Wednesday, April 23, 2014

Yellow-rumped Warbler

Another spring arrival at our water feature was this male Yellow-rumped Warbler. I previously wrote about how western (Audubon’s) and eastern (Myrtle) populations differ. Spring males are easy—the Audubon’s Warbler’s throat is bright yellow. Myrtle’s, like this one, have white throats.
Females and fall birds can be much trickier. The middle photograph is of a fall Myrtle Warbler that I banded in September 2010, and which I used in my previous post. Note the distinct eye-line and the distinct ear (auricular) patch.  The bottom photo shows an Audubon’s Warbler. Note its more hooded appearance, with an indistinct eye-stripe and its uniformly colored sides to the head.
I handed this Audubon’s Warbler on 8 November 2004 in Aberdeen, South Dakota. Not only is this date fairly late for the species, Audubon’s Warblers are also very rare in the eastern half of the state.

Tuesday, April 22, 2014

Winter Wren

Last week, after hard work, Erika and I turned on our water feature for the season. Running water is a bird magnet. This Winter Wren was one of the first birds to appear—it flew from the backyard adorned with a shiny, new Federal bird band.

Winter Wren systematics are complex and confusing. I have previously posted notes about Winter Wrens in 2010 and 2013. North American birds depend on old-growth forests. Clear-cutting and other logging have greatly reduced this wren’s habitat (Hejl et al. 2002). European Wrens, on the other and, inhabit gardens and urban areas, further evidence that the two populations are distinct species. Our birds, looking like tiny rodents, forage in deep woodland, under snags, in tangles, and among fallen logs. Where they breed, these birds are more often heard than seen. During migration, seeing Winter Wrens can be tricky—except, occasionally, at the water feature.

Monday, April 21, 2014

Review: Rare Birds of North America

Rare Birds of North America by Steve N. G. Howell, Ian Lewington and Will Russell is a fascinating book that most birders will enjoy. The bulk of the book consists of large, lavish, color illustrations of the approximately 262 birds that have appeared in North America five times or fewer. This total is a tad confusing, since the authors consider a flock of rare birds seen but once as a single occurrence. The book also includes a few records that are not officially accepted by the ornithological community.

This coverage presents something of a conundrum since most birders are unlikely to encounter any of these rare species. But browsing this book presents a perfect opportunity for armchair birders to daydream about rare birds and about traveling to where the birds might be found. Presumably by knowing what rare birds look like, birders will be prepared to identify them if the birds are found. On the other hand, having all these illustrations may make it easier for birders to make mistaken identifications.

Species accounts include a summary of where these birds have been seen, their taxonomy, and their distribution. Field marks and similar species are also discussed. Finally short statements about the birds’ habitat and behavior are included.

The 41-page introduction (out of 428 pages in the book) makes for interesting reading. Highlights include a long discussion of the definition of a vagrant bird. Vagrants may be typed into seven classes (e.g., drift or overshooting). These definitions come complete with world maps with hypothetical routes rare birds may have taken to North America. The result is illustrations of paths that look eerily like routes taken by lost jetliners.

Another fascinating graphic indicates those areas areas in which vagrants are most likely to be encountered. Best areas to look for rare birds? Alaska, British Columbia, and the Pacific Coast of the United States. The Northeast Coast is good for rarities too, but, surprisingly second to Minnesota and the Canadian provinces directly to our north. Where do these rare birds originate? If you answer “Latin America,” as I did, you would be wrong! Fifty-one percent come from the Old World, almost twice as many as the 33% from the New World. Pelagic species come in at a distant 16%.

This hardback book costs $35.00, but can be bought on-line at a substantial discount. An eBook version is also available. Both formats can be accessed by clicking the graphic above this post. (I receive no profit from sales and have not been paid by Princeton University Press for writing this review.)

Sunday, April 20, 2014

Mourning Cloak

This individual appears to me to be a very striking Mourning Cloak. Brock and Kaufman write “for winter-weary northerners, few sights can be as welcome as that of the first Mourning Cloak, emerged from its hibernation…during the first spring thaw.” This, our first Mourning cloak of 2014, appeared substantially later than in 2011 (19 April vs. 7 April).

Mourning Cloaks are found across almost all of North America, from northern Canada and Alaska south to northern Mexico. Adults are long-lived, up to ten months.  They emerge in the summer, hibernate during the winter, and breed the following spring. This photo was taken in the Carleton College Arboretum.

Saturday, April 19, 2014

Caspian Tern

Except for Antarctica, Caspian Terns are found around the world. In North America they breed along our coasts and in the interior of the United States and the prairie provinces. Their colonies are adversely affected by changes in water levels, competition with gulls, predators and people. Caspian Terns will often desert their colonies when they are disturbed. Nevertheless, North American populations have increased. In Europe and Africa, however, this tern has declined and is now absent from many parts of the Old World (Cuthbert and Wires 1999).

This Caspian Tern flew overhead as Erika and I explored the South Padre Island Birding and Nature Center on 20 February 2014. These terns subsist almost entirely on fish. They forage with their bills pointing downward. When they find fish, they hover, and then dive, usually completely under water.

Friday, April 18, 2014

Common Gallinule

The birds at the South Padre Island Birding and Nature Center were so tame that I wondered if they were captive. These gallinules appeared to be adorned with red leg bands. This color proves to be a good field mark on any closely observed breeding Common Gallinule. Common Gallinules look like ducks but are actually rails. Note the long, unwebbed toes. This species has had a recent, rocky systematic history. Not so long ago, the ornithologists merged North American Common Gallinules with nearly identical European Common Moorhens, and the resulting species was named Common Moorhen. Now the name has reverted to Common Gallinule, due to differences in calls, bill structure, and DNA.

Common Gallinules are found across much of eastern North America, Mexico, and Central and South America. In many areas they are considered to be game-birds. Bannor and Kiviat (2002) note that the effects of hunting pressure on gallinules is unknown, as are environmental interactions between these birds and other marsh-loveing inhabitants such as muskrats. Wetland pollution and destruction also are threats. The aforementioned authors also relate the story told in Hawaiian mythology that the gallinule’s forehead was scorched red while the bird brought fire to the Hawaiian people.

Thursday, April 17, 2014

Tricolored Heron

We left Atascosa National Wildlife Refuge and drove over to South Padre Island, on the Texas coast. Erika and I had never visited South Padre, and, upon arriving, we figured out why—nothing but high-rise condos and hotels as far as the eye could see. The visit was rescued, however, by my remembering Kirk Mona, a Minneapolis blogger whom I follow, and his post from last January and his account of the South Padre Island Birding and Nature Center. This center charges admission to walk through their small marshland on an elevated boardwalk. Kirk wrote that “there were birds everywhere.” He is right. Most of the birds were tame and easily photographed. Actually the experience was a little like going to a birding Disneyland. I was slightly put off by the zoo-like experience.

Our first bird was this Tricolored Heron. in the 1950s, this species was probably the most common North American heron. Its population was not decimated by the plume-hunters of the previous century. Unfortunately, now Tricolored Herons are declining, often dramatically, throughout their southeastern North American Range. The species depends on estuaries and other coastal areas—habitat that is rapidly being lost to draining, development, and pollution (Frederick 2013).

Wednesday, April 16, 2014

Falcons, Songbirds, and Seriemas

We did not stay at Laguna Atascosa National Wildlife Refuge for very long on 20 February. It was noon, a bad time to look for birds, windy, drought-stricken, and we had plans to visit South Padre Island. We did take a quick drive over to Osprey Lookout, guarded by this spectacular Crested Caracara.
Caracaras are falcons that look like hawks but act like vultures. They share a common ancestor with typical falcons, like the American Kestrel we found later in our trip in New Mexico. More distantly related are forest and Laughing falcons (Morrison and Dwyer 2012). I took this photograph of a Laughing Falcon, in the early 1960s, in Veracruz, Mexico. I have also seen this species in Peru.
Much of the birding world is all a-twitter at the recent discovery that falcons are not closely related to hawks, but are another example of convergent evolution. Their closest relatives appear to be parrots and songbirds. The American Ornithologists’ Union and the newest Sibley guide now place falcons and parrots between the woodpeckers and songbirds (ABA).

The story gets stranger. Genetic evidence suggests that another family of birds, Seriemas, are also closely allied with falcons, parrots and passerines (BirdsEye Birding). Seriemas are odd, South American birds that were thought to be related to cranes. I photographed the Red-legged Seriema in the last photo in northern Argentina in the mid-1960s.

Tuesday, April 15, 2014

Great-tailed Grackle

Great-tailed Grackles also fed at Laguna Atascosa refuge during our February visit. I have previously blogged about this species’ northern expansion, beginning in southern Texas in the early 1900s and continuing by century’s end across much of the central United States, including Minnesota, and even at least three Canadian provinces.

Great-tailed Grackles are fairly omnivorous. Their diet is composed mainly of plant material in the winter; arthropods and other animals in the summer. They are reported to kill small birds, but to leave them uneaten (Johnson and Peer 2001). These authors provide an extensive list of food items, but do not mention fruit, such as the grackle below appears to be devouring. I assume Great-tailed Grackles limit their fruit consumption to bird feeders and that they do not normally attack orchards.

Sunday, April 13, 2014

Olive Sparrow

The National Wildlife Refuges and many of the State Parks in Texas feed birds and build viewing blinds. At Laguna Atascosa refuge we got great views of an Olive Sparrow. This sparrow forages on or near the ground in dense cover. As a result, little is known about Olive Sparrow biology.

This species was a new one for my USA list. I previously listed one in Mexico. Although a common resident from southern Texas south through Costa Rica, Olive Sparrows have large gaps in their range. Many ornithologists believe, among at least 9 races currently recognized, perhaps as many as three species exist—the Texas Sparrow, found in Texas and eastern Mexico, the Yucatan Sparrow, found in the Yucatan Peninsula through Belize and Guatemala, and the Pacific Sparrow, found along the west coast of Mexico. These potential species differ in size and color (Brush 2013).