Verification of Unusual Sight Record
For Utah

Rec. # 2020-18

Common name:

Mexican Duck

Scientific name: Anas diazi
Date: 05-17-2020
Time: 3:45PM
Length of time observed: 10 minutes
Number: 1
Age: ?
Sex: male
Location: Powell Lake
County: Utah
Latilong: 40.380143,-111.9033374
Elevation: 4500ft
Distance to bird: 20m
Optical equipment: 10x50 Nikon Binos, Canon SX50 Digital Camera
Weather: Mostly sunny
Light Conditions: Good
Description:        Size of bird: 23 inches
(Description:)       Basic Shape: Typical Duck
(Description:)  Overall Pattern: Uniformly dark brown
(Description:)            Bill Type: Flat dabbling duck bill
Field Marks and
Identifying Characteristics:
Dark brown body, with a paler brown head contrasting with the breast, and a bright yellow bill. This drake had no sign of any curl in the tail, or any black in the rump, or green in the crown that one would expect with a Hybrid with a (Northern)Mallard. The only thing that gave me pause was the tail which appeared rather pale, however upon closer examination, the tail can be seen to be brown, but with the individual feathers having lots of pale edging, but is not truly white. Since Dabbling Ducks molt into alternate plumage in the fall, by this date their feathers often show a lot of wear and I attribute the paleness in the tail to wear of the feathers rather than to the presence of (Northern)Mallard genes in the bird. Terry Reid got a great photo of the spread tail which shows its true colors, which can be seen here:
(see photos)
Song or call & method of delivery: None heard
Behavior: Feeding on freshwater pond by submerging head under water, hard to get good shots of the head because of active feeding.
Habitat: Fresh Water pond near Jordan River and Utah Lake
Similar species and how
were they eliminated:
 (Northern) Mallard: I won't get into the debate as to whether Mexican Duck is a ssp of Mallard or not, but I have seen many pure Mexican Ducks over the years, in both Utah and Arizona, and even more hybrids. Typically Hybrids have a noticeably darker rump, a half curl to the tail, and variable amounts of green on the crown, plus have white outer tail feathers, none of these traits were shown by this duck

Mottled Duck: Mostly by range, but they also have a cleaner buffy cheek and dark corner on the gape of the bill that this duck lacked.

American Black Duck:Also mostly by range, but typically are a darker sooty brown overall with a more greenish bill
Previous experience with
this & similar species:
Yes, many
References consulted: Macaulay Library
Description from: From photo(s) taken at the time of the sighting
Observer: Bryant Olsen
Observer's address: 84102
Observer's e-mail address: **
Other observers who independently identified this bird: Max Malmquist was with me, also reported by many other to eBird
Date prepared: 5-20-2020
Additional material: Photos
Additional comments: eBird checklist: