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.

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.

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.

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.

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.

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.

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.

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.

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.

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.