According to Birds of North America Online, 97% of female Gadwall are paired by November. These pairs of ducks are obviously strengthening their pair bonds at this point. Here is the list of “Courtship Displays” from BNA Online:
Introductory Shake. Male’s head-feathers become ruffled, and head is sunk on body and shaken repeatedly; bird then rears up high out of the water and flicks head forward. Prelude to major displays.
Head-Up-Tail-Up Display. Male throws head back in arched position, then jerks abruptly upward and turns toward female. Tail feathers are vertically erect and spread, and wing coverts are lifted, exposing white speculum. Almost always followed by Down-Up Display.
Down-Up Display. Male quickly thrusts bill into water, with breast low in water. Then jerks head up quickly with breast still low, raising a small fountain of water. Emits a whistle when head is at its highest, followed by Burp. White speculum visible during this display. Almost always follows Head-Up-Tail-Up Display.
Grunt-Whistle Display. Male rears high out of water with head arched forward, raking bill through water as bill rises. Then presses bill to breast and sinks slowly back to water. This display accompanied by loud whistle, followed by low Burp. Most frequent of the major displays.
Burp Display. Most common male vocalization; a loud low grunt uttered with neck extended and bill usually pointing toward female.
Turn-the-Back-of-the-Head Display. As female incites, male swims in front of her while performing the display.
Mutual Chin-Lifting. While facing (more or less) one another, male and female repeatedly raise and lower heads, with bills pointing somewhat above horizontal when raised.
Preen-Behind-the-Wing Display. Performed by both sexes. Places bill behind slightly lifted wing as if to preen but does not actually preen. Performed frequently and tends to be linked with ritualized drinking in males. Frequently performed by female toward actual or potential mates.
Inciting. While following her mate or potential mate, female arches neck and head toward water and moves head back and forth from front to the side away from her mate and directed toward (“threatening”) other males or rivals. Alternates threatening movements with Chin-Lifting toward preferred male.
Larry Jordan was introduced to birding after moving to northern California where he was overwhelmed by the local wildlife, forcing him to buy his first field guide just to be able to identify all the species visiting his yard. Building birdhouses and putting up feeders brought the avian fauna even closer and he was hooked. Larry wanted to share his passion for birds and conservation and hatched The Birder's Report in September of 2007. His recent focus is on bringing the Western Burrowing Owl back to life in California where he also monitors several bluebird trails. He is a BirdLife Species Champion and contributes to several other conservation efforts, being the webmaster for Wintu Audubon Society and the Director of Strategic Initiatives for the Urban Bird Foundation. He is now co-founder of a movement to create a new revenue stream for our National Wildlife Refuges with a Wildlife Conservation Pass.
Pat’s 2017 Year List – 603
Corey’s 2017 Year List – 448
Donna’s 2017 Year List – 370
Clare M’s 2017 Year List – 256
Tom’s 2017 Year List – 183
Jochen’s 2017 Year List – 125
Pat’s 2016 Year List – 882
Donna’s 2016 Year List – 709
Clare M’s 2016 Year List – 464
Pat’s 2015 Year List – 700
Donna’s 2015 Year List – 514
Corey’s 2015 Year List – 506
Duncan’s 2015 Year List – 491
Redgannet’s 2015 Year List – 394
Clare M’s 2015 Year List – 340
Jochen’s 2015 Year List – 160