Proposal (1075) to South American Classification Committee

 

 

Split Tufted Flycatcher Mitrephanes phaeocercus into two or three species and modify English names

 

Note: This proposal is here repurposed for SACC, having been considered by NACC.

 

Summary

 

Although vocal differences have formed the basis for many recent changes in species limits within Tyrannidae, the striking vocal differentiation within the Mitrephanes phaeocercus complex has not yet been formally considered as a basis for revision of the species limits, although it has been known for some time (see for example Dyer and Howell 2023). Tufted Flycatchers in northern Middle America have position calls and dawn songs that differ strikingly from those of birds from Costa Rica south, and this division aligns well with plumage differences and is supported by evidence of a strong genetic break between Honduras and eastern Panama. The differences in position note are less striking between Costa Rica/Panama (M. p. aurantiiventris) and e. Panama/Colombia/Ecuador (M. p. berlepschi), but the differences in primary song, dawn song, and plumage strongly suggest that those should also be recognized at the species level. The only other described taxon in Mitrephanes (there is a putatively undescribed taxon on Cerro Tacarcuna), Olive Flycatcher Mitrephanes olivaceus, is already recognized as specifically distinct. Acceptance of this proposal would require change in English names of the daughter taxa of phaeocercus, and we recommend a minor change to that of M. olivaceus as well.

 

This proposal does not give statistical measurements of the songs and calls, in part because the differences are so striking: the position notes are so dissimilar between phaeocercus and aurantiiventris that it is challenging to find relevant measurements. The Macaulay Library (ML) provides ample audio recordings to support the vocal differences, and supporting links are provided below.

 

Background

 

The genus Mitrephanes is thought to be closely related to Contopus (pewees), which includes multiple species that are nearly identical in appearance and differ primarily in vocalizations.

 

A screenshot of a computer AI-generated content may be incorrect.

 

Fig. 1. The Birds of the World Phylogeny Explorer shows the position of Mitrephanes as sister to Contopus; see https://birdsoftheworld.org/bow/phylogeny#tuffly; Miller et al. (2025).

 

Webster (1968) summarized the taxonomic history within Mitrephanes as follows:

 

“Ridgway (1907) recognized five species, although he was able to examine only two. Hellmayr (1927) lumped the entire genus in a single species, as did Zimmer (1930; 1938a) in the most thorough revision thus far. Griscom (1932) restated the specificity of M. berlepschi, and Sutton and Burleigh (1940), while they did not discuss the South American forms, distinguished M. aurantiiventris (of southern Central America) as a species separate from M. phaeocercus. It should be noted that Zimmer had only 76 specimens altogether and Sutton and Burleigh only 38 from north of the Isthmus of Tehuantepec.”

 

The AOS-SACC has followed the recommendation of Webster (1968), which was to recognize two species within Mitrephanes. AOS-NACC considered the genus monotypic until 2018, when it finally voted to conform with the AOS-SACC interpretation by recognizing M. olivaceus (Olive Flycatcher), which is extralimital to the AOS-NACC area. That 2018 proposal (Chesser 2018; https://americanornithology.org/wp-content/uploads/2020/02/2018-A.pdf) was straightforward and explicitly recommended following Webster (1968) and the AOS-SACC interpretation.

 

Thus, as of 2018, both AOS-NACC and AOS-SACC follow the recommendations on species limits from Webster (1968) wherein he recommended “A moderate course between the extreme points of view, which recognize four species or one, seems best to express the phylogeny of the genus. I would recognize two species--M. phaeocercus and M. olivaceus.”

 

Webster (1968) recognized all the below taxa in Mitrephanes; eBird/Clements and AviList treat at least four subspecies in synonymy, as below; taxa recognized by eBird/Clements (Clements et al. 2025) and AviList (AviList Core Team 2025) are listed in bold type. Ranges are modified from those in eBird/Clements.

 

o   M. p. tenuirostris Brewster, 1888: mountains of western Mexico (southeastern Sonora and southwestern Chihuahua to western Jalisco)

o   M. p. phaeocercus (Sclater, 1859): mountains of eastern and central Mexico (southwestern Tamaulipas, Zacatecas, and central Jalisco to Oaxaca and Chiapas) southward to northeastern Nicaragua

§  M. p. burleighi Phillips, 1966: central Jalisco to w. Oaxaca

§  M. p. phaeocercus (Sclater, 1859): mountains of eastern and central Mexico (southwestern Tamaulipas and Zacatecas southward to e. Oaxaca

§  M. p. nicaraguae Miller & Griscom, 1925: northern Chiapas to northeastern Nicaragua

o   M. p. aurantiiventris (Lawrence, 1865): highlands of Costa Rica and Panama (eastward to Serranía del Darién*)

§  M. p. aurantiiventris (Lawrence, 1865): highlands of Costa Rica and Panama (eastward to e. Chiriquí and Ngäbe-Buglé provinces)

§  M. p. vividus Griscom, 1927: central Panama (highlands of e. Coclé and w. Panamá; affinities of birds in Veraguas is unclear); treated as synonym of aurantiiventris in eBird/Clements and AviList.

o   M. p. berlepschi Hartert, 1902: far eastern Panama to northwestern Colombia and northwestern Ecuador

§  M. p. eminulus Nelson, 1912: eastern Panama (Darién, including Cerro Pirre and Tacarcuna ranges) and presumably far nw. Colombia

§  M. p. berlepschi Hartert, 1902: northwestern Colombia and northwestern Ecuador

o   M. olivaceus Berlepsch & Sztolcman, 1894: east slope of Andes of northeastern Peru (Piura) to northwestern Bolivia

 

*“Serranía del Darién” is evidently incorrectly included in the range of aurantiiventris in Clements et al. (2025 and previous) and will be modified to “(eastward to Altos del Maria area in eastern Coclé and western Panamá provinces)” in the 2026 Clements update.

 

Thus, eBird/Clements and other authors treat burleighi and nicaraguae as synonyms of phaeocercus, vividus as a synonym of aurantiiventris, and eminulus as a synonym of berlepschi. eBird/Clements has long recognized these subspecies groups within the species:

 

·      Mitrephanes phaeocercus phaeocercus/tenuirostris Tufted Flycatcher (Mexican) 

·      Mitrephanes phaeocercus aurantiiventris Tufted Flycatcher (Costa Rican)

·      Mitrephanes phaeocercus berlepschi Tufted Flycatcher (South American)   

 

Below, we refer to these three groups as phaeocercus Group, aurantiiventris, and berlepschi; when differences between phaeocercus and tenuirostris are relevant, the specific subspecies name is used. Note however that Webster (1968) treated nicaraguae as a distinctive plumage class separate from phaeocercus/tenuirostris.

 

Genetics

 

We are not aware of a robust genetic study with complete taxon sampling of the key groups within Mitrephanes, but Harvey et al. (2020) sampled M. olivaceus (San Martín, Peru; La Paz, Bolivia), M. p. phaeocercus (Honduras), and M. p. berlepschi (Darién, Panama). Their time-calibrated tree (Table 1 in their supplementary material) estimated the divergence times as follows: Mitrephanes from Contopus (~5.75 mya), M. phaeocercus/berlepschi clade from M. olivaceus (3 mya), M. p. phaeocercus from M. [p.] berlepschi (2 mya). The divergence time between berlepschi and phaeocercus is thus estimated to be older than or in a similar range to several other well-established species pairs in their study, including:

 

·      Empidonax traillii and E. alnorum (~1.5 mya)

·      E. atriceps and E. fulvifrons (1.75 mya)

·      E. affinis and E. oberholseri (1.5 mya)

·      E. flavescens and E. difficilis (~2 mya)

·      Contopus pertinax, C. lugubris, and C. fumigatus (~1.75 mya)

·      C. cinereus and C. nigrescens (1.5 mya)

·      Sayornis phoebe and S. nigricans (~1.75 mya)

 

The fact that aurantiiventris was not sampled leaves a significant question about how divergent it may be from berlepschi and the phaeocercus Group, but it is clear that M. phaeocercus and M. berlepschi should be treated within different species and more than meet a genetic yardstick for related species in Tyrannidae.

 

 

Fig. 2. Table 1 from Harvey et al. (2020) shows a divergence time of ~2 million years ago between Mitrephanes in Honduras (M. p. phaeocercus) and Darién, Panama (M. p. berlepschi), which is consistent with treating these as different species. See also https://tree.opentreeoflife.org/curator/study/view/ot_2015

 

Habitat

Significant differences in habitat between at least two of these taxa. Webster (1968) describes habitat differences as follows:

 

“My own field experience with Mitrephanes has been confined to México. There M. phaeocercus inhabits the more humid parts of the pine-oak forest and cloud (subtropical) forest. In winter it lives in tropical deciduous forest, tropical evergreen forest, and tropical thorn forest as well as in lower-elevation pine forest and cloud forest; it deserts higher elevation pine forest. All that I encountered in pine or pine-oak forests were foraging out from exposed perches at the rims of barrancas or mountain ridges. In cloud forest they were foraging out over openings or low trees and returning to perches 20 to 100 feet above the ground, in the manner of a pewee (Contopus).

 

“Skutch (1960) states that from Guatemala to western Panama the Tufted Flycatcher is a permanent resident of subtropical forest and of temperate pine-oak forest. He describes the behavior briefly, including evidence of a close relationship with the pewees. All localities in central and eastern Panamá reported in the literature and on specimen labels (M. p. viridus and M. p. eminulus) are from elevations of 2,000 feet or more, apparently in the subtropical zone. But the few localities in which M. p. berlepschi has been found, in western Colombia and northwestern Ecuador, are near sea level in the humid tropical zone! On the other hand, M. olivaceus in Peru and Bolivia occurs in upper humid tropical and subtropical forests at elevations from 4,000 to 8,000 feet (Zimmer, 1938a).”

 

Although the habitat differences between the phaeocercus Group and aurantiiventris in part follow the changeover in montane forest type, it does seem notable that berlepschi is more of a lowland taxon than aurantiiventris.

 

Morphometrics

 

Webster (1968) provided an in-depth phenotypic analysis, working from 728 museum specimens from all named taxa and from all regions throughout the range of Mitrephanes (except Ecuador) to quantify plumage and morphology. He (Webster 1968) provided detailed information on the measurements of the various populations in Mitrephanes. In general, these follow Bergmann’s Rule, with measurements increasing with distance from the equator. The full tables for measurements are provided in his paper.

 

Webster noted these specific observations that he considered significant:

 

·      wing length: smooth cline from northeastern Mexico to western Panama, but sharp break between Colombia and Peru with a nonoverlap gap of 4mm (over twice the standard deviation), and lesser breaks (with slight overlap) between Colombia and eastern Panama and between central and western Panama.

·      tail length: sharpest break between Honduras-El Salvador and Guatemala

·      bill width: two smallest (shortest-winged) populations, vividus and berlepschi, have the broadest bills

 

Thus, the morphometrics given by Webster (1968) do not align particularly well with the recognized subspecies groups.

 

Plumage

 

For a group of birds in which plumage differences can be extremely subtle (e.g., Eastern vs. Western wood-pewees, various taxa of Tropical Pewee, Alder vs. Willow flycatchers, etc.), the plumage differences among the four main groups of Mitrephanes are striking. Underparts coloration is especially strikingly different between the groups, but differences also exist in upperparts coloration. The composites below show the differences well (see also Appendix A for photo galleries from different regions):

 

 

Fig. 3. Clockwise from top left: tenuirostris, Quinn Diaz, Nayarit, MX, ML 626188382; aurantiiventris, Gary Rosenberg, Panamá, PA, ML610105559; berlepschi, Eric VanderWerf, ML610105559, Panamá, PA; olivaceus, Itamar Donitza, ML646534080, Cusco, PE.

 

 

 

Fig. 4. Clockwise from top left: tenuirostris, Dylan Osterhaus, ML632797034, New Mexico, US; aurantiiventris, Dubi Shapiro, ML281494981, Chiriquí, PA; berlepschi, Guillermo NAGY / ARAMACAO TOURS, ML625759985, Chocó, CO; olivaceus, Eric Atwell, ML 612973767, Junín, PE.

 

Webster (1968) assessed fresh-plumaged birds (Aug-Feb) and attempted to quantify the differences, and in doing so he identified five classes (which include two classes in the northern group from Mexico south to Nicaragua).  [Note that while eBird/Clements and IOC previously recognized nicaraguae, these were synonymized with phaeocercus around 2005, and that treatment has carried over to AviList v2025. However, the analysis by Webster (1968) would seem to support recognizing nicaraguae at least; see below.]

 

Webster (1968) noted five classes for underparts coloration, with 100% separation: (1) pale tawny--tenuirostris, burleighi, and phaeocercus; (2) dark tawny--nicaraguae; (3) buffy yellow--aurantiiventris and vividus; (4) yellow--eminulus and berlepschi; (5) lime--olivaceus.

 

Below is a summary of the differences demonstrated by Webster (1968):

 

phaeocercus Group

·      underparts pale tawny (tenuirostris, burleighi, and phaeocercus) to dark tawny (nicaraguae)

·      moderate and gradual transition between anterior underparts (throat and breast) and posterior (belly, crissum, and undertail coverts)

·      Upperparts varying from pale to dark olive and pale to dark brownish olive

·      Juvenal plumage: Ventrally a smooth cline from pale buffy brown in Sonora darkening southeastwardly to deep tawny buffy brown to brownish tawny in Chiapas and Nicaragua, while dorsally a smooth cline ran from pale sepia tipped with pale tawny in Sonora, darker southeastward to dark sepia tipped with tawny in Chiapas, Guatemala, Nicaragua, and Honduras

·      moderate clinal variation detected, with general increasing darkness to the south

 

aurantiiventris

·      underparts buffy yellow—aurantiiventris and vividus

·      prominent and sharp transition between anterior underparts (throat and breast) and posterior (belly, crissum, and undertail coverts)

·      upperparts approximately dark, yellow lime-olive

·      Juvenal plumage underparts slightly paler and distinctly yellowish buffy brown, and dorsally the upperparts were paler (than phaeocercus Group) and had more yellowish tawny tips

·      no geographic variation detected in color

 

berlepschi

·      underparts yellow—eminulus and berlepschi

·      prominent and sharp transition between anterior underparts (throat and breast) and posterior (belly, crissum, and undertail coverts)

·      in underparts coloration, two specimens from Cerro Tacarcuna, eastern Panama, are warmer, more orangish on both areas than two specimens from southern Colombia. In this class the anterior underparts are medium, brownish Buffy Yellow; the posterior are pale Yellow.

However, note that seven worn old (March-June, 1912 and 1928) specimens from Cana, eastern Panama, show distinct variation; they are colder, less buffy than those from Cerro Tacarcuna, although paler, less greenish anteriorly and less purely yellow posteriorly than specimens from Colombia, either northern or southern.

·      upperparts varying from medium to dark olivaceous Yellow-Lime

 

olivaceus

·      underparts lime

·      moderate and gradual transition between anterior underparts (throat and breast) and posterior (belly, crissum, and undertail coverts)

·      Juvenal plumage tawny buffy brown below, paler and buffier (than aurantiiventris), buffy-brown tipped tawny above

·      little geographic variation, including between Peru and Bolivia

 

 

Webster (1986) furthermore stated:

 

“The gap between groups 2 [aurantiiventris] and 3 [berlepschi] is prominent, with the eastern Panamá birds distinctly greener than those from western and central Panamá.

 

I see no geographic variation within the 39 specimens from Costa Rica and western Panamá, and the gap from class (2) [nicaraguae] is considerable.

 

Two specimens from Cerro Tacarcuna, eastern Panamá, are warmer, more orangish on both areas than two specimens from southern Colombia. In this class the anterior underparts are medium, brownish Buffy Yellow; the posterior are pale Yellow. Seven worn old (March–June, 1912 and 1928) specimens* from Cana, eastern Panamá, show a distinct variance; they are colder, less buffy than those from Cerro Tacarcuna, although paler, less greenish anteriorly and less purely yellow posteriorly than specimens from Colombia, either northern* or southern.”

 

See Appendix B regarding the possibility of an undescribed taxon on Cerro Tacarcuna.

 

Regarding the upperparts, Webster (1986) stated:

 

“A prominent north to south cline of increasing greenness runs from northwestern Mexico to Peru. In Mexico north of Tehuantepec the trend is from the Pacific slope to the Atlantic slope, but in Central America no Pacific versus Atlantic slope differences are apparent.

 

A two-way cline of darkness decreases from maximum in Chiapas northwest and southeast to minimum, or pallor, in northwestern Mexico and Peru. This seems to follow Gloger's Rule north from Chiapas, but to proceed almost inversely to, Gloger's Rule from Chiapas southward.”

 

We recommend reading the full text of Webster (1968: https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=18739&context=auk).

 

Webster (1968) assessed juvenal plumage and found marked differences between the phaeocercus Group, aurantiiventris, and olivaceus:

 

“Color of juvenal plumage.—A series of 43 specimens from all subspecies except vividus and berlepschi showed prominent geographical variation. Ventrally a smooth cline from pale Buffy Brown in Sonora darkened southeastwardly to deep tawny Buffy Brown to brownish Tawny in Chiapas and Nicaragua; in Costa Rica and eastern Panamá the underparts were a little paler again and distinctly yellowish Buffy Brown; in Peru tawny Buffy Brown. Dorsally, a smooth cline ran from pale Sepia tipped with pale Tawny in Sonora, darker southeastward to dark Sepia tipped with Tawny in Chiapas, Guatemala, Nicaragua, and Honduras; in Costa Rica and eastern Panama the upperparts were a little paler again and had more yellowish Tawny tippings. In Peru the upperparts were still paler and buffier, Bully Brown tipped with pale Tawny.”

 

Webster's (1968) review focused on measurements, appearance, and habitat, and from that he recommended a two-species treatment. However, his only defense for the treatment as two species is his section on SPECIFIC LIMITS on page 288–289. The entirety of his argument is reproduced below:

 

“All the forms of Mitrephanes are allopatric. When Zimmer (1930) described the juvenal plumage of Peruvian M. olivaceus as more similar to that of the Central American forms than is the adult plumage, he argued that this showed their essential conspecificity. As shown in the section on variation below, present evidence shows distinct discontinuities in variation. The most abrupt break occurs in Ecuador, between the coastal forest of western Colombia and northwestern Ecuador on the one hand and the eastern slope of the Andes in Peru on the other. Lesser breaks occur in Central America--one between Nicaragua and Costa Rica, and another between central and extreme eastern Panama.

“A moderate course between the extreme points of view, which recognize four species or one, seems best to express the phylogeny of the genus. I would recognize two species--M. phaeocercus and M. olivaceus:

 

 

phaeocercus

olivaceus

Range

Northern Mexico to northwestern Ecuador

Eastern Peru and Bolivia

Habitat

Temperate pine and pine-oak forest, subtropical forest, and humid tropical forest

Subtropical forest and upper humid tropical forest

Size

Larger to smaller

Larger than adjacent forms

Color

Brown to yellowish green

Green—contrast marked with phaeocercus ventrally, but moderate dorsally

 

If an intermediate population exists, it may probably be found in the central Andes of Colombia.”

 

It strikes us that this is an exceptionally weak argument for both AOS-NACC and AOS-SACC to use as the basis for their species-level taxonomy. Although we agree that the separation of olivaceus as a distinct species is the correct course, we stress that Webster (1968) acknowledged the possible alternate arrangement and made no argument for or against it.

 

An alternate hypothesis, using Webster’s own phenotypic data, might look like this:

 

 

phaeocercus

aurantiiventris

berlepschi

olivaceus

Range

Northern Mexico to Nicaragua

Costa Rica to central Panama

Eastern Panama to n. Ecuador

Eastern Peru and Bolivia

Habitat

Temperate pine and pine-oak forest and subtropical forest

Humid tropical forest in highlands

Humid tropical forest in lowlands

Subtropical forest and upper humid tropical forest

Size

Larger

Moderate-sized

Small

Larger than adjacent forms

Color of underparts

Pale tawny to dark tawny; moderate breast-belly contrast

Buffy yellow; strong breast-belly contrast

 

Yellow; strong breast-belly contrast

 

Lime; moderate breast-belly contrast

Color of upperparts

Pale to dark olive or brownish-olive

dark, yellow lime-olive

varying from medium to dark olivaceous yellow-lime

varying from medium to dark olivaceous yellow-lime

 

An equal, or stronger case, could be made that the populations with the traits above merit recognition as four species, and that when the strong vocal break between phaeocercus Group and aurantiiventris, and the moderate vocal break between aurantiiventris and berlepschi, are taken into account, one must arrive at a three- or four-species treatment.

 

The below graphic shows typical phenotypes on the combined range for the taxa currently lumped as Tufted Flycatcher (M. phaeocercus sensu lato). The breaks (red dotted lines) between northern Nicaragua and Costa Rica and between central and eastern Panama are breaks that define numerous other species limits of highland taxa:

 

 

 

Vocalizations

 

Comparing homologous vocalizations is of course of major importance with flycatchers, with their innate vocalizations. Below, we identify six main classes of vocalizations, but focus especially on position note, primary song, and dawn song, which seem to show species-level differences among each of the four groups. See also Appendix A for galleries of sound recordings from different regions.

 

Position note: repeated, commonly given series either while perched or immediately after landing. These tend to be repeated in rapid succession from 3x to 12x or more

Primary song: short, high-pitched phrases of single, well-spaced notes; these are given primarily in the breeding season

Alternate song: combining elements of the position note and the song, these tend to be phrased a pip-pip-pip-seeeu or something similar

Dawn song: given pre-dawn or just after dawn, these are longer and complex series but have well-established phrase patterns

Contact calls: various pip notes; occasionally burry interaction calls as well; these do not seem particularly distinctive and are similar between taxa

Other calls: occasionally burry interaction calls and other less consistent vocalizations may be given as well; these do not seem particularly distinctive and are similar between taxa

 

The vocalizations of the four main groups of Tufted Flycatchers are substantially different and more than exceed the vocal differences between many flycatcher species. We did not detect significant differences across the ranges of any of the taxa, although a quantitative analysis may shed more light on this aspect.

 

Most striking is the difference in position notes: those of phaeocercus are utterly unlike the position notes of any of the other taxa. The position notes of aurantiiventris and berlepschi are similar, and while those of olivaceus are similar in pattern, they have a very different note shape, being descending vs. ascending. Figure 5 summarizes the differences.

 

 

Fig. 5. Position calls. Clockwise from top left: phaeocercus, Cd. de Mexico, MX, Miguel Aguilar @birdnomad, ML650288423; aurantiiventris, Alajuela, CR, Nick Tepper, ML427663091; olivaceus, Amazonas, PE, Guilherme Melo, ML608680193; berlepschi, Valle de Cauca, CO, Paula Caycedo, ML264163. Below, graphic showing typical position calls of taxa in M. phaeocercus s.l.

 

 

The primary songs (below) are all a similar short, high-pitched note and reportedly are given primarily in the breeding season. However, the shape of the notes differs substantially between the taxa, with more similarity between phaeocercus and aurantiiventris (despite the massive differences in position calls), while berlepschi and olivaceus differ substantially both from each other and from the two more northerly taxa.

 

 

Fig. 6. Primary song. Clockwise from top left: phaeocercus, Querétaro, MX, Alvaro Rojas Qro. Birding Tours, ML548036141; aurantiiventris, Cartago, CR, Jay McGowan, ML48408511; berlepschi, Esmeraldas, EC, Niels Krabbe, ML244679; olivaceus, San Martín, PE, Fabrice Schmitt, ML593143251.

 

Vocalizations that we refer to as alternate songs combine elements of the position call and the primary song. It seems not be given frequently in the phaeocercus Group, or potentially the preceding notes are reduced to a single pip with an element of the position call (https://macaulaylibrary.org/asset/109246). The other three taxa all have multiple examples of the alternate song, with multiple pip notes preceding a high-pitched element that is analogous to the primary song.

 

A close-up of a graph AI-generated content may be incorrect.

 

Fig. 7. Alternate song. From the top: aurantiiventris, Puntarenas, CR, Thomas Brooks, ML590274961; berlepschi, Esmeraldas, EC, Mark L. Robbins, ML63198; olivaceus, Amazonas, PE, Nick Athanas, ML288261481.

 

The dawn songs are audio-recorded much less frequently, but the several examples for each taxon show differences in pattern, speed, and quality of delivery that suggest that each taxon is a species. The final notes for each phrase seem to be an especially important element of the dawn song in these taxa and do not have much similarity between the phaeocercus Group, aurantiiventris, and berlepschi.

 

A screenshot of a graph AI-generated content may be incorrect.

 

Fig. 8. Dawn song. From the top: phaeocercus, Hidalgo, MX, Andrew Spencer, ML277665301;  aurantiiventris, Puntarenas, CR, David L. Ross, Jr., ML184565; berlepschi, Valle de Cauca, CO, Daniel Uribe-Restrepo BIRDING TOURS COLOMBIA, ML90360501. Below, a graphic mapping a different selection of dawn-type songs for the taxa of M. phaeocercus s.l.

 

 

We found no obvious examples of dawn song of M. olivaceus on Macaulay Library or xeno-canto; the one example of a complex song was more like a complex version of the alternate song and was quite unlike the other three taxa: https://xeno-canto.org/20777

 

The below table summarizes the differences in vocalization. The alphanumeric codes in parentheses refer to the vocal analyses in Appendix C and identify the vocalization type and taxon.

 

 

context

phaeocercus grp.

aurantiiventris

berlepschi

olivaceus

position notes

Loud series given perched or just after landing; elements repeated 3x or up to 10x or more; a very common vocalization in the genus

strident, burry tchwee-tchwee- tchwee (A1)

loud and rapid, repeated series pui-pui-pui-pui… (A2)

loud and rapid, repeated series pee-pee-pee-pee… (A3)

loud and rapid, repeated series tip-tip-tip-tip… (A4)

primary song

High-pitched single note that varies in pitch; given in breeding season and often repeated every few seconds; not unlike like song given by many Contopus

high, thin rising and falling pseeeu; dome-shaped spectrogram with peak near front of note (B1)

high, thin rising and falling seer or peew; symmetrical, dome-shaped spectrogram or sometimes with peak at the front (B2)

wheep (B3); rising note that levels off at the end

sieeuu (B4); fast peak and then long descending note

alternate song

Series that combines short elements from the position call with the primary song or a modified primary song

rarely given, perhaps absent; pip-weet (C1)

pip-weer (C2)

tsu-tsu-tseét (C3)

tip-tip-tip-tip-seeert, with strong descending note (C4)

dawn song

Complex series covering a wide frequency range, given primarily at dawn

variable phrases of 4-7 notes, pit-whit-ooh-whee-ohh… pit-whit-ooh-whit-wheet… with last element alternating between whee-ohh (L-shaped note) and weeet (scythe-shaped note)

variable phrases of 4-7 notes, pit-whit-ooh-whee-weeot… pit-whit-ooh-whit-wheet… with last element alternating between double-humped wheeot (double-humped descending note) and weeet (scythe-shaped note)

variable phrases of 4-7 notes, pit-whit-ooh-whee-weeot… pit-whit-ooh-whit-wheet… with last element alternating between double-humped wheeot (double-humped descending note) and weeet (scythe-shaped note)

no examples found

contact calls

Short single “pip” notes, recalling Alder or Hammond’s Flycatcher; given frequently and similar in each taxon to a lone element of the position call

pip, peaking around 5 kHZ (E)

pip, peaking around 4 kHZ (E)

pip, peaking around 4 kHZ (E)

tip, peaking around 5 kHZ (E)

 

Field guide descriptions are as follows:

 

Howell and Webb (1995) - phaeocercus Group: A burry, bright, rolled tchwee-tchwee or turree-turree, less often a single tchwee or longer series, a sharp, usually fairly quiet pic or beek suggesting Hammond’s Flycatcher, and a bright, slightly emphatic to penetrating seeu or pseeu, repeated every few s and given mainly in breeding season.

 

Howell et al. (2014) - phaeocercus Group: Bright, slightly burry whistled tch’wee-tch’wee or tureee-turee call is given year-round, as well as quiet pik, suggesting call of Hammond’s Flycatcher.

 

Stiles and Skutch (1989): aurantiiventris Group

A high-pitched, rapid series of liquid, rather confiding notes: weet weet weet…or pui-pui-pui-pui-pi-pi , often upon returning to perch; a thin seer or peew or, especially in breeding season, peew-peew or peep-wit wit; quaint, prolonged dawn song a very rapid series of high, thin notes: bip-bip-bip-dididi-up-bip-bip-bibibiseer.

 

Wetmore (1972): aurantiiventris - Eisenmann describes their calls as a piping pip-pip-pip-pip varying in the number of notes and occasionally uttered at a faster pace.” He remarks that the notes suggest those of the much larger Dark Pewee but are higher in pitch.

 

Angehr and Dean (2010): Call a rapid series of high chirping pip notes [presumably aurantiiventris Group, no distinction made between western and eastern birds]

 

Ridgely and Gwynne (1989) – berlepschi Group: Frequently gives a piping whistle, pee-pee-pee (up to eight notes).

 

Ridgely and Greenfield (2001) – berlepschi Group: Call an often-heard fast series of pee or pik notes. Song a repeated fast phrase of high, thin notes, e.g., tsu-tsu-tseét, with softer notes sometimes interspersed between phrases (P. Coopmans).

 

Hilty and Brown (1986) – berlepschi Group: Frequently repeats a spirited bubbly ser. of 4-7 pee or pik notes as flicks tail; call reminiscent of that of Greater Pewee but faster, weaker, and not as sharp.

 

Effect on NACC area: If successful, this proposal would result in the recognition of either one or two additional species for the region.

 

 

Recommendation

 

Mitrephanes olivaceus is already recognized as a distinct species, and we recommend no change to that classification; it is included above to allow for yardstick comparisons to the other taxa.

 

Within the current Tufted Flycatcher M. phaeocercus there are three vocal groups that match the described subspecies, show well-defined plumage breaks (as described by Webster 1968), and match well-known biogeographic regions (Mexico to Nicaragua, Costa Rica/western Panama, and eastern Panama to northwest Ecuador, west of the Andes).

 

The differences in vocalizations (especially contact call and dawn song) are especially striking between Nicaragua and Costa Rica but are much more similar between central Panama and e. Panama/Colombia. A conservative option would be to recognize M. phaeocercus and M. aurantiiventris, with berlepschi included as a subspecies of M. aurantiiventris.

 

However, it is also clear that aurantiiventris and berlepschi show fairly strong plumage differences between central and eastern Panama and also have substantial differences in primary song and dawn song (although reduced differences in position calls relative to other taxa). For many other taxa of flycatchers, vocal differences of this magnitude would be sufficient to warrant species status, and we think that given the correlated differences in plumage, and the different elevational preferences and habitat of berlepschi, these should be treated as separate species as well.

 

Whether to split phaeocercus (with tenuirostris) from the other taxa is primarily a NACC issue, but both this split and whether to further split berlepschi from aurantiiventris affect SACC inasmuch as the name berlepschi is junior to both other names. The options for SACC thus are:

 

OPTION A: Recognize three species:

 

·      Mitrephanes phaeocercus from Mexico to n. Nicaragua

·      Mitrephanes aurantiiventris from w. Costa Rica to central Panama

·      Mitrephanes berlepschi from e. Panama to nw. Ecuador, west of the Andes

 

OPTION B: Recognize two species:

 

·      Mitrephanes phaeocercus from Mexico to n. Nicaragua, including M. p. tenuirostris from nw. Mexico as a subspecies

·      Mitrephanes aurantiiventris, from w. Costa Rica to n. Ecuador, including M. p. berlepschi from e. Panama to nw. Ecuador as a subspecies

 

English names: If this proposal passes, a separate proposal may be needed to address English names. Dyer and Howell (2023) have used Mexican Tufted Flycatcher for M. phaeocercus sensu stricto and Costa Rican Tufted Flycatcher for M. aurantiiventris. Cinnamon and Tawny Tufted-Flycatcher could also be used for M. phaeocercus s.s. and Isthmian or Yellow-bellied Tufted-Flycatcher could be used for M. aurantiiventris, and Choco Tufted Flycatcher for M. berlepschi (if split). Habitat-based names would also be possible, with Pinewoods or Pine-forest Tufted-Flycatcher for M. phaeocercus and Cloud-forest Tufted-Flycatcher (with Choco Tufted-Flycatcher for M. berlepschi). Should the latter two not be split, many of these English name options would not be appropriate, and perhaps Northern and Southern Tufted-Flycatcher should be considered.

 

However, we strongly recommend adopting as a group name either Tufted Flycatcher or Tufted-Flycatcher, which would align with AviList v2025. IOC (Gill et al. 2025) and AviList have used Northern Tufted Flycatcher for Mitrephanes phaeocercus s.l. and Olive Tufted Flycatcher for M. olivaceus, while AOS-NACC, AOS-SACC, and BirdLife International (e.g., del Hoyo and Collar 2016) have used Tufted Flycatcher for M. phaeocercus and Olive Flycatcher for Mitrephanes olivaceus. If this proposal passes and Mitrephanes expands from a two-species genus to a genus with three or four species, then it would be a good time to consider whether it would be better to follow IOC and AviList and use “Tufted-Flycatcher” for all members of the genus.

 

Just in the New World, there are 105 species across 31 genera that bear the name of "flycatcher". For the lay birder, it certainly can be hard to keep track of which English name goes with which genus without knowing the bird very well. Only the two Royal Flycatchers have a name that helps tie them together and distinguish from the other tyrannids. If the Old World is considered, yet another 151 species across 22 additional genera are involved, although Crested Flycatchers, Blue Flycatchers, and Jungle Flycatchers do help to orient birders toward assemblages of congeneric, or at least similar, species. While adopting Tufted Flycatcher would not solve the core problem of too many unrelated birds with the name of “flycatcher”, it would help birders to orient correctly on Mitrephanes and to transfer familiarity more readily from one species to another.

 

Tufted Flycatcher is also a highly appropriate name that would be a shame to lose with this revision. While a lot of tyrannids have elongated crown feathers that can be raised as a crest, there may not be any others with such long and pointed crests as Mitrephanes. For a notoriously difficult-to-identify family, Mitrephanes is wonderfully straightforward to identify precisely because of their sharply pointed crests that are usually fully raised. We strongly feel that maintaining the most distinctive feature of the genus within the name of all its members follows best practices for naming.

 

Especially relevant to SACC, Olive Flycatcher is an extremely ambiguous and non-distinctive name for M. olivaceus—how many tyrannids could be described as olive? Renaming it to Olive Tufted Flycatcher or Olive Tufted-Flycatcher would be a significant improvement, as it is the only Mitrephanes that is aptly described as olive. When NACC first recognized Olive Flycatcher as distinct in 2018 (Proposal set 2018-A) six voters opted not to use a compound name Tufted-Flycatcher, most citing the fact that SACC was not doing so. Three voters felt it was important to not use something as ambiguous as Olive Flycatcher and to follow IOC in using Olive Tufted-Flycatcher. Assuming passage of this proposal, there would be 3-4 species in this genus, it feels even more important to use the compound name to tie all Mitrephanes together as Tufted-Flycatchers. Therefore, we recommend the use of Tufted Flycatcher or Tufted-Flycatcher for all species of Mitrephanes.

 

In hopes of a speedy resolution, we recommend the following names for SACC-region species (YES or NO):

 

Choco Tufted-Flycatcher Mitrephanes berlepschi

Olive Tufted-Flycatcher Mitrephanes olivaceus

 

 

Literature Cited

 

Angehr, G. R. and R. Dean (2010); The Birds of Panama: A Field Guide. Comstock, Ithaca, NY, USA.

 

AviList Core Team (2025). AviList: The Global Avian Checklist, v2025. https://doi.org/10.2173/avilist.v2025

 

Chesser, R. T., K. J. Burns, C. Cicero, J. L. Dunn, A. W. Kratter, I. J. Lovette, P. C. Rasmussen, J. V. Remsen, Jr., D. F. Stotz, B. M. Winger, & K. Winker (2018). Fifty-ninth Supplement to the American Ornithological Society’s Check-list of North American Birds. Auk 135: 798–813.

 

Clements, J. F., P. C. Rasmussen, T. S. Schulenberg, M. J. Iliff, J. A. Gerbracht, D. Lepage, A. Spencer, S. M. Billerman, B. L. Sullivan, M. Smith, and C. L. Wood. 2025. The eBird/Clements checklist of Birds of the World: v2025. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/

 

del Hoyo, J., and N. J. Collar (2016). HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions, Barcelona, Spain.

 

Dyer, D. and S. N. G. Howell (2023).  Birds of Costa Rica. Princeton Field Guides. Princeton University Press, Princeton, NJ, USA.

 

Farnsworth, A. and D. J. Lebbin (2020). Tufted Flycatcher (Mitrephanes phaeocercus), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.tuffly.01

 

Gill, F., D. Donsker, & P. C. Rasmussen. Eds. 2025. IOC World Bird List (v 15.1).

http://www.worldbirdnames.org/

 

Harvey, M. G. et al. (2020). The evolution of a tropical biodiversity hotspot. Science 370: 1343–1348.

 

Hilty, S. L. and W. L. Brown (1986). A Guide to the Birds of Colombia. Princeton University Press, Princeton, NJ, USA.

 

Howell, S. N. G. and S. Webb (1995). A Guide to the Birds of Mexico and Northern Central America. Oxford University Press, Oxford, UK.

 

Howell, S. N. G., I. Lewington, and W. Russell (2014). Rare Birds of North America. Princeton University Press, Princeton, NJ, USA.

 

Miller, E. T., E. J. McTavish, J. A. Gerbracht, M. Schloss, M. J. Iliff, D. Lepage, P. C. Rasmussen, and B. L. Sullivan (2025). The Phylogeny of the Birds of the World. Tree v1.6/Taxonomy v2025. Cornell Lab of Ornithology, Ithaca, NY, USA.

 

Ridgely, R. S. and J. A. Gwynne (1989). A Guide to the Birds of Panama. With Costa Rica, Nicaragua, and Honduras. Princeton University Press, Princeton, NJ, USA.

 

Ridgely, R. S. and P. J. Greenfield (2001). The Birds of Ecuador. Cornell University Press, Ithaca, NY, USA.

 

Stiles, F. G. and A. Skutch (1989). A Guide to the Birds of Costa Rica. Cornell University Press, Ithaca, NY, USA.

 

Webster, J. D. (1968). A revision of the Tufted Flycatchers of the Genus Mitrephanes. The Auk 85(2): 9. Available at: https://digitalcommons.usf.edu/auk/vol85/iss2/9

 

Wetmore, A. (1972). The Birds of the Republic of Panama - Part 3. Passeriformes: Dendrocolaptidae (Woodcreepers) to Oxyruncidae (Sharpbills). Smithsonian Institution Press, Washington, D.C., USA.


 

Appendix A: Media galleries

 

Audio Galleries:

Mexico: https://tinyurl.com/w6e5scm6

Northern Central America + Chiapas: https://tinyurl.com/4rx9evau

Costa Rica and Panama (except Darién): https://tinyurl.com/4s8mk2ur

Darién and Colombia: https://tinyurl.com/msaz8wrs

 

Photo Galleries:

Tufted Flycatcher (South American): https://tinyurl.com/mrhvthuz

Tufted Flycatcher (South American), Cerro Pirro area, Panama: https://tinyurl.com/34ve4jx2

Tufted Flycatcher, Tacarcuna: https://tinyurl.com/47hpzzzx

Tufted Flycatcher, El Valle: https://tinyurl.com/rdvetx5z, https://tinyurl.com/yc3hecj5, and https://tinyurl.com/mr5ks26d

Costa Rica: https://tinyurl.com/5xvjdrva

 

 

 

Appendix B. Undescribed taxon at Cerro Tacarcuna?

 

As noted by Webster (1986), comparison of photos from Cerro Pirre with those from Cerro Tacarcuna in Darién show plumage differences that suggest there is an undescribed taxon on Cerro Tacarcuna.

 

A screenshot of a bird on a tree branch AI-generated content may be incorrect.

 

https://media.ebird.org/catalog?birdOnly=true&taxonCode=tuffly&regionCode=PA-5&mediaType=photo&view=grid&unconfirmed=incl

 

In the above image, the three images from the Cerro Tacarcuna range (outlined in orange) suggest that there are significant morphological differences between the birds in the Cerro Tacarcuna area (e.g., https://macaulaylibrary.org/asset/42900761) and those from Cerro Pirre (e.g., https://macaulaylibrary.org/asset/144776101), which match images of berlepschi well from nearby areas in Colombia. The birds from the Tacarcuna region appear to have rich cinnamon-rufous breasts, which extends to the nape, and a whitish belly, while typical berlepschi (and the Cerro Pirre) completely lack cinnamon or rufous tones, and instead show bright lime green bird with a yellow breast lightly washed with orange and pale yellow belly. Our suspicion is that there exists an undescribed taxon in the Tacarcuna area. The general coloration, with cinnamon breast contrasting with a paler belly best matches aurantiiventris (which has a yellowish belly) and we recommend provisionally treating this taxon within that species until the Tacarcuna birds can be described and their species limits assessed with vocalizations, a more detailed study of morphology, and ideally, genetics.

 

 

Appendix C. Detailed comparison of vocalizations

 

The below analysis of vocalizations (by MJI) attempts to use the context of vocalizations to cluster them in analogous groupings. Each vocalizations equates roughly with the songs vs. calls of related taxa (e.g., Contopus) which have high pitched simple songs, more complex dawn songs that incorporate elements of the song, and calls that often involve single or repeated pip calls. The set of vocalizations termed the position note match the pip-pip-pip calls given by Greater Pewee but seem to be given even more frequently.

 

When vocalizations differ significantly between taxa, I have split those as vocalization 1, 2, 3. Thus, in the example below all examples of Vocalization A are believed to be analogous contact calls. These calls are among the most commonly given, heard year-round, and all are often given immediately after birds return to perches. With the exception of A1 (phaeocercus Group), all have obvious audio similarities.

 

VOCALIZATION A1 – Position calls

Taxa: Mexican phaeocercus Group

Context: position call, given commonly, especially right after landing

Description: burry, breeep given singly, (often) doubled, less commonly delivered 3x, 4x or 5x.

Howell and Webb (1995) describe this as a “burry, bright, rolled tchwee-tchwee or turree-turree, less often a single tchwee or a longer series” while Howell et al. (2014) describe it as a “bright, slightly burry whistled tch’wee-tch’wee or tureee-turee call is given year-round”

Discussion: This vocalization is entirely unique within the group and greatly exceeds the vocal differences between many other flycatchers considered different species. The difference here is on par with the vocal differentiation between the bik and twitter calls of Couch’s and Tropical Kingbirds, for example. The notes are burry, often doubled and rarely given in longer series, and completely unlike the analogous calls (repeated pip series) for all other taxa in the genus. It seems hard to argue that this vocalization from a member of Tyrannidae could be conspecific with aurantiiventris or berlepschi.

 

 

Nayarit, MX https://macaulaylibrary.org/asset/524465   Nayarit, MX (delivery 3x or 4x) https://macaulaylibrary.org/asset/38749101 or even 5x

 

https://macaulaylibrary.org/asset/130035001

https://macaulaylibrary.org/asset/64233221

Recordings from the far south of the range of phaeocercus (in Nicaragua) are clearly still of this call type:

https://macaulaylibrary.org/asset/523408

 

VOCALIZATION A2 – Position calls

Taxa: aurantiiventris

Context: position call, given commonly, especially right after landing

Description: repeated pip notes, often trailing off a bit at the end (more spacing between notes, descending somewhat in pitch). Described by Wetmore (1972) for aurantiiventris as “Eisenmann describes their calls as a piping pip-pip-pip-pip varying in the number of notes and occasionally uttered at a faster pace.” He remarks that the notes suggest those of the much larger Dark Pewee but are higher in pitch.” Angehr and Dean (2010) “Call a rapid series of high chirping pip notes” [no distinction made between western and eastern birds] and Ridgely and Gwynne (1989) say “frequently gives a piping whistle, pee-pee-pee… (up to eight notes).” Stiles and Skutch (1989) give the best description of vocalizations “a high-pitched, rapid series of liquid, rather confiding notes: weet weet weet…or pui-pui-pui-pui-pi-pi, often upon returning to perch. Hilty and Brown (1986) state: “Frequently repeats a spirited bubbly ser. of 4-7 pee or pik notes as flicks tail; call reminiscent of that of Greater Pewee but faster, weaker, and not as sharp.”   

 

 

repeated 4x or 5x, https://macaulaylibrary.org/asset/48409211 (Cartago, CR)                           or up to 14x https://macaulaylibrary.org/asset/48408511 (Cartago, CR)

 

 

https://macaulaylibrary.org/asset/264163 (Valle de Cauca, CO) 7x-12;  https://macaulaylibrary.org/asset/163965

 

VOCALIZATION A3 – Position calls

Taxa: berlepschi

Context: position call, given commonly, especially right after landing

Description: repeated pip notes, often trailing off a bit at the end (more spacing between notes, descending somewhat in pitch). Described by Hilty and Brown (1986) as “frequently repeats a spirited bubbly ser. of 4-7 pee or pik notes as flicks tail; call reminiscent of that of Greater Pewee but faster, weaker, and not as sharp.” [not clear what Greater Pewee vocalization is referred to here.”] Ridgely and Greenfield (2001) describe as “call an often-heard fast series of pee or pik notes.”

Discussion: The only vocalization from eastern Panama are Cerro Pirre recordings of this call type (A3) in Macaulay Library with up to 11 notes https://macaulaylibrary.org/asset/25779, up to 22 notes (see below), and on Xeno-canto https://www.xeno-canto.org/360141 with up to 22 and 31 notes in a series. This sounds generally like aurantiiventris, but the number of notes in each series are markedly longer. Others also sound similar but also tend to give longer series, such as 12 notes https://www.xeno-canto.org/108571 or up to 24 notes https://www.xeno-canto.org/85120. This distinction seems to be enough to potentially consider this vocalization to be different, although the quality of the pip notes is quite similar.

 

 

Cerro Pirre, Panama https://macaulaylibrary.org/asset/31166

 

VOCALIZATION A4 – Position calls

Taxa: olivaceus

Context: position call, given commonly, especially right after landing

Description: repeated tup notes, often trailing off a bit at the end (more spacing between notes, descending somewhat in pitch)

The quality of these notes is markedly different from examples in Vocalization A2, with each note more like a chup or tup than a pip or peep. These differences seem to equate to species-level differences in vocalizations.

 

 

olivaceus, Peru https://macaulaylibrary.org/asset/519282

 

 

VOCALIZATION B1 – primary song

Taxa: phaeocercus Group

Context: Primary song

Description: Clear, high-pitched whistled song, vaguely recalling some Contopus (e.g., Tropical Pewee (Tumbes) Contopus cinereus punensis) (MJI). Howell and Webb (1995) describe a bright, slightly emphatic seeeu or pseeeu, repeated every few s and mainly in breeding season.

Discussion: This high, whistled note appears to be the song, and this is quite similar to the songs of several pewees. There appear to be subtle but noticeable differences between all four groups, so these are separated here.

 

 

Sinaloa, Mexico https://macaulaylibrary.org/asset/109246; Chiapas, Mexico https://macaulaylibrary.org/asset/110202591; Quetzaltenango, Guatemala https://macaulaylibrary.org/asset/30442651

 

VOCALIZATION B2 – primary song

Taxa: aurantiiventris

Context: Primary song

Description: Clear, high-pitched whistled song, vaguely recalling some Contopus (e.g., Tropical Pewee (Tumbes) Contopus cinereus punensis) (MJI). Stiles and Skutch (1989) describe “a thin seer or peew, especially in breeding season”

Discussion: This high, whistled note appears to be the song, and this is quite similar to the songs of several pewees. There appear to be subtle but noticeable differences between all four groups, so these are separated here. In addition to the obvious differences in the shape of the sonogram, Mexican birds sound more like a peaaar vs. Costa Rican wheeeerr.

 

 

Cartago, Costa Rica, https://macaulaylibrary.org/asset/48408511; Heredia, CR https://macaulaylibrary.org/asset/165896

 

VOCALIZATION B3 – primary song

Taxa: berlepschi

Context: Primary song

Description: Clear, high-pitched whistled song, vaguely recalling some Contopus (e.g., Tropical Pewee (Tumbes) Contopus cinereus punensis) (MJI).

Discussion: This high, whistled note appears to be the song, and this is quite similar to the songs of several pewees. There appear to be subtle but noticeable differences between all four groups, so these are separated here. In addition to the obvious differences in the shape of the sonogram, the song of South American birds sounds like Sweet! as compared to peaaar or wheeeerr, for Mexican or Costa Rican birds. It is too bad that we don’t have a comparable example of this from eastern Panama.

 

 

Esmeraldas, Ecuador https://macaulaylibrary.org/asset/244679

 

VOCALIZATION B4 – primary song

Taxa: olivaceus

Context: Primary song

Description: Clear, high-pitched whistled song, descending more than in other taxa and thus quite different.

Discussion: Species-specific and quite distinct high song.

 

High sieeuu song: Bolivia https://www.xeno-canto.org/44221

 

 

olivaceus, San Martín, Peru https://macaulaylibrary.org/asset/593143261

 

 

VOCALIZATION C1

Taxa: phaeocercus Group

Context: Alternate song; pip-weet song

Description: Similar to the high, whistled note but with introductory pip notes. This is sort of a combination of vocalization A (introductory notes) and vocalization B (primary song). It may serve as a dawn song or a variation on the primary song; note however that a more complex dawn song is clear in some other examples (see Vocalization D below). Stiles and Skutch (1989) describe peew-peew or peep-wit wit, although it is not clear that this is the same vocalization in examples below.

Discussion: I found no good examples that equate to berlepschi or olivaceus, but this taxon does seem to occasionally add a pip note before the song in a semi-structured way. Here is one example:

 

 

Sinaloa, Mexico https://macaulaylibrary.org/asset/109246

 

VOCALIZATION C2

Taxa: aurantiiventris

Context: Alternate song; pip-weet song

Description: Similar to the high, whistled note but with introductory pip notes. This is sort of a combination of vocalization A (introductory notes) and vocalization B (primary song). It may serve as a dawn song or a variation on the primary song; note however that a more complex dawn song is clear in some other examples (see Vocalization D below). Stiles and Skutch (1989) describe peew-peew or peep-wit wit, although it is not clear that this is the same vocalization in examples below.

Discussion: In aurantiiventris, this may or may not equate to the examples for berlepschi and olivaceus below, which seem like more structured, more regular, and probably more commonly given vocalizations. Still, the short pip notes before the song so match the general structure of the examples C3 and C4.

 

 

Heredia, Costa Rica https://macaulaylibrary.org/asset/165896

 

VOCALIZATION C3

Taxa: berlepschi

Context: Alternate song; pip-weet song

Description: Similar to the high, whistled song but with introductory pip notes. This is sort of a combination of vocalization A (introductory notes) and vocalization B (primary song). It may serve as a dawn song or a variation on the primary song; note however that a more complex dawn song is clear in some other examples (see Vocalization D below). Ridgely and Greenfield (2001) describe “song a repeated fast phrase of high, thin notes, e.g., tsu-tsu-tseét, with softer notes sometimes interspersed between phrases (P. Coopmans).”

Discussion: In berlepschi, this seems like a well-structured and very intentional song. It is not totally clear how its significance differs from vocalization B3 and is perhaps just a variation.

 

 

Valle de Cauca, Colombia https://macaulaylibrary.org/asset/264163; Esmeraldas, Ecuador https://macaulaylibrary.org/asset/31412321; Esmeraldas, Ecuador https://macaulaylibrary.org/asset/63198

 

VOCALIZATION C4

Taxa: olivaceus

Context: Alternate song; pip-weet song

 

 

Peru, https://macaulaylibrary.org/asset/35814 (both)

 

VOCALIZATION D1

Taxa: phaeocercus Group

Context: Dawn song

Description: pit-whit-ooh-wheer… pit-whit-ooh-whit-wheer… pit-whit-ooh-wheer

Notes: Quite similar to Costa Rica recording, with some minor differences in the shape of the notes and delivery.

 

 

Sololá, Guatemala https://macaulaylibrary.org/asset/118300461

 

VOCALIZATION D2

Taxa: aurantiiventris

Context: Dawn song

Description: pip-pip-pip-pip-pip-pip-WHEEooo pip-pip-pip-pip-wheEEE

Notes: Markedly slower delivery in Costa Rican birds compared to Colombia recording. Stiles and Skutch (1989) describe quaint, prolonged dawn song a very rapid series of high, thin notes: bip-bip-bip-dididi-up-bip-bip-bibibiseer

 

 

https://macaulaylibrary.org/asset/526236

 

VOCALIZATION D3

Taxa: berlepschi

Context: Dawn song

Description: pi-pit pi-pi-pit pi-wheoo….pi-pit wheer…

 

 

Valle de Cauca, Colombia https://macaulaylibrary.org/asset/90360501

 

VOCALIZATION E

Taxa: all subspecies groups (except no examples found for berlepschi)

Context: short contact call

Description: Short, abrupt "pip", recalling Alder Flycatcher Empidonax alnorum (MJI). Howell and Webb (1995): a sharp, usually quiet pic or beek, suggesting Hammond's Flycatcher

 

  A screenshot of a cell phone Description automatically generated

 

Left: phaeocercus Group, https://macaulaylibrary.org/asset/524464 (Sinaloa, MX). Multiple examples on this cut vary in strength and are sometimes given in advance of Vocalization D (see below). See also https://macaulaylibrary.org/asset/216981; center: aurantiiventris, https://macaulaylibrary.org/asset/72888 (Costa Rica); right: olivaceus, https://macaulaylibrary.org/asset/35814 (Peru).

 

Probably sounds fuller and lower in olivaceus and maybe diagnosably different from the other taxa. I did not find examples for berlepschi, so it is unclear if they have a similar note, but it seems likely. A single note given in https://xeno-canto.org/85120 at 0:11 is likely analogous to this note. Given that the strength and stridency of this note varies according to how excited the individual is, I did not detect obvious differences between the taxa in this note. They may exist, but it would require a larger sample to confirm this. To my ear, in the examples I heard, this note seems similar across the genus, even between the two taxa currently treated as separate species (phaeocercus sensu lato and olivaceus).

 

VOCALIZATION F

Taxa: Costa Rican aurantiiventris only [likely all?]

Context: aggression calls

Description: kew…kew

 

 

https://macaulaylibrary.org/asset/48408511

 

VOCALIZATION G

Taxa: Costa Rican aurantiiventris only [likely all?]

Context: aggression calls

Description: kew…kew

 

 

note "pip" at end

https://macaulaylibrary.org/asset/48409211

 

 

Marshall Iliff and Pamela C. Rasmussen, May 2026

 

 

 

Vote tracking chart:

https://www.museum.lsu.edu/~Remsen/SACCPropChart1044+.htm

 

Comments from Stiles: “A very interesting exposition of the variation within the M. phaeocercus group, which clearly merits splitting into 3-4 species. Most of this variation in centered in NACC territory, and the options for recognition by SACC boil down to two, labeled options A and B, which differ in treating the South American form berlepschi as a species, or as a subspecies of the taxon aurantiiventris (which occurs from Costa Rica southward). The two options given for SACC are to consider M. phaeocephalus as consisting of three species (A: nominate phaeocephalus, aurantiiventris (Costa Rica and western Panama) and berlepschi (eastern Panama to northwestern Ecuador), or B: two species, phaeocephalus and aurantiiventris with berlepschi as a subspecies, thus including Costa Rica through NW Ecuador).

 

“My vote is YES for option A (three species). I consider that berlepschi differs from aurantiiventris in most of its vocal repertoire, plumage color and pattern, biogeography (habitat, elevation) to an extent comparable to the species-level differences in several related genera of tyrannids (genetic data are incomplete but do not conflict with this interpretation). Regarding E-names, I agree that all Mitrephanes taxa are distinctive enough within the family to justify the group-name of Tufted-Flycatcher, and that a suitable name for berlepschi would be Chocó Tufted-Flycatcher.”

 

Comments from Lane: “YES, tentatively, to option A. With only a cursory listen, I hear only weak differentiation between voices of aurantiiventris and berlepschi, but I suspect if I really studied the two, I would be more impressed by their differences. Plumage-wise, they seem pretty distinctive, and it is clear to me that M. phaeocercus is truly the vocal outlier of the complex, with M. olivaceus being an outlier in having no obvious dawn song (I’ve certainly never detected one, and it’s a bird I have encountered a fair amount… though rarely at dawn, admittedly).”