Saturday, December 31, 2016

Common Whitetail

A Common Whitetail in the Carleton College lower arboretum from 30 May 2016. This dragonfly is “ubiquitous” across the United States and southern Canada (DragonflyID). Males are aggressive and often try to steal females from other males. Their white abdomens are raised in challenge as they fly after their competitors. After mating, females each lay about 1000 eggs.

Across their range, Common Whitetails are found near almost any body of water. They venture from aquatic habitat, and are often seen along walkways, on the grournd, or perhced in shrubbery. They are common in Erika’s garden.

Friday, December 30, 2016

Scarlet Tanager

I banded this Scarlet Tanager in Northfield on 12 September 2016. Notice the molting wing coverts. These tanagers molt into their basic, winter plumage from July through September. They do not, however acquire new regimes or rectrices (wing or tail) feathers. Males molt into their bright scarlet plumage beginning in January while they are in their tropical wintering grounds.

Thursday, December 29, 2016

Olive-sided Flycatcher

Erika and I discovered this Olive-sided Flycatcher in Carleton College’s lower arboretum on 3 June 2016. Typical of the species, this bird foraged from and returned to the dead tops of a tall tree. From these perches, they sally forth in search of flying insects and especially bees (Altman and Sallabanks 2012). Its relatively large bill and vested appearance are among this flycatcher’s field marks.

Tuesday, December 27, 2016

Ebony Jewelwing

Ebony Jewelwings occur across much of the eastern United States and southern Canada. They can be abundant along shady streams and rivers. I took these photos on 6 June 2016 in the Carleton College lower arboretum. The first image is of a male. Females have a white spot on their wings.

These damselflies have a long flight season, from May through October (and all year in southern parts of their range). Individual adults, however, survive only a couple of weeks (Dragonfly ID). Ebony Jewelwings were among the first odonates I discovered during my dragonfly odyssey.

Monday, December 26, 2016

Midland Clubtail

Midland Clubtails are difficult to identify. I photographed this one in the Carleton College lower arboretum on 6 June 2016. Some of the field-marks are not visible in this photo. The underside of the third abdominal segment is white in the Plains Clubtail—it is usually yellow in the Midland, which tends to have narrower colored bands on the sides of its thorax. Midland Clubtails in our part of Minnesota tend to be quite variable. Our population is in a blend zone between a western and eastern subspecies, Gomphus fraternus fraternus and Gomphus fraternus manitobanus. Most our our Midland Clubtails have a yellow triangle on the top of their 8th abdominal segment. The 9th segment is variable, sometimes yellow, other times dusky, and can be black. In any event, this species is a voracious predator that often consumes other dragonflies.

Saturday, December 24, 2016

Eastern Kingbird

On 24 July 2016, Erika and I hiked in the Carleton College Upper Arboretum. We photographed a curiously speckled Eastern Kingbird. Turns out that the speckles are typical of juvenile plumage—this bird was hatched this year.

Eastern Kingbirds are monogamous. If the pair survives their winter sojourn to South America, they usually remate and use the same territory. “Nevertheless,” write Murphy (1996), “extra-pair copulations and intraspecific brood parasitism may be common.”

Pairs only raise one brood of young per year. One reason for single brooding may be that catching enough flying insects to raise a brood is difficult, especially during cool, wet summers. The result is an extended period of parental care.

Thursday, December 22, 2016

Northern Rough-winged Swallow

I photographed this Northern Rough-winged Swallow at the River Bend Nature Center in Faribault in May 2016. This swallow gets its name from the rough outer edge of its outer primary feather. This edge is caused by feather barbs, recurved in males, or pointed in females. The swallow’s scientific name is Stelgidopteryx serripennis, which translates to “scrapper-wing saw-feather” (De Jong 1996), The function of this structure eludes ornithologists.

Tuesday, December 20, 2016

Gray-cheeked vs Swainson’s Thrush

Gray-cheeked Thrush (7 September 2016) and Swainson’s Thrush (1 September 2016), two often difficult to identify species. These birds migrate through Northfield.

Generally Gray-cheeks lack the bright tan-colored eye rings of the Swainson’s Thrush. Some individuals are so similar that they have been thoguht to be hybrids. Genetic or other evidence of hybridization, however, is lacking.

I band more Swainson’s than Gray-cheeked thrushes. In their breeding range, Swainson's forage closer to the ground than Gray-cheeks, which may account for this difference. On small islands that lack Gray-cheeked Thrushes, Swainson’s forage higher in the forest (Mock and Yong 2000). I doubt, however, that these ecological differences are maintained during migration.

Monday, December 19, 2016

Intergrade Flicker

The best bird we saw during Saturday’s Northfield Christmas Bird Count was this odd Northern Flicker. I think it is an intergrade between the western Red-shafted and eastern Yellow-shafted races of the species. The two races interbreed where their ranges overlap in the upper Great Plains.

It is quite different from the intergrade flicker we saw in Wyoming last summer. The Wyoming bird looked much like a yellow-shafted bird. Saturday’s bird looks like a female Red-shafted Flicker. It has gray sides to the face and reddish wing and tail feathers. But the red nape feathers are red, a yellow-shafted field mark, which should be lacking in a red-shafted female.

Recent research indicates that Yellow-shafted Flicker feathers sometimes turn orange after the birds eat non-native honeysuckle berries. The gray sides to this bird’s face, however, argue against this bird’s being an orange-shafted Yellow-shafted Flicker.

Sunday, December 18, 2016

Eastern Screech-Owl

Saturday’s Christmas Bird Count was run despite dire predictions from the weather service. We got about six inches of fluffy snow on Friday night, but the winds were not fierce and the temperatures stayed above zero. We saw a couple of interesting birds. One, the Eastern Screech-Owl was found by others outside our count area. After lunch, we drove over to take a look.

Friday, December 16, 2016

Gray Catbird

This Gray Catbird is an exception to the rule that this species inhabits dense, shrubby vegetation. I found this bird foraging for insects from a Frisbee course basket. I was searching for dragonflies along Carleton College’s Lyman Lakes last June. Catbirds sometimes earn farmers’ ire by consuming fruit. This individual ate small caterpillars, perhaps redeeming its berry-eating reputation.

Gray Catbirds are one of the few birds that regularly eject cowbird eggs from their nests. This ability is learned. Catbirds only destroy cowbird eggs after they learn what their own eggs look like. If cowbirds lay their eggs in the nest before the catbirds, then the catbirds destroy their own eggs! Ornithologists do not know if, in subsequent years, older catbirds have to relearn the appearance their eggs (Smith et al. 2011).

Wednesday, December 14, 2016

Great Crested Flycatcher

Great Crested Flycatchers are another species that is probaby more common now than before the great forests of eastern North America were destroyed. Forest fragmentation caused increases in woodlots and woodland edges favored by this flycatcher. I took this photograph last summer in Erika’s garden.

This species is the only flycatcher that nests in cavities, either natural, excavated by woodpeckers, or human built. Great Crested Flycatchers are famous for often using shed snakeskin in their nest, presumably to discourage potential predators. Other items that look like snakeskin, like plastic wrappers, are occasionally used instead (Miller and Lanyon 2014).

Sunday, December 11, 2016

Common Baskettail

Flying dragonflies are always a challenge to photograph. I captured this Common Baskettail on 11 June 2016 over the Lyman Lakes of Carleton College. This baskettail was making patrolling flights back and forth along the edge of the lake.

Common Baskettails are often abundant across most of eastern North America. The are found over almost any body of quiet water. Although not present on all individuals, the dark spotted hindwings are good field marks for identifying this species.

Saturday, December 10, 2016

Blue and Green-winged Teal

On 24 August 2016, I found a large flock of Blue-winged Teal at the Dennison, Minnesota, sewage treatment ponds. The ducks circled the facility as I took photos. To my surprise, when I got home and worked on the images, I discovered that one of the ducks was not a Blue-winged Teal. The lowest bird in the center of the photo is actually a Green-winged Teal.

Thursday, December 8, 2016

Eastern Pondhawk

Eastern Pondhawks from 2016. The first two photos, both taken on 1 June, are from Carleton College’s Lower Arboretum here in Rice County, Minnesota. The first one is male, the second, female.
The third photo is of an immature male taken at the Savannah National Wildlife Refuge in Jasper County, South Carolina on 24 March. The last image is from St Marks National Wildlife Refuge, Wakulla County, Florida on 23 March.
Considering their wide range, almost all of the eastern United States east of the Rockies, I am surprised that local, isolated populations have not evolved into distinct species. On the other hand, Eastern Pondhawks are abundant and not very particular in their habitat selection. Almost any slow moving or still water will suffice.

Tuesday, December 6, 2016

Snow Goose

Yesterday, 5 December, Erika and I found two Snow Geese at the Jefferson Parkway Wetlands in eastern Northfield. These birds were first reported by Gerry Hoekstra on 29 November, but had not been seen since. Gerry returned later in the day and found a third, young Snow Goose.

White and “blue” Snow Geese are color morphs of a single species. Only in 1983 did ornithologists figure out this situation. One gene controls this color difference. The dark gene is incompletely dominant over the white one.  The dark gene is unequally distributed across the Snow Goose’s range. Most dark-morph geese breed and winter in central areas of North America. Finally, ornithologists discovered that the two morphs’ ranges did not overlap until about 70 years ago (Mobray et al. 2000).

Monday, December 5, 2016

Chestnut-sided Warbler

I banded this Chestnut-sided Warbler this spring in Northfield. In Audubon’s time, this species was hardly ever encountered (Byers et al. 2013). An inhabitant of forest edges and secondary growth, this warbler benefited from humans’clear-cutting the continent’s old growth forests. Now it can be the most abundant breeding warbler in early succession woodlands.

Saturday, December 3, 2016

Common Green Darner

A perched Common Green Darner can be hard to see, even when you are looking right at one. This female, from last summer, was resting in the Whitetail Woods County Park in Dakota County, Minnesota.

As its name suggests, this dragonfly is common across most of North America. The species migrates south into Central America. They arrive in the north well before local dragonflies have emerged. Their migration is cued by warm fronts (DragonflyID app). After breeding, they head south, sometimes in large numbers. Common Green Darners are an important component of many bird diets, including those of American Kestrels, nighthawks, and Purple Martins.

Thursday, December 1, 2016

Purple Martin

I photographed this female Purple Martin on 13 June 2016, at Lake Byllesby Regional Park, Dakota County, Minnesota. Martins in Canada and the northern United States have a lot going against them. They depend on flying insects. Cold weather kills their insect prey, which, in turn, can wipe out local martin populations. By out-competing nesting martins, introduced starlings and House Sparrows can also wipe out these swallows.

Tuesday, November 29, 2016

Halloween Pennant

Halloween Pennant—24 July 2016—along the Jefferson Parkway Wetlands in Northfield, Minnesota. I should have posted this image on Halloween. This image lay forgotten in my blog queue. I am going to try to empty the queue during the next several weeks.

According to the DragonflyID app, this large dragonfly is common and widespread across most of the eastern United States. Minnesota is about as far north as they get. Like this one, pennants perch atop vegetation and wave in the breeze like flags. The fore and hind wings often lie on separate planes—this field mark can be seen in my photo.

Sunday, November 27, 2016

Red Fox

While we photographed the Great Gray Owl in Yellowstone Park, up trotted a Red Fox. These foxes are found from the Arctic Circle through most of North America, North Africa, and Eurasia. Their range has expended into suburban areas and they are introduced into Australia, where Red Foxes are considered to be invasive pests. They mainly take rodents, but also feed on rabbits, game birds, reptiles and invertebrates. Red Foxes are often found in pairs or in small family groups. Young remain with their parents and assist in caring for other young (Wikipedia). We, however, only saw this single fox.

Saturday, November 26, 2016

Great Gray Owl

We found the Great Gray Owl in Yellowstone National Park last September. It was not hard to spot. The poor bird was surrounded by birdwatchers. A park ranger kept vigilance over the birders. Actually this bird does not look too healthy. Hopefully it was just napping at midday. Great Grays hunt both by night and day.
The owl performed a few maintenance behaviors, like preening its legs in this second photo. I find the pine needles on the bird’s side odd. I would have thought that the owl would have cleansed itself of miscellaneous vegetation. Preening is common for this species. Stretching is another frequent behavior. I am not sure what is happening in the last picture. Several times the owl appeared to face upwards, perhaps stretching? Or trying to become invisible to the enthusiastic birders?

Thursday, November 24, 2016

Rocky Mountain Elk

Yellowstone National Park is a good place to see Rocky Mountain Elk. Elk were once found across much of North America, but their range is now greatly contracted. 

The elk in this photo is a female. Females and young live in herds. Males either live alone or in groups of batchlors. During rutting season, females and young will move into harems with one or two males. Males coat themselves with urine-soaked mud, which attracts the females. I did not notice it at the time, but this female is urinating. This behavior is probably not marking territory, and no more complicated than it seems. (As we raced across Yellowstone in search of the Great Gray Owl, this photo is the only elk image I captured.)

Tuesday, November 22, 2016

Bison and Magpie

Look closely at this Bison from Yellowstone National Park. A Black-billed Magpie is perched on its head. Magpies form symbiotic relationships with large ungulates. The magpie feeds on ticks and other ectoparasties. The advantage to the bison is obvious, but the situation may be more complicated. Magpies cache the ticks for later consumption, but often don’t kill the ticks first. If the ticks survive, they reproduce, thus increasing tick numbers. For the bison, tick borne illnesses and outright blood loss from tick wounds can cause deaths. Magpies feast on the bison carcasses, and both carcasses and ticks are probably critical food sources for the birds (Trost 1999).

In yet another twist, I have been told that ranchers often treat cattle with poisons to kill ticks. If their cattle die from other causes, the poisons sometimes collaterally kill scavengers like magpies and Golden Eagles.

Magpies are omnivorous, consuming grains, vegetable matter, and both living and dead animals. Magpies cache food for only a couple of days. Often their caches are stolen by other magpies, that find the caches by smell. Female magpies watch males cache food and later steal the males’ hoard. Males will often move caches away from carcasses on which they feed and take the food closer to their nests. Magpies cache whatever food is most abundant. Both wild and pet magpies also cache shiny trash.

Sunday, November 20, 2016

Greater White-fronted Goose

On 16 November, John Holden and I checked out the New Prague, Minnesota, sewage treatment ponds. This location often harbors migrating waterfowl, and this day was no exception. Nearby, among a large flock of loafing Canada Geese, we spied a solitary Greater White-fronted Goose.

White-fronted Geese breed in arctic regions around the the world. They migrate over much of Canada and the United States, and winter in California, the Southeast, and in Mexico. In our country, it is most common west of the Mississippi River. The numbers of this goose have fluctuated greatly since the early 1950s, declining from over-hunting and habitat destruction (Ely and Dzubin 1994). Nevertheless, over a million birds inhabited North America in 1994.

Saturday, November 19, 2016

Green-winged Teal

On 5 November, Erika and I walked along the Minnesota Valley National Wildlife Refuge. We parked at the Bass Ponds and turned around at the renovated pedestrian bridge that crosses the river. Along the way, we observed a flock of 30 Green-winged Teal. These ducks were relatively unwary and busily washed and preened.

This individual appears to me to be a first-year male. Males desert their mates while the females are incubating. Females then do all the incubation and any further parental care. In the winter, large flocks are common. These teal eat arthropods and marsh plant seeds (Johnson 1995).

Friday, November 18, 2016

Yellowstone Falls

We spent most of the morning of 23 September driving from West Yellowstone to the shores of Yellowstone Lake. Erika’s sister and her husband were excited about showing us the Great Gray Owl they found the day before. We did not have time for geysers and paint pots. But we did stop at the Lower Falls of the Yellowstone River.

The National Park Service writes “the caynon was a barrier to early travel.” Indeed, the falls do not look like good news for the canoeist going in either direction. At 308 feet, the falls are twice the size of Niagara. Obviously, however, the Niagara sports more gallons per second. 

Thursday, November 17, 2016

Common Raven

This Common Raven greeted us in a parking lot in West Yellowstone, Montana, on 23 September 2016. We detoured south from Belgrade and I-90 to spend the morning with Erika’s sister and her husband. They were excited about seeing a “huge” owl feeding near Lake Yellowstone, so that was our goal. My brother-in-law and I rode in our car, while Erika and her sister visited in theirs.

Ravens and people have had a long and often contentious relationship. For better or worse, ravens are an integral part of human cultures. The authors cited below write, “It is difficult to imagine any other bird being associated with so much myth, mystery, and misinformation.”

Ravens, the largest of the passerines, are widespread around the world. Ravens followed Bison herds in the Great Plains, but are now largely absent there. On the other hand, this corvid is reestablishing itself in the forests of eastern North America. In other areas Ravens are considered pests that eat crops and young livestock, resulting in eradication programs. Other raven populations have declined so drastically that people have tried to reintroduce them. Ravens have been implicated in the decline of several endangered species, including California Condors and Least Terns (Boarman and Heinrich 1999).

Tuesday, November 15, 2016

Gray Jay

Gray Jays are found across Canada and Alaska, with populations penetrating the northernmost  United States, and south through the Rocky Mountains. This jay flew overhead as we hiked in Mount Rainier National Park last September.

They are odd birds. Their salivary glands are enlarged and are able to glue food under tree bark and lichens.  Even perishable food items are scatter-hoarded across their territories. Perhaps stranger yet, this jay breeds in late winter, incubating eggs when temperatures can approach -30 degrees C.  These birds don’t even try to breed in the warmer temperatures of May or June. Strickland and Ouellet (2011) further report that global warming may be causing stored food to spoil. As a result, some southern populations of Gray Jays appear to be declining.

Sunday, November 13, 2016

American Pipit

In the alpine meadows surrounding Mount Rainier’s snow, we found a flock of American Pipits. These birds breed in Alaska and arctic Canada, south through the Rocky Mountains. The birds are common migrants or winter residents in much of the rest of North America. I have blogged about migrant pipits in Minnesota.

Pipits survive their harsh breeding environment. All About Birds reports that 17 pipit nests in Wyoming were buried by snow for a day. Nestlings over 11 days survived. Most younger birds died.

Saturday, November 12, 2016

Hoary Marmot

On our walk up the Sunrise Trail in Mount Rainier National Park, we saw marmots. These giant squirrels did not look right. We remembered marmots that were much more uniformly brown. These animals seemed to be silver-haired, hence their name. This species is found in western Canada, Alaska, and in our Pacific Northwest.

Not surprisingly, we saw several marmots along the trail. They live in colonies consisting of up to 36 individuals. The colony includes an adult male, perhaps three adult females, and various young marmots. Colony size is limited by food availability.

Hoary Marmots hibernate for seven or eight months a year. In the summer, they often sun themselves on rocks. About half their day is spent this way. The remainder of their time is spent foraging for various plant materials.

Friday, November 11, 2016

Golden-mantled Ground Squirrel

Golden-mantled Ground Squirrels ran up the Sunrise Tail in Mount Rainier National Park on 21 September 2016. This rodents are common in the Rocky Mountain West. I am surprised this post is my first for the species.

These ground squirrels lack the facial stripes of chipmunks. They hyburnate in burrows during the winter. They collect seeds and other vegetation in cheeck pouches, storing some of their food in their burrows. They have litters of four to six young in the summer. Ground squirrels are imported prey items for hawks and various larger mammals (Wikipedia).

Thursday, November 10, 2016


Yesterday, 9 November 2016, John Holden and I photographed a Merlin near the 180th Street Marsh in nearby Dakota County. John was with me when I last captured a Merlin image in Rice County on 27 November 2012. Compare the two birds in this post. The first is yesterday’s falcon, the bottom is the Rice County bird.

When I wrote about the Rice County Merlin, I explained that three races of Merlin are described. I hesitantly concluded that our bird was a taiga race due to its overall dark coloration, creamy eye-stripe, and buffy breast. Our more recent individual seems clearly to be a Prairie Merlin. Note the very pale sides of the face, the white stripe above the eye, and the non-buffy, white breast markings.

Wednesday, November 9, 2016

Sooty Grouse

On 21 September, we began our journey home. Our first stop was Coeur d’Alene, Idaho. This destination promised us a short day, but we both know that, no matter how many miles we have to cover, our days always seem to take 11 hours—especially if you detour and go by way of Mount Rainier National Park. We found ourselves with a little over an hour at the park. We walked a short distance up Skyline Trail, which runs towards the peak from the park headquarters. The morning was breath-takingly beautiful.
The trail was relatively crowded. We can’t imagine what a zoo it must be in season. We came upon the bend in the trail in the first photograph. To our surprise, a flock of seven Sooty Grouse fed along the edge of the trail. The grouse were completely unperturbed by our presence. In fact, the birds appeared to defend their territory from us. Because they are often quite tame, grouse are often called Fool's Hen or Trail Chicken.
Grouse systematics are confusing. Until very recently, Blue Grouse were considered a single species. DNA research confirms what some ornithologists suspected. Blue Grouse are actually two species, the darker, coastal Sooty Grouse, and an interior Dusky Grouse. I had never seen a Blue Grouse or either of the two newly described species. One of the joys of birding is the serendipity of being at the right place at the right time. Twenty minutes later, on our return down the trail, not a grouse was to be found.