Flycatcher ID challenges in a Central American context

By eBird Centroamérica abril 30, 2017
Hammond's Flycatcher Empidonax hammondii

By John van Dort & Oliver Komar

During the months of April and May, flycatchers of the genera Empidonax and Contopus are some of the most common and difficult birds to identify in Central America. To help you with this challenging group, we have prepared an overview of the expected species in the region. We hope this will prove useful as you prepare for Global Big Day, and for everyday birding during these months.

When confronted in the field with one of these generally drab flycatchers, the first thing to figure out is whether you’re looking at a Contopus wood-pewee or an Empidonax flycatcher. Wood-pewees are larger than Empidonax flycatchers, with longer wings; they have darker flanks and shorter legs than Empidonax flycatchers; and they often return to the same spot when fly-catching (Empidonax usually don’t). Several empids show strong eye rings; wood-pewees don’t. Empidonax flycatchers usually show a subtly darker breast band; wood-pewees don’t. Contopus tend to favor higher, more exposed perches, but there’s much overlap. Generally, empids have stronger, wider wing bars than Contopus flycatchers; these can be pale in the adults of many species, or more buffy in young birds.

Contopus

Let’s start with the genus Contopus. There are three migratory species in the region, and four resident species. The three migratory species are Olive-sided Flycatcher (Contopus cooperi), Eastern Wood-Pewee (C. virens), and Western Wood-Pewee (C. sordidulus). Note that the latter also has breeding populations in Mexico and parts of northern Central America. The resident species are Greater Pewee (C. pertinax) in the pine-oak forests of northern Central America; Tropical Pewee (C. cinereus) throughout Central America; and Dark Pewee (C. lugubris) and Ochraceous Pewee (C. ochraceus), both in the highlands of Costa Rica and western Panama. Of these resident species, only Tropical Pewee is similar to the two migratory wood-pewees; the other three species are quite distinct and will not be treated further in this overview. Look them up in eBird’s Media Explorer to see photos and hear recordings of these species.

Olive-sided Flycatcher (Contopus cooperi)

A typical view of an Olive-sided Flycatcher: high on an exposed perch. May, Missouri (USA). Photo © Lisa Owens / Macaulay Library.

This is a large flycatcher that likes to perch high in the top of a bare tree. That is already a good clue for identifying this species, as the other pewees and flycatchers are less likely to perch high in tall, leafless trees. Note also the chunky shape with a large head and a strong ‘vest’ (i.e. darker flanks), and the identification is relatively straightforward. The famous “quick—three beers” song is sometimes heard in Central America, but in our region this species is usually quiet. For an exhaustive overview of Olive-sided Flycatcher vocalizations, check out the amazing online companion to the Peterson Field Guide to Bird Sounds.

Eastern Wood-Pewee (Contopus virens)

Eastern Wood-Pewee; May, Texas (USA). Photo © Edward Plumer / Macaulay Library.

This species is similar to Western Wood-Pewee and to Tropical Pewee. The songs of the three species are distinct, and good identification clues, but some of the contact call notes of the wood-pewees can be similar. Compared to Western Wood-Pewee, Eastern usually has two equally bright wing bars, while the upper wing bar in Western Wood-Pewee is usually weaker than the lower wing bar. Most adult Eastern Wood-Pewees have the lower mandible mostly pale orange with a dark tip; in Western Wood-Pewee, the lower mandible is often more extensively dark, with only the base of the bill paler. (Beware in fall migration, many young Easterns have mostly dark lower mandibles as well.) Tropical Pewee has an even paler lower mandible, with no dark tip, and is a slightly smaller bird with shorter wings. Eastern Wood-Pewee often gives a slightly paler impression than Western Wood-Pewee, which can look dark, especially on the sides of the head. Note that these differences are subtle, and impressions of light or dark can easily be influenced by lighting conditions. When identifying non-singing wood-pewees, try to use multiple field marks, because none of these marks is reliable 100% of the time just on its own.

Comparison of an Eastern Wood-Pewee vocalization (top) and a Yellow-bellied Flycatcher vocalization (bottom). Note how pattern and frequency are rather similar, although the Yellow-bellied Flycatcher call is much shorter. Photo @ Macaulay Library.

The Eastern Wood-Pewee often sings during migration, and its long song is distinctive, and quite different from both Western and Tropical Pewees. Yellow-bellied Flycatcher (Empidonax flaviventris) gives a similar call that’s shorter (see right). Note that Eastern Wood-Pewee sometimes also gives a series of “pwik” calls that may suggest an empid, like Alder for example (the call is given at 0:29 and at 0:33 in this recording). When confronted with a ‘medium-large flycatcher’ giving such short calls, note whether the bird has darker flanks (wood-pewee) or a darker breast band (Empidonax), whether the primary extension is long (wood-pewee) and whether it returns often to the same perch (wood-pewee). A great overview of Eastern Wood-Pewee vocalizations can be accessed here.

Western Wood-Pewee (Contopus sordidulus)

Western Wood-Pewee, May, Oregon, USA. Photo © Greg Gilson / Macaulay Library.

Gives the impression of being slightly darker and more uniformly colored than Eastern Wood-Pewee, which often shows a bit more contrast, especially on the head. The upper wing bar is typically less bright than the lower wing bar, and the lower mandible is usually mostly dark. It tends to hold the tail in a straight line with the back more often than Eastern Wood-Pewee, which more often holds the tail slightly down, but this is a secondary field mark at best. The tail appears slightly shorter on Western Wood-Pewee, compared to Eastern. The song, sometimes heard in spring and fall migration, is burry, not clear (it can be confused with a song of the Greenish Elaenia Myiopagis viridicata). Check here for an extensive overview of Western Wood-Pewee calls.

Tropical Pewee (Contopus cinereus)

Tropical Pewee, February, Costa Rica. Photo © Ian Burgess / Macaulay Library.

This species is slightly smaller than the two wood-pewees, and has slightly shorter wings, and a slightly darker cap. The belly often has a yellowish wash, but note that this is also true of freshly molted wood-pewees. It vocalizes frequently, and the short referee whistle sounds nothing like the calls or songs of the wood-pewees. The Tropical Pewee song sounds a little bit like the call of the Tropical Kingbird (Tyrannus melancholicus), but is shorter and descending, not ascending as in Tropical Kingbird. It also has a shorter, sharply upward inflected call note that can be heard at 0:09 and following in this recording. Their relatively small size (for a Contopus) make them look intermediate between wood-pewees and the larger empids, especially Willow and Alder.

Empidonax

Flycatchers in the genus Empidonax are smaller than those in Contopus; their wing bars are often more pronounced; and they often reposition themselves after fly-catching, rarely returning to the same spot. They don’t have dark vests like Contopus, but rather subtly darker breast bands. Vocalizations are often helpful to support an identification, but require careful study, as many empids give a variety of call notes. Check out this blog entry and also this one for more information. That said, let’s take a closer look.

As in Contopus, some members of this genus are resident in our region, while others are migratory. Some of the most difficult identification challenges occur in this group, but luckily not all Empidonax that breed in the United States winter in Central America. Notoriously difficult species pairs like Cordilleran (Empidonax occidentalis) and Pacific-Slope Flycatcher (E. difficilis) for example do not occur in Central America, so we do not have to consider them in the field. Some other Empidonax, like Gray Flycatcher (E. wrightii) and Dusky Flycatcher (E. oberholseri), do not occur in Central America either. Distinctive resident species such as Buff-breasted Flycatcher (E. fulvifrons) in the pine-oak forests of northern Central America and Black-capped Flycatcher (E. atriceps) in the highlands of southern Central America will not be treated here. They generally do not pose the same identification challenges, but if you want to compare them, look them up in eBird’s Media Explorer.

Acadian Flycatcher (Empidonax virescens)

Acadian Flycatcher, April, Honduras. Photo © Oliver Komar / Macaulay Library.

This species breeds in the eastern United States, and winters in southern Central America and northern South America. It is relatively large for an Empidonax, with a long primary projection and a relatively large bill with a pale lower mandible. The legs are dark gray (not black as in other Empidonax), but this is only visible at very close range. The throat is pale, but there is no contrast between the pale throat and the darker sides of the head, as the color change is gradual and subtle. Appears greener on the upperparts than other Empidonax species. A common Acadian call note is similar to one given by Yellow-bellied Flycatcher. An excellent overview of Acadian Flycatcher vocalizations is available here.

Alder Flycatcher (Empidonax alnorum)


Alder Flycatcher, April, Honduras. This photo illustrates well the contrasting white throat, which has the potential to lead observers astray into thinking they are looking at a White-throated Flycatcher. Photo © John van Dort / Macaulay Library.

This species is very similar to Willow Flycatcher, and silent birds are best left identified as Alder/Willow, or “Traill’s Flycatcher” as these two species were called before they were split in 1973. It is relatively large for an Empidonax, with a fairly long primary projection, though shorter than Acadian, or indeed any wood-pewee. In most of Central America, this species is a transient twice a year, as the majority winter in northern South America. (Note that Willow Flycatchers generally winter further north, including in most of Central America.) The white throat contrasts sharply with the darker rest of the head, inviting confusion with a resident Empidonax species, the White-throated Flycatcher (Empidonax albigularis). The eye ring is usually thin. Gives a wide variety of vocalizations in migration, including “pip… pip” (or “peet… peet”) quite different from the majority of Willow Flycatcher calls, recalling call notes of Myiarchus flycatchers like Brown-crested Flycatcher (M. tyrannulus) or Ash-throated Flycatcher (M. cinerascens). For an excellent overview of Alder Flycatcher vocalizations, head on over here.

Willow Flycatcher (Empidonax traillii)

Willow Flycatcher, May, Montana (USA). Photo © Daniel Casey / Macaulay Library.

A large Empidonax very similar to Alder, and before 1973 was considered the same species (“Traill’s Flycatcher”). Note that there is some geographical variation in this species, with eastern Willow Flycatchers showing a slightly more pronounced eye ring and showing less brown on the back, thus appearing identical to Alder Flycatchers. Western Willow Flycatchers typically look slightly paler and grayer, with less defined eye rings and wing bars, making them look more like a wood-pewee or Tropical Pewee. Willow Flycatcher often gives sharp, liquid “whit” calls, similar to calls produced by Least Flycatcher, but unlike any Alder calls. The song of Willow, which is also heard on the wintering grounds, is a distinct “FITZ-beeyew”; Alder sings “rrree-BEEEo”. Willow Flycatcher is larger than Least Flycatcher, with a less distinct eye ring. Check this site for an excellent overview of Willow Flycatcher vocalizations.

Yellow-bellied Flycatcher (Empidonax flaviventris)

Yellow-bellied Flycatcher, August, New York (USA). Photo © Tim Lenz / Macaulay Library.

Perhaps a better name for this species would be “Yellow-throated Flycatcher”, as most Empidonax have some yellow on the belly, especially in fresh plumage. This species, however, does appear more yellow overall than most other empids, especially on the underparts, including the throat. This is a common winter visitor in humid forests throughout the region, and should be learned well as a yardstick with which to measure other empids. It is relatively small, and often appears large-headed and short-tailed. The eye ring is yellowish, not white. There is relatively little contrast in its plumage, except for the dark wings that contrast with the rest of the body and with the bright wing bars. Observers should do well to learn the various call notes, including this typical one and a “turreee” call that sounds quite like the short song of the Eastern Wood-Pewee. The two most similar species to the Yellow-bellied are the Hammond’s and the Yellowish flycatchers. Hammond’s lacks the greenish tones to the upperparts and the yellowish tint on the throat. Yellowish is darker olive-green on the upperparts, has darker wing bars, and a stronger eye ring. See the excellent online companion to the Peterson Field Guide to Bird Sounds for an overview of Yellow-bellied Flycatcher vocalizations.

Least Flycatcher (Empidonax minimus)

Least Flycatcher, January, Mexico. Photo © Ian Davies / Macaulay Library.

Like Yellow-bellied, a small Empidonax, but unlike Yellow-bellied, usually found in drier and more open situations. The strong eye ring, small size with relatively big head, narrow tail, and relatively short wing projection are all good identification clues. Compared to Yellow-bellied, its colors are more gray and brown than yellow and green. The “whit!” call is similar to that of Willow Flycatcher; some observers report that it is given more frequently. An extensive overview of vocalizations is given here.

Hammond’s Flycatcher (Empidonax hammondii)

Hammond’s Flycatcher, October, Honduras. Photo © John van Dort / Macaulay Library.

This species winters in the pine-oak forests of northern Central America, and is most similar to two species that thankfully do not occur in Central America: Dusky Flycatcher and Gray Flycatcher. In our region, Hammond’s Flycatcher shares the pine-oak habitat with only two other Empidonax: the distinctive Buff-breasted Flycatcher and Yellowish Flycatcher. A third species, Yellow-bellied Flycatcher, is regularly seen in pine-oak forest during migration. Hammond’s Flycatchers are superficially similar to Least Flycatchers, which are sometimes found at the edge of pine-oak forests (virtually never inside the forest). Note that Hammond’s has a much shorter, narrower bill than any other empid, and that the lower mandible is mostly dark (pale on the majority of Empidonax in our region). The eye ring is usually broader behind the eye (although not teardrop-shaped as in Yellowish Flycatcher; see below). The throat is grayish, not white or yellowish. The most frequently heard call note of Hammond’s is similar to that of the Yellow-bellied Flycatcher.

Pine Flycatcher (Empidonax affinis)

Pine Flycatcher, January, Mexico. Photo © Nathan Pieplow / Macaulay Library.

The distribution of this non-migratory flycatcher is largely Mexican, and reaches our region only in Guatemala. Found in open pine savanna and pine-oak forest, this species is intermediate in size, and has a relatively narrow bill with a mostly or entirely pale lower mandible, and relatively long wings and tail. Similar species within its range include Hammond’s and Yellowish flycatchers. Hammond’s has a smaller bill and a mostly dark lower mandible, and Yellowish has a wider bill and more olive-green tones in the plumage. A common call note is similar to one given by Willow Flycatcher.

White-throated Flycatcher (Empidonax albigularis)

White-throated Flycatcher, May, Honduras. Photo © John van Dort / Macaulay Library.

Similar to Alder and Willow Flycatchers, with which it shares a contrasting white throat. In most of the region, the overall color is warmer brown than other empids, and the head shape is rounder, with little or no peak on rear crown, as in Alder and Willow. The slightly paler rump is not always visible, but a useful character when obvious. The eye ring is often weak (as in Willow and Alder). In many parts of the range this species is an altitudinal migrant that winters near water, often at the edges of marshes (like Willow Flycatcher) and breeds in open, brushy areas in the highlands of Central America. Like other empids, this species gives a variety of vocalizations, many of which can be heard in this excellent longer cut.

Yellowish Flycatcher (Empidonax flavescens)

Yellowish Flycatcher, January, Costa Rica. Photo © Jay McGowan / Macaulay Library.

Generally darker olive-green than other Empidonax, with usually buffy wing bars, and a strong eye ring that’s wider behind the eye. This resident species is usually found in cloud forest, humid pine-oak forest, and middle elevation humid forest. Listen for its short, high-pitched call, reminiscent of but more strident than the even shorter Slate-throated Redstart call note. The only possible confusion species are Pine Flycatcher and Yellow-bellied Flycatcher, sometimes found in the same habitat. The former is less olive-green, while the latter species is paler, with paler wing bars, darker wings, and its eye ring is not (much) wider behind the eye.

Finally, a word of caution

For both these difficult groups, don’t rely on any single field mark, but use multiple field marks. Realize that you cannot identify every flycatcher you see in the field: sometimes all we get are brief views of silent or backlit birds. Experts leave those birds unidentified, or at best identified to a category, like “Western/Eastern Wood-Pewee”, “Alder/Willow (“Traill’s”) Flycatcher”, or even Empidonax sp. And that’s fine! At eBird, we prefer that you report birds you carefully identified, and we don’t expect you to name every bird you encounter in the field. We do hope that these pointers are useful within a Central American context, and wish you success in the upcoming Global Big Day!

Western (?) Wood-Pewee, May, British Columbia (Canada). Photo © John Reynolds / Macaulay Library.

To illustrate the point of no single field mark being error-proof, take a look at this (presumably) Western Wood-Pewee from the Vancouver area in western Canada, photographed in May 2016. Note that this is very far from the normal range of Eastern Wood-Pewee. The dark lower mandible, drab dark face, and overall dark, dusky brownish color suggest Western, but just look at those wing bars: equally bright! If we were to encounter this bird in Central America—and we have seen silent birds like this in Honduras—we would identify it as Western/Eastern Wood-Pewee.

Acknowledgments:

We wish to thank Roselvy Juárez for helpful comments on an earlier version of this article.

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