No. 193BATON ROUGE, LADecember 2000

LOS NEWS
Newsletter of the Louisiana Ornithological Society

LOS NEWS, Page 2

Table of Contents

Dr. George Archibald to Speak
LOS Winter Meeting (+)
Linking Birds & People
How a Birding Trip "Sealed My Fate"
Louisiana Southwest Birding Festival
The Botanical Birder
LOS Fall Meeting Report
Myiarchus ID
Myiarchus Figures
Swallow Tornado
LOS Officers (+)
LOS Sales (+)
New Members
Membership Form (+)
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Let's take another look: Myiarchus flycatchers
It's late fall. Temperatures and humidity have dropped, mosquito numbers are down, and CBCs and holidays are on the horizon. It's not only a pleasant time to get back into the woods, but late fall and early winter can be an exciting time to search cheniers, hedgerows, and woodlots for late migrants and other rarities. Among the trophies possibly lurking are Myiarchus flycatchers. Our common breeding species has long departed, two species are "regular" late fall and winter visitors, and a couple of other species are eagerly anticipated to wander (some day) to Louisiana. This group offers ample ID challenges.
 
Status

Great Crested Flycatcher (Myiarchus crinitus) breeds from east-central Alberta, central and southeastern Saskatchewan, southern Manitoba, southern Ontario, southern Quebec, New Brunswick, Nova Scotia (except northeast), and (occasionally) Prince Edward I. south to Florida and the Gulf Coast, and west to the eastern Dakotas, eastern Nebraska, western Kansas, west-central Oklahoma, and central Texas. The species winters in southern Florida and (rarely) Cuba, but the main wintering range extends from southern Veracruz, Oaxaca, and the Yucatan Peninsula south along both slopes of Middle America to western and northern Colombia and northern Venezuela. Great Crested Flycatchers breed virtually throughout "mainland" Louisiana in forested areas, but are absent or rare as breeders in chenier woodlands along the immediate coast.
 
Early spring migrants have been found as early as mid-March, but the main spring arrival begins in late March and early April and peaks mid-April to early May; on the coast, late spring migrants have been recorded into late May and early June. Fall migrants have been found on the coast as early as 10 July, with the main passage occurring August-September and a trickle of birds continuing into early October. The latest fall specimen at LSUMNS is from 12 October, and the latest sight records are for 23-25 October. Some exceptionally late records included in the seasonal bar graphs in Louisiana Birds (Lowery 1974), including a specimen reportedly taken in Cameron Parish on 25 November 1956 (could not be located), and a sight record for Lafayette on 26 November 1965, are best considered "hypothetical" without further corroboration. Surprisingly, although this species is our most abundant Myiarchus and they regularly winter as close as southern Florida, there are no accepted winter records for Louisiana.
 
Ash-throated Flycatcher (M. cinerascens) breeds throughout the western U.S. from central Washington, southern Idaho, southwestern Wyoming, western and southern Colorado, southwestern Kansas, western Oklahoma, and the western two-thirds of Texas south to southern Baja California, southern Sonora, and, on the central Mexican Plateau, to Jalisco, Michoacan, Guanajuato, San Luis Potosi, and Tamaulipas. Ash-throateds spend the winter from the extreme southwestern U.S. to Central America, mainly on the Pacific slope. The species breeds at lower and middle elevations in a variety of habitats, including desert scrub, riparian woodland, and open oak or dry coniferous woodland.
 
Ash-throated Flycatcher was first recorded in Louisiana in East Baton Rouge Parish on March 20, 1943. Through the 1950's-1970's, the species was encountered nearly annually, and, from the 1980's to the present, records have averaged several per year and increasing (to the point that the species was removed from the LBRC Review List in 1996). The vast majority of records are from the immediate coast of Cameron Par., but there are a considerable number of records from slightly inland in Cameron, Jefferson Davis, Vermilion, Acadia, and Lafayette parishes, and from southeast Louisiana in Orleans and Plaquemines Parishes. There are a handful of records from farther inland in central and northern Louisiana in East Baton Rouge, Pointe Coupee, Evangeline, and Bienville parishes. In Louisiana, the species is most often encountered in hackberry-acacia dominated chenier scrub and woods, in small woodlots or along the edge of larger woodlands, second-growth riparian scrub along old canals and spoil banks, or Chinese tallow tree/elderberry-dominated second growth woodland.
 
This species is an early (mainly July-September) fall migrant in the West, but the earliest fall record for Louisiana is 24 September. Interestingly, there are only about 3 other records through 4 October, then no records for the period 5-20 October. Then, from 21 October-14 November there are at least 19 records involving 24 individuals, all on or near the coast and mainly southwestern (about half these records are coincidental with heavier observer coverage in Cameron Parish during the last week of October). Most of these records presumably pertain to migrants, but some could involve potentially wintering individuals. Winter occurrences extend from 18 November-1 April, and total about 67 records involving about 72 individuals, mainly from on or near the extreme southwestern or southeastern coasts. Again, there is no way to be sure that some of the late fall or early spring records don't pertain to exceptionally late or early migrants, respectively. About half of all winter records coincide with heavier observer coverage during the Christmas Bird Count period the last two weeks of December and the first week of January. Known or presumed wintering individuals have remained into late February and early March. There are only about 6 records of spring migrants, 18 April-12 May, all from Cameron Parish or oil platforms in the Gulf of Mexico. Four of the six records are for the period 23-28 April, coincidental with traditionally heavier observer coverage in Cameron Parish during the last week of April.
 
Brown-crested Flycatcher (M. tyrannulus) occurs from the southern U.S. to northwestern Costa Rica, and is also widely distributed in eastern South America peripheral to Amazonia. Two forms are widespread in Mexico and have limited distributions in the southwestern U.S. The Pacific slope subspecies magister breeds from southeastern California, extreme southern Nevada, extreme southwestern Utah, southern Arizona, and southwestern New Mexico south along the Pacific slope of Mexico to western Chiapas. The Gulf-Caribbean slope subspecies cooperi breeds from eastern Coahuila and southern Texas south and east to western Honduras. Breeding habitat includes riparian forest and columnar cactus desert scrub for magister, and a variety of open riparian and thorn woodlands for cooperi. U.S. breeders spend the winter in Mexico or Central America.
 
Brown-crested Flycatcher is a rare migrant and winter visitor to Louisiana, and the species is on the LBRC Review List. It was first collected in Louisiana in Plaquemines Parish, on 24 November and 4 December 1961. Additional specimens were not obtained until 1983-1984, 1987, and 1996 in Cameron Parish, and 1993-1995 in Plaquemines Parish. A number of additional sight or photo records exist, mostly for Plaquemines Parish during the 1990's, many of which lack diagnostic identification details, but which, taken as a whole and combined with the specimen records, indicate that small numbers regularly winter in the lower delta. As with the other regularly occurring U.S. Myiarchus, this species is an early fall migrant (mainly August-September) within its normal distribution, but only a couple of the Louisiana records are from relatively early in the fall: 14 & 23 September, Cameron Parish. There are no October records. One in Cameron Parish, 7 November, could have been either a migrant or a wintering bird. Winter records (all from Plaquemines Parish except for one in Cameron Parish, 17 December 1983) extend from mid-November to late March. The only acceptable (pending LBRC acceptance) record of a spring migrant is a sight record from Cameron Parish, April 1993. In Louisiana, individuals have mainly occurred in second growth scrub, either along spoil banks or as large expanses with denser thickets of fruiting elderberry and Chinese tallow tree. They have also occurred in coastal hackberry-acacia chenier scrub/woods, or within (or along the edges of) large woodlots dominated by mature live oaks. Most Louisiana records pertain to the "expected" eastern Gulf-Caribbean slope subspecies cooperi, but the Pacific slope subspecies magister has also been documented on one occasion (2 specimens, 26 January 1994, near Ft. Jackson, Plaquemines Parish).
 
Other Myiarchus species worth considering as potential vagrants to Louisiana:
Dusky-capped Flycatcher (M. tuberculifer) is a widespread neotropical species that reaches its northern limit in southeastern Arizona and extreme southwestern New Mexico. Northern populations are migratory. Only the subspecies olivascens breeds in the U.S., and it also has occurred as a vagrant to central and western Arizona, California (fall-winter), Texas (mainly late spring, possibly breeding), and Colorado. A second subspecies (lawrenceii) is found not too far away in the mountains of eastern Mexico and would be a potential vagrant to southern Texas or elsewhere in the eastern U.S (Pyle 1997 lists this subspecies as occurring as a vagrant to southwestern Texas, but other sources indicate Texas records pertain to olivascens, and Pyle's source is not known).
 
Nutting's Flycatcher (M. nuttingi), widespread in Mexico and Central America, is a long-shot vagrant possibility. Nutting's is a more sedentary species and occurs mainly on the Pacific slope, but there are a couple of winter records for Arizona, and the species makes it as close as east-central Mexico. Because of its extreme similarity to Ash-throated Flycatcher, detection and documentation would be difficult, but not impossible.
 
La Sagra's Flycatcher (M. sagrae) occurs on the Bahamas, Cuba and the Isle of Pines, and the Cayman Is. It is a vagrant to the southern US. Amazingly, the first U.S. record was from relatively close by in Alabama; all other confirmed records are from extreme southern Florida. Records span from mid-September through mid-May.
 
Identification basics

 
Basic ID hints and some ID pitfalls
Myiarchus are an easy group of flycatchers to recognize by virtue of their generally gray-brown upperparts, gray chest (throat usually paler) and yellow belly. All are rather big-headed, slim-bodied, and long-tailed, with a bushy crest and a relatively large, mostly or all-dark bill with a hooked upper mandible (largest species with most prominent hook). The wings are dark brown with two pale wing-bars. Primaries have prominent (in northern species) rufous edges giving the folded wing the classic rusty "Myiarchus wing panel." Secondaries are also pale-edged. [[Remember that, in official wing topography, the primaries are numbered from inner to outer (proximal to distal), but the secondaries are numbered in the opposite direction, from the middle of the wing inward (distal to proximal; Fig. 1). This reflects the sequences in which these groups of feathers begin to molt (although the entire set may not be replaced in numerical sequence). Thus, the true inner secondaries would, technically, actually be those that are farthest (more distal) from the body (e.g., #1-3). In birder terminology, however, the inner secondaries are those closest (more proximal) to the body (even though these are the "outer" secondaries using the official numbering sequence). Furthermore, birders often refer to the "innermost inner" secondaries (#7-9) as "tertials," even though, anatomically, passerines do not have true "tertial" feathers as are found in groups such as ducks and shorebirds. Having said all that, in order to avoid confusion in comparisons with various identification guides, we will herein perpetuate "birder terminology" by using "innermost" or "tertial" when referring to the proximal secondaries, and "outermost" when referring to the distal secondaries (Fig. 1).]] The innermost 3 (#7-9, "tertials") are usually conspicuously pale-edged (white, yellowish white, or gray), and are "graduated" in length. The remaining secondaries (#1-6) are also conspicuously pale-edged with yellow or white, but they are more uniform in length and form a pale "secondary panel" on the folded wing between (Fig. 1). The tail is dark gray-brown, with varying amounts of rufous.
 
Myiarchus are often spotted on prominent perches in woodland or open habitats where they hunt prey ranging from small arthropods to small vertebrates (rarely including small mice, lizards, and even hummingbirds!). The preferred foraging tactic is to sit and wait until a food item is spotted, capture it by sallying to foliage, ground, or air, then move on to a new perch. Breeding birds are primarily insectivorous, but migrants and wintering birds will regularly consume small fruit. In Louisiana, they are known to eat the fruit of Chinese tallow tree, elderberry, hackberry, etc. Myiarchus are relatively noisy and conspicuous on the breeding grounds, but migrants and winterers are generally more silent and secretive.
 
Myiarchus are often dreaded as "one of those difficult identification groups." Early field guides stressed size and coloration, habitat, and voice as the main species identification criteria, and each new generation of guides has tried to include more detailed ID information. This interest is certainly partly stimulated by observers who need better information to identify vagrant individuals. The problem with Myiarchus is that there are very few diagnostic field marks, the diagnostic characters (usually a combination of mouth color, certain aspects of the tail pattern, and certain vocalizations) are generally difficult to see (or hear, especially during migration and winter), and, when dealing with vagrant individuals, there is little opportunity to compare species. The subjectivity of many other potential ID characters is further complicated by considerable individual variation within species. Ultimately, most identifications are based on some combination of diagnostic and subjective characters such as overall size and shape, bill size and coloration, and plumage coloration, along with known patterns of geographical-seasonal occurrence, and habitat. When used with caution, plumage coloration can be helpful for species ID; particular attention should be paid to the color of the breast and sides, crown, nape, and cheek areas. Patient, experienced observers, that are prepared and well-equipped (e.g., with camera, videocam, or tape-recorder) for documenting their finds, will achieve a high level of correct identifications. Inexperienced observers, when faced with trying to interpret and apply field guide descriptions to this extremely superficially similar group, will be more prone toward misidentifications or, more conservatively, toward leaving birds as "Myiarchus sp." Voice will always be one of the most valuable identification tools. All species have one or more diagnostic calls, but some species also share superficially similar sounding calls, and vocalizations are notoriously difficult for observers to remember and to interpret phonetically. How do the most recent field guides handle this group? The new Kaufman Focus Guide, Birds of North America (using photographs within a traditional "facing-page" field guide format), sticks to the basics and is definitely aimed at beginner- or intermediate-level birders. Kaufman keeps it very simple and does a decent job of depicting body and bill size, underparts colors, and tail patterns, but can't begin to address the multitude of complex variations. Both the National Geographic (3rd Edition has "better" illustrations and info than 2nd Edition) and The Sibley Guide to Birds contain "new" information unavailable in earlier guides. NGS definitely does a better job presenting identification criteria. The illustrations of the birds in NGS, however, are kind of "off" color-wise and are too skinny and long-tailed; Sibley tends to capture the shape and colors better. Both guides indicate important ID features, but do not caution observers that many of these characters exhibit individual variation or overlap among species. Both guides tend to highlight "new" information, but don't necessarily put it into the proper perspective. For example, NGS includes the following in the Nutting's Flycatcher account: "rufous primary edgings blend to yellow-cinnamon secondary edges." Although this is essentially correct, NGS fails to alert the reader that the other species of Myiarchus (including Ash-throated, for which this mark is being used as a distinguishing characteristic) have rufous edgings on the secondaries in Juvenal plumage. Or, again in NGS, for La Sagra's Flycatcher: "inner tertial edge stronger than Ash-throated." In this case, there is complete overlap of this character between the two species, with some Ash-throateds being more conspicuously marked than La Sagra's. In Sibley, for Great Crested Flycatcher: "longer winged than Ash-throated Flycatcher." Although this may be somewhat true in absolute measurements or in relative wing-tail proportions, there is certainly overlap with other species, and it is difficult to imagine the usefulness of this "mark" under field conditions. Field guides should avoid misleading observers into thinking that a character such as wing length can assist in an identification, especially when most of the relevant species show considerable overlap and are proportionately so similar.
 
Body size and bill differences between species are frequently exaggerated. Certainly, there is a substantial size difference between the largest (Brown-crested) and smallest (Dusky-capped) species. Unfortunately, there is plenty of overlap among the several mid-sized species and subspecies, as well as between the mid-sized group and the larger or smaller species. So, while some individual birds can easily be grouped in a "size class," it is not so clear-cut for others. In general, males average slightly larger than females of the same species. There is also some geographic variation in size within all of these species. Size can sometimes be misleading in the field, especially when there are no other birds to use as size standards. This is especially the case for often-solitary Myiarchus. A "large" Ash-throated Flycatcher, for example, can be mistaken for a Brown-crested even by a fairly experienced observer. Bill size also varies within and overlaps between species. For example, some Ash-throated Flycatchers appear very short-billed, whereas others appear as long-billed as a Brown-crested. In addition to individual variation in bill length, observer interpretation of bill length is very subjective! Field guides do not provide a means to estimate the relative size of the bill (e.g., bill length compared to "head length"), even if such measurements were helpful. These measurements are expressed in subjective terms, such as massive, long, short, heavy, thin, etc. Sibley goes one step further and includes (perhaps ill-advisedly) percent differences for bill length (e.g., "Eastern Brown-crested bill is 10% longer than Great Crested; Western Brown-crested is 20% longer than Great Crested"). Though David Sibley indicates in his Introduction that variation is presented as "average differences," these percent differences may not only mislead observers, but are often incorrect (e.g., male Great Cresteds from Florida average only about 3% smaller than male eastern (cooperi) Brown-cresteds, and have longer bills than female cooperi. Mentioned in these guides, but not stressed, are bill width and depth, which are probably better field characters than bill length.
 
The tail is an important ID character. Both guides discuss this character; NGS includes nice illustrations of the typical ventral tail patterns (not well illustrated in Sibley). On Myiarchus, the extent and location of dark brown versus rufous on the inner web of individual tail feathers (singular=rectrix, plural=rectrices) is important for species ID. This pattern is usually best observed from the ventral side rather than the dorsal side of the tail. This is because the central pairs of rectrices overlap on top of each subsequent pair, thus obscuring most or all of the inner webs. So, from behind (dorsal/back view), the tail appears all or mostly dark brown, depending on how tightly it is closed (Fig. 2). Unfortunately, this is how most older guides illustrated Myiarchus tails. The amount of rufous observed is dependent on the extent the tail is spread, exposing the rufous inner webs. The central pair (R1s) is predominately dark brown in adults of all species, and therefore is not a useful ID character. On the other hand, if the tail is observed from below, then the outer rectrices (R6s) are completely visible, even when the tail is closed (Fig. 3). The pattern of this feather pair can be seen when the bird is perched and facing the observer. Each feather is divided into two parts by the shaft, which separates the inner and outer webs; the inner web is broader than the outer web, especially on R2-6 (Fig. 3). The outer web of R6 can be rufous or grayish-white; the inner web is rufous, with or without some amount of dark brown between the shaft and the rufous area (see NGS 3rd edition, p. 297 for nice color illustration). Note: the outer webs of R2-5 are dark brown; the inner webs of R2-6 repeat the species-specific pattern of rufous and dark brown found on R6 (Fig. 4).
 
There are some drawbacks to using the tail pattern as a primary ID character. First, there is variation within species in the extent of brown versus rufous in adult feathers. Juveniles usually show more rufous throughout the tail, including the R1s, and outer webs of 2-5. Variation is generally consistent within species, so the observer needs to be aware of this range to properly assess tail pattern. This variation is not discussed in field guides that depict only one or two (adult, juvenal) patterns. Another problem is that tail feathers may be missing, molting, damaged, or very worn/faded. All Myiarchus have 12 rectrices (numbered 1-6 on each side; Fig. 2). All feathers are fairly similar in length so that the tail appears barely notched or square when closed, or slightly rounded when spread. Molting or damaged feathers will be shorter. Worn feathers will appear faded (lacking darker rufous and deep brown tones) or have tattered tips. In some cases, birds may have two different generations of feathers. These can be recognized by slight differences in color or pattern. If the R6s are missing, the pattern of dark brown will appear more extensive (because the R6s have paler outer webs, R2-5 have dark outer webs; Fig. 4). Finally, it can be difficult to get a good look at the underside of the tail, because Myiarchus are often wary and do not allow close approach, or there may be poor lighting. It may take careful maneuvering to get sufficiently adequate views of the individual rectrices. A telescope, and more importantly, photographic equipment, are not only helpful, but often necessary to adequately document your find.
 
Voice is a useful identification tool for this group. Myiarchus can be quite vocal, but interpreting their calls can be difficult, especially from phonetic renditions from field guides. Most species of Myiarchus have a couple of distinctive components (calls) to their vocal repertoire. These components can be strung together in various combinations, "expanding" an individual bird's repertoire. The most common calls (especially those heard during the non-breeding season) are described below. As in the case of any phonetic description of a bird vocalization, it is always best for the observer to listen to the bird's call and render his/her own interpretation. Commercial CDs and tapes are helpful; some voice clips can even be found on the internet (e.g., check USGS-Patuxent site for Dusky-capped call, and www.naturesongs.com for Brown-crested and Ash-throated flycatchers). Again, Myiarchus are much less vocal in migration and on the wintering grounds.
 
One final character used for identification, and mentioned in recent field guides, is the color of the mouth-lining. The "mouth-lining" is the inside of the bill, the inner surface of the maxilla and mandible, including the tongue and the beginning of the throat. With patience, it is actually possible to view mouth color, especially when a bird is foraging, calling, or panting.
 
Molt
The range of appearance of each species of Myiarchus is not very complicated. The biggest differences are often the result of wear on the individual feathers. As with other passerines, the first true plumage is the Juvenal plumage. Juvenal plumaged Myiarchus tend to be somewhat duller and paler (especially on the yellow underparts) than adults in Definitive Basic plumage. The difference between these two plumages is very slight. Specific differences include rustier margins to rump, or wing and tail covert feathers, and paler primary coverts. Juveniles have rusty or buffy instead of white or yellow edges to the secondary feathers. These edges are more similar in color to the primary edges, so a secondary "panel" is less defined or not obvious. Juveniles tend to have more rufous in the tail feathers and some species (especially Ash-throated) have a very different tail pattern. Most species are assumed to replace all or part of the juvenal feathers during the first Pre-basic molt. This molt may include the tail, as in the case of the Ash-throated Flycatcher. Most individuals replace their Juvenal plumage prior to fall migration. Birds with retained Juvenal plumage are often more washed-out in appearance as juvenal feathers are more delicate and wear and fade more quickly than adult feathers. Following molt to First Basic Plumage, immatures now look like adults, except for the retention of some or most of the primary-coverts and some alula feathers; up to half of individuals retain several middle secondaries (resulting in a mix of rusty and yellow-edged feathers), and, occasionally, some of the innermost primaries. A limited Pre-alternate Molt is reported to occur on the wintering grounds. It involves a partial molt of the underparts and replacement of any flight feathers that were retained from Juvenal plumage, but it does not appreciably change the overall appearance of the plumage. Timing and extent of this molt are poorly understood; presumably, it occurs before birds head back north in spring. First-year birds are more or less identical to adults by their first breeding season. During the late spring and summer, the plumage wears and fades. Sometime following breeding (there is variation between species and individuals), birds begin Definitive Pre-basic Molt. This molt is complete; it may initiate and be completed on the breeding grounds, completed on the wintering grounds, or mostly take place on the wintering grounds. Birds in fresh Basic plumage are most colorful; birds in the late summer and early fall (before molt) are the drabest. Molting juveniles with a mixture of adult and juvenal feathers may show patches of different colored feathers, notably on the crown, back, and underparts. There are a few records of partial albinos (birds with patches of white feathers).
 
Myiarchus flycatchers

Great Crested Flycatcher
Great Crested is common in Louisiana as a migrant and breeding species. For that reason, it is the most convenient Myiarchus for Louisiana observers to study. Familiarity of size and body proportions, plumage characters, and the range of variation of these characters, will be helpful as a reference for other Myiarchus species.
 
Great Crested Flycatcher is a fairly large species, with a relatively stout body. Because Great Crested is slightly longer-winged than the other species, it can appear proportionately somewhat shorter-tailed. The bill is fairly large, deep, and wide-based (Fig. 5). Most birds show a prominent pale flesh or horn-brown area at the base of the otherwise black lower mandible. Although this is generally a good mark for Great Crested, some individuals can have all-dark lower mandibles. For that reason, the absence of a pale base to the lower mandible should not automatically be used as an ID mark for other species.
 
Great Crested is the most colorful U.S. species. In all plumages, it is easily recognized by the combination of a dark gray area that extends from in front of the eye, down the face, and across the breast. The throat is barely paler than the chest. The crown and cheeks are brown and there is no pronounced gray hindneck collar (although the gray of the throat can extend up around the cheeks on the side of the neck. The gray abruptly meets the fairly bright, deep yellow of the lower breast, belly, and undertail coverts, and there are usually extensive olive-green areas on the sides of the upper breast where the gray and yellow "blend" together; these olive "patches" are generally lacking in other species. On very colorful individuals, the olive wash crosses the center of the breast. The back is olive-brown, with little or no contrast between the crown and nape. The wings are dark brown, the coverts edged white or pale gray. The edges of the primaries are rufous, forming a rusty "panel" on the folded wing. The edges of the secondaries are pale yellow or white, with the innermost "tertial" boldly edged with white. The overall effect is a "dark"-colored bird, an impression that is often enhanced by this species' preference for the shady subcanopy of mature woodlands. Juveniles are browner above and have paler underparts than adults. The belly is pale yellow and there is little olive wash on the sides of the breast. Juveniles have rusty secondary edges (except for white innermost 3) and edges to the wing coverts. The Juvenal plumage is held only briefly; immatures replace most of the body feathers prior to fall migration, and replace the flight feathers and tail on the wintering grounds. Occasionally, very pale gray-chested and pale yellow-bellied Great Crested Flycatchers are encountered during migration. These First Basic individuals have retained many juvenal feathers. These paler birds could be mistaken for Brown-crested or Ash-throated flycatchers, but they usually retain the typical "tertial" pattern (see below), tail pattern (see below), and olive wash on the breast (at the junction of the gray and yellow). A cautionary note: a bird observed in a bright, sunny situation will look more washed-out compared to the same bird viewed in heavy shade.
 
A good mark for Great Crested Flycatcher is the prominent white outer margin to the innermost (#9) secondary ("tertial;" Fig. 6). Typically, this white (or off-white) margin occupies >50% of the outer web of the feather and has a crisp, straight inner edge, forming a conspicuous wedge or stripe that is noticeably bolder than on the next two secondaries. This is a very easy mark to see when the feather is fresh, and quickly identifies a bird as a Great Crested--even when the bird is viewed only from behind! This "lower back stripe" gradually becomes less conspicuous as the feather becomes worn and faded (Fig. 6). Brown-cresteds have a relatively narrow white border to all of the innermost secondaries; Ash-throateds have a somewhat more prominent edge to the innermost feather, but it is still not as extensive and bold as in Great Crested, and is not appreciably broader than the next two feathers (NGS gets this correct, but Sibley does not).
 
Great Crested Flycatcher has the most extensively rufous tail. From above, the central tail feathers can be wholly brown with only a narrow rusty fringe to the inner web or (in the case of some juveniles) may have an extensive rusty inner web. The later pattern makes the tail appear "striped," even when it is barely spread. From below, R6 is almost entirely rufous (Fig. 7). On R6 from above, the outer web is pale rufous-brown, and the inner web is almost entirely rufous; there may be a narrow dark brown stripe along the shaft, mostly on the outer web, but sometimes up to 1-2 mm along the shaft on the inner web, and the brown is usually darkest near the tip of the feather (but the dark area is still narrow and rufous clearly extends to the feather tip). Compare to Brown-crested, which usually shows a substantially wider dark "shaft stripe" on the inner web (but the rufous still extends to the feather tip, as in Great Crested; Fig. 7), and to Ash-throated's dark "tear drop" tip (rufous does not extend to feather tip; Fig. 2, 3, 7). On R2-5, the outer web is entirely dark brown and there may be a 0-2 mm dark shaft stripe on the inner. A Great Crested missing both R6s may suggest a Brown-crested because the tail feathers will be striped, but close examination should still reveal little or no dark shaft stripe on the inner web. Juveniles are similar in this regard.
 
Voice, mouth color. Great Crested Flycatchers are very vocal upon arrival on the breeding grounds, much less so during (especially fall) migration. The typical call of the Great Crested is a rising "whee-eep." The mouth-lining is usually bright orange-yellow, although some individuals are flesh-colored or dull yellow.
 
Ash-throated Flycatcher
Ash-throated Flycatcher is rare in Louisiana, but it is our next most "expected" species. Several wintering birds are usually located each year, and directions to their locations are often announced on rare bird alerts or email bulletin boards. With patience, these individuals can often be relocated, allowing opportunities to become familiar with this western species.
 
Ash-throateds are more slender in body proportions than Great Crested Flycatcher. Although averaging slightly smaller, most individuals look proportionately longer-tailed compared to a Great Crested. The bill is quite variable in length, overlapping with Great Crested. The bill is generally narrower and shallower than Great Crested (Fig. 5). The bill is all or mostly black, with a slightly paler brown or flesh-colored base to the lower mandible on some individuals.
 
Compared to adult Great Crested, the plumage of Ash-throated is paler. The whitish-gray throat and pale gray breast are very different from the dark gray colors shown by Great Cresteds. Juvenal plumaged Great Cresteds, with their paler whitish-yellow bellies, can be more similar to Ash-throateds, but will still have relatively darker gray throats and breasts. Most Ash-throateds show a whitish or yellowish-white transition between the gray chest and pale yellow belly, and there is no olive-green suffusion on the breast. This combination is lacking in Great Crested Flycatcher. Even the palest Great Cresteds (rare) will show an abrupt junction between the gray breast and yellow belly. Ash-throateds have a brown crown and back, which are typically separated by a subtle grayer collar across the hindneck (although this is more pronounced in Juvenal and Basic I plumages). The face and cheeks are gray. Like Great Crested, the wings are brown, the primaries are edged rufous, and the secondaries are dull white to pale yellow (buffy or rusty in juveniles). Each pale feather edge is approximately the same width, which is another good way to exclude Great-crested (Fig. 6).
 
Basic plumaged Ash-throateds have a distinctive tail pattern: on R6, the narrow dark brown shaft stripe flares across the tip of the mostly rufous inner web (but see Nutting's Flycatcher below) forming a "tear drop" pattern; the rufous does not extend to the tip of the feather. On some individuals, the "tear drop" prominently hooks up around the inner edge of the feather tip, which is diagnostic for Ash-throated Flycatcher (Fig. 3). A cautionary note: the pattern on R6 is variable and the pattern is not necessarily repeated on the other rectrices (R2-5). If the pattern on R6 is not pronounced, or if this feather is missing, then the result might be a pattern more suggestive of Brown-crested Flycatcher. In Juvenal plumage, the tail pattern is very different. The tail is more entirely rufous (including the R1s) and lacks the distinctive flares of dark brown across the feather tips. A good clue that a bird has a juvenal tail is that the tail is predominately rufous from above (juvenal plumaged birds also have more whitish bellies). Individuals that have partially molted into first Basic plumage (and have brighter yellow bellies), but that have retained their juvenal tails have been recorded in Louisiana and elsewhere in the eastern U.S. Although a Basic plumaged Ash-throated with a juvenal tail is superficially more similar to a Great Crested, the combination of size, shape, body proportions, and other plumage characters, as noted above, should make most identifications straightforward.
 
Ash-throated Flycatcher is virtually identical to Brown-crested Flycatcher in overall coloration, except that fresh-plumaged Brown-cresteds have slightly darker grays and yellows on the underparts. These species are best distinguished by relative size and proportions, voice, and tail pattern. Western (magister) Brown-cresteds average substantially larger, with a longer, heavier (deeper and more broad-based), and usually more hooked bill. Although Ash-throateds and eastern (cooperi) Brown-cresteds are much more similar in size, these Brown-cresteds will still have slightly darker/brighter underparts, proportionately longer, heavier bills, and different tail patterns and vocalizations (see below). Worthy of consideration would be a situation in which both Brown-crested subspecies are found together (this has actually been documented in Louisiana on one occasion). With this size combination, an observer expecting only eastern Brown-cresteds to occur as vagrants, might be prone to correctly identify the magister as a Brown-crested, but to misidentify the cooperi as an Ash-throated based on relative size and proportions.
 
Voice, mouth color. On the breeding grounds, Ash-throateds are vocally conspicuous. The most familiar breeding season calls are "ka-brick" and "ha-wheer." In migration and winter they are much less vocal, and the calls most likely to be heard are a soft "prrrrt" or "perp," or a soft "whit" (these calls are also given on the breeding grounds). The mouth-lining is usually flesh-colored, although some individuals have dull yellow mouths.
 
Brown-crested Flycatcher
Brown-crested Flycatcher is very rare in Louisiana, but, in recent winters, one or more individuals have usually been located in extreme southern Plaquemines Parish. With perseverance, these birds can often be relocated after they are initially reported, providing observers a great opportunity to expand their Myiarchus expertise. Sometimes, Ash-throated Flycatchers are also present in this area, and Great Cresteds might be found in early spring before the wintering species have left, making for twice or three times the fun!
 
The western subspecies magister is the largest of all the Myiarchus, and is appreciably larger in all aspects in comparison with the other North American Myiarchus species; there is only minor size overlap with Great Crested and Ash-throated flycatchers, and magister literally dwarfs the much smaller Dusky-capped Flycatcher. In particular, the bill of magister is proportionately longer and deeper, and has a more exaggerated hook, than all other Myiarchus. The eastern Brown-crested subspecies cooperi, however, is smaller and there is extensive size overlap with Great Crested Flycatcher, and limited size overlap with Ash-throated Flycatcher. The bill of cooperi is the same size as, or slightly larger than, Great Crested, and is mostly dark, sometimes with a slightly paler base to the lower mandible. Great Crested and cooperi have similar absolute tail lengths, but Great Cresteds average slightly longer wings, which can make them look proportionately shorter tailed. There is also some overlap in body size and bill length between some cooperi and Ash-throated Flycatchers, but cooperi's bill is deeper on average than Ash-throated.
 
In body plumage, Brown-crested is almost identical to Ash-throated, except that there is more abrupt gray-yellow contrast on the breast (without the intervening whiter area seen on most Ash-throateds), and the gray and yellow areas of the underparts are slightly darker/brighter (but still closer to Ash-throated than to Great Crested). Brown-cresteds in fresh plumage will appear brighter than the worn and faded individuals that many observers may have experienced on the breeding grounds out west, and so will seem relatively more similar to Great Crested. Otherwise, Brown-cresteds will differ from Great Cresteds by being paler gray on the face and chest, and lacking olive on the sides of the breast. A cautionary note: rarely, Great Cresteds can be as pale on the underparts as Brown-crested. Brown-crested Flycatchers will lack the two prominent white "lower back stripes" (formed by the broad white margin on the outer web of the innermost secondary/tertial; Fig. 6) found on most Great Cresteds; instead, the three innermost secondaries are narrowly, less crisply edged with grayish-white. Another cautionary note: remember that worn or molting Great Cresteds could lack the broad white "lower back stripes," so don't automatically conclude that such a bird is something other than Great Crested (especially if you see such a bird in Louisiana during spring, summer, or early fall, when probability favors Great Crested)!
 
As usual, the color pattern of the tail is an important distinguishing characteristic. From below, the outermost rectrices (R6) of a Brown-crested will show a relatively broad (> 1.5 mm wide) dark brown shaft stripe on the inner web; the remaining inner portion of the inner web is rufous, and the rufous extends to the tip of the feather. Great Cresteds generally lack a dark shaft stripe on R6 (the inner web is usually completely rufous), or it is ill-defined and very narrow (<2 mm wide). Ash-throateds typically lack the dark shaft stripe on the outer 5 pairs of rectrices, except for a dark wedge that flares across the inner web at the feather tip (rufous does not extend to the feather tip on the inner web; see Fig. 7).
 
Older identification guides usually illustrated only the larger western (magister) subspecies, and didn't even bother mentioning in the text that a smaller subspecies occurs in southern Texas and eastern Mexico. Thus, there is still at least some perception that all Brown-crested Flycatchers are large, magister-like birds with massive bills. Unfortunately, the new Kaufman guide perpetuates this misconception. NGS 3rd Edition and Sibley (as well as a few other recent publications on Myiarchus identification), on the other hand, have included both subspecies in their Brown-crested accounts and field guide users now have the benefit of comparing illustrations and descriptions of these two subspecies. Unfortunately, Sibley continues to exaggerate the differences between the size of cooperi and Great Crested. Size and bill proportions are better illustrated in NGS.
 
Voice, mouth color. Many of the breeding season calls are reminiscent of Great Crested Flycatcher, including a rough burrrk or keeerp that is descending rather than ascending as in Great Crested. Most of the individuals found in Louisiana have been silent, but a few wintering birds have been heard giving single sharp whit calls. The mouth-lining is flesh-colored to yellowish-flesh, much like Ash-throated, although some individuals can apparently be more yellow-orange or orange-flesh.
 
Dusky-capped Flycatcher
Dusky-capped Flycatcher is overall smaller than Ash-throated, but it overlaps in bill size with Ash-throated and thus appears, proportionately, relatively large-billed (Fig. 5). The small, pale northwestern subspecies olivascens, which breeds in the mountains of the extreme southwestern U.S., is the form most familiar to North American birders. In general, the plumage is somewhat richer and darker than Ash-throated. The belly is slightly deeper yellow, the center of the breast is darker gray, and the sides of the breast are suffused with olive (similar to Great Crested). Dusky-capped has a fairly abrupt gray-yellow transition on the breast and lacks the intervening whitish area of Ash-throated. The head, including cap and cheeks, is uniformly brown, sometimes giving the bird a capped appearance. Perhaps the best specific plumage character for identifying adults is that the rectrices are almost entirely dark gray-brown, with only a narrow rufous margin to the outer and inner webs of R2-R6. The tail looks basically all brown, even when spread. Juveniles have a more pronounced stripe of rufous along the inner edge of the inner web. The subspecies found in eastern Mexico (lawrenceii) is somewhat larger, darker, and more colorful than olivascens. It has a darker cap and more rufous in the tail. The inner webs of all the rectrices are edged with rufous. The tail still appears predominantly dark compared to Ash-throated or Brown-crested flycatchers. The upperwing coverts are duller compared to other species: gray (olivascens) or rufous (lawrenceii) and thus, making the wing bars less conspicuous. The primaries, as in the other species, are edged with rufous. The secondaries are edged with rusty-yellow in adult olivascens. Note field guide references to rufous edges on the secondaries as an ID character- this is only conspicuous on juveniles and lawrenceii. Note: juveniles of other species also show rusty-edged secondaries (e.g., Ash-throated, Great Crested, and Brown-crested flycatchers).
 
Voice, mouth color. The species is often first detected by its unusual voice. The most familiar call is a distinctive, mournful, descending whistle, peeeeuuuu. The whistle is sometimes preceded by a whit note. The mouth-lining is orange.
 
Nutting's Flycatcher
This vagrant to the extreme southwest U.S. is very similar in size and overall appearance to Ash-throated Flycatcher. Though measurements overlap, it averages shorter- tailed, shorter-billed, and has a shorter, more rounded wing. Nutting's is best separated from Ash-throated by voice and mouth color (see below). In fresh plumage there are subtle but consistent plumage differences between Nutting's and Ash-throated: 1) Nutting's tends to be more Brown-crested -like on the underparts, with a slightly darker gray breast and brighter yellow belly, and a relatively abrupt gray-yellow transition (and without the intervening whitish area of Ash-throated). 2) In adult Nutting's, the first (distal-most) secondary edge is usually rufous, and the others blend towards pale rufous or brownish-white; compare to the whitish or yellowish-white secondary edges of Ash-throated. Beware: juveniles of both species have rusty/buffy edged secondaries, and immature Ash-throateds frequently retain some rusty edged middle secondaries into their first spring. 3) Nutting's have a brownish auricular patch and nape (versus grayish in Ash-throated). 4) From below, the pattern on R2-6 of Nutting's is variable and ranges from an Ash-throated -like pattern of dark flaring across the inner web at the feather tip, to more Brown-crested -like with distinctive dark shaft stripes on the inner web and rufous extending to the feather tip (Fig. 8). To further confuse the situation, Ash-throateds will occasionally lack the flared or hooking all-dark tips to R2-6. Such "problem" individuals can usually be properly identified in the hand by looking at both R6 and R2: Nutting's with Ash-throated -like R6s usually also have a dark shaft stripe on R2; Ash-throateds with atypical R6s will lack the dark shaft stripe on R2. Identification of Nutting's versus Ash-throated flycatchers was thoroughly covered by W. E. Lanyon way back in 1961, but some modern field guides continue to oversimplify or mislead, e.g., for Nutting's, NGS states "dark on outer tail feather does not cross tip;" this is simply incorrect. There is a nice series of published photos of the 1998 Arizona Nutting's in FieldNotes 52(2): 148 (+cover).
 
Voice, mouth color. A mournful, whistled, peer. This note can be preceded by a pip note that is somewhat similar to the soft whit of Ash-throated. The mouth-lining is always orange, instead of flesh-colored or yellowish.
 
La Sagra's Flycatcher
Except perhaps for Juvenal plumaged Ash-throated Flycatcher, this species is the palest Myiarchus. It averages slightly smaller than Ash-throated Flycatcher. The crown and back are colder brownish-gray, the nape somewhat grayer. The cheeks and side of the face are slightly darker, so most individuals appear "capped." The chest is pale gray, similar to an Ash-throated, but with darker gray at the sides of the breast. The belly is very pale yellow, nearly white. At first glance, the plumage is more suggestive of an Eastern Phoebe rather than a "typical" Myiarchus. The typical rufous "Myiarchus wing panel" is less conspicuous in La Sagra's because the primaries are only very narrowly edged with rufous. The secondaries are narrowly edged with white. The upperwing coverts are edged with light gray. The tail pattern is quite variable. Rectrices 2-6 may be mostly brown with a very narrow fringe of rufous along the outer edge of the inner web, therefor resembling the pattern shown by Dusky-capped Flycatcher (Fig. 8C) or with a fairly broad stripe of rufous on the inner web as illustrated in Fig. 8A. La Sagra's Flycatcher is reported to be relatively more secretive than other Myiarchus, preferring to stay within thicker vegetation (Smith and Evererd 1992). The species also differs from our more familiar North American species by its more leaning posture, and by keeping its crest flattened most of the time.
 
Voice, mouth color. Call is a high-pitched whit. The mouth-lining is pale yellow.
 
Specimens at LSU Museum of Natural Science provided an invaluable resource.
 
Main references consulted for this article:
American Ornithologist's Union. 1998. Check-list of North American birds. 7th Ed. Am. Ornithol. Union, Washington D. C.
Cardiff, S. W., and D. L. Dittmann. 2000. Brown-crested Flycatcher (Myiarchus tyrannulus). In The Birds of North America, No. 496 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
Cardiff, S. W., and D. L. Dittmann. In press. Ash-throated Flycatcher (Myiarchus cinerascens). In The Birds of North America, No. ??? (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
Lanyon, W. E. 1961. Specific limits and distribution of Ash-throated and Nutting flycatchers. Condor 63: 421-449.
Lanyon, W. E. 1997. Great Crested Flycatcher (Myiarchus crinitus). In The Birds of North America, No. 300 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
Pyle, P. 1997. Identification Guide to North American Birds, Part I: Columbidae to Ploceidae. Slate Creek Press, Bolinas, CA.
Smith, P.W. and D. S. Evered. 192. La Sagra's Flycatcher. Birding XXIV (5): 294-297.
 
Donna L. Dittmann & Steven W. Cardiff
435 Pecan Drive
St. Gabriel, LA 70776
 
Figures by Donna L. Dittmann: Fig. 1 || Fig. 2 || Fig. 3 || Fig. 4 || Fig. 5 || Fig. 6 || Fig. 7 || Fig. 8
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posted 26December2000