Mottled Duck - Mexican Mallard: question about ID (1 Viewer)

[Mark B Bartosik]

Although I do not have much interest in Mallard/Mottled behavior during this winter I took occasionally a few photos here and there (Texas Upper Coast) just to have them on file for future references. When checking photos and study some field marks I have a problem with two specimens that show in my humble opinion traits of Mexican Mallard (Mexican Duck) based solely on illustration in Sibley’s (2001 p. 82). When taking these photos I thought it was Mottled so did not try too hard. I know that Mexican Mallard population is not recognized recently as a separate species and Sibley suggests that virtually no pure Mexican Mallards occur in North America and, I also know that I have limited experience with Mallard/Mottled, none with Mexican Mallard. I will appreciate comments and suggestions about pictured specimen and, as well, explanation how to quickly separate Mexican/Mottled without too many doubts in the field . What I can see in my photos: a yellow bill with no dark center (attributed to males); finely streaked neck and throat/cheeks areas (so no much of unmarked throat and cheeks of Mottled (as illustrated in Sibley’s but I see some black spots on its bill in the gape area); crown looks sort dark to me; dark undertail coverts; very narrow white bars on wings.

Again, I will appreciate help with an ID and perhaps a short lecture on important field marks (Mallard/Mexican/Mottled/hybrids)

General view: http://www.pbase.com/mbb/image/122879925
Close up - Throat/cheeks/bill/gape: http://www.pbase.com/mbb/image/122879921
Very narrow white bars: http://www.pbase.com/mbb/image/122879905

More photos: http://www.pbase.com/mbb/duck_id

Thanks in advance

Mark
http://www.pbase.com/mbb/from_the_field

 

[Kryptos18]

The pale cheek, unicolor bill, and limited eye-stripe that does not continue to the crown points to Mottled Duck rather than Mexican Duck. Plus, the range fits.

 

[Mark B Bartosik]

The pale cheek, unicolor bill, and limited eye-stripe that does not continue to the crown points to Mottled Duck rather than Mexican Duck. Plus, the range fits.

Thanks, Kryptos18 but...

What about this … from BNA account:

Mottled Duck lacks anterior white edges on speculum, and usually lacks or has thin, faint, posterior white edges, whereas Mexican Ducks and female Mallards invariably have both anterior and posterior white borders around the iridescent blue speculum.

See these photos:
http://www.pbase.com/mbb/image/122879905
http://www.pbase.com/mbb/image/122879933

And they can fly.

All the best,

Mark

 

[Kryptos18]

Sibley's says that Mottled Duck can have "very narrow" anterior wing bars on the speculum. In addition, Mexican Duck would have slightly gray secondaries and tertials, while those of the Mottled are the same color as the body feathers. It's on odd bird, definitely, but to me it skews much closer to Mottled Duck than Mexican Duck.

 

[Mark B Bartosik]

Sibley's says that Mottled Duck can have "very narrow" anterior wing bars on the speculum. In addition, Mexican Duck would have slightly gray secondaries and tertials, while those of the Mottled are the same color as the body feathers. It's on odd bird, definitely, but to me it skews much closer to Mottled Duck than Mexican Duck.

Above I cited Mottled Duck monograph: Moorman, T. E. and P. N. Gray. 1994. Mottled Duck (Anas fulvigula), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/081
doi:10.2173/bna.81

Also check here:
http://www.npwrc.usgs.gov/resource/birds/duckplum/mottled.htm

In popular guides very often details are omitted because of the lack of space.