When Rails Don't Act Like Rails

Crack open your favorite field guide and the text next to the rail plates will invariably describe them as "secretive" or "more often heard than seen." For about 10 months of the year, this is the case. From about October 1st through July 31st, views of rails range from fleeting to non-existent. On those rare occasions when you spot an adult rail out in the open, it normally sees you at about the same time and promptly sprints for the cover of dense marsh vegetation...GONE! For birds that look a bit clumsy and appear to have been assembled by a committee, they can run incredibly fast. Rails get their name from having bodies that are somewhat compressed laterally, as in thin as a rail. This structural advantage allows them to run swiftly through dense marsh vegetation, so they rarely fly in the face of danger.


When out in the open, young Virginia Rails (above) and Soras (below) look like part chicken and part sandpiper, with tails on loan from a wren. Long, sturdy legs make for quick getaways and their over-sized feet and long toes work like snowshoes, allowing them to run across soft mud without sinking in.


Despite their retiring nature, there is a short period following the breeding season when the newly-independent juveniles of some rail species are much more likely to be seen in plain view. During a recent birding trip to Malheur National Wildlife Refuge (in southeastern Oregon), I came across a partially evaporated wetland where I found no fewer than seven juvenile rails--four Soras and three Virginia Rails--feeding on the exposed mud around the remaining pools. I spent nearly an hour photographing the hatch-year birds in this photo essay. They were in full view for almost the entire time. They were startled once or twice and jetted back to cover, but each time they came back into view in less than a minute.


Note the short, rather dull brownish bill on this young Virginia Rail. It is not as long it would be on an adult and it lacks the bright reddish-orange lower mandible one would see on an adult. Also note the olive-green eye color on this bird. Adult Virginia Rails have blood-red eyes. This bird also shows extensive black feathering below with white on the chin, throat, lower breast, and belly. Adults Virginia Rails are almost entirely burnt orange on the throat, neck, breast and upper belly.

Apparently, juvenile rails are not hard-wired to run for cover, or at least they don't stay there long. When they do scamper out of view, quite often they come wandering back out into the open within a minute of two and resume feeding as though nothing had happened.

Like the young of many shorebirds, quail, and grouse, rails are precocial. They can leave the nest almost immediately after hatching. When first hatched, most young rails look like black cottonballs with legs and a beak. During this period, they may be seen darting across an opening in the vegetation in the company of their parents. Within a few weeks they grow to full size and attain their first complete feather set. By the time they are a month old, they are fully independent (Conway 1995, Melvin et al. 1996). In this juvenal plumage young birds often look quite different than their parents, which was the case with the unattended juvenile Soras and Virginia Rails that I photographed at Malheur on 29 August 2009. 


At first glance, one might mistake this juvenile Sora for a Yellow Rail. It shows none of the gray on the underparts or black in the face that would be seen on a adult Sora. Unlike Soras and Virginia Rails, Yellow Rails are nearly impossible to see, regardless of age. Note the extensive white barring on the lower flanks and the narrow white edges on folded flight feathers. A Yellow Rail would show just a few thin white bars on the mostly blackish flanks and broad buffy edges to the folded flight feathers. Additionally, Yellow Rails look like they have no tail, while Soras show a comparatively long tail that is almost always cocked up and flicked with each step as they walk about with a lurching motion.

Since rails are so infrequently seen, it is easy to spend many minutes watching them on those scarce occasions when they are viewer-friendly. August and early September seem to be prime time for actually seeing rails. By this point in the year the young are fully grown, independent of their much more wary parents, and they have yet to migrate. Here in the Pacific Northwest, where rainfall is minimal July-September, water levels at the marshes and seasonal wetlands where these species breed start drying up during late summer/early fall, forcing rails out into the open to reach the water's edge.


Virginia Rail is an uncommon to common wintering bird along much of the West Coast and Sora winters regularly north to central California and occasionally winters in Oregon. However, across much of North America, these species are only present during the breeding season. By early October they will have migrated south to more temperate climates where, presumably, they learn to act more like rails.

Literature Cited:

Conway, Courtney J. 1995. Virginia Rail (Rallus limicola), The Birds of North American Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from The Birds of North America Online: http://bna.cornell.edu/bna/species/173

Melvin, Scott M. and James P. Gibbs. 1996 Sora (Porzana carolina), The Birds of North American Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.cornell.edu/bna/species/250

All photos taken by Dave Irons using a Canon EOS XSI 450D camera and Canon EF 100-400mm f/4.5-5.6 lens. 

The Many Plumages of Late Summer Forster's Terns

It is often interesting what you discover when you start sorting through bird photos. This past weekend David Fix, Jude Power, Jennifer Brown and I spent the weekend birding around three of the larger playa lakes--Abert, Summer, and Goose--in south central Oregon. At Summer Lake, the northernmost of these three basins, I spent over an hour taking flight photos of Forster's and Black Terns. As is usually the case when photographing birds in flight, about one out of every ten images is worth saving.

The images below were all taken at the Summer Lake Wildlife Management Area, Lake County, Oregon on 15 August 2009. They depict some of the many looks that Forster's Terns can present at this season. Given that one species can show this much variation on a single calendar date, one has to wonder how the editors of standard field guides ever decide which illustrations they will use. We'll start with a juvenile (hatched during summer 2009) and work forward through several age classes to a definitive alternate-plumaged bird. Most of these birds are showing some signs of molt that we will point out along the way.


These two photos (above and below) show hatch-year Forster's Terns still sporting juvenile plumage. Note the warm orangish buff wash on the crown and nape, the isolated black eye patch that does not connect across the nape, extensive black on the underside of the primaries (outermost flight feathers). Other than the outermost tail feathers, the tail is fairly short. I was somewhat surprised that these birds showed so much black on the corners of the tail. This is not shown well in the standard field guides.


One of the interesting things that I learned when I started researching Forster's Tern molt sequences is that they do not attain their first alternate plumage (often referred to as "summer" or "breeding" plumage) until their third year of life (Mcnicholl et al. 2001). In other words, birds hatched this summer will not attain an alternate plumage until the spring/summer of 2011.  Instead, they molt from Basic I directly to Basic II. Basic plumage is a non-breeding or winter plumage acquired via pre-basic molt.


This Forster's Tern appears to be transitioning into "basic II" plumage, which tells us it hatched during the summer of 2008. It has none of the orangish-buff in its plumage shown by the hatch-year birds seen above. Its bill is starting to show some orange towards the base, whereas the bills of hatch-year birds are entirely dark. Also, note the wear on the flight feathers, which will be replaced later this fall. Since these primaries and secondaries are nearly a year old, they are frayed and somewhat irregular in length. Compare them to mint condition of the weeks-old flight feathers of the juvenile pictured above. This bird does show a bit of gray mottling above and behind the black eye patch. Some first summer (after hatch-year) Forster's Terns molt in a few alternate-type feathers, which may explain the gray across the hindcrown and nape of this bird.

In their third year, Forster's Terns finally attain their first alternate plumage, which is referred to as "alternate I" by many sources (Mcnicholl et al. 2001). In most aspects, alternate I birds look exactly like older adults in definitive alternate plumage. They are entirely white below, unmarked gray on the back and upper wings, and they have bi-colored bills that are at least 50% orange towards the base and black towards the tip. However, birds in this plumage do not have the long streaming outer tail feathers and they show clean white foreheads and forecrowns. The black on the head is limited, starting in front of the eye and then extending through the eye and around the back of the head, connecting across the nape and hindcrown. 


Here is an example of an apparent alternate I Forster's Tern, which would have hatched during the summer of 2007. The eye patch is solid black and connects across the nape and yet the forehead and forecrown are clean white. The bill is more than 50% orange with a black tip. It has abbreviated outer tail feathers, but otherwise the plumage resembles that of a definitive alternate adult.

Finally, Forster's Terns attain a definitive alternate plumage in their fourth year. This plumage, held during the breeding season, is characterized by long streamer-like outer tail feathers and a solid black cap.  The black cap extends from the base of the bill across the forehead, crown and nape and surrounds the eye. The bills of full adults are generally brighter orange towards the base and the orange covers about about two-thirds of the total bill length. Once the breeding season begins to wane (late July-early August), adults commence their pre-basic molt. Typically, the first indication of this molt is the appearance of a few white feathers on the otherwise black forecrown. Within a few weeks, adult birds will show completely white foreheads, and by winter--when the pre-basic molt is complete--the head will be entirely white except for a black patch surrounding the eye. Unlike the basic plumages of other similar-sized Sterna terns, the black on the head of a Forster's does not wrap across the nape. Only Gull-billed Tern, a species which has a much more limited range in the U.S., shows a similar head pattern in basic plumage. We did not see any adult Forster's sporting a basic plumage head pattern on the day these photos were taken.


This Forster's Tern, which is in definitive alternate plumage, has commenced its pre-basic molt, as evidenced by the emerging white feathers on the dark forecrown. Note how the black on the forehead extends right to the base of the bill. It also has longer outer tail feathers (not shown well from this angle). The flight feathers of this individual are in surprisingly good shape, although the primary tips are looking a bit frayed. Most of the adults we saw on 15 August 2009 had extremely battered outer primaries.

While the images above show an array of ages and plumages, they do not capture the full range of variation that we saw on this date. At this time of year--late summer, early fall--nearly every bird you see will be replacing feathers (molting). The fall (pre-basic) molt results in a generally less colorful basic or "winter" plumage. The late winter/spring (pre-alternate) molt results in a typically brighter alternate or "breeding"  plumage." Unfortunately, not all sources use the same terminology to describe the plumages that result from these molts, which creates a bit of confusion for those trying to better understand the feather replacement process.  It is important to remember that the timing of molts and migrations is not sychronized among all individuals of a particular species, so it can be expected that certain individuals in a large homogenous flock may not look like all the rest. Just yesterday, I received an e-mail with a "mystery" shorebird photo. The image showed a dull, basic-plumaged adult Least Sandpiper. This bird, which was in a plumage one typically sees during the winter months, had been seen with a large flock of juvenile Leasts, all of which were brightly plumaged. The resulting confusion was understandable.

Molt also results in birds that bear no resemblance to the paintings in your field guides. At this season, hatch-year birds are usually the sharpest looking birds in the crowd. Their newly acquired feathers seem perfectly matched and show no signs of wear. Conversely, adults often have wings and tails that look like they went through the lawn mower. In some cases, after hatch-year birds have newly grown feathers right next to old faded ones.  The new feathers may look like someone stuck them on the wrong bird. A basic understanding of these fairly logical molt sequences can be a major help when it comes to properly ageing and identifying those birds that don't look anything like the illustrations in your favorite field guide. We encourage you to take a closer look at the feather condition of the common birds in your midst.

Literature Cited:

Mcnicholl, Martin K., Peter E. Lowther and John A. Hall. 2001. Forster's Tern (Sterna forsteri), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/595

We Have A Winner: Great Blue Heron Story Retitled

After a week of collecting creative suggestions, our cracker jack panel of esteemed voters has selected a winner in the contest to retitle our "Great Blue Whitewashes BirdFellow Headquarters" offering. We wish to thank all those who commented on this piece and shared it with friends and family. Obviously a story like this has a mass appeal that goes beyond our typical audience.

More than half of the suggested headlines received votes from our panel of six judges, who were asked to rank their top five favorites. Points were awarded based on these rankings, with five points for each first place vote, four for each second place vote, and so on down to one point for a fifth place vote. Though voting was close, three headlines received widespread support from the judges and outpaced the other entries. The following headlines were the top three vote-getters:

1. Irate Heron Demanding Equal Press Tries Smear Tactics -- Doug Schonewald

2. Official City Bird Pays Its Respects -- Lew Ulrey

3. Ardea herodias hideous -- Judie Hansen

The story will now be retitled using Doug's headline and all three of these winners will receive BirdFellow wearables. Who know's when we will have another event like this one that warrants a headline contest, perhaps never. But we enjoy having our readership comment on what we publish. It's apparent that bathroom humor is a sure-fire way to get you to interact with us. Thanks again to all of you who played along.