Loose Feathers #97

Wilson's Snipe / Photo by Gary Kramer (USFWS)

News and links about birds, birding, and conservation

• A report by the National Research Council on wind farms concludes that there is too little data to predict their effects on wildlife populations. The council recommends thorough study of each proposed location before a wind farm is built, as well as regular monitoring afterwards. See the full report.
• Some waterfowl species have very complex genitals. A recent study suggests that complex genitals evolved first in females as defense against forced copulation, and later in males in response. (See also the takes by evolgen and microecos)
• A study of great tits found that curiosity depends on variations of a gene that controls dopamine receptors in the brain. (See abstract.)
• Dutch researchers determined that the migrating Bewick's swans' ability to benefit from forage sites varied with the distance from roads and the distance from their roost sites.
  
• The International Ornithological Committee's list of recommended English names is now online. (via Birds Etcetera)
• Birders in Louisiana are increasingly birding by kayak to avoid access problems and approach birds more quietly.
• A mallard is nesting downtown at the side entrance to the Office of the US Trade Representative.
  
• Arctic sea ice is melting faster than climate change computer models had predicted.
• Climate change may alter the biodiversity of Welsh streams.
• The IPCC has approved affordable recommendations for slowing climate change through reductions in greenhouse gases. The American representative, of course, complained that they were too expensive.
• Like Malta, Cyprus is pushing the envelope with a spring hunting season targeting a declining species.
  
• Rock Creek Park is developing guidelines for future wireless communications facilities within the park. If you wish to comment on this issue, write them a letter before May 13th. The towers currently in the park went up in the face of strong opposition.
  

Birds in the blogosphere

• Coffee and Conservation: Organic Coffee Safe for Now (see also Gristmill).
  
• Wildbird: Prothonotary Warbler in political history
• 10,000 Birds: Mike is compiling a list of birding tour guides. Let him know if you know of any good ones.
• Charlie's Bird Blog: Know what I'm talking about? (an explanation of a few birding terms)
• Born Again Bird Watcher: Birding Babylon Couldn't Happen Today
• BrdPics: Well, it's a marvelous day for a sky dance!
• Firefly Forest: Blue-winged Teal
• sphere: Owl Nest
• Greensboro Birds: Bird in the Park: Veery
• GrrlScientist: Song and Plumage Evolution in New World Orioles
• Bell Tower Birding: Separating Louisiana and Northern Waterthrushes
  

Carnivals and news links

• Friday Ark #137
• I and the Bird #48
• Festival of the Trees #11
  
• Birds in the News #81

American Bittern / Photo by Gary Zahm (USFWS)

The Strange Genitals of Waterfowl

Just in time for avian breeding season, PLoS ONE published an interesting article on the evolution of avian genitals. While the males of most bird species lack phalluses, some waterfowl have extremely complex organs. The most complex genitals are owned by members of the genera Anas, Clangula, and Oxytura. Some males have an extraordinarily long phallus (up to 40 cm), which twists counterclockwise and sometimes has spines along its length.

The research team led by Patricia Brennan found that female duck genitals varied to match those of males. When the male of waterfowl species has a long and complex phallus, the female of the species will have a long and complex vagina, but when males have short and simple genitals, females will also. However, unlike phalluses, vaginas spiral clockwise rather than counterclockwise. Some vaginas have pouches that form dead ends for sperm.

(A) Harlequin duck (Histrionicus histrionicus) and (B) African goose (Anser cygnoides), two species with a short phallus and no forced copulations, in which females have simple vaginas as in Fig 1a. (C) Long-tailed duck (Clangula hyemalis), and (D) Mallard Anas platyrhynchos two species with a long phallus and high levels of forced copulations, in which females have very elaborate vaginas (size bars = 2 cm). ] = Phallus, * = Testis, ★ = Muscular base of the male phallus, ▹ = upper and lower limits of the vagina. [Source; click for larger image]

Mating among waterfowl sometimes becomes violent. Mallards especially are known for incidents of forced copulation (see here and here). Some have even been known to engage in necrophilia. Forced copulation threatens to negate the careful mate selection that a female has made in the process of pair bonding. The authors of this paper suggest that waterfowl vaginas evolved to become more complex to give a female greater control over which male fertilizes her eggs. By catching the sperm of an aggressor in a pouch and later expelling it, a female can ensure fertilization only by her chosen mate.

As Carl Zimmer notes, apparently no one who observed the genitals of male waterfowl had thought to examine the corresponding female structure. This paper suggests that the evolution of complex genitals may be spurred by a female's defenses and not by competition among males.

I and the Bird #48

Field guides come in many forms. Some use photographs; some use painted illustrations; some are general; some are limited to family groups. Some field guides instruct on the finer points of distinguishing a few difficult species. Whatever the form, no birder can start without a good field guide.

In that spirit, Greg Laden presents a field guide to bird posts as his theme for the 48th I and the Bird.

Birding by Metro: Metrobus

Previous editions of my birding by Metro series covered sites along the major Metrorail lines. Metrorail, of course, is not the only way to get around Washington, even if it is what most people mean by the word "Metro." This week, we will look at birding sites that can be reached only or primarily by Metrobus. Unlike other posts in this series, which were arranged by route, this post is organized by location.

Riding Metrobus requires a $1.25 fare, which can be paid in exact change or with a SmarTrip card. Ask for a transfer, which can be used (even on the same route) for a free ride until the time indicated on the transfer paper. The downside, of course, is that riders on Metrobus are more likely than rail riders to become stuck in traffic. For most weekend birders this will not be a problem; weekday birders may need to consider their routes.

Northwest

Rock Creek Park is the largest forested tract in the District, making it a classic migrant trap. The best birding areas are located on top of the park's western ridge, near the Nature Center. During spring and fall migration, the usual birders' route is to start at the Nature Center, walk south to visit picnic areas 17/18 at dawn, and then check the maintenance yard later in the morning. I prefer the maintenance yard for birding since most birds there will be at or below eye level. All northeastern species of warblers have been recorded in the park. On any given day during the peak period, one can expect to see 10-15 warblers, and more than that on really good days. In addition to the flood of warblers, attentive observers can expect to see both cuckoos, all eastern thrush species, tyrant flycatchers, orioles, and many sparrow species. Directions: Take the E2, E3, or E4 bus to the corner of Military Road and Glover Road, near the Nature Center. These routes run between the Friendship Heights and Fort Totten stations on the Red Line, and connect to many other bus routes along the way.

Georgetown Reservoir is one of several storage reservoirs maintained for the Washington Aqueduct. Water birds find the reservoir attractive. Though the reservoir is surrounded by a chain-link fence, birders may view the impoundments from the sidewalk. Ring-necked ducks, scaup, canvasback, coots, and grebes can be seen throughout the winter. This is a reliable spot for finding lesser black-backed gulls. Directions: The D3, D5, and D6 buses stop right at the reservoir on MacArthur Boulevard. These bus routes connect to the Red Line at Dupont Circle.

Fletcher's Boathouse is a favored access point and birding location on the C&O Canal. Check the trees around the boathouse for nesting orioles and warbling vireos. Prothonotary and yellow-throated warblers breed in swampy woods along the towpath east and west of the boathouse. In winter, mergansers and other diving ducks may be seen on the river. From Fletcher's Boathouse, you can walk a mile northwest to the Chain Bridge, which is a good location to find waterfowl, herons, and raptors around the pools in the rock formations. Directions: Take the D3, D5, or D6 bus to the intersection of MacArthur Boulevard and Reservoir Road. (These bus routes connect to the Red Line at Dupont Circle.) Walk down Reservoir Road and VERY carefully cross Canal Road to the entrance drive for Fletcher's Boathouse.

Glover-Archbold Park is a thin strip of forest that acts as another migrant trap in northwest Washington. The most interesting section for birders is just above Reservoir Road. The park is generally good for bird species that prefer forest and edge habitats. Go during spring and fall migration to look for warblers and thrushes, including the veeries that breed in the park. Directions: The D3 and D6 run along Reservoir Road and stop near the entrance to the park. (If you are coming from the east, it will be right after the French Embassy.) Both routes connect to the Red Line at Dupont Circle.

McMillan Reservoir, one of the Washington Aqueduct's water treatment plants, is an irregularly-shaped body of water across Michigan Avenue from the Washington Hospital Center and near Howard University. East of the reservoir there is a grasslands area where water was formerly filtered through sand tanks. Both areas are fenced and off-limits to the public, but birders can view birds from the sidewalk. The best viewing area for the reservoir is at the corner of Michigan Avenue and 4th Street. The reservoir is good for waterbirds in migration. Directions: The 80 bus stops at North Capitol and Michigan Avenues, next to the grasslands. The H1, H2, H3, and H4 buses stop at the reservoir.

Northeast

The National Arboretum consists of 446 acres of fields, woods, and display gardens, with some of the largest stands of conifers in D.C. Some of the better birding spots are in the Azalea Gardens, the Asian Gardens, and a trail that runs parallel to the Anacostia River. In spring and fall, check the Azalea and Asian Gardens for migrating warblers, thrushes, and other songbirds. The Azalea Gardens in particular are very good for thrushes, including gray-cheeked and Swainson's thrushes. Any of the pine groves may hold a pine warbler or red-breasted nuthatch in late winter or early spring. In winter, check conifers for owls. Directions: Use the X6 from Union Station on weekends. On weekdays, the closest bus stop to the Arboretum is the B2 at R Street and Bladensburg Road. The B2 connects with the Blue and Orange lines at the Stadium-Armory station.

Kingman and Heritage Islands are artificial islands in the middle of the Anacostia River just south of Benning Road. Access to the islands is via a wooden bridge from the RFK stadium parking lot. Currently access to the islands is limited, but plans are in the works to create a nature center and walking trails. Waterfowl and herons use the river year-round. Gulls, terns, and shorebirds may be present on the mudflats around the islands during migration. Check brushy areas for songbirds. Directions: The X2 bus stops near Kingman Island on Benning Road. The Stadium-Armory station on the Blue and Orange lines is close by, but requires a longer walk.

Southeast

Fort Dupont is an underbirded park despite its good habitat. It consists mainly of upland forest, with some edge and scrubby areas, and has a well-maintained trail system with easy public access. Ovenbird, pine warbler, and scarlet tanager breed in the woods here. Check the shrubs around the fort for white-eyed vireos, indigo buntings, blue grosbeaks, and wild turkeys. Directions: The V7, V8, V9, and U2 buses run along the park on Minnesota Avenue on the west side of the park, and the A11 and M6 run near the park of Alabama Avenue on the east side of the park.

In addition to the sites listed here, many of the other sites listed in previous editions of Birding by Metro can be reached by Metrobus, which in some cases may be easier than rail. To find routes, use the "Trip Planner" on the WMATA website. If you know of good, Metro-accessible sites not listed here, please note them in the comments. I especially would appreciate learning about sites outside of Washington's borders. Any feedback is welcome.

Other posts in this series: Introduction, Green/Yellow, Blue/Orange, Red

American Bittern

Since I saw an American Bittern over the weekend, here is a video of one feeding in someone's backyard. The mix of prey items is interesting. It includes some small oblong creatures that I assume are large insects, plus one thing that appears to be a small snake.



Link