Category: Bird Walks

Red-winged Blackbird male with Common Grackle male in background at far left. Photo courtesy of Stephen VanGorder.

FRBC Boulder’s May 11 bird walk started on a clear to partly cloudy and a balmy 50-degree morning in Boulder, Colorado for our group of twelve birders on Bobolink Trail. Bobolink Trail is a flat, walkable trail that runs north to south along a section of South Boulder Creek between Baseline Rd and South Boulder Rd just west of Baseline Reservoir. We started the walk from the East Boulder Community Center at 55th St and Sioux Dr, on a path which connects to Bobolink Trail in about the middle of its run. A walking trail runs close to the creek, while a multi-use trail runs along an open – and sometimes wet – field where cattle graze. There are patches of cattail marsh throughout the open space, and there are a couple of ponds at the East Boulder Community Center. Having all of these different habitats in one place means that there are opportunities to see and hear many different bird species: riparian birds like warblers and flycatchers, birds of the open fields like meadowlarks and Bobolinks, marsh birds such as rails and Red-winged Blackbirds, and waterfowl at the ponds.

American Kestrel female with prey. Photo courtesy of Stephen VanGorder.

We had hardly left the parking lot to head to the trail when we had our first highlight of the day: a female American Kestrel with prey perched on the trail sign near 55th St. The kestrel looked as though she had gone for a swim to catch her prey, which appeared to be a small mammal. The trail was fairly busy that morning with numerous walkers, joggers, cyclists and pets on the trail, and yet this kestrel sat calmly on her perch, watching the traffic go by. Moments later we saw a male American Kestrel – presumably her mate – flying around in the same area.

As we approached the trail sign, the whinnying call of a Sora rang out from a tiny patch of cattails mere feet away from the concrete path. The Sora is a short-billed species of rail, birds which excel at not being seen as they skulk through tall, thick marsh vegetation. Have you ever heard the expression “thin as a rail?” To get around more easily in said tall, thick marsh vegetation, rails’ bodies are laterally compressed, making them look tall and thin from the front. The jury is still out on whether the expression “thin as a rail” refers to the shape of these birds, but it makes sense when you see one head-on! Unfortunately but unsurprisingly, we never did see the stealthy Sora, but just knowing it was nearby was pretty cool. Even better, on our way back by this spot later, we heard the whinny calls of not one but TWO Sora in these cattails!

American Robin. Photo courtesy of Stephen VanGorder.

As we approached the pedestrian bridge over South Boulder Creek, we paused for several moments to watch a Blue-gray Gnatcatcher forage and a female Common Grackle busy herself with nest-building, both birds in trees very close to the bridge for great viewing.

The morning was full of spring birdsong: Red-winged Blackbirds, American Robins, Yellow-rumped Warblers, Western Meadowlarks, and House Wrens could all be heard singing from wherever we were on the trail. We had some beautiful views of singing Western Meadowlarks in the spotting scope. Another earbirding highlight of the day was a Brewer’s Sparrow singing in a mixed flock of Chipping and Brewer’s Sparrows near the playing fields at the East Boulder Community Center. And speaking of warblers, the group had some great looks at the Audubon’s and Myrtle forms of Yellow-rumped Warbler, a somewhat-cooperative Orange-crowned Warbler, and a beautiful singing male Yellow Warbler on the way back to the trailhead near where the Sora were calling.

Canada Geese with goslings. Photo courtesy of Stephen VanGorder.

Another sign of spring: the Canada Geese already have goslings hatching! We observed one little family grazing together near the community center and other pairs with young swimming on the ponds.

Thank you very much to Stephen VanGorder, who generously sent us these great photos he took during the bird walk for use on our blog.

See you next time – let’s go birding!

~Sarah Spotten

Bobolink Trail in Boulder, Colorado, May 11, 2019
36 species (+2 other taxa)
Canada Goose 20 (estimated)
Mallard 6
Eurasian Collared-Dove 3
Mourning Dove 4
Broad-tailed Hummingbird 4
Sora 2
Killdeer 1
Wilson’s Snipe 4
Double-crested Cormorant 1
Great Blue Heron 3
Turkey Vulture 1
Red-tailed Hawk 2
Downy Woodpecker 2
American Kestrel 2
Blue Jay 2
Black-billed Magpie 3
American Crow 1
Violet-green Swallow 7
Barn Swallow 4
Cliff Swallow 2
swallow sp. 20 (estimated)
House Wren 5
Blue-gray Gnatcatcher 1
American Robin 10
European Starling 6
House Finch 2
American Goldfinch 8
Chipping Sparrow 5
Brewer’s Sparrow 5
Song Sparrow 4
Western Meadowlark 4
Red-winged Blackbird 30 (estimated)
Brown-headed Cowbird 6
Common Grackle 30 (estimated)
Orange-crowned Warbler 1
Yellow Warbler 2
Yellow-rumped Warbler (Myrtle) 4
Yellow-rumped Warbler (Audubon’s) 6

American Wigeon – male (c) Bill Schmoker

Given the icy roads and the snow we received Friday night this outing almost got cancelled, but we pulled it off, and had four intrepid souls show up that elected to embrace the day regardless of the conditions.  AND the morning turned out to be a beautiful one in which we got to see a great variety of birds.

American Wigeon – female (c) Bill Schmoker

The wintering ducks are still hanging around, with migratory ones increasing the local populations.  I was especially glad to see a few American Wigeon, as they have been pretty ilusive for me the last month and a half.  The male is remarkable for having a white (or buffy) forehead; short, light-blue bill with a dark tip; a glorious green swoosh through his eye; warm, pinkish-brown flanks; a pointed, black tail with a striking white hip-patch just in front of it; and, in flight, that have a distinctive white patch on the upper secondary coverts (this is for those of you desiring homework terminology). The female is also very warmly colored, has the blue bill, and is noted for her “smeared mascara” look.  Finally, they have one of the more distinctive (dare I say, “cute”) calls.

Red-tailed Hawk – rufous morph (c) Bill Schmoker

For those of you tracking some of the “usual suspects” at Hudson Gardens, we did, once again, see the rufous (or Intermediate) morph Red-tailed Hawk.  He, or she, has been a regular in the area now for a few years, and has been breeding with a light morph Red-tail.  Keep your eyes open for the pair sitting on top of the powerline poles just west of the river.

Bushtit -female (c) Bill Schmoker

We also had a couple of small groups of Bushtits, which in my estimation have increased their wintertime presence in this part of Colorado over the last few decades (climate change?).  Note that the female has a yellow eye, and the male a dark eye.  And we got to see some newly-arrived migrants, three Common Grackles.  Wahoo!  This is a species that has increased dramatically in Colorado over the last hundred years, apparently making their way here initially from the eastern United States due to the planting of shelter belts across the Great Plains, and then continuing to thrive in eastern Colorado with increases in urban and agricultural development.

Good Birding!  Chuck

Hudson Gardens, Mar 30, 2019
29 species (+1 other taxa)

Cackling Goose  35
Canada Goose  170
Cackling/Canada Goose  75
Gadwall  28
American Wigeon  3
Mallard  18
Green-winged Teal  7
Bufflehead  12
Hooded Merganser  8
Rock Pigeon (Feral Pigeon)  23
Eurasian Collared-Dove  1
Ring-billed Gull  2
Great Blue Heron  2
Bald Eagle  1
Red-tailed Hawk  1
Belted Kingfisher  2
Downy Woodpecker  3
Northern Flicker  15
Say’s Phoebe  2
Blue Jay  3
Black-billed Magpie  1
American Crow  4
Black-capped Chickadee  4
Bushtit  6
American Robin  27
European Starling  3
House Finch  11
Song Sparrow  2
Red-winged Blackbird  16
Common Grackle  3

Fourteen of us began the morning by scoping and binocularing (why not, in an era when we are “verbizing” so many of our nouns?) South Platte Reservoir.  This large reservoir was completed in 2007, having been converted from an old gravel mine.  While its surroundings are rather sterile and vegetation almost non-existent, it continues to be a reliable haven for rare winter waterfowl in the south metro area. Almost every year we get one or more Long-tailed Ducks here, last year there was a Yellow-billed Loon, this year there were some Trumpeter Swans, and generally we get one or more of the three scoter duck species here.

We were fortunate to see a single female Black Scoter, a single male Red-breasted Merganser, and a good representation of the more common winter ducks.  Black Scoters breed primarily in northern Quebec and northern Alaska.  Their major wintering areas are the coastal waters of Maine, Massachusetts, Alaska, British Colombia, and Washington.  Any occurrence in the center of the continent is unusual. Red-breasted Mergansers are not as rare an occurrence as the scoters, but it is certainly a special treat when we get to see them – a personal favorite of mine.  We ended up with fourteen species of ducks which was pretty good.

Our other somewhat unexpected bird of the morning was an American Dipper under the C-470 bridge amidst all the current highway construction.  We were easily within twelve feet of this bird, and it was totally unperturbed, even going so far as to sing a little bit for us.  And, they have a delightful song!

  What makes this sighting unusual is that Dippers don’t tend to venture too far out on to the eastern plains.  They can make it about as far east as Loveland, Longmont, the Rocky Mountain Arsenal, and Cherry Creek Reservoir, but those occurrences are fairly unusual.  Of additional interest is that a Dipper was seen in this exact same location on a Front Range Birding Company walk led by Jennifer O’Keefe on January 5^th– presumably the same individual.

Hope to see you soon on our next walk.

Chuck

South Platte Park–C470 area, Feb 2, 2019 
35 species

Canada Goose  14
Northern Shoveler  19
Gadwall  16
American Wigeon  1
Mallard  15
Green-winged Teal  9
Redhead  13
Ring-necked Duck  17
Lesser Scaup  14
Black Scoter  1 
Bufflehead  20
Common Goldeneye  13
Hooded Merganser  12
Common Merganser  1
Red-breasted Merganser  1
Pied-billed Grebe  1
Rock Pigeon (Feral Pigeon)  14
American Coot  9
Killdeer  2
Ring-billed Gull  2
Great Blue Heron  1
Bald Eagle  2
Red-tailed Hawk  3
Belted Kingfisher  2
Northern Flicker  1
American Kestrel  3
Black-billed Magpie  7
American Crow  5
Black-capped Chickadee  6
American Dipper  1 
European Starling  7
American Pipit  1
House Finch  2
American Goldfinch  1
Song Sparrow  1

We had a raucous start as music blared across the parking lots at Hudson Gardens in anticipation of the Frosty’s Frozen 5 and 10 mile races.  Fortunately, we were ahead of the nine o’clock start time, and got out along the South Platte trail before the runners came by, and then safely sequestered ourselves well away from the action at the appropriate moments – all done very serendipitously.

So, to begin with, though the temperature was only about 30 degrees, it seemed to feel much colder, and we initially had only a few landbirds, an American Robin and some House Finches, but then as we got over to the river things picked up significantly.  The middle of the river was packed with Cackling Geese with their heads tucked away.  There were at least 600, possibly as many as 800.  Over the next forty minutes or so they gradually began to untuck, but they were in no hurry to leave.  

Distinguishing Cackling Geese from Canada Geese is one of the great birding challenges.  Up until 2004 they were considered one species, and it’s easy to see why – they look VERY similar.  As with so many bird taxonomy questions, genetic analysis has led to this reclassification.  Generally speaking, Canada Geese are bigger, and Cackling Geese are smaller, but this all gets complicated by the fact that there are roughly seven subspecies of Canada Geese and four of Cackling Geese, all of which are of variable size and with some overlap between groups.  So, not to prolong this any further, a good place to start in distinguishing Cackling Geese is to look for a stubbier, shorter bill rising into a steeper forehead; the head itself is small and squarish; the neck is proportionally shorter and thicker, and some of these guys are only slightly bigger than a Mallard.  Canada Geese have longer bills rising gradually into a sloping forehead, giving the head a more rounded look; the neck is proportionally longer and thinner, with a tendency to be more “S” shaped.  Finally, we have Canada Geese year-round in Colorado, and Cackling Geese breed in northern Alaska and Canada and are only here in the winter.  ‘Nuff said!

Being right beside the Platte we also had ample opportunity to become experts at distinguishing male and female ducks of several species, both dabblers and divers.  One of the interesting winter phenomena in the Denver area is that as we get really cold weather the lakes and ponds can start to freeze over and the ducks then become more congregated along the flowing rivers and streams.  We generally see more dabblers along the river, e.g. Gadwall, Mallard, and Green-winged Teal, but with the colder weather the divers tend to show up more, e.g. Ring-necked Duck, Bufflehead, Common Goldeneye, and Hooded Merganser. With regard to diet the dabblers are primarily vegetarians, with only a small portion of their diet coming from various insect larvae.  Among the divers, about a fourth of the Ring-necked Duck’s diet is animal based (insects, nymphs, beetles, and mollusks).  Animal food constitutes the majority of the diet of Common Goldeneye, Bufflehead, and Hooded Mergansers.

Other highlights of the morning included an intermediate morph Red-tailed Hawk, which we picked up on flying away from us, but then it accommodatingly flew back towards us and landed right above us on a utility pole.  The majority of our Red-tail Hawks tend to be “light morphs,” that is they are pale in the breast and undertail coverts with a streaked belly band.  Roughly ten percent of Red-tails, however, are either “dark morph” birds that are all dark chocolate brown, or “intermediate or rufous morph” birds that are reddish-brown on the chest with a dark belly.  During breeding season in recent years there has been a breeding pair near Hudson Gardens of a light morph individual with an intermediate morph bird.  It seems likely to me that our bird on Saturday may have been the same one that breeds in this area.

Besides getting great looks at a number of songbirds such as Black-capped Chickadee, American Goldfinch, Dark-eyed Junco, Song Sparrow, and Spotted Towhee, one of our more interesting observations was of an all-male flock of Red-winged Blackbirds.  They were mostly first-year males just starting get their red epaulets, but also some beautiful adult males sporting wonderfully colorful bright red and yellow epaulets. But, no females.  Red-wings sexually segregate during migration but I’m puzzled by this mid-winter “all boys club.”

A great morning with a great group of enthusiastic birders!  Hope you can make it to the next Hudson Gardens walk or one of the other Front Range Birding Company outings!

Best!  Chuck

Hudson Gardens, Jan 26, 2019 
25 species (+2 other taxa)

Cackling Goose  600
Canada Goose  42
Gadwall  10
Mallard  21
Green-winged Teal  1
Ring-necked Duck  9
Bufflehead  8
Common Goldeneye  3
Hooded Merganser  8
Eurasian Collared-Dove  9
Great Blue Heron  1
Red-tailed Hawk  2
Downy Woodpecker  1
Northern Flicker  2
Black-billed Magpie  5
American Crow  1
Black-capped Chickadee  7
American Robin  1
European Starling  2
House Finch  11
American Goldfinch  5
Dark-eyed Junco (Slate-colored)  1
Dark-eyed Junco (cismontanus)  1
Dark-eyed Junco (Oregon)  3
Song Sparrow  5
Spotted Towhee  1
Red-winged Blackbird  18