Friday, April 28, 2017

Ruby-crowned Kinglet

Ruby-crowned Kinglets are among the smallest songbirds in North America. (Google assures me that the Verdin is smaller—and hummingbirds are not songbirds.) They do, however, lay the largest clutch for their size of any North American bird—12 eggs (Swanson et al. 2008).

Erika and I encountered this kinglet in the Cannon River Wilderness Area on 22 April 2017. Unlike most Ruby-crowned Kinglets, this one perched stock-still. Usually, they constantly flick their wings. Thus it took me a few seconds to figure out its identity.  Note the thin, white eye-ring and the golden edges to the wing feathers. Without being able to see the color of its crown, you can not tell this bird's sex.

Wednesday, April 26, 2017

Yellow-headed Blackbird

Erika and I found a half-dozen Yellow-headed Blackbirds at the 180th Street Marsh in nearby Dakota County on 24 April. This species is conspicuous in North American prairie wetlands and across western North America in general. Except during migration, this blackbird is seldom found east of Lake Michigan. It winters in the Southwest and in northern Mexico. Ornithologists have recently concluded that this species is an odd relative of meadowlarks (Fraga and Bonan 2017)

Tuesday, April 25, 2017

Swamp Sparrow

Even though you can’t see the side of this bird’s face or its bill, you can identify this species as a Swamp Sparrow. Note the gray eye line and breast. The breast is very slightly streaked. The shoulders and the crown are relatively bright rufous.

As its name suggests, this species inhabits marshes, bogs, swamps as well as brushy meadows. A common bird, it breeds across eastern Canada and the northeaster United States. It winters in the southeastern US and eastern Mexico. I found this individual at Sprague Lake in Rice County, Minnesota, on 23 April 2017. Just like one of my sons, it refused to look at the camera.

Monday, April 24, 2017

Lincoln’s Sparrow

A Lincoln’s Sparrow at the feeders at the River Bend Nature Center on 22 April 2017. Ammon (1995) considers this sparrow to be “among the most elusive of  North American birds.” Its biology is not well known. Not that uncommon a bird, accessing its boggy breeding habitat is difficult. It nests across boreal Canada and the northern United States, and further south through the Rocky Mountains. It winters in the southern US, south into Central America.

Identification is made by noting its thin breast streaking over an ochre wash. Note the gray sides to the head and the bird’s brownish wings.

Sunday, April 23, 2017

House Finch

I banded this mottled red and yellow House Finch at Carleton College on 14 April 2017. Color in House Finches is complicated. Red, yellow, and/or orange color are due to deposition of combinations of 13 carotenoids. These pigments are formed in the blood plasma, liver, and feather follicles. Red and yellow pigment levels vary widely in individual finches. Pigment levels may depend on age, speed of molt, population of finch, and diet (Badyaev et al. 2012).

Saturday, April 22, 2017

Blue-winged Teal

Erika and I found Blue-winged Teal in a small pond on 15 April 2017 in the Carleton College Arboretum.  The flock consisted of three males and three females, not surprising, since teal pairs form in the late winter or as they migrate north.

Blue-winged Teal populations crashed in 1990 after several drought years. By 2000, their numbers more than doubled. This increase may mean, if appropriate conservations are initiated, teal can recover from recent wetland destruction of prairie pothole wetlands (Rohwer et al. 2002).

Friday, April 21, 2017

Eastern Phoebe

We are happy to see (and hear) Eastern Phoebes in the backwoods. They were absent last summer after a hard frost in May. Whenever I band a phoebe, I am following in the steps of John James Audubon. In 1804 in Pennsylvania, he tied small strands of silver thread to the legs of phoebe nestlings. Birds returning the next year still bore the threads. Most phoebes winter in the southeastern United States, some continuing south into Mexico.

Thursday, April 20, 2017

Carolina Wren

Early this morning, I did not need eBird to tell me that Carolina Wrens were rare in Minnesota. This wren was in my banding net. Eckert reports that this species is regular but local and perhaps casual in the state. Most records are during migration and in the winter (in southeastern Minnesota). The Birds of South Dakota suggests that most records in our region are the result of post-breeding dispersal by young birds. On 20 April, however, this individual was clearly an adult.

Wednesday, April 19, 2017

Orange-crowned Warbler

In the Cannon River Wilderness Area on 17 April, the high point of our wildflower walk was actually a warbler. Because of its yellowish belly, lack of wing bars, and faint white eye stripe, I had no difficulty identifying this Orange-crowned Warbler, often a very common early migrant. eBird, when we tried to enter this record, alerted us that this bird was rare! Too early! Turns out that this bird, while not the earliest Orange-crowned Warbler in Minnesota history, is among the earliest.

A documenting photograph was required, but our warbler was not cooperative. It fed low in dense undergrowth. This image was the best I could take. The camera could not auto-focus through all the tangle, and the bird would not come out into the open. If you look closely, notice that it appears to be feeding on a small beetle; Despite the warm day, arthropods were not abundant.

Tuesday, April 18, 2017

Red Admiral and Spring Emphemorals

On 17 April, Erika and I took our annual spring ephemeral hike at the Cannon River Wilderness Area near Northfield. We were not disappointed. We found mats of Wood Anemone (above) and Spring Beauty (below). A half-dozen other wildflower species littered the forest floor. (Ephemerals are wild flowers that bloom before the forest leafs out.)
Common among the ephemorals flitted Red Admiral butterflies. Robert Pyle, in his entertaining book,  Mariposa Road, explains that Red Admirals are misnamed. They should be named Red Admirables. 
Admiral actually refers to butterflies in the genus Limenitis. This name was mistakenly applied to our American butterfly, Venessa atlanta. Pyle consistently refers to this species as Red Admirable. Whatever you choose to call them, these butterflies are highly migratory but can also overwinter. This one probably overwintered, since fresh specimens are more red.