Verification of Unusual Sight Record
For Utah

Rec. # 2022-19


Common name:

Mexican Duck

Scientific name: Anas diazi
Date: May 2, 2022
Time: 10:00
Length of time observed: 1 min
Number: 1
Age: Adult
Sex: Male
Location: Left bank of San Juan River at mile 24.5 below Sand Island launch
County: San Juan
Latilong: 37.170472, -109.835317
Elevation: 4,080 feet
Distance to bird: 5 yards
Optical equipment: None, very close observation from raft
Weather: Clear, no wind, approx 60 deg F.
Light Conditions: Good morning light, full sun, no shade
Description:        Size of bird: Mallard size
(Description:)       Basic Shape: Dabbling duck
(Description:)  Overall Pattern: Various shades of brown similar to female mallard
(Description:)            Bill Type: Yellow mallard-like dabbling bill
(Description:)                              
Field Marks and
Identifying Characteristics:
Male MEDU having plumage similar to female MALL but with medium to dark chestnut brown body, sharply changing to a lighter brown neck and head, dark eye line, no white on curl-less tail and a yellow bill. Observed at close range while we floated by on the raft. Familiar with MALLxMEDU hybrids which usually show slight greenish tinge on head and/or white on tail, sometimes curled. This duck had none of those attributes. At the time, and still, we thought it quite serendipitous that Mexican Hat Rock was in view across the river from the MEDU. Did not have camera.
Song or call & method of delivery: Silent bird
Behavior: Swimming in shallow eddy then moved to sandy bank to stand and watch us as we slowly floated by.
Habitat: River and river bank.
Similar species and how
were they eliminated:
Most easily confused with female mallard and/or MALLxMEDU hybrid. Yellow bill quickly eliminated female MALL. All brown head lacking any signs of green tinge, no white or curls on tail feathers make hybrid less likely.
Previous experience with
this & similar species:
Have observed and documented MEDU several times in nearby Montezuma County, Colorado.
References consulted: Experience
Description from: Notes taken at the time of the sighting
Observer: Mike Thompson
Observer's address: 18032 Road G, Cortez, CO 81321
Observer's e-mail address: **
Other observers who independently identified this bird: Karmen King
Date prepared: 5/9/22
Additional material:  
Additional comments: