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.

Friday, November 29, 2013

Review: The Crossley ID Guide/Britain & Ireland


Richard Crossley and Dominic Couzens have published a new guide to the birds of Britain and Ireland. This book adheres to the Crossley system of bird identification in which plates are crammed with dozens of bird photographs. The birds in these photos come in different sizes (ranging from adequate to frustratingly tiny) and postures, all against busy habitat scenes. Ascertaining the relative sizes of the species is difficult. Sample plates can be viewed at the Amazon site links in this post.
Crossley’s hypothesis is that we learn to identify birds by knowing size, shape, behavior, probability, and color patterns. You don’t get this synthesis in a normal field guide. Crossely writes, “repetition and familiarity are the best tools for learning any subject.” He believes that traditional portraits with arrows indicating salient field marks are not the most effective educational tool. Nevertheless, the guide begins with 12 pages with small photographs of single birds, often with up to three dozen species per page. Although small range maps accompany each plate, the book lacks a detailed map of Great Britain. The text accompanying the plates is short and in very small font.

So how did you learn to identify birds? While I was in the seventh grade, my two brothers and I competitively quizzed each other with a stack of 5 x7 cards with Agassiz bird portraits on them. I think these cards were from the Audubon Society. That year my teacher, John Trott, initiated a year-long bird identification unit in conjunction with his banding birds. Much of my birding involved peer learning. If I were learning birds today, undoubtedly I would be using the Thayer Birding Softwarequizzes and attending birding field trips.

Although I own Crossley’s earlier book on eastern birds (see link below), when I need a field guide, I first turn to my Sibleyguide. But Crossley claims his book is not aimed at me, but, rather beginning and intermediate birders. His goal is to teach neophytes. I would love to know if he has evidence that his system is better than traditional field guides. 

Wednesday, November 27, 2013

Black-throated Sparrow


Black-throated Sparrows breed across much of the western United States and Mexico. Northern populations migrate south in the winter. The species can be common and consumes insects in the breeding season, and grass seeds, and, while breeding, also a variety of arthropods. Populations in the United States may be declining with thr growth of urban areas and the clearing of mesquite lands for agriculture (Handbook of Birds of the World Alive). I took this photo along I-10 in New Mexico.

Monday, November 25, 2013

Black Walnut

Last week, Erika and I found these Black Walnut fruits on a tree in the Carleton College Arboretum. Black Walnuts are found across eastern North America. Black Walnuts have been widely introduced elsewhere in North America and Europe. The nuts are often expensive, but offer "a gourmet touch to cookies, breads, and cakes” (UMN Extension). This source gives instructions for the harvest, curing, and storage of Black Walnuts. Nuts are harvested by hand from wild trees, mostly from Missouri. The fruits in this photo are past their optimal harvesting stage.

Black Walnuts are large, long-lived deciduous trees. Fruiting begins when the tree is about five years old—the tree may live about 130 years.  The tree produces high-quality wood. The shells are used as an ingredient in abrasive cleaners, cosmetics, oil well drilling, and water filtration (Wikipedia).

Saturday, November 23, 2013

Ginkgo

Readers can find a plethora of information on the Ginkgo on the WEB. This tree has been used medicinally for thousands of years and is now one of the top-selling items American herbal remedy stores (Mayo Clinic); they are also eaten as food. But be careful gentle reader, the Mayo Clinic lists only two or three diseases, out of nearly 100 claims of efficacy, that ginkgo has been firmly and scientifically proven to alleviate. Even these few ailments are not prevented, like some types of dementia and pain from clogged leg arteries. These diseases are perhaps equally well-treated by conventional medicines. Note that various Ginkgo tissues can be poisonous, depending on the dose and the part of the tree from which the herbal medicines are derived. The seeds are poisonous, but, as an enzyme in the seeds speeds up alcohol metabolism, were traditionally served with alcoholic drinks in Japan (Encyclopedia.com). People can also suffer various and potentially serious allergic reactions to Ginkgo. 
But the Ginkgo’s pharmacological potential is not what interests me most. Last week I was surprised to find a female Ginkgo at the Minnesota Landscape Arboretum. Females are not often planted because their fruit is messy and smells like rancid butter or vomit. Most Ginkgo trees you see in city parks are males, which can be propagated by grafting or grown from shoots. Look for these magnificent trees along major city boulevards.

The Ginkgo is a “living fossil.” Until one was discovered in 1690 in a Japanese temple garden, European botanists knew the tree only from 270-year-old fossils. Because of its high status in Buddhism and Confucianism, the tree was widely planted in Japan and Korea. Trees in those countries now found in the wild are so genetically uniform that they are generally believed to have escaped from cultivation (Wikipedia). 

Some temple trees are thought to be over 1500 years old. Ginko trees survived the bombing of Hiroshima and some of those trees live today. The tree has now been cultivated around the world and has been grown in the United States for the past 200 years. Nevertheless, in our country, the Ginkgo does not grow in the wild (Wikipedia).

Note the parallel veins in the leaf in the photograph below (taken several years ago at the Landscape Arboretum—the same tree, in fact, as in the first photo). Such venation is typical of primitive plants, as is the single split in the central part of the leaf. Their reproductive cycle is also primitive. Their exact relationship to other plants is uncertain, but may be most closely related to seed ferns (Wikipedia). They have no close living relatives.

Thursday, November 21, 2013

Great Blue Heron

I found this Great Blue Heron in almost the only open water I encountered on 19 November 2013. Air temperatures were slightly below freezing and most of the local lakes sported a thin coat of ice. (The relatively warm weather of the last two days has transformed the lakes back to a liquid state, but the bitter cold predicted for the weekend should reverse the ice-free trend.)

When they are cold, herons droop their wings to absorb warmth from the sun (although this bird stood in the shade); they also avoid wind by seeking shelter, in this case behind a steep riverbank. Note that the heron is standing on one leg, keeping the other tucked up under its ruffled feathers. Presumably the heron is also using a counter-current exchange in the wet leg. This system exchanges the warmth of arterial blood with the cold venous blood coming from the lower foot. The result is that most of the bird’s heat is retained near the body rather than lost to the cold water.

Stragglers are known to attempt to winter in Minnesota, but most Great Blue Herons winter south of the state. The spots on the wing coverts and the solid-gray crown indicate this bird is in its first year. This heron did not appear to be wounded or sick (although it walked away rather than flying).

Tuesday, November 19, 2013

Jabiru

Jabirus breed from southern Mexico to southern Bolivia, northeastern Argentina and Uruguay. This stork is abundant only in the Chaco Pentanal of Brazil, Paraguay and Argentina, otherwise this bird is considered to be a threatened species. I took this photo at Yarinacocha in Amazonian Peru on 26 July 1972 and, despite my years in Peru and Ecuador, I have never seen one since.

A few vagrants have been reported from south Texas and one from Tulsa, Oklahoma. I think these records should be accepted with caution—perhaps as few as 250 Jabiru survive in Central America (Handbook of Bird of the World—Alive; AOU Checklist). More likely the Texas birds are escaped from captivity, as Jabiru are occasionally kept in zoos.

A number of reasons exist for the decline of the Jabiru. Typically they nest on the crowns of tall palm trees. The nests are made of sticks and mud, which are added to each year. Note the large stick being carried by the Jabiru in my photo. Eventually either the palm is killed or the nests, getting to be 2 meters wide and 1 meter deep, fall. Adults also often desert their nests, which are also attacked by Crested Caracaras. The species is also vulnerable to habitat destruction and hunting. The fat young are a popular food item in the Amazon Basin (Handbook of Bird of the World—Alive).

Jabiru eat almost any small animal they can catch, including fish, frogs, crabs, snakes, insects, turtles, and even young caimans (which are subdued by the Jabiru beating them against logs). Fish are often herded by groups of Jabirus into shallow water. Jabiru are not adverse to stealing food items from other storks or ibis (Handbook of Bird of the World—Alive).

Sunday, November 17, 2013

Mountain Caracara

While Crested Caracaras are the only caracaras found in the United States, other species inhabit South America. Mountain Caracaras are found in the Andes from southern Ecuador to central Chile. I took this photo high in the Peruvian Andes.

Although these large, atypical falcons are strong fliers, they feed on the ground, scratching and stomping to disturb arthropods, rodents or birds. They also feed, often with vultures, upon carrion and human garbage. They build unsubstantial nests on cliffs, while others build larger nests on electric towers (Handbook of Birds of the World—Alive).

Friday, November 15, 2013

Crested Caracara

Crested Caracaras are found from southern Texas and southern Arizona to northern South America. An isolated population also breeds in central Florida. The first photo was one of my first (taken almost 50 years ago!), a caracara in eastern Mexico. The orange spot in the middle of its breast is probably its naked, extended crop. I photographed the second bird a couple of years ago in the Rio Grande Valley of Texas.

Caracaras are opportunistic feeders that specialize in carrion. They often feed in flocks and with vultures. They are classified as falcons but are often mistakenly thought to be vultures or hawks. Locally known as Mexican Buzzards, in Mexico they are sometimes called “Quebrantahuesos,” which I translate as Bone-breakers. They enjoy carrion but also search for whatever invertebrates or vertebrates they can find. The name caracara is thought to be derived from “traro-traro,” a Native American word mimicking one of the caracara’s calls. The Aztecs were inspired to build their city Tenochtitlan (now Mexico City) by a caracara eating a snake while perched on a cactus. This legend is depicted on the Mexican flag and on their coat of arms (Morrison and Dwyer 2012).

Wednesday, November 13, 2013

Pileated Woodpecker

Banding a Pileated Woodpecker, like this female caught last week, is often a noisy, bloody affair as the bird drills holes in the bander’s hands (see gif on a previous post). This woodpecker is a “keystone species” in forest ecosystems (Bull and Jackson 2011). The holes excavated in trees by this species are used by many birds and mammals for shelter and nesting (Boreal Owl, Wood Duck, martens). Furthermore, Pileated Woodpecker workings decompose and recycle forest logs. Because their deit consists of carpenter and other wood-eating ants and beetles, forest trees are protected from attack by these arthropods.

Monday, November 11, 2013

Brown Creeper

Brown Creepers breed from Alaska, and southern Canada, south to the northern United States and through the Rocky Mountains to Mexico and Central America. They winter across much of North America. Here in the southern half of Minnesota, they are often abundant migrants and common winter residents. Elsewhere, populations have declined as mature forests are logged and dead trees cleared.

We banded this creeper among a flock of Ruby-crowned and Golden-crowned kinglets. This photo is one of the few in this blog that is heavily photoshopped (to erase my hand from the picture, but leaving the bird mysteriously floating in space). My goal here was to show you how this often-considered to be drab bird is actually quite elegant. When they are abundant in our back woods and as they furtively creep up forest tree trunks, Erika often calls these brownish birds "tree lice." But look closely at the checkered wing patches and the rusty rump!

Small birds like creepers and kinglets often struggle to maintain their body heat during frigid Minnesota winters. During cold spells, creepers roost in tree cavities and often roost in tight masses of 20 or more individuals behind loose pieces of tree bark (Paul and Bernice Noll).

Saturday, November 9, 2013

Giant Water Bug

I was surprised to find this Giant Water Bug trucking across the Carleton College Arboretum. They are common across the northern United States and Canada. They are among our largest bugs and are active all year. They normally live under water. In the fall, these bugs fly about looking for deeper waters where they continue hunting their prey under the winter ice. Often they are attracted by lighted areas at night as the bugs are moving to suitable ponds and rivers.

They eat a variety of invertebrates and tadpoles, salamanders, small fish and even birds (eduwebs). Their larger prey is caught by their powerful front claws and subdued by enzymes injected to the prey’s body. Their bite is painful, but they are otherwise harmless to people.

Thursday, November 7, 2013

Eastern Bluebird

Eastern Bluebirds, like this young bird Erika and I saw in the Carleton College Arboretum, are always pleasant to find. Previously, I posted a few times on this species—try the search box to the right side of this blog.  Recently I published posts about Western and Mountain bluebirds.

All three species of bluebirds are known to hybridize, albeit infrequently. Genetic studies indicate that Eastern and Western bluebirds diverged in the late Pliocene, some 2.45 million years ago (Gowaty and Plissner 1998, Power and Lombardo 1996). These studies also conclude that bluebirds, although definitely thrushes, are not closely related to other members of the thrush family.

Tuesday, November 5, 2013

Greater Yellowlegs

On Saturday, 2 November 2013, I saw a large shorebird feeding in a riffle in the Cannon River. My first thought was “Willet,” but soon I observed yellow legs. The leg color, the large size, and long, somewhat up-curved bill add up to Greater Yellowlegs.
Elphick and Tibbitts (1998) list a wide variety of wetland habitats for the Greater Yellowlegs. Although these authors include slow-flowing streams, this yellowlegs’ river was slightly beyond slow-moving. Up to its belly in water, the yellowlegs moved quickly, occasionally feeding like an egret, plunging its bill, head, and neck into the river. Both yellowlegs consume invertebrates, but, unlike Lesser Yellowlegs, Greaters also eat small fish.

Sunday, November 3, 2013

Golden-crowned Kinglet

At the end of October, we banded a few small, mixed-species flocks of kinglets and creepers. We caught a couple of dozen birds. All but one of the kinglets, both Ruby-crowned and Golden-crowned, were male. In the fall, male Ruby-crowned Kinglets migrate later than their females, thus the lack of females this year is somewhat perplexing. This Golden-crowned Kinglet is a male—note the orange feathers at the back and under the center of the crown.

Golden-crowned Kinglets breed further south and winter further north than Ruby-crowneds. Golden-crowneds, however, are hardier and migrate later than Ruby-crowneds. Wintering birds here in Minnesota can withstand nighttime temperatures below −40 degrees C. In such conditions, small groups of kinglets may huddle together to keep warm (Swanson et al. 2012).

DNA studies indicate that kinglets are closely related to titmice and Old World warblers. Golden-crowned Kinglets are closely related to European Goldcrests. Ruby-crowned Kinglets, on the other hand, are only distantly related to Golden-crowned Kinglets (Swanson et al. 2012).

Friday, November 1, 2013

New Zealand Fantail

New Zealand Fantails are Old World Flycatchers that occur in two morphs, a pied morph such as in this photograph, and one that is black. Erika and I photographed this fantail in 1990 at Arthur’s Pass in New Zealand’s South Island.  Here 75 to 88% of the birds are pied. On New Zealand’s North Island, 99% of the birds are pied. This bird’s buffy eye stripe indicates that it is young.

New Zealand Fantails are widespread and occur in both native habitats and in parks, farmland, and pine plantations. They eat arthropods, most often flycatching, and occasionally seeds. Often they follow other birds, and also feed near livestock or humans. These small, tail-swishing birds are threatened by introduced species such as cats, possums, and mynas—furthermore they are often roadkill (Handbook of Birds of the World—Alive).

Wednesday, October 30, 2013

American Robin


More evidence of this year’s poor fall migration at the banding stations in Northfield: last year I banded 31 American Robins in October; this year only 7.  I do not have any definitive answers to this year’s poor migration except to mention that other people in parts of southern Minnesota have also complained of a lackluster showing of birds this fall. Realize that I am not saying anything about birds away from my banding stations—a few days ago Erika and I observed about 100 robins feeding on basswood trees at River Bend—but the birds sure are down in numbers in my yard in Northfield.

Monday, October 28, 2013

Australian Bush Turkey

Megapodes, or bush-turkeys, are found on the islands of southeast Asia and Australia. This Australian Bush-Turkey, as its name implies, is found in eastern Australia. This bird is odd looking—its tail appears to be stuck on sideways. The species originally inhabited coastal rainforest. Cutting of the rainforest has forced bush-turkies into disturbed areas and suburbs. These are omnivorous birds, they eat about anything, and are often found at landfills.

Megapodes (also known as mound-builders) share with some reptiles the curious behavior of building nesting mounds. They lay their eggs in big piles of leaves and earth; mounds can contain 4 tons of material and average 85 cm high (and up to 700 cm). By adding or taking leaves off these compost piles, they keep their eggs at an optimal temperature of about 33.3 degrees C.  The mounds can retain their heat for several weeks, not requiring attention from the birds.

Males are polygynous and build the mounds. Curiously, bush-turkeys occasionally use human compost piles, modifying them for their own use. Females are serially polyandrous (they stay with a single male for several weeks, but then move on to new mates). Several females may lay in one male’s mound. Males can have two active mounds, each containing up to 58 eggs, although only only up to 27 come from each female.

Most of this information is from The Handbook of the Birds of the World Alive, a web-based resource that I recently reviewed in this blog. I took this photograph in 1990 a city park in Port Macquarie, Australia, when our family toured after Erika and I presented a paper at an ornithological congress in New Zealand.

Saturday, October 26, 2013

Great (October) Egret

On a cold, gray 23 October 2013, John Holden and I were surprised to find a Great Egret approaching us along the shore of Circle Lake in Rice County. The end of October is a bit late for this egret in Minnesota, although birds are known to linger into November.
I quickly realized that this egret presented a photographic opportunity—a white bird against a smooth gray background and no horizon line or distracting sandbar or vegetation.
During the half hour we observed, the egret slowly strolled towards us. Every two or three minutes, the bird speared what appeared to be young bullfish, an abundant Minnesota catfish, inhabiting even muddy, shallow, or polluted waters of the state.
We did not think the egret was in any way impaired, escecially considering its apparent fishing success. When the bird finally flew, however, its legs seemed to dangle to the right and its muddy toes appeared to be oddly opened. While the bird foraged, however, nothing seemed to be amiss.