Thursday, April 30, 2015

Speckled Green Fruitworm Moth

Scott King told me the identity of this moth. Field marks include the large, liver-shaped spots on the back of the wings—spots that have a large black dot on the inner halves. I found this moth, to my surprise, on a fake, floating waterlily in our water-feature. (The water-feature is always too shady and now is too early for waterlilies for the pond to support real waterlilies.)

A wide variety of deciduous trees serve as hosts for Speckled Green Fruitworm Moth caterpillars. These caterpillars are, indeed, green and often damage fruit crops. The genus is usually nocturnal and can be baited with sugar water or light (Peterson (2012). To me, because of its furry body and black eyes, this moth looked like a caped, extra-terrestrial creature from a Star Wars movie. In fact not extra-terrestrial, this species is found throughout eastern North America.

Wednesday, April 29, 2015

Spring Beauty

Every spring, Erika and I find Spring Beauty flowers. Usually they are solitary or in small clusters. This year, however, we were surprised to find them growing in luxuriant mats. I blogged about Spring Beauty in 2011 and 2013.

Spring Beauty's scientific name is Claytonia virginica. The species name, virginica, simply means that the plant is from Virginia. Claytonia has a more interesting derivation. In the early 1700s, John Clayton was a Virginia county clerk whose passion was botany. He sent specimens to Mark Cateby (a naturalist who was also a famous ornithologist) who forwarded many of Clayton’s specimens to European botanists. Among these Europeans was Linnaeus, who, in 1730, using Clayton’s collections, named 400 new plant species, including Spring Beauty (Gracie 2012).

Tuesday, April 28, 2015

Hermit Thrush

I took this photo of one of the Hermit Thrushes I banded this spring to show off some of its field marks. A little creative Photoshopping erased my hand. Two things to consider first. The Hermit Thrush is the only thrush expected in the Upper Midwest in April—it is an early migrant, usually seen before the other thrushes arrive. Next, the Hermit Thrush habitually bobs its tail up and down.

The distinct spots on the breast might tempt you to call this a Wood Thrush. But Wood Thrushes are larger birds that have reddish heads, brighter than their backs and tails. The Hermit thrush only has a reddish tail. Veerys are uniformly reddish above. Finally some observers might say this is a Swainson’s Thrush, because of the tan eye-ring. Swainson’s Thrushes do have a tan eye-ring, but lack any rufous color anywhere on their head, back, or tail.

Sunday, April 26, 2015

Double-crested Cormorant

When I took this photo near Dallas, Texas, this spring, I was not positive as what kind of cormorant this one was. The facial skin is yellow like a Double-crested Cormorant, but its bill seems more the size of a Neotropic Cormorant. The Neotropic, however, should have a more distinct white line behind the bill. Likely this individual is a juvenal Double-crested Cormorant molting into adult plumage, since young cormorants often have smaller bills than do adults. In any case, the yellow face is diagnostic of Double-crested Cormorants.

Saturday, April 25, 2015

Yellow-bellied Sapsucker

I banded this female Yellow-bellied Sapsucker on 22 April. Because the facial markings are rather indistinct, I assume this is a second-year bird molting into its adult plumage. Several crimson feathers in the sapsucker’s otherwise white throat fascinated me. I band but a few sapsuckers a year, and I have never noticed red feathers such as these. Male sapsuckers have red throats, but I do not think this bird is a young male. No red adorned the bird’s nape, so it is unlikely to be a hybrid with a Red-naped Sapsucker of the Rocky Mountains.

My Sibley field guideshows nothing like this plumage. When I looked up sapsuckers in Peter Pyle’s Identification Guide to North American Birds, Part I, I discovered that female Yellow-bellied Sapsuckers molt later than do Red-bellied Sapsucker (although molt should be finished by April). Furthermore, female Yellow-bellieds’ throats, while normally pure white, occasionally contain a few red feathers. Pyle’s book, by the way, is a guide to identifying, aging, and sexing North America's songbirds (and a few others). The book is essential for bird banders, and, despite its lack of color illustrations and dependence on written text, is probably well worth the money for intermediate to advanced birders.

Friday, April 24, 2015

Carolina Wren

Carolina and Bewick’s wrens can be difficult to tell apart. Juvenal and worn adult Carolinas can be quite pale below. Bewick’s tend to be browner, less chestnut above—they are also smaller than Carolinas. Finally, as I mentioned in my last post, Bewick’s Wrens have a relatively longer tail that the bird flips about, almost like a gnatcatcher.

This bird in this photograph is clearly a Carolina Wren. This species is common in the southeastern United States and is found in almost every woodland and even in urban areas. This wren’s call is a loud, distinctive “tea-kettle, tea-kettle, tea-kettle,” and the bird is often heard before it is seen,

Thursday, April 23, 2015

Bewick’s Wren

On one morning’s walk near Dallas, Texas, I heard an unfamiliar bird song. It sounded vaguely like a Song Sparrow with a loud trill. I made bird noises—squeaking and such—and attracted the songster’s attention—a Bewick’s Wren.

My not knowing the Bewick’s Wren’s call may be forgiven, as the species has mostly disappeared from the eastern United States. Now they are a bird of the West (see my 2012 post). One field mark worth noting is this wren’s tail, much longer than the somewhat similar Carolina Wren. This particular wren, however, was too shy to let me photograph its tail.

Bewick’s calls vary greatly across their range. Males learn their songs from neighboring birds and they tend to have large repertoires (Kennedy and White 2013). These repertoires gradually change geographically. Here is a link to several Bewick’s Wren songs.

Wednesday, April 22, 2015

White-throated Sparrow

Each spring I am impressed by the beauty of the White-throated Sparrow. Previously in this blog I explained that both male and female White-throated Sparrows appear in one of two morphs, one bright and the other dull. The morphs come out of the same nests, behave differently, and usually breed with opposite morphs.

In the same blog, I also joked about how different people interpret this sparrow’s plaintive song. White-throated Sparrows in the United States sing "Poor Sam Peabody, Peabody, Peabody" but, upon entering Canada, sing "Oh sweet Canada, Canada, Canada!" Minnesota White-throated Sparrows, on the other hand, sing, "Poor Sven, Pederson, Pederson, Pederson."

Tuesday, April 21, 2015

Sunbathing Roadrunner

While visiting family near Dallas, and under the tyranny of Erika’s new Fitbit,we often took morning strolls. “What is on the roof of that house?” we asked each other. “An exhibitionist roadrunner raising its feather dress well above its hips!” We had never seen anything quite like this behavior (although I have blogged on the species several times).

Sunbathing roadrunners are described in the ornithological literature. Hughes (2011) writes that roadrunners sunbathe, while standing on fenceposts or rooftops, for two to three hours in the early morning. The wings “are drooped and held away from the body, “ while the “cervial plumage is erect, exposing black skin of the interscapular apterium…"

Sunday, April 19, 2015

Northern Mockingbird

Northern Mockingbirds are rare in Minnesota, so seeing them is always a pleasure. This mimic-thrush is common within its range, and most abundant in Florida and Texas. I have previously blogged on the species, which is found in parks, yards, and brushland. These photos are from the Dallas, Texas suburbs where we recently visited family.
Across the country, with few, local exceptions, mockingbird numbers are generally declining by almost 2% a year. Farnsworth et al. (2011) note that mockingbirds have “disappeared as a breeding species in Minnesota.” Biologists are unable to explain this trend.

Saturday, April 18, 2015

Possible Myrtle x Audubon’s Warbler hybrid

During the last two days in Northfield, Minnesota, I banded my first Yellow-rumped Warblers of this spring. I always double-check to make sure the bird I am banding is not a western “Audubon’s,” instead of the expected eastern “Myrtle” race. See my previous blog about identifying these two races.

One of the four Yellow-rumped Warblers I captured this morning startled me. The throat, which I expected to be pure white, was definitely washed with a relatively intense yellow. Otherwise the bird sported typical Myrtle field marks—a white supercilliary stripe above the eye, and the lack of a white wing patch. I believe this bird is a hybrid between an Audubon’s and Myrtle warbler. Overall, the bird is quite similar to Sibley’s illustration of a hybrid in the most recent edition of his field guide.

I have banded hundreds (if not thousands) of Yellow-rumped Warblers. Over the years, I have encountered at least two typical Audubon’s Warblers in eastern South Dakota. They breed in the Black Hills of western South Dakota. Minnesota enjoys about a half-dozen Audubon’s Warbler sightings. Today’s bird, however, is my first record that I have suspected of being a hybrid. Sibley writes that, although hybridization is common, hybrids are infrequently reported away from the Canadian Rockies, where the two forms overlap.

Friday, April 17, 2015

House Sparrow and Tree Swallow

On Tuesday I watched House Sparrows and Tree Swallow compete to occupy bluebird houses. Last year I wrote about Tree Swallow and bluebird interactions. Swallows also compete with House Sparrows. In the late 1800s, House Sparrows spread across the country. I have also blogged about this phenomenon. This rapid range expansion is somewhat paradoxical, since local House Sparrow populations tend to be relatively sedentary. Apparently cities and towns served as islands of safety for the expanding House Sparrow populations—islands that lacked occupants of the niche that sparrows occupy. Lowther and Cink (2006) write that, if you want to discourage House Sparrows’ supplanting bluebird or swallow nest boxes, then you should place the boxes at least 100 meters from farmyards and other sparrow habitat (such as livestock pens).

Wednesday, April 15, 2015

Bald Eagle

Back on the road on 12 March 2015, Erika and I found ourselves with a little extra time. I searched for nearby “hotspots” in eBird, and found the Tonkawa Sewage Ponds, a short distance from I-35 in Oklahoma. Perhaps a strange tourist site, but promising a variety of waterfowl. To our dismay, we found the area posted (as are most sewage ponds), and sewage personnel refused our request to enter. (eBird hotspots are supposed to be accessible to birders.)

The only saving grace was this juvenal Bald Eagle. We listed eagles in many locations during our travels. The fact that eagles were recently (like in the mid-1900s) endangered is hard to remember. They were the victims of human persecution and DDT and other pesticides that interfered with reproduction. Their recovery “represents one of the continent’s most successful conservation stories” (Buehler 2000). By the late 1900s, all the Canadian provinces and all but two states in the continental United States boasted breeding Bald Eagles.

Tuesday, April 14, 2015

Black-capped Chickadee

When we head south on our various winter trips, in order to escape the frozen Northland, we try to drive about as far as we can. This usually means we aim for Andover, Kansas, about ten hours south of Northfield. Nevertheless, this marathon drive does not always guarantee freedom from icy roads.

This year our escape was successful. The next morning, 12 March 2015, Erika and I took a short stroll. Chickadees greeted us. At first I assumed these must be Carolina Chickadees, and eBird did not warn me that the range of the Black-capped Chickadee dips into most of Kansas. Sibley’s guideshows that the Carolina barely ventures north into the state.

I was uneasy about the amount of white on the edges of the flight feathers—too much for most Carolinas. Then a bird started to call, “Chick-a-dee, Chick-a-dee-dee!” This call was typical of a Black-capped Chickadee; Carolinas usually sing five to seven “dees” at their call’s end.

Sunday, April 12, 2015

Bloodroot

Today, 12 April 2015, upon our return from a month’s traveling to Texas and Florida, we were greeted by the first Bloodroot of the spring as it bloomed in Erika’s garden. Bloodroot seeds are often propagated by ants, and, thus, like this individual, can appear unexpected places.

Bloodroots are poppies, and like many plants in this family, have colored, sappy liquid in their roots—in this case blood red. They are early bloomers, and are able to do so because of the relatively warm microclimate along the forest floor.  Their main polinators are bees.

Native Americans used bloodroot as a dye and for various medical remedies, including bronchitis, asthma, and sore throats. The sap is reputed to have hallucinogenic properties and contains propotine, also found in the opium poppy. Another name for Bloodroot is Sweet Slumber. Sanguinarine is another alkaloid found in Bloodroots. In the late 1900s, it was used in mouthwash as an antiplaque agent. Sanguinarine was later found to cause a ten-fold increase in mouth cancers, and has since been removed from the market (Gracie 2012).

Wednesday, April 8, 2015

White-bellied Sea-Eagle

One of our more unlikely outings during our 1990 trip to Australia was to take a mangrove tour out of   Forster. At one point, to entertain us tourists, the guides threw hunks of chicken off the back of the boat. This sea-eagle, in the same genus as our Bald Eagle, made repeated and successful swoops for the bait. In more normal circumstances, sea-eagles consume a wide variety of prey (mammals (including rabbits and wallabies), birds, reptiles, fish, and crustaceans), and even highly venomous sea snakes (Handbook of the Birds Alive). The species is generally common across much of Southeast Asia and coastal Australia.

Monday, April 6, 2015

Ebony Jewelwing

These Ebony Jewelwing photos are from last summer. I found these damselflies in the Carleton College arboretum. Unlike males, females, like in the first picture, have white spots on their wings. These markings are called stigma. Sigma have several, non-mutually exclusive functions. They can serve as signals to potential mates or rivals. They may act as weights to dampen wing vibrations. Finally, they may increase wing flexibility and thereby guard against stress fractures (Seattlepi.com).

Thursday, April 2, 2015

Blue-winged Warbler

I photographed this Blue-winged Warbler last spring. Elsewhere in this blog, I discussed the genetics of Blue-winged and Golden-winged warbler hybrids. Blue-winged numbers have greatly increased since their discovery. Because they prefer brushy scrublands, they benefited from the cutting of the Eastern forests and eventual abandonment of farmlands. As their numbers increased, their range expaned northward, often replacing the genetically similar Golden-winged Warbler (Gill et al. 2001). Only in recent years have populations declined, as a result of forest regeneration or urbanization of scrublands.