Sunday, April 30, 2017

Yellow-rumped Warbler

On 29 April 2017, Erika and I gave a banding demonstration at Big Woods State Park here in Rice County, Minnesota. The day began in the low 30s F. We felt our prospects for succuss were low. We were greeted, however, by swarms of Yellow-rumped Warblers. The campground hosts erected a dozen feeders laced with lard, peanut butter, and sugar.

In three hours, we banded 82 birds. fifty-one were Yellow-rumps. Many were males, told by their striking black and blue plumage. Others were dull and were probably females. The sex of a drab bird, however, can not be ascertained for certain. (These first two photos were actually taken the day previous at the University of Minnesota Landscape Arboretum.)

Among the males we caught two individuals with yellowish throats. These birds may be hybrids between eastern Yellow-rumped (Myrtle) and western Yellow-rumped (Audubon’s) warblers. Audubon’s Warblers’ throats are much brighter yellow; Myrtle Warblers’ throats ought to be white. Once before in Rice County, I banded similar warblers and I discussed hybridization elsewhere in this blog. The general consensus among ornithologists is that hybridization between these races is quite limited and many experts are lobbying to split them, once again, into two species. 

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.

Monday, April 17, 2017

Trumpeter Swan

I find myself slipping behind with blog posts—a good situation, I suppose. Erika and I took this Trumpeter Swan photo on 7 April at the Bass Ponds in the Minnesota Valley National Wildlife Refuge in semi-urban Bloomington, Minnesota. Who knew that swans can make bubbles with their necks?

Trumpeter Swans were reintroduced to our region beginning in the 1960s.  They are now fairly common. Not all swans show such rusty heads and necks. This stain is caused by iron-rich water and mud (Mitchell and Eichhotz 2010).

Sunday, April 16, 2017

Common Green Darner

My first dragonfly of 2017. Migrating Common Green Darners are often the first odonates of the year, appearing even before local populations emerge from their ponds. They fly from as far south as Veracruz, migrating to southern Canada. Migration is assisted by warm fronts, exactly the weather phenomenon that occurred in Northfield yesterday. A warm front parked right on top of us!

I found this individual tangled in my bird net. Dragonflies don’t get stuck in the nets very often, but, when the do, they are often very difficult to free. After liberation, this darner shivered for a few minutes and then disappeared.

Friday, April 14, 2017

Hooded Merganser

Hooded Mergansers appear to be abundant this year. This photo was taken on Cody Lake here in Rice   County, Minnesota. I did a quick literature search and was surprised to learn that ornithologists really don’t know much about current Hooded Merganser population trends. They think that numbers are increasing, but have little scientific data to support that hypothesis (Dugger et al. 2009). Eckert writes that this species is an uncommon breeder across Minnesota, but is more common during migration.

Thursday, April 13, 2017

Bloodroot and Siberian Scilla

Spring just can’t be far off. Bloodroot and Siberian Scilla (Squill) are blooming along the edge of our backwoods. 

Scilla is “a classic case of gardening gone awry” (Minnesota Wildflowers). This pretty, early-blooming flower is introduced to the United States. It is cold-tolerant.  It spreads out of control. Local wildlife ignores it. The plant is hard to eradicate. Broken roots resprout. In other words, this plant, although sold in stores, is a noxious invasive species.

I hope our native Bloodroot withstand the scilla invasion. Bloodroot is also a harbinger of spring. Bloodroot gets its name from its red sap. The sap produces alkaloids that kill animal cells. Bloodroot, although disfiguring, has been unsuccessfully used as a home remedy for skin cancer (Wikipedia). Obviously eating Bloodroot is not recommended and is potentially fatal.

Wednesday, April 12, 2017

Great Blue Heron

On 2 April 2017, this Great Blue Heron hunted the edges of Circle Lake in Rice County, Minnesota. This species is among the most abundant North American wading birds. They mainly eat fish, but also stalk small mammals and amphibians in fields and other upland habitats. They will take almost any animal they can pierce with their dagger-like bills.

Tuesday, April 11, 2017

Yellow-bellied Sapsucker

On 9 April 2017, I banded a female Yellow-bellied Sapsucker. This individual gave me pause, because I thought females’ crowns were red. (Males also have red throats.)

A quick review of the literature indicates the female crowns vary. Often they are red, like the one in this previously posted image. You can find females with black crowns. In the second edition of his guide, Sibley illustrates a black-crowned sapsucker. Crowns can also be “mixed red and black, black with red spots on [the] forehead, or [be] black with buffy markings” (Walters et al. 2002).

Monday, April 10, 2017

Scarlet Cup

Scarlet Cups are called “harbingers of spring” (Smith). These mushrooms fruit from early April through May. I discovered these in the leaf litter below my banding net on 9 April. Amazingly, I found this species at the same location and on the same date in 2011. Scarlet cups are found in North American hardwoods.

Smith does not recommend eating Scarlet Cups, although this fungus is consumed by rodents in the winter and slugs in the summer The Iroquois used this mushroom as an antibiotic to treat the belly buttons of newborn babies. These cups are also occasionally used for table decorations (Wikipedia). 

Sunday, April 9, 2017

Mourning Cloak

Our first butterfly of 2017, despite freezing temperatures the previous night. A Mourning Cloak circled us on 7 April and then landed on the trail in front of us, as Erika and I strolled along the Bass Ponds in the Minnesota River Valley National Wildlife Refuge near Minneapolis. 

In Minnesota, Mourning Cloaks are the first butterflies in the spring. They often emerge in the fall and then hibernate during the winter. Coincidentally, 7 April also marked our first Mourning Cloak in 2011. This butterfly is probably in for hard times, since snow is predicted tomorrow night.

Saturday, April 8, 2017

Mallard on the Roof

Zelda and Scott are our resident Mallards during the ten years we have run our water feature. When approached this year, they flew to the roof of our house. Previously they just flew away. We have no clue if we get the same individuals every year, nor do we know where they nest. 

Friday, April 7, 2017

Red-breasted Nuthatch

Red-breasted Nuthatches are smaller than White-breasted Nuthatches. The Red-breasted has a different call and has different habitat preferences, preferring conifers over deciduous woodlands. They range across Canada and the northernmost United States, with more southern populations in the Appalachian and Rocky mountains. The planting of conifer forests recently caused the species’ breeding range to expand to the south. Unlike sedentary the White-breasted Nuthatch, Red-breasteds irrupt southward, even to the Gulf Coast and northern Mexico, during years with poor conifer seeds. 

A few Red-breasted Nuthatches have visited our feeders this winter. I banded this male on 1 April 2017. I did not remember that this species’ bill is bicolored. In the second image, on the base of the lower mandible, notice the lovely pale horn hue.

Wednesday, April 5, 2017

Eastern Bluebird

On 31 March, Erika and I watched a flock of six male Eastern Bluebirds make their way through a forest edge at the Whitetail Woods Regional Park in Dakota County. We were impressed by the brilliance of their blue.  Bluebirds appear even more brilliant to each other. They see ultra-violet light. Male bluebirds reflect this color especially well (Gowaty and Plissner 2015).

This bluebird shows a couple of interesting features. I expected only young bluebirds to show the yellow base to the bill. If you look closely, notice the white-tipped secondary coverts on the wing. In other thrushes, these tips are held-over juvenile feathers. I suspect this bird, therefore, is a bird hatched last year.

Tuesday, April 4, 2017

Eastern Meadowlark

This Eastern Meadowlark sang from the top of a cedar sapling in the Great Western Industrial Park near  Randolph, Dakota County, Minnesota (29 March 2017). I previously posted on the perils of meadowlark identification. The non-gurgly, clear whistle and the yellow throat color not penetrating the sides of its head indicate Eastern Meadowlark.

The Eastern Meadowlark’s range is strange. They breed across most of central and eastern Minnesota and much of the eastern United States. They are almost absent in North Dakota and much of South Dakota. They breed in southwestern South Dakota and, curiously, much of the Southwestern United States, south into Central America.

In any event, this bird’s long hind toes indicate that it forages on the ground. Meadowlarks are generally in decline across North America. Loss of grassland habitat and industrialization of agriculture both contribute to this trend. Severe winters also take a toll on meadowlark populations.

Monday, April 3, 2017

Red-winged Blackbird

Red-winged Blackbirds have made their spring return to Minnesota. This male sang at the Dennison Water Treatment Ponds. The species may be the most abundant bird in North America (Yasukawa and Searcy 1995). Winter populations may exceed 190 million birds. Historically Red-wings were marshland breeders, but changed to nesting in pasture and grain fields. The species has flourished with the spread of American agriculture. Furthermore, Interstate Highway roadsides, with their barrow and drainage ditches, also support this species’ expansion.

Sunday, April 2, 2017

American Tree Sparrow

Another bird present at the Dennison Water Treatment Ponds was this American Tree Sparrow. This sparrow is headed north—the species breeds across remote areas of northern Canada. It winters across the northern and central United States, where it inhabits weedy fields and marshlands. Tree Sparrows often visit suburban bird feeders.

American Tree Sparrows are abundant birds. Somewhat surprisingly, considering their wide habitat tolerances and remote breeding areas, tree sparrows have declined by 53% between 1970 and 2014 (Naugler et al. 2017). Ornithologists do not have an explanation for this downward trend. Industrialized agriculture and loss of weedy fields in their winter range is one hypothesis for the decline.

Saturday, April 1, 2017

Song Sparrow

Song Sparrows are common and widespread across most of the United States, southern Canada, and parts of Mexico. In our part of the world, Song Sparrows are migratory. Many coastal populations are year-round residents. The species occupies a wide range of habitats—often near water—including forest edges, chaparral, marshes, and hedgerows. This bird sang from brush along the Dennison Water Treatment Ponds and, on 28 March, was my first Song Sparrow for this year.