Sunday, December 29, 2013

Red-headed Woodpecker

Yesterday, 28 December 2013, Erika and I took advantage of 43-degree (F) weather for a short walk at Big Woods. This State Park is a reliable location to find Red-headed Woodpeckers, which can be elsewhere difficult to find. We found three—this first fed in an interesting manner. Notice that the bird is not propping itself by its stiff tail. Instead the woodpecker ran/hopped sideways in the upright posture evident in the first two photos. It tore at the rotten wood and devoured what appears to be a large grub.
As indicated by the striking black patches in its white wings, the last woodpecker is relatively young. The bird carried a large acorn to the top of a tall tree. If only I took this photograph more quickly, before the bird cached the acorn in the  top of the tree!

Thursday, December 26, 2013

Mourning Dove

Despite Mourning Doves' being “notoriously sensitive to cold weather” (SD Game Fish and Parks), they do attempt to winter in our northern states. I saw two on Monday at a local bird feeder near Dundas.

They require cover, preferring river valleys with plentiful food sources like bird feeders or left-over grain. They do not always survive. In South Dakota, I once found two Mourning Doves that buried themselves in a snow drift, making themselves a snow cave, but were overcome by −40 degree temperatures. 

Inspection of this photograph will indicate that this dove’s portrait was not taken in the winter, but during a South Dakota spring near Aberdeen. The odd, greenish wash on the dove’s body is due to reflections from the Russian Olives in which the bird roosted.

Tuesday, December 24, 2013

Waved Albatross

Like the penguins of my last post, Waved Albatross are also restricted to the Galapagos Islands. Most breed on Española Island, which is where Erika and I took this photograph in the mid-1970s. Birds sighted on one other Galapagos island and Isla de la Plata, much closer to the mainland of Ecuador, may have been breeding. When not nesting, these albatross are encountered off the coasts of western South America (Wikipidia).

Birds of the World—Alive lists the Waved Albatross as “Critically Endangered.” Despite breeding in a national park, populations have declined since 2001. These birds scavenge dead prey, mainly squid and large fish. Over-fishing and El Niño fluctuations reduce prey populations. Local people also harvest albatross for feathers and/or food. Recently introduced Southern House Mosquitos, which are a vector for avian malaria, are also a threat.


We were impressed that the Waved Albatross, which has “obligate bi-parental care,” builds no nest. Eggs are laid in depressions on the ground. Once researchers were dismayed that they could find none of the eggs they had previously marked. They discovered that the albatrosses pick up their eggs with their feet and breast feathers and may move the eggs up to 30 feet a day!

Sunday, December 22, 2013

Galapagos Penguin

The Galapagos Penguin is a bird in trouble. Numbers have sharply declined since the 1970s (when Erika and I took this photograph). First, the species breeds only on the Galapagos Islands—95% of the 1000 existing individuals mostly breed on but two islands; the species is seldom found further than 40 miles from the archipelago (Birds of the World Alive).

More and more frequent El Nino fluctuations result in marine “perturbations” from which the penguins have a difficult time recovering (Birds of the World Alive). In the early 1980s, El Nino currents caused a 77% reduction in numbers and in late 1990s the penguins suffered a 65% decline. Apparently females suffer higher mortality than males, making recovery more difficult.

That’s not all. Feral and domestic cats kill about half the breeding birds each year. Tourists and fishermen also disturb breeding penguins. The birds are often drowned after being tangled in fishing nets. Overfishing also wipes out the bird’s prey. 

Maybe worse yet, in the 1980s the Southern House Mosquito was accidentally introduced to the Galapagos. The mosquitos carry avian malaria and Galapagos Penguins are highly susceptible to this disease. On top of that, the feral cats carry Toxoplasma, which has also been found in the penguins. 

Perhaps the only good news for this penguin is that the entire population breeds within Ecuador’s Galapagos National Park. These islands lie 575 miles from the South American mainland.

Friday, December 20, 2013

Red-tailed Hawk

This Red-tailed Hawk took up residence this December at the bird feeders at the Holden’s home. This young bird—its tail was not red—perched over the feeders but did appear to be interested in the plethora of goldfinches, chickadees, and Downy Woodpeckers. This hawk might not last long—it showed no concern about us, and allowed our close approach.

The hawk continually stared at the ground. I think the raptor waited for a mouse or a vole to venture from under the porch in search of seed. Curiously, the small birds seemed to pay little or no attention to the hawk in the midst. When an Accipiter investigates the feeders, the small birds either freeze or scatter. The small birds appeared to assume that a Red-tailed hawk posses little threat.
According to Preston and Beane (2009), Red-tailed Hawks mostly prey upon mammals (mice, ground squirrels, and rabbits), large birds (mostly pheasants and quail), snakes, and also, rarely, small birds. These authors cite a Wisconsin study of the winter diet as 44% cottontails, 28% voles and mice, and 10% Ring-necked Pheasants. In the spring, Red-tailed Hawks consumed 38% cottontails, 23% Ring–necked Pheasants, 14% squirrels and muskrats, 10% passerines and other small birds, and only 7% voles and mice.

Wednesday, December 18, 2013

December Great Blue Heron

On 19 November 2013, I found a Great Blue Heron west of Northfield, about which I blogged. Very likely this heron is the same bird. John Holden, Erika and I discovered it in exactly the same spot during the Faribault/Northfield Christmas Bird Count (14 December 2013). The bird looks a bit the worse for ware. After a week of subzero (Fahrenheit) weather, almost no open water is to be found in the vicinity. There can’t be too much around for the bird to eat.

My photo is not stellar. Snow fell from dark skies. To our surprise, the heron took flight and slowly flew down the otherwise frozen creek. We doubt the bird will survive the winter.

Monday, December 16, 2013

Herring and Thayer’s Gulls

The blog is a repost of one originally posted earlier today. I recieved a lot of good gull advice from various experts. Herring Gulls have variable plumages. I am confident that this first photo is a Herring Gull. The wing tips are extensively black. The second photo I thought might have been a Thayer’s Gull. But the general consensus is that, despite the reduced amount of black on the wing tips, it is also a Herring Gull. The wing tips just are not white enough for it to be a Thayer's.
On Sunday, 15 December 2013, Gerry Hoestra took me gull chasing to the west overflow of Black Dog Lake in Dakota County, just south of Greater Minneapolis. After taking a flurry of photos, we retired to our car since the temperature hovered around zero degrees Fahrenheit. When we returned to the gulls, we immediately noticed a new bird, somewhat smaller than the Herring Gulls, and definitely paler. This Thayer's Gull sported only the tiniest black spots on its wing tips. The fifth primary is black-tipped, typical of Thayer’s and absent in similarly plumaged Iceland Gulls (fide Hendrickson).

Saturday, December 14, 2013

Pacific Loon

In a post last year, I wrote about identifying Common and Red-throated Loons. The Red-throated Loon in the top photo has a speckled back and a relatively small, slightly up-turned bill. The Common Loon in the middle photo has a much larger bill and more white around the eye. The third photo is of a Pacific Loon that I found below Lake Oahe Dam near Pierre, South Dakota. Field marks include the small, but straight bill and the dark sides to the neck. Little or no white surrounds the eye.

The Pacific Loon may be the most common loon in North America. It is rare, however, in the central United States. After breeding across North America’s arctic tundra, most individuals winter at sea.

Thursday, December 12, 2013

Muscovy Duck

These photos depict Muscovy Ducks. While most domestic ducks come from Mallard stock, some are descended from Muscovys. Clearly these are ducks that only their mothers would love. Wild Muscovy’s differ from feral birds in a number of features, but especially by the amount to white on the feral birds’ heads and necks. Wild birds, which are found from Mexico through much of South America, do not have white on their heads of necks. Feral birds—those escaped from domestication—have variable amounts of white.

Wild stock has been introduced to south Florida and Texas. Both birds in this post are feral. The first photo was among a small flock strolling through the Key West (Florida) botanical garden. The second bird was near Victoria, Texas at Saxet Lake County Park. As feral birds, Muscovy Ducks are sort of like Rock Pigeons, not quite wild and often not really domestic. Despite the Texas birds being free flying, I notice that eBird did not confirm my report, presumably classifying them as domestic birds. My other record, no less feral, was accepted by the Florida eBird reviewers.

Tuesday, December 10, 2013

Mallard

Erika and I found this Mallard flock (plus one Canada Goose) lounging on Lyman Lake at Carleton College. We were impressed by the contrast in color between the red honeysuckle bushes’ red fruit and the ducks’ bright orange legs. Mallards are the most abundant duck in North America. They are cold-hearty (a good thing if you are going to survive a Minnesota winter) and they become tame when fed by people. Their food habits are described by Drilling et al. (2002) as “catholic,” meaning these ducks will eat just about anything.

Feral populations, often half wild, half domesticated, live in urban areas around the world. Mallards have been bred by people at least from the 12th century in Europe, and for more than 2000 years in Asia—the resulting in feral Mallards in great variety of shapes, sizes and colors—often confusing to beginning birders. Mallards are the source of the world's domestic ducks (the only exception is the Muscovy Duck, a species I will write about in an upcoming post).

Sunday, December 8, 2013

American Crow

This American Crow launched from the top of an overhead Hackberry tree in the Carleton College arboretum. This species is one of the most common North American birds, described by Verbeek and Caffrey (2002) as a “cunning, inquisitive, vocal opportunist.” I don’t think this crow fed on the Hacberry—about a half dozen of his noisy compatriots flew about, perhaps scolding us.

I have blogged about American Crows at least once before. The modern clearing and colonization of America created ideal crow habitat. People persecuted crows, who quickly learned that cities provide relatively safe havens from guns and also provide abundant food. Crows roost communally and, as most residents of the Twin Cities are aware, these roosts can contain thousands of birds.

Friday, December 6, 2013

Ring-necked Duck

Returning from Carleton College last Sunday, John Holden and I found this drake Ring-necked Duck in the small creek that runs through the Northfield Country Club. I have posted about this species a few times before—you can search for these musings with the search-box on the right-hand column of this blog.

I am surprised to find this diving duck so late in the season and in such shallow water. I wonder if this bird is wounded. Migrants, however, often feed in flooded fields, so our shallow creek should not be unexpected. They also like shallow lakes and other freshwater wetlands. Ring-necked Ducks enjoy a more general diet than other North American diving ducks, and thus survive where other species might have trouble. These habits have led to population increases, but, on the other hand, leave this species vulnerable to ingesting poisonous lead shot (Roy et al. 2012).

Wednesday, December 4, 2013

Black Scoter

On Wednesday (27 November 2013) along the St Croix River at Prescott, Wisconsin, John Holden and I discovered a strange duck. I was uncertain what to name the bird until other birders began reporting a Black Scoter, both in Wisconsin and across the river in nearby Minnesota. Identification of female Black Scoters hinge on their pale cheeks and fore-neck, contrasting with their dark crown.

Black Scoters are rare fall migrants in central Minnesota. The species is, indeed, “one of North America’s least known waterfowl” (Bordage and Savard 2011). They have disjunct breeding grounds in northern Alaska and western Canada and in northern Quebec. Most winter on our Atlantic and Pacific coasts. Very few nests have been described from the western hemisphere. Populations suffer significant cycles, and, therefore, are sensitive to hunting during low years.

P.S.: Peter Nichols reported to the MOU listserv on 7 December 2013, "Shortly after 10 AM this morning, I  … saw a Bald Eagle swoop down and fly off with the Black Scoter."

Tuesday, December 3, 2013

Trumpeter Swan

Last Wednesday, John Holden and I checked out Point Douglas Park in Washington County, near the junction of the Mississippi and St. Croix rivers. We found a few waterfowl, including this Trumpeter Swan. Coincidentally, this location is the same as where I last blogged on the species in December 2010. In that post I discussed the reestablishment of these swans in North America.

Identifying field marks of this swan include the long, straight bill, the lack of yellow in front of the eye, and the overall large size. Tundra Swans are smaller and usually have yellow on the bill, which has a more curved profile.

Despite a number of challenges to the swans’ success, Trumpeter Swans are on the increase. In 2005, a continent-wide survey came up with 34,803 of these swans, an increase of over 11,000 birds in five years (Mitchell and Eichholz 2010). Challenges, however, include disturbance at their nesting and roosting sites, shooting, environmental contamination, and habitat degradation and destruction.

Sunday, December 1, 2013

Cackling Goose

Among the Canada Geese roosting on Carleton College’s Lyman Lakes, Erika and I found a few Cackling Geese. We were alerted to the presence of these small geese by our BirdsEye app on our new iPad. They had been originally reported by Gerry Hoekstra. Our first Cackling Goose is in the top photo—the closest bird on the bottom left-hand corner. I previously summarized how to identify Cackling Geese—suffice to repeat here that the Cackling Goose is generally smaller with a tiny, stubby beak. Note, however, that larger races of Cackling Geese overlap in size with smaller subspecies of Canadas. Mark Stackhouse warns “identifying Cackling and Canada Goose [sic] by size alone will only work at the extremes of both species."
We took the second photo to illustrate some of the differences between the two species. Note the feather stuck to the tip of the smaller Cackling Goose. In the field, we did not notice the white forehead on the larger Canada Goose. This variation in head pattern is occasionally found in all populations of Canada-like geese and is illustrated in Sibley(2000). Some internet sites erroneously suggest the white forehead is characteristic of the largest race of the Canada Goose, often called the Giant Canada Goose.