Immature Bald Eagle in flight. Photo by Jamie Simo

Milavec Reservoir, January 8th–with Jamie Simo

Hybrid Greater White-fronted Goose x Cackling Goose. Photo by Jamie Simo.

Milavec Reservoir in Frederick, Colorado is always a good place to see ducks and geese in the winter. I like to go at least once every year to see what I can see. This past Saturday was cold and windy and because of that a lot of the reservoir was frozen, but just enough remained open that it drew some interesting waterfowl and even some hungry raptors,

Hybrid Snow Goose x Cackling/Canada Goose. Photo by Jamie Simo.

including 4 Bald Eagles and a Northern Harrier.

Hiding among the masses of Canada and Cackling Geese were a Greater White-fronted Goose and a couple of interesting hybrids. One of these hybrids was clearly a cross between a Greater White-fronted Goose and probably a Cackling Goose going by the bright orange beak and feet (indicative of a Greater White-fronted Goose) and the dark  head and neck with a paler cheek patch (indicative of either a Canada or Cackling Goose). It’s small size hints that the other parent was probably a Cackling Goose rather than a Canada Goose.

The other hybrid was a lot harder to pin down to parentage. The white, blotchy head points to either a Snow Goose or a Ross’s Goose parent with the blocky head shape being more of a Snow Goose than Ross’s Goose trait. The dark bill and dark body indicates the other parent was either a Cackling or a Canada Goose.

We also had some great diving ducks, including good looks at both male and female Canvasbacks. The “ski slope” head shape of the Canvasback is distinctive and makes it unique from our other duck species. The Canvasback is named for the male’s white body, which resembles the color of unpainted canvas. The highlight for me was the lone Red-breasted Merganser that helpfully hung out next to a male Common Merganser to give a good indication of its slightly smaller size. This merganser had dark patches on the face, which I suspect would’ve been green feathers coming in if we’d been able to get closer to it. Immature male Red-breasted Mergansers resemble females with their brown heads and grey bodies. Mature males have green heads.

Red-breasted Merganser. Photo by Jamie Simo.

If you get a chance, check out Milavec this winter. I doubt you’ll be disappointed whatever you end up seeing!

Milavec Reservoir

20 taxa

Greater White-fronted Goose 1
Greater White-fronted x Cackling Goose (hybrid) 1
Snow x Canada Goose (hybrid) 1
Cackling/Canada Goose 2500
Northern Shoveler 16
Mallard 27
Canvasback 19
Lesser Scaup 1
Common Goldeneye 23
Common Merganser 21
Red-breasted Merganser 1
Rock Pigeon (Feral Pigeon) 5
Ring-billed Gull 2
Northern Harrier 1
Bald Eagle 4
Northern Flicker 1
Blue Jay 1
American Crow 6
Black-capped Chickadee 1
House Finch 7

Milavec Reservoir, Jan 11, 2020–with Jamie Simo

Cackling Goose (left) vs Canada Goose (right) (c) Jamie Simo

Milavec Reservoir in Frederick, CO is one of the best places along the Front Range to see all the possible (read: non-rare) interior goose species. Sometimes, like last year, it even plays host to some rarities like the Colorado-record Pink-footed Goose and Barnacle Goose. As hoped for, while we didn’t see any Colorado-record geese on this frigid, but sunny, Saturday morning, we did see all the usual goose suspects. We also had some great ducks and raptors.

Nearly all Coloradans are familiar with our only breeding goose species, the Canada Goose, but winter brings migrant Cackling, Greater White-fronted, Ross’s, and Snow Geese from the arctic to our lakes, reservoirs, and fields. The most similar to the Canada Goose, the Cackling Goose was only recognized as a species in its own right in 2004. There are 4 subspecies of Cackling Goose varying in size and color, but some of the common characteristics include smaller body size than the majority of Canada Geese (there may be some overlap with the smallest subspecies of Canada Goose), a shorter neck, and a bill that looks “stubby” because of a more rounded or square head shape. Because of the difficulty of distinguishing between the smallest subspecies of Canada Goose and the largest subspecies of Cackling Goose, small white-cheeked geese are sometimes referred to as “Cackling-ish.”

Ross’s Goose (foreground) vs Snow Goose (background) (c) Jamie Simo

Like the Canada Goose, the Snow Goose also has a “mini-me” doppleganger, the Ross’s Goose, but that doppleganger is much easier to pick out than the Cackling Goose. Firstly, Snow Geese come in either the expected white plumage with black wingtips or a darker, grey-blue body plumage with white head and neck. Both have pink bills and feet as adults. The latter is sometimes referred to as a “blue goose, “blue morph,” or “blue phase” Snow Goose. There are only 2 subspecies of Snow Goose, but both have a black “grin patch” that gives them a sneering appearance, and a sloping forehead. By contrast, the Ross’s Goose, which is usually white but also occurs rarely in a blue phase, has a steep forehead leading to a rounded crown and lacks the grin patch.

The final expected goose species in Colorado is the Greater White-fronted Goose. This goose is mostly brownish-grey with darker belly bands, orange legs and bill, and white feathers around the base of the bill from which is gets its name.

Other stand-out species were 2 adult Bald Eagles, a Northern Harrier, a Red-breasted Merganser, a female Canvasback, and even a coyote. Not bad for a cold, January morning!

Female Northern Harrier (c) Chris Friedman

Frederick Lake (Milavec Reservoir) & Recreation Area, Jan 11, 2020
25 species

8 Snow Goose
3 Ross’s Goose
1 Greater White-fronted Goose
2000 Cackling Goose
4000 Canada Goose
60 Northern Shoveler
10 Mallard
1 Canvasback
7 Lesser Scaup
3 Bufflehead
20 Common Goldeneye
7 Common Merganser
1 Red-breasted Merganser
1 Ruddy Duck
3 American Coot
1 Northern Harrier
2 Bald Eagle
1 Red-tailed Hawk
1 American Kestrel
1 Blue Jay
6 European Starling
6 American Tree Sparrow
1 White-crowned Sparrow (Gambel’s)
2 Song Sparrow
1 Red-winged Blackbird