Western Forktail

On 17 July 2014, Erika and I found another new odonate for us along the Madison River, Gallatin Co., Montana. The green thorax stripes and the blue-notched tip of the abdomen are indicative of the Western Forktail. Separating Eastern from Western Forktails can be nearly impossible in the field, but, fortunately, only the Western is found in western Montana—the Eastern venturing only to the Dakotas and eastern Montana, Wyoming, Colorado and New Mexico.

Males like this one are usually vastly outnumbered by their females. Similar to the Eastern Forktail, females need copulate only once, and then use one male’s sperm to fertilize their eggs. By fluttering their wings and curling their abdomens, the females, in fact, often repel males’ advances (Paulson 2009).

American Bittern

I still don’t know how John Holden saw this American Bittern. On Wednesday morning, we drove slowly across the 180th Street Marsh in Dakota County, Minnesota. “Stop the car!” shouted John, “I think that’s a bittern!” “Where?” I asked. “Right in front of us,” he exclaimed. “Where?” I asked again, “In the green grass?” “No, in the corn field.” Only when the bittern finally moved, did I finally see the bird.

I never thought to look for a bittern in a corn field—they usually inhabit wetlands. They favor marshes with tall reeds or cattails, where they cryptically blend into the background. Bitterns usually do not pursue their prey, but wait motionless for the prey to come to them. They are usually most active at dawn or dusk. In a previous blog post, I wrote about the bitterns’ declining numbers due to wetland degradation and destruction.

But the bittern was not finished with us. The bird casually strolled out of the cornfield and walked towards us across a dry, grassy patch. Now and again it struck and consumed prey—what appeared to us to be either grasshoppers or perhaps small frogs. (They also eat other insects, amphibians, crayfish, small fish, and even small mammals.)

When disturbed, bitterns sometimes freeze or even play dead—but this American Bittern walked right up to our car, so close I could no longer take photos. I got out of the car and took more photos.  The bittern did not move, though occasionally it puffed up its neck feathers. Only when I turned around to my side of the car did the bittern fly the short distance back to the cornfield. 

Lowther et al. (2009) comment that “remarkably little is known about basic aspects of [bittern] biology.” They are usually too secretive and their habitats too inaccessible. Erika and I marveled at the last photo—the eyes clearly afford the bittern with binocular vision, and the eyes are oddly placed on the bottom half of the head. Perhaps this placement allows the bittern to keep its eyes on you while it points its bill skyward to further blend into its environment. 

Turkey Vulture

Erika and I kicked up a Turkey Vulture along the roadside on a very windy 3 October 2014. The black-tipped bill suggest that this bird is relatively young. I was impressed this bird’s ragged plumage. Almost nothing is known about Turkey Vulture molting patterns (Kirk and Mossman 1998). Molt may continue throughout the year.

Turkey Vultures are one of the few birds than have an acute sense of smell. When Erika and I were in Ecuador, beetle collectors visited us. On the jungle floor, the entomologists left leaf-covered coffee cans laced with excrement. These traps did not wreak, but quickly attracted numbers of vultures, even though the birds could not see the bait. I have read that oil companies sometimes locate pipeline leaks by pumping carcass odor into the pipes and then waiting to see where the vultures congregate.

Downy Woodpecker Deformed Bill

On 9 June 2014 I banded a male Downy Woodpecker with a deformed, elongated bill. Having previously banded a Black-capped Chickadee with a deformed bill, this woodpecker record is my second for deformed bills at our Dundas banding station.

Allaboutbirds.org reports that an Alaskan study found 25 species with deformities. Contrary to that report, none of the Alaskan birds were first-year birds (Van Hemert, pers. com.). Other banding studies found that deformities develop in birds between six months and two years of age. My woodpecker was over two years old, as evidenced by its black primary coverts (but, of course, this age does not indicate when the bill began developing abnormally).  This woodpecker does not seem to be in very good health, its feathers are soiled and its weepy eye is surrounding by missing feathers. I have not recaptured or seen this individual since the initial banding.

What causes bird to develop abnormal bills is not known. Hypotheses run from injury, disease, parasites, poor nutrition, genetic defects, exposure to contaminants, and exposure to extreme heat (Allaboutbirds.org).

Review: National Geographic Complete Birds of North America, 2nd Ed.

Today, 7 October 2014, National Geographic is publishing the second edition of its book, Complete Birds of North America. This 744-page guide lists for $40.00. The book is edited by Jonathan Alderfer, and written by “America’s top birding authorities.” The guide is touted at a “companion” to the National Geographic Field Guide to the Birds of North America.

This guide is in search of a slightly different niche than other bird books on the market. It is not a field guide. For one thing, it has slightly larger dimensions than the Sibley Guide to Birds, and is about 140 pages longer, and relatively heavy, making it impractical to take into the field. You would use it to identify birds after a field foray. This new book has much more text than a typical field guide, and that is its strength. Birders’ attention is verbally directed to salient field marks.

Twenty-one artists contributed the uniformly excellent color illustrations for this book. Frustratingly, the illustrations often do not allow multiple, side by side species comparisons. Many of the illustrations are the same as in the 6th edition of the National Geographic Birds of North America. The back cover, however, boasts that 600 art “pieces” are new. About a 44 species are new to this edition; there are about 200 more pages.

Range maps are large, clear and updated. Unlike Sibley’s field guide, accounts that deal with subspecies have maps showing the races’ ranges. Racial range maps were included at the end of previous Geographic field guides, but having the maps on the same page as the account is more convenient. Furthermore, the illustrated subspecies are clearly labeled, unlike in Sibley, which does not include a race’s scientific name.

Unique in the new Complete Birds of North America are box-essays on difficult identifications. These essays include photographs. Photographs of single species also accompany family introductions throughout the book. These family accounts also mention pertinent taxonomic issues. The text includes sections on identification, similar species, geographic variation, voice, status and distribution, and population trends.

Curiously lacking is any in-depth discussion of other aspects of avian biology and ecology. For example, heat conservation by small birds does not seem to be mentioned. Hybridization is not discussed between Black-capped and Mountain chickadees in areas where both species overlap but are scarce. On the other hand, hybridization between Black-capped and Carolina chickadees is mentioned and the reader is wisely warned “where the two species occur together, it is probably best to leave many of them unidentified.”

The Complete Birds of North America's target audience is probably the intermediate to advanced birder. I think any birder should give it a close examination, either at a bookstore or by clicking on the link at the beginning of this review. Finally, no birder would turn down a gift of this book.

Eight-spotted vs. Twelve-spotted Skimmer

One problem with Montana is that  its almost impossible to drive across and search for birds and dragonflies at the same time. I have a favorite rest area where Interstate 90 crosses the Madison River near Three Forks in Gallatin County. This spot is not an official rest area, but a fishing access off the frontage road on the north side of the Interstate.

Despite windy, chilly conditions on 17 July 2014, a few dragonflies chased each other above cattail-edged pools. At first I thought these were Twelve-spotted Skimmers, like the one in the second photo from the Lebanon Hills Regional Park near Minneapolis (photographed in July 2013). But they appeared a bit odd. The wings seemed short, maybe because they lacked terminal black spots. The white spots on the hind wings blended together. The abdomens appeared very bright blue-gray.

All dragonflies should be so easy to identify! These odes were my first Eight-spotted Skimmers. This dragonfly is found across much of the western United States, east only to Colorado and Wyoming. The skimmer was difficult to photograph until one repeatedly returned  to a nearby perch. Paulson (2009)describes this behavior well, saying they "move constantly, not defending fixed territories…[showing] much aggression to other males of their own and other similar-sized species."

Black-headed Grosbeak

Roughlock Falls in the South Dakota Black Hills is an easy place to find Dippers. We spied this semi-aquatic land-bird, but they did not cooperate for photographs. We did find a pair of Black-headed Grosbeaks feeding among the cars in a parking lot—presumably searching for car-killed arthropods.

Black-headed Grosbeaks are closely related to Rose-breasted Grosbeaks. The two species hybridize in the Great Plains where their ranges overlap. Some ornithologists consider them to be well-marked races of the same species. Alan Phillips named the resultant species, the Common Grosbeak. This hybridization, however, occurs in areas of low density and patchy habitat. It is not as frequent as where Yellow and Red-shafted flickers or Indigo and Lazuli buntings meet (Ortega and Hill 2010).

Least Chipmunk

On 16 July 2014, Erika and I drove across South Dakota. Along the way, we drove through the Badlands National Park and stopped at Roughlock Falls in the Black Hills. We added a new mammal to our photography collection—a Least Chipmunk. At first I thought the first chipmunk, from the Badlands, and the second one, from the Black Hills, might be different species. This rodent turns out to be quite variable, with pale individuals found in arid habitats and more richly colored, tawny ones in moister areas (Higgins et al. 2002).

As the name implies, the Least is the smallest of the chipmunks. It has, however, the widest range of any chipmunk—found in western North America from the Yukon south to Arizona and New Mexico. Least Chipmunks occur at many elevations and consume a wide variety of vegetation and insects. They are not true hibernators and, in the winter, move about in their burrows where they consume food caches.

Yellow-breasted Chat

This Yellow-breasted Chat was the highlight of our stop at the Cliff Shelf Nature Trail in South Dakota’s Badlands National Park. As we walked through the cedars along the loop, I heard a unfamiliar bird song. I am not sure why I would recognize it as a chat, since male chats have song repertoires of around 62 song types. Chats often mimic other species’ calls (e.g., robins, buntings, vireos, kingfishers and yellowlegs) (Eckerle and Thompson 2001). Chat songs are given, however, at a relatively low frequency, which may have been what tipped me off.

I banded this large warbler annually in South Dakota, but never photographed one. Ornithologists have long argued just what a Yellow-breasted Chat is—the bird seems too big to be a warbler. The songs are far more varied than in other warblers. The behavior and some anatomical features differ from typical warblers. Genetic data, however, support the chat’s being an atypical but definite warbler.

Rock Wren

Erika and I saw several Rock Wrens during our July stop-over at the Badlands National Park in South Dakota. The birds gave us a mini-course in Rock Wren eating habits. Studies in Utah have compiled a list of 13 insect orders being eaten by Rock Wrens. Lowther et al. (2000) that Rock Wrens mostly eat insects, mainly crickets, grasshoppers, ants, leaf-hoppers, bugs and beetles. We concur. The bird in the first photo seems to be consuming a grasshopper or cricket. The second wren has a butterfly or moth caterpillar, an order known to be on the Rock Wren’s menu.