Rarity in disguise, Jefferson County

[Tom Wilberding]

Hello birders,

Yesterday afternoon Barb and I strolled three miles along Clear Creek Trail in Jeffco near I-70, hoping to see a rare warbler, like the Mourning Warbler photographed by James McCall on May 15. But most migrating warblers, as you may have noticed, have already moved northward, except for some Yellow Warblers in the process of nesting.
 

We were pleased to hear and see a couple of Spotted Sandpipers fluttering along the bank, probably nest building. We noticed a few Mallards loafing here and there. But then a strange sight: a female Merganser with two chicks. Seemed to us very early for a duck with chicks, although there are lots of Canada Geese goslings following their parents around in local parks.

An expert birder friend pointed out that the merganser family was quite a find. Not just early, but they’re not supposed to breed here, and certainly not below a busy and vast construction site like the one on the south side of Clear Creek.

Per Cornell: “Hooded Mergansers breed in forested wetlands throughout the eastern half of North America and the Pacific Northwest. They are most common in forests around the Great Lakes.”

Was this hoodie family a fluke, or are Hooded Mergansers staying in Colorado to breed? I believe the state’s first documented breeding site of the species was found at Quincy Farm at Cherry Creek last year. Yesterday's photo below.

Cheers,
Tom Wilberding
Littleton, CO

[John Shenot]

Great find, Tom!

Hooded Mergansers have been breeding at a gravel pit pond in Fort Collins since at least 2015. There is at least one eBird checklist documenting an adult with chicks. I have no idea why they favor that site. As you note, it isn’t where they are supposed to breed!

John Shenot
Fort Collins

[Donna Stumpp]

So while out on my daily walk in the Standley Lake Open Space this morning, I saw what I believe is another Hooded Merganser family! See Photos.

Donna Stumpp

Westminster, CO

[Tom Wilberding]

Maybe becoming not so rare.  Here is an eBird breeding map for Hooded Merganser which shows reports from the front range of Colorado. https://ebird.org/science/status-and-trends/hoomer/range-map-breeding

These eBird maps for Hooded Merganser are interesting. Some hoodies spend the winter in Wyoming, others in southern states. Wyoming is a lot colder than southern states in the winter. Maybe there is a cold-loving subspecies. And a gravel reservoir sub-species?

Tom Wilberding

[Donna Stumpp]

So today I saw another Hooded Merganser family (mom with 3 babies) in the Standley Lake Open Space, but across the lake from the ones I saw yesterday, so clearly a different family. I also saw a pair without babies in the same pond (not Loon Lake). In talking with other birders, it would seem Standley has been a bit underbirded in general until the past year or so.

That breeding map Tom posted yesterday was really insightful. It would appear there are some HOMEs breeding along the central front range in CO. I have to say I was surprised to find 2 broods here, although without the boat noise, maybe not. The big lake just filled a few days ago so there is almost no shoreline (just a few random places), but it's quiet, and has some decent habitat, so must be attractive for breeding.

I know I've enjoyed getting to know my local patch much more than I would have without these unusual circumstances, and seeing and reporting much more as a result. 

Donna Stumpp

Westminster, CO