannover Zoo (Germany), 24th October 2012 - copyright Joern Lehmhus
(photo ID: 0584)

A pair of similar birds were present in the zoo (but free-flying) in 2014. Here is the female:

female Yellow-billed Duck x Indian Spot-billed Duck hybrid, Hannover Zoo (Germany), 25th January 2014 - copyright Joern Lehmhus

(photo IDs: 1598-1600)

And here's the male:

male Yellow-billed Duck x Indian Spot-billed Duck hybrid, Hannover Zoo (Germany), 25th January 2014 - copyright Joern Lehmhus

(photo IDs: 1601-1604)

I guess this is the same bird...

Yellow-billed Duck x Indian Spot-billed Duck hybrid, Hannover (Germany), 26th October 2014 - copyright Joern Lehmhus

(photo IDs: 1676-1677)

Yellow-billed Duck Anas undulata

Indian Spot-billed Duck Anas poecilorhyncha

Yellow-billed Duck x Mallard hybrid, Porthloo Duckpond, St Mary's (Scilly, UK), 3rd October 2007 - copyright Dave Appleton

(photo ID: 0357)

This bird shared a duckpond with a variety of escaped or released ducks. Superficially it resembles Yellow-billed Duck but the green head and curled tail feathers are obvious evidence of Mallard genes.

Yellow-billed Duck x Mallard hybrid (same bird as in photo ID 0357 above), Porthloo Duckpond, St Mary's (Scilly, UK), 3rd October 2007 - copyright Dave Appleton

(photo ID: 0358)

The next bird was with the one above and the pale plumage presumably indicates that the Mallard parent was a domestic bird.

Yellow-billed Duck x domestic Mallard hybrid, Porthloo Duckpond, St Mary's (Scilly, UK), 3rd October 2007 - copyright Dave Appleton

(photo ID: 0359)

A return visit to Scillies three years later found a similar, but not identical, pair elsewhere on the same island. The bill was more strongly orange, rather than yellow, and they lacked green on the head. If it wasn't for the birds seen in 2007 I'm not sure I'd reach this conclusion but the coincidence leads me to think these may be the same hybrid? The orangey bills and the straight tail feathers make me wonder if these are females whereas one of the birds above was clearly a male.

presumed Yellow-billed Duck x domestic Mallard hybrid, Porth Hellick, St Mary's (Scilly, UK), 9th August 2010 - copyright Dave Appleton

(photo IDs: 0360-0361)

As with the males above, the second bird was pale suggesting a domestic Mallard ancestor.

presumed Yellow-billed Duck x domestic Mallard hybrid, Porth Hellick, St Mary's (Scilly, UK), 9th August 2010 - copyright Dave Appleton

(photo ID: 0362)

Meanwhile the original duckpond where the first pair had been observed in 2007 now contained a number of domestic ducks and the next peculiar bird. Could it be a backcross between one of the original hybrids and a Mallard? Another possibility perhaps is domestic Mallard x Pintail, as on a previous visit I noted a couple of very strange and possibly hybrid Pintails on the pond. The same pond plays host to at least one domestic Mallard resembling the pink-billed "Aylesbury" breed, so if such a bird was a parent this may explain the pink colour on the bill. Any thoughts on any of these birds would be welcome.

possible Yellow-billed Duck x domestic Mallard hybrid, Porthloo Duckpond, St Mary's (Scilly, UK), 7th August 2010 - copyright Dave Appleton

(photo IDs: 0363-0364)

possible Yellow-billed Duck x domestic Mallard hybrid, Porthloo Duckpond, St Mary's (Scilly, UK), 6th August 2010 - copyright Dave Appleton

(photo ID: 0365)

Here is one of 4 similar hybrids found among Yellow-billed Ducks and Mallards at Hannover Zoo. In the first photo the hybrid is the bird facing the camera towards the back left, with a pure Yellow-billed Duck to its left and 3 to its right.

captive possible Yellow-billed Duck x Mallard hybrid (with Yellow-billed Ducks, Mallards and Moorhens), Hannover Zoo (Germany), 24th October 2010 - copyright Joern Lehmhus
(photo ID: 0578)

Here is the same bird, asleep to the left of 3 Mallards:

captive possible Yellow-billed Duck x Mallard hybrid (with Mallards), Hannover Zoo (Germany), 24th October 2010 - copyright Joern Lehmhus

(photo ID: 0577)

Joern considers that the parentage of the next bird is unclear, but a free-flying Yellow-billed Duck and some presumed Yellow-billed Duck x Spot-billed Duck hybrids have also been found in Hannover for a few years. He writes:

This bird was paired with a female mallard. The plumage resembles some hybrids Mallard x American Black duck and also some presumed hybrids Mallard x Yellow-bill with the green stripe on the head and the not fully developed tail locks. The reddish brown breast was not uniformely coloured as in Mallard, but speckled. The flanks were a mixture of greyish vermiculated feathers as in Mallard, and feathers with a brown centre and a slightly vermiculated greyish-brown fringe. The bill was yellow with a black nail as in Mallard drakes, but there was a small black area in the middle of the upper mandible.

This bird from South Africa has some resemblance :

www.hardaker.co.za/blog040710-02.jpg
or see this Mallard x Mexican duck for comparison:

www.sabo.org/images/mallardx3.JPG
American Black Duck x Mallard is a bit darker, but can show similar pattern types:

www.charliesbirdblog.com/~charlie/mankymallards/JFK_02.jpg www.birds-of-north-america.net/images/mallard-x-american-...
and Mallard x Spotbill can also be similar:

www.charliesbirdblog.com/~charlie/mankymallards/momo.jpg
So Mallard relatives in which there is no great difference between the sexes, can produce similar-patterned ducks if they breed with Mallard (and the only such ducks at the moment in Hannover are the single Yellowbill and the presumed Yellowbill x Spotbill hybrids) But can a pure Mallard show a plumage as this bird, at the end of March? I have never seen one like this before...

Here are his pictures:

possible Yellow-billed Duck x Mallard hybrid (with Mallards), Annateich, Hannover (Germany), 25th March 2012 - copyright Joern Lehmhus

(photo IDs: 0607-0611)

The next three birds from the same area (but this time from within the zoo from which the above birds may have originated) are quite similar to the last one: