Bald Eagles and Common Mergansers at Clear Creek Valley Park, S. Adams County

Lowell Blvd. Bald Eagle. (R. Rrince photo)

Had hoped to go north today in the area around Windsor and Greeley to look for eagles who are plentiful this time of year around the juncture of the Poudre and South Platte Rivers. An annual trek. But a forecast of high winds – up to 50, 60 miles an hour on the high plains, and 90 miles an hour in the mountains  held me back. Instead I ventured up Lowell Blvd. to Clear Creek Valley Park to hike around Jim Baker Reservoir just to the north and search for a bald eagle we had seen on our way to the movies yesterday (Bohemian Rhapsody).

I didn’t expect to see much of an interest today – just a gazillion Canadian geese perhaps. This time of year, there are birds, but they tend to be rather scarce, the ducks that I like to watch and photograph off further south most of the winter. A few days ago, on a similar hike with Molly, didn’t see much, but then got a fine view of an American kestrel, the continent’s smallest falcon which more than made up for not seeing anything else. Today again, not a great deal, but what there was, was genuinely pleasing – a soaring bald eagle (above) early on and then making the 1.3 mile walk around Jim Baker Reservoir, a bevy of common mergansers (just below) amidst the Canadian geese.

I had seen a bald eagle last year at this time at the same spot he (I believe it was a “he”) was perched yesterday, just north of the railroad crossing on Lowell Blvd. A row of trees sits just south of a pond, the private preserve of a gated community – just east of Lowell and across from Jim Baker. It was about 2:30 in the afternoon and as we road north both David Fey and I saw him clearly sitting high up on the branches of a tree reconnoitering the pond below.

Would he be there today? Never know.

This time the surprise came quickly, as soon as I parked my car at the Clear Creek Valley Park. There he was – soaring high into the sky, most of the time between the sun and me but occasionally wondering out beyond, circling, looking for food down below. He did that for a good ten minutes before flying off the east, perhaps following Clear Creek to where it empties out into the South Platte River. Still, he was in range for my camera for enough time to get a bunch of pictures. As usual – most aren’t that interesting or that good, but one, the one above that isn’t too bad.

Not a bad time to see the water birds that have stayed for the winter, particularly when the ice on ponds and reservoirs begins to thaw and there are little pools of water for them to congregate. Jim Baker hold a good deal of water; the reservoir extends west from Lowell Blvd to Tennyson Street – which I would guess is a good half mile in total length. Most of it remains frozen but there are some spots where the ice is melted and where the birds congregate in droves. So it was today.

Nor was I sure of the identity of the ducks I had photographed other than I had not seen that variety before in the greater metro Denver area where I frequently hike. A white body with a strip of black across the vertebral column , bluish-black neck and a long thin orange beak. And quite a few of them, at least 25 or 30 among hundreds of Canadian geese.

My handy and usually accurate new “Sibley’s Guide to Birds, 2nd Edition” did not fail me. These are common mergansers. Pictured here are all males, but the group included a number of females with their rusty-red heads, already in their breeding season. Last summer and fall the place was thick with their cousins, the hooded mergansers, the breeding males easily identifiable by their “hoods,” hoods missing in their non-breeding brethren.

Like wood ducks, common and hooded mergansers build their nests in the holds of trees where they lay their eggs and the young hatch. From the moment that the young hit the water they can, like their parents, fly, swim and dive for food. In the winter, the current season, mergansers tend to cluster in large groups, like the ones I saw today, – they hang out together. Mergansers did not tend to nest in Colorado north of Denver until recently. But starting in 1996 birders – and there are many in Colorado – began to witness their “spectacular courtship rituals” throughout the winter and to find merganser ducklings with their mothers in early summer.

As Stephen Jones and Ruth Carol Cushman noted in a March 1, 2018 article in the Boulder Daily Camera:

The males circle around a single female, raising their dazzling white crests, throwing their heads back and gabbling excitedly. This “lekking” behavior, where a group of males selects a single place to strut their stuff, seems more typical of grouse and wild turkeys than ducks.

The female tends to look on dispassionately, but she may raise her cinnamon crest and bob her head before pairing up with a preferred male. Shortly after mating, she begins searching for a suitable nest site, often a nest box or a flicker hole in a dead tree

I’d like to see that ritual and might start probing the ponds around Boulder where others have seen these courtship activities in early March.

As soon as the winds die down, I’ll head north for a day to look for eagles.

Common Mergansers at Jim Baker Reservoir. January 7, 2019. (R. Prince photo)