Friday, March 31, 2017

Wood Duck

Reports of Wood Ducks bought us to the Dennison Water Treatment Ponds last Tuesday. My 2017 Year List seems to be progressing at a snail’s pace. We were delighted when a group of four Wood Ducks swooped low over the pond and spashed down in fromt of us. This image shows a drake with a hen.

In the early 1900s, Wood Ducks were thought to be doomed because of habitat destruction and over-hunting. The species has made a comeback, thanks to the Migratory Bird Treaty Act, hunting regulations, and conservation efforts. Expanding beaver populations have also contributed to habitat for expanding Wood Duck populations.

Thursday, March 30, 2017

Ross’s Goose

On Tuesday, Erika and I discovered seven Ross’s Geese at the Dennison Water Treatment ponds in Rice County. Its not every woman who gets dates to sewage treatment ponds! Ross’s Geese are very similar to Snow Geese. The Ross’s Goose’s bill, however, is much shorter than a a Snow’s, the bill lacks a black grinning patch (the line running along the top of the lower mandible), and Ross’s usually show blue warts at the base of their upper mandibles.

In the final photo, you can see the longer, black-ribbed, and non-warty Snow Goose bill. The bird to the right is problematic, since it is clearly larger than the Ross’s Goose to the left.  It does not help that these birds grazed between me and the sun, but, enlarging the photo, seems to show the blue wart field mark. Male Ross’s Geese are, in fact, six percent larger than the females, which may explain the size difference.

The two species also hybridize. In the photo of the Snow Geese (taken years ago in South Dakota), you see both color phases of Snow Geese—white and blue. The blue form is apparently the result of recessive genes in Snow Geese. Very rarely, blue Ross’s Geese are reported. Recent research indicates that  Ross’s Geese lack the blue allele. The blue forms, therefore, are thought to be hybrids between Snow and Ross’s geese breeding back with Snow Geese (Jonsson et al. 2013).

Tuesday, March 28, 2017

Downy Woodpecker Pattern Diversity

Downy Woodpeckers exhibit diversity in their head patterns. This variation allows observers to recognize individuals. The bird in the first photo caught my eye on 24 March 2017 because it seemed to lack the black line that runs from the bill to the shoulder on most Downys. As a result, this individual showed what appeared to be too much white on its head. Compare the first Downy with the one with a normal stripe in the second image taken on 1 January 2017.
The first Downy Woodpecker also sports a black line along the back of its head. Compare that pattern with the woodpecker in the final image, taken 27 February 2013. This difference in pattern is more common than the first. Clearly the books are mistaken that suggest this pattern difference is a way to tell Downy from Hairy woodpeckers.

Monday, March 27, 2017

House Sparrow

On Tuesday at Afton State Park, Erika and I saw something strange at a bluebird house. The opening of the box was protected from mammalian predators by a wire sleeve. We discovered a House Sparrow huddled in the sleeve.

House Sparrows, Tree Swallows, and House Wrens all compete for use of Eastern Bluebird houses. These species will even kill bluebirds during territorial fighting. Even competing female bluebirds are known to kill bluebird competitors. Cold and/or wet weather, however, may be the leading cause of bluebird fatalities (Gowaty and Plissner 2015).

Sunday, March 26, 2017

Sandhill Crane

On Tuesday morning, 21 March 2017, I stopped at a large marsh along side Albers Avenue north of Highway 19 here in Rice County, Minnesota. When I heard the unmistakable bugling of distant Sandhill Cranes, I jumped out of my car. Two cranes circled high over the wetland.

The cranes were probably flying over and defending breeding territory. During the decade since we retired to Northfield, cranes have become increasingly common local breeders. Rice County is near the southern limit of their Minnesota range. Although once common, by the mid-1940s the Minnesota Department of Natural Resources estimated only about 25 pairs nested in the state. Since then breeding cranes have made a steady, statewide recovery.

Saturday, March 25, 2017

Red-shouldered Hawk

Red-shouldered Hawks are considered to be uncommon and local raptors in Minnesota (Ekert). I have seen only a few of them over the past decade. Erika and I found this one actively hunting along the west shore of the Canby Pond along Circle Lake in Rice County. The hawk briefly perched in some small trees before working its way low along the lakeshore.

This bird’s field marks are strikingly evident in the bottom photo. Note the evenly barred, black and white tail. The left wing clearly shows a white crescent towards the tip and reddish-brown shoulders. The right wing is clearly russet underneath, as is the breast.

Friday, March 24, 2017

Golden-crowned Kinglet

On 23 March 2017 I banded two Golden-crowned Kinglets. Both birds were males. This fact may surprise some birders, who assume yellow-crowned birds are females. In fact, the orange crown of this male kinglet is hidden under the yellow feathers. If you look closely, you can almost see an orange hue under the yellow crown.

Golden-crowned Kinglets winter further north than Ruby-crowns. The species tolerates night temperatures below -40 degrees C. At such temperatures, Golden-crowns may huddle together, but they are not known to become torpid (Swanson et al. 2012).

Wednesday, March 22, 2017

Ring-billed Gull

I birded a small pond near Circle Lake in Rice Co. on 21 March 2017. About two dozen Ring-billed Gulls greeted me, The flew low to the water around the lakeshore. They tended to bunch up at the north edge of the lake, where the gulls flew against the 32 degree cold wind, Here they flew very slowly, using their legs as air-breakes, The birds carefully watched the water surface, and occasionally wheeling around, diving, and catching prey, which I assume, on such a cold day, were small fish.

Tuesday, March 21, 2017

American Robin

This morning, the first day of spring (20 March 2017), American Robins are everywhere. Because of the worn wing feathers and the pale-tipped wing coverts, I think this may be a second-year bird. I can’t be sure of this birds gender. If it is a local breeder, then this robin is definitely a male, Northfield females have duller backs and gray heads. Female robins from more northern latitudes, however, are often very dark and can not be told from their mates by plumage. Regardless of this bird’s destination, its good to have robin calls once again echoing in the backwoods.

Monday, March 20, 2017

American Coot

Running errands on Sunday, we stopped by Cannon Lake in Rice County. Surprisingly, we saw few waterfowl. We did encounter a flock of about two dozen American Coots foraging on a lakeside lawn. As always, I was impressed with how odd-looking these birds are. They look a bit like ducks or chickens. Their toes aren’t webbed. Instead the toes all have flaps along their edges. Coots are in the rail family, which is classified in the same order as cranes.

Sunday, March 19, 2017

Great Blue Heron

In this strange world of ours, a 2011 computer is an antique. Mine blew its graphics card, which Apple no longer manufactures. So I have a new computer. I spent the last two days upgrading software for my new operating system. This task is time-comsuming and often frustrating—and occasionally expensive. 

Although the job is not quite finished, I am, at least, up and running. I photographed this Great Blue Heron, on 18 March 2017, at the Superior Drive Pond here in Northfield. This winter, a few herons lingered in Minnesota. Migrants have already been seen by others. This bird was my first for the year.

Friday, March 17, 2017

Black-and-white Warbler

The computer from which I blog is experiencing "The Blue Screen of Death." Here is a posting I never got around to last year.

Black-and-white Warblers are a common migrant in Northfield. In the fall, males and females can be tricky to tell apart. In these photos, the male’s underparts are bright white. The female is pale buffy below. Because they winter north to the Gulf and the southeast Atlantic Coasts, Black-and-whites are among our first warblers to appear in the spring. By that time, the males throats have become mostly black.

Wednesday, March 15, 2017

Common Goldeneye

Despite being a common early spring migrant in our region, a decent Common Goldeneye photo has proved elusive for me. This image is, at least, interesting. On 14 March 2017, this male goldeneye flushed by the roadside near Sakatah State Park in southern Rice County.

Despite being vulnerable to environmental pollution, Common Goldeneye populations remain relatively stable. This duck breeds in northern forests across the world. Although some breed in northernmost United States, most breed across Canada. They winter in the United States when ice-free water persists. Most are found along the Atlantic and Pacific coasts. In the summer, Common Goldeneyes are insectivorous. In winter, fish, crustaceans and mollusks are added to their diet (Eadie et al. 1995).

Tuesday, March 14, 2017

Red Squirrel

Just before the snow on 12 March, I took this photograph of an American Red Squirrel, Tamiasciurus hudsonicus. Red squirrels are found across much of northern North America, venturing further south through the Appalachian and Rocky mountains. Red Squirrels are common and their range is expanding in our region. Although their diet specializes on conifer cones, the species has moved into deciduous forest, and even into prairies of southwestern Minnesota.

As I explored the Internet for something new to write about American Red Squirrels, I discovered an article by Ed Yong in the November 2016 issue of The Atlantic. I discovered that Eurasian Red Squirrels carry leprosy. I thought that armadillos are the only animals aside from humans to carry this disease. Armadillos got leprosy from European human explorers to the New World. Much of the world’s leprosy research takes place in Louisiana, where armadillos are abundant.

Luckily for our red squirrels, the European squirrels do not overlap with ours—and the two squirrels are not closely related. Eurasian Red Squirrels, Sciurus vulgaris, are in a different genus than ours. Armadillos can pass Leprosy back to humans, Although Eurasian Red Squirrels carry the same strains of Leprosy that infected medieval Europeans, there is no evidence of their passing the disease to humans.

Although once common, Eurasian Red Squirrels are endangered in Britain. Gray Squirrels, introduced from North America, have outcompeted them. The remnants of the British red squirrels are now mostly found in Scotland. Gray Squirrels also carry squirrel pox, a viral, tumor-producing disease that often kills the red squirrels. Squirrel Pox is also found in eastern North America, but here many infected squirrels survive the disease (Michigan DNR).

Monday, March 13, 2017

Brown Creeper/Downy Woodpecker

The recent warm weather left us with no snow cover. Beneath the bird feeder is white with suet crumbs, which brought several tree-haunting birds onto the ground. A Brown Creeper (8 March—upper photo), Hairy Woodpecker (10 March), and several Downy Woodpeckers (11 March)—lower photo) all feasted on the detritus. As I write this on 12 March, the cold weather has returned. We expect 10 inches of snow by midday Monday.

When I took the photo of the Downy Woodpecker, I did not notice the faint, red stain on the back of her crown. This area is where male Downys are bright red. What caused this abnormality?  Too much testosterone in a female bird? Too much red pigment in the bird’s diet? Left-over juvenal plumage? A gynandromorph? No clue.

Saturday, March 11, 2017

Ring-billed gull

It is hard to imagine that in the early 1900s, Ring-billed Gulls were almost persecuted to extinction. Populations have since rebounded into the millions and continue to increase (Pollet et al, 2012). These authors report that “Ring-billed Gulls are opportunistic feeders that mostly eat insects, earthworms, fish, rodents, and grain.”

I found a flock of several dozen Ring-billed Gulls feeding and loafing at a small pond near Faribault, Rice Co., Minnesota, on 7 March 2017. If you look closely, you can see the black rings on their yellow bills.

Friday, March 10, 2017

Bald Eagle

I took this second-year Bald Eagle photo on 7 March near Faribault, Rice Co., Minnesota. I almost deleted the image from my camera. The bird was far away. I hoped that I would get some interaction between the eagle and the crow; or, at least, the eagle taking flight. But the eagle paid little or no attention to the crow. As eagles do, this bird strolled along the shoreline, consuming dead fish.

When I got home, I noticed the eagle’s bulging crop. Bald Eagles gorge on large amounts of food. They are then able to fast for many days. Eagles avoid foul-tasting prey. I shouldn’t think that fish stored in a crop would be tasty. Fortunately, they have little sense of smell. In any case, captive eagles have gone without food for up to 32 days (Buchler 2000).

Wednesday, March 8, 2017

Cackling Goose

Canada Geese were always known to show remarkable size variation. DNA studies indicate small Canada Geese are quite different from larger ones. Recently ornithologists declared that the smaller ones are a separate species named Cackling Geese. One problem is that larger Cackling Geese are about the same size as smaller Canadas.

Birders and ornithologists have always been confused by goose races. An recent study proposed splitting Canada and Cackling geese into six species and 200 subspecies. This study, however, remains controversial. In any event, this photograph is definitely of a Cackling Goose. It is about the same size as nearby Mallards. I took the image at the Superior Drive Pond in Northfield on 4 March 2017.

Tuesday, March 7, 2017

American Coot

Because American Coots look ungainly on land and can’t swim without rocking their heads back and forth, some people say that coots are evidence that God has a sense of humor. Evolutionary biologists suspect that coots are derived from gallinules that became adapted for diving (Brisbin and Mowbray 2002). In any event, on Saturday, while searching for new birds of the year, I spied two coots on the Superior Drive Pond in Northfield. 

Monday, March 6, 2017

Common Grackle

My first Common Grackle of the year—on 4 March along the Superior Drive Pond here in Northfield. The bird squawked and puffed its feathers. Although I did not observe them, other males must have been nearby.

Common Grackles are common. They thrive in a variety of habitats and are not particular in their feeding habits. Their numbers have increased as eastern forests were cleared for agriculture. Their range moved west as shelterbelts were planted across the prairies. Only recently have populations declined after persecution for being pests. They damage sprouting corn and other crops (Peer and Bollinger 1997). They are not always welcome at bird feeders either. They are voracious consumers of seeds and sometimes kill and eat small birds.

Sunday, March 5, 2017

American Goldfinch

I banded a goldfinch on Friday. I have ringed very few birds this year. This goldfinch shows a hint of spring to come—note the black crown splotches. More interesting are this bird’s bright yellow shoulders. Goldfinches take two years to acquire this color. Second-year birds sport dusky shoulders. This bird, then, is aged ASY—After Second Year. See also my 2010 post on aging and sexing goldfinches.

Saturday, March 4, 2017

Eurasian Collared Dove

On Friday, I checked the town of Dennison in western Goodhue County for Eurasian Collared Doves. I’ve seen these birds there in previous years. Dennison is a tiny hamlet, dominated by its grain elevators. Grain, whether spilled from elevators or offered at bird feeders, accounts for the collard dove’s survival.

The birds originate from the Middle East and Europe. The first birds appeared in Florida, after being introduced to the Bahamas. Multiple releases cloud the origins of other North American collared doves, now found across much of the United States. Little seems to exist to halt their continued range expansion, and, in may areas of the United States, the species is abundant.

Friday, March 3, 2017

Tufted Titmouse

This photo is one of the strangest I have ever taken. The bird is a Tufted Titmouse. It flew to a Rice County bird feeder on 1 March. The titmouse grabbed a sunflower seed and flew away. Never have I seen a bird look so much like a four-legged creature.

The secondary wing feathers sweep in side view along the bird’s flanks. These feathers are attached along the ulna of the forearm. (The humerus is hidden beneath the body feathers; the radius lies along side the ulna.) Beyond the ulna lies the carpometacarpal bone—fused and elongated carpals and metacarpals homologous to the bones in our wrists and palms. The primaries are attached here and to the remnants of two of the bird’s three fingers. The primaries are being forced downward to generate upward thrust as the bird fled the feeder. I have never seen such a gap between primaries and secondaries.

Thursday, March 2, 2017

Bald Eagle

This Bald Eagle watched ducks with me at Wells Lake, just west of Faribault, Minnesota, last Sunday. It is hard not to be impressed with these large raptors, and I have posted accounts of these eagles on many occasions. The dark splotches on this bird's head indicate that it is just over 4 years old. In the next year, the head will molt into bright white heads and the body will become black.

Suffice to repeat here that the recovery of our Bald Eagles is one of our most successful conservation stories (Buehler 2001). After being listed under the Endangered Species Act of 1973, populations have dramatically increased. During this time, DDT levels have dropped and human persecution has decreased. They now breed in all Canadian provinces and every American state except Rhode Island and Vermont.

Wednesday, March 1, 2017

Lapland Longspur

As I reported yesterday, a few days ago I discovered a mixed flock of Lapland Longspurs and Horned Larks. Here are two of the longspurs. Both species fed on roadside weed seeds. Males (below) and females (above) can be difficult to identify. Note the chestnut wing patches of both sexes. The flanks are heavily streaked. Both sexes also have a dark line surrounding their ear patches. Males have faint chestnut collars and their heads and breasts become blacker as spring approaches.

Lapland Longspurs breed across arctic Canada. Like the Horned Lark, these longspurs are holarctic. They winter across most of the United States, except Florida, and the Southwest. They get their name from their elongated hind toe. Such toes are often typical of ground-walking birds.