Saturday, March 30, 2013

Western Meadowlark


On Saturday, 30 March 2013, Erika and I photographed a Western Meadowlark near Lake Byllesby, Goodhue Co., Minnesota. This species is not that rare in eastern Minnesota, just hard to identify. See my discussion on telling Eastern and Western meadowlarks apart. I based my identification of this bird on the fact that the yellow of the throat runs up the malar stripe on the side of the head—the area below the eye and above the throat. The black tail bars not touching may also indicate that this bird is a Western Meadowlark.

Friday, March 29, 2013

Red-breasted Merganser

We are just back from a quick trip to Northern Virginia. One of the birding highlights was finding courting Red-breasted Mergansers at the Riverbend Park run by Fairfax County. This 400 acre preserve lies upriver, on the Potomac River, from the Great Falls National Park. Unlike the federal park, this county park does not charge admission.
The two male mergansers in the upper photo appear to be displaying Sprint behaviors. Here the birds rush along the water to create waves in the water. This behavior allows the males to approach the females. In the second photo, you can see the males were successful. Often females lower their bills towards the water in order to incite male courtship.
Male displays often involve several males and one female. Here the males are showing a Salute Behavior, indicating their interest in the female. Their white neck patches and white backs are especially evident. Their tails are often dropped downward. Males regularly synchronize this behavior.
Females, on the other hand, are not very active participants in these displays. The female in the last photo appears to be stretching, a comfort movement used to keep feathers dry and properly arranged. My source for this ethology is Titman (1999).

Wednesday, March 27, 2013

White-tailed Deer

A few days ago, I came face to face with three White-tailed Deer. Because they eat the shrubs, injure trees, carry Lyme Disease, and potentially damage the water feature, deer are not my favorite visitors the back yard. I have previously posted in this blog why more deer now inhabit the United States than in other time in our history.

Monday, March 25, 2013

Sidewinder


Obviously I am not much of an herpetologist. About as close to a rattlesnake I care to get to is when they are run-over on the highway, as is this Sidewinder many years ago in Arizona's Organ Pipe Cactus National Monument. Sidewinders are encountered in the deserts of the far southwest (Arizona, Nevada, California, and northwestern Mexico).

Note the "horns" above its eyes. These are actually elongated eye scales, perhaps used to help shade the eyes or prevent sand from drifting over the eyes.

The Sidewinder is named for its sideways locomotion, the result of which are J-shaped marks left in the sand. You can almost see these marks in the dirt road. Other desert snakes also sidewind, as do many snakes on slippery surfaces (Wikipedia). This kind of movement is excellent for traction on sandy soils.

Wikipedia claims that Sidewinder venom, although extremely painful, is weaker than other rattlesnake poison. Nevertheless, any rattlesnake bite can be fatal. Remember my warning in the last post on the Prairie Rattlesnake: recently deceased snakes retain the reflex to strike.

Sunday, March 24, 2013

Prairie Rattlesnake

Prairie Rattlesnakes are found across the western Great Plains of the United States and southern Canada.  Stebbins (1985)considers this snake to be a race of the Western Rattlesnake, but recent genetic research indicates that rattlesnakes west of the Rocky Mountains are, in fact, a separate species.

Prairie Rattlesnakes give birth to live young (instead of laying eggs) and often females give birth at communal dens. Up to 25 young are born at a time (Wikipedia).  These rattlesnakes feed on a wide variety of small mammals, and young will also take ampibians or reptiles. I suspect the swelling halfway down this snake may be a small mammal. Once a Prairie Rattlesnake got twisted in the lowest trammel of my bird net. Later I autopsied the snake and found two field mice, which created a similar swelling (reminiscent of the boa that swallowed an elephant in The Little Prince).

Usually only careless people are struck by this venomous snake and then only if the snake is injured or feels threatened. Inquisitive children are more often hit than are adults. The snake in this photo, taken at the Theodore Roosevelt National Park in southwestern North Dakota, was one of many we found dead on the road. Seeking souvenirs, some people are tempted to cut the rattles off dead snakes. But these people are unaware that freshly dead snakes still retain a striking reflex. Thus more people have been bitten by dead rattlesnakes than by live ones. Being bitten by a rattlesnake is often a very unpleasant experience, often resulting in gangrene, amputation, and, occasionally, death.

Friday, March 22, 2013

A Few Good Terns

This photo was taken on the causeway that runs downstream from the Oahe Dam near Pierre, South Dakota. This location, in my opinion, is one of the region’s premier birding spots. Interesting birds can be seen during any season. The huge Lake Oahe attracts vagrants like Long-tailed Ducks and jaegers and, as can be seen in this picture, a host of more common species. The Missouri River in South Dakota hosts both eastern and western North American birds.

Five species of gulls and terns loafed on the causeway. The gull in the foreground is a Ring-billed. The large bird behind the gull is a Caspian Tern. The black terns scattered throughout the background are Black Terns. Most of the gray and white terns in this photograph are Common Terns. The two terns with back sides to their heads and white crowns are non-breeding Forster’s Terns. A sixth species, a Least Tern, occurred nearby.

Although Forster’s Terns are more common than Common Terns in Minnesota, Common Terns are the most widespread North American tern. Note the Common Terns’ orange-red bills and grayish underparts. It is hard to see here, unlike in Forster’s Tern, the tails are usually shorter than the wingtips. All of these field marks can be subtile. I suspect the bird directly to the right and slightly behind the Caspian Tern is a breeding-plumaged Forster’s Tern. It is brighter white underneath and appears of have a more yellowish bill.

Wednesday, March 20, 2013

Forster’s Tern

In Minnesota, Forster’s Terns are more common than Common Terns. They are local breeders in the west and northern southeast areas of the state (Eckert). They also breed elsewhere in the Upper Great Plains and Great Basin, and also in northern California and the Gulf Coast. This photo is from the Sand Lake National Wildlife Refuge near Aberdeen, South Dakota. In our region, they breed in fresh water, marshy wetlands. The species is adaptable to changing environmental conditions and is able to switch nesting marshes in times of drought (Mcnicholl et al. 2001).

Identification marks to look for include their white-edged flight feathers and upper wing coverts, the orange-yellow bill, and their tail, which sticks out beyond the wingtips. Be careful for juvenile and first-winter Forster’s Terns, which sport darker primaries than do adults and, thus, can be mistaken for Common Terns.

Monday, March 18, 2013

Grinning Red Squirrel

I do not believe I have ever seen a grinning Red Squirrel. Usually they aggressively go about in a business-like fashion. This one was enjoying sunflower seeds under the bird feeder on St. Patrick’s Day. I have written before that, although they do not hibernate, Red Squirrels are often inactive during bad weather. The 17th of March was a sunny day, with blizzards predicted for that night and the next morning. Perhaps this squirrel is replenishing its food cache.

For those of you who blog on Blogspot, you may have noticed that the blog searching app has not been working.  A fix that is better than the original is available at http://www.ericm.ca/2009/10/21/bloggers-search-box-gadget-not-working.

Saturday, March 16, 2013

Eastern Chipmunk

Today, 16 March 2013, the first Eastern Chipmunk appeared under the bird feeders. As you can see, winter holds on and, indeed, this weekend we are only between snow storms. I have posted previously that chipmunks spend much of the winter in torpor, awaking occasionally only to eat from their food caches, but usually not leaving their dens. Surely this appearance indicates spring will eventually return to Minnesota!

Friday, March 15, 2013

Short-horned Lizard

Short-horned Lizards are the only horned lizards found in North Dakota, where Erika and I discovered this one in the Theodore Roosevelt National Park. In North Dakota, they are only found in badlands of the western tier of counties. Otherwise they range across semiarid and mountainous areas of the Western United States (and barely to Canada, where it is considered to be endangered) into central Mexico. The reptile is more cold tolerant than other species, allowing a distribution into high elevations and northern regions. They subsist on ants, spiders and sowbugs (Northern Prairie Wildlife Research Center).

They are often called “horned toads,” but most of my readers are probably aware that horned lizards are not amphibians. Horned lizards give birth to 5 to 48 live young. They are also infamous for squirting blood from their eyes. This defense mechanism is accomplished by an ability of increase blood pressure in its head. According to Wikipedia, foxes, coyotes, and dogs are deterred by the sight of this blood; horned lizards seldom use this defense against people. When disturbed, they can also become more intensely colored. 

Wednesday, March 13, 2013

Rock Wren

Several years ago, Rock Wrens were a highlight of the combined meetings of the South Dakota Ornithologists’ Union and the North Dakota Bird Society in the Theodore Roosevelt National Park in southwestern North Dakota. This wren inhabits rocky and craggy habitat across most of the western United States and Mexico, spilling over to both adjacent Canada and Central America. Rock Wrens nest in crevices, and often build curious walkways of small, flat stones that lead to the otherwise hidden nests (Lowther et al. 2000). This Rock Wren sang boisterously and in the open high above the Little Missouri River.

Monday, March 11, 2013

Bison

Several years ago the South Dakota Ornithologists’ Union and the North Dakota Birding Society met near Theodore Roosevelt National Park in southwestern North Dakota. As is the case in most state bird organization meetings, the birding and the fellowship were excellent.

Various factors, including intentional and unintentional over-hunting, draught, and conversion of prairie to agricultural land, combined, by 1894, to nearly cause the extinction of North American Bison (Hämäläinen 2009). In that year, the United States initiated protection of the species. Today more than 500,000 Bison survive—the descendants of several private, small herds. Only some 15000 are considered “wild,” which is to say not confined primarily by fencing (Wikipedia). In 1956, Bison from Nebraska were introduced to Theodore Roosevelt National Park. Now between 300 and 700 animals roam the park.

Bison are among the most dangerous animals in western national parks. They can charge at speeds up to 40 mph, and will do so if they feel provoked. At Theodore Roosevelt National Park, visitors are warned that “if the tail is straight up in the air, a charge may be imminent.” At Yellowstone National Park between 1980 and 1999, more than three times as many people were injured by Bison than by bears (79 vs. 24). Of those injured, one was killed by a Bison and three by bear (Wikipedia). When we came upon the Bison in the lower photo, we gave it wide berth and were relieved to see its tail not sticking straight up!

Saturday, March 9, 2013

Pine Warbler

Northeastern Minnesota lies on the northwestern limit of the Pine Warbler’s breeding range. In Minnesota they are uncommon—I have seen one in Duluth, but never in Rice County. The species is common in pine forests of eastern United States and adjacent Canada. Unique among warblers is that Pine Warblers breed and winter almost entirely within North America. One reason for this hardiness, which also results in their being early spring and late fall migrants, is that Pine Warblers are also one of the few warblers that regularly consume seeds. Notice the seed in this Pine Warbler’s beak. This photo was taken in the winter along the boardwalk at the Corkscrew Sanctuary in central Florida. Actually, “few data exist on the frequency of [seed-eating] away from feeders and the importance of seeds in the fall or winter diet” (Rodewald et al. 1999).

Thursday, March 7, 2013

Townsend’s Solitaire

In December 2011, I posted about seeing a Townsend’s Solitaire at the Carpenter Nature Center in Washington County, Minnesota. I do not have much to add to my previous account of this bird’s biology. Yesterday, following leads on the MOU listserv, Erika and I visited St. Mary’s Cemetery in Minneapolis. Since the trail was a couple of days old, we were not overly optimistic for success.  In the cemetery, we were stopped by another visiter, who asked, “Are you looking for the solitaire?”  “Yes,” we replied. “I just saw it, follow me!” After a very short wait, the solitaire flew to the top of a very tall cedar.  Later it moved to the top of a nearby deciduous tree. We do not often chase after birds reported on the listserv, but this year we are three for three—Boreal Owl, screech-owl, and solitaire—with a little help from our fellow birders. This camaraderie is certainly one of the attractions of birding.

Tuesday, March 5, 2013

American Three-toed Woodpecker

Once thought to be the only woodpecker found in boreal forests of both the Old and New Worlds, ornithologists recently determined that North American birds are genetically distinct from European and Asian birds. Because they are now considered to be separate species, our birds are now named American Three-toed Woodpeckers.

This woodpecker breeds across Alaska and Canada, and south through the Rocky Mountains almost to Mexico. In Minnesota the species is rare, with very few confirmed breeding records (Eckert). This photograph was taken in the Black Hills of South Dakota. The range corresponds with spruce forests. This woodpecker specializes on eating bark beetles. In South Dakota we often looked for three-toed woodpeckers in and near dead trees left by forest fires. Indeed, Leonard (2001) writes that this species is threatened by “fire suppression and salvage logging of trees damaged by fire or insects.”

Leonard also relates a rather macabre Native American tale in which "many ages ago, in a time of famine, [the three-toed woodpecker] devoured his mate, and wiped his claws clean on the back of his head; … [a] yellow mark of the ‘fat,’… remains [on the bird’s head] till this day."

Sunday, March 3, 2013

Eastern Screech-Owl

A friend directed Erika and me to this gray-phase Eastern Screech-Owl in Minneapolis. In the field, we thought this owl kept its eyes tight shut, but, looking at this photograph, this bird did keep almost half-an-eye on us. Notice that the owl’s right eye is open by a slit—you can barely see its greenish-yellow eye and its black pupil.

Eastern Screech-Owls come in gray and rufous morphs. Northern birds are more often gray, while more southern birds are often rufous. Both phases can hatch out of the same nest. Although the situation may be more complex, the rufous plumage appears to be due to a dominant gene, and gray is recessive. Apparently rufous feathers are not as robust as gray ones, so the rufous birds may have less insulation in cold climates. Females are more often rufous than males. Females tend to be larger than males, and, because of the resultant relatively low surface area to body mass ratio, retain heat better than males. Finally, urban populations contain more rufous individuals than do surrounding rural areas. Cities often create heat traps during cold winters—allowing urban rufous birds to survive (Gehlbach 1995).

Friday, March 1, 2013

Reddish Egret

I have previously posted about the Reddish Egret’s feeding dance. The species, found from our Gulf Coast and along both coasts of Mexico and Central America, is our least common heron. Only some 2000 pairs remain in the United States (Lowther and Paul 2002). As previously mentioned, this species comes in a dark and a white phase. In our country, dark birds are more often observed.  White morphs are more common in the Greater Antilles.