I usually see the Hooded Mergansers for the first time of the season somewhere during the first or second week in November, depending on the weather. The last cold front that came through our area apparently hurried the waterfowl along, bringing cold weather to their summer ranges and shoeing them southward.
I got an email from Michele Kloda (exhibits) on Monday saying that she spied the mergs in the Wetlands (11/1). I went down to have a look myself today (11/2) and sure enough, one male and two female Hooded Mergansers were on the far side of the water, oddly enough, with two Mutt Mallards (domestic x Mallard).
Sometime between closing time on Saturday (11/30) and Monday morning, the mergansers returned to the Wetlands. They have been gone since March, hopefully spending the summer up north raising young, feeding, and getting ready for their migration south.
Welcome back, mergansers!