COTINGA 2 Myiarchus flycatchers 20 COTINGA 2 Myiarchus flycatchers Field identification of M y i a r c h u s flycatchers in M exico Steve N. G. Howell and Sophie Webb Resum en El género Myiarchus incluye algunos papamoscas (Tyrannidae) bastante grandes que se encontran desde Norteamérica y el Caribe hasta Sudamérica. Este artículo versa sobre la identificación de seis especies de Myiarchus de extraordinaria similitud, variadamente simpátricas encontrados en Méjico: M. cinerascens, M. nuttingi, M. tyrannulus, M. crinitus, M. tuberculifer, y M. yucatanensis, junto con la especie cercana Deltarhynchus flammulatus. Introduction The Mexican Myiarchus flycatchers are all The genus Myiarchus comprises a number of fairly slender and large-headed with peaked fairly large tyrant-flycatchers found from to slightly crested napes (Plate opposite). North America and the Caribbean to South Their upperparts are grey-brown to olive with America. This paper treats the identification paler edgings to the wing coverts, and rufous of the six species of Myiarchus found in Mexico: edgings to the remiges (flight feathers). The Ash-throated M. cinerascens, Nutting’s M. throat and chest are grey and the belly pale nuttingi, Brown-crested M. tyrannulus, Great yellowish. Juveniles differ from adults by hav­ Crested M. crinitus, Dusky-capped M. ing more extensive cinnamon-rufous edgings tuberculifer, and Yucatan M. yucatanensis fly­ to their remiges which, in migratory species, catchers, together with the closely related are generally not moulted until after migra­ Flammulated Flycatcher Deltarhynchus tion. The sexes are similar in appearance, al­ flammulatus. though males average larger-billed than fe­ males. For field identification purposes, geo­ Plate: M yiarchus, streaked flycatchers, graphic variation is obvious in one species and allies, by Sophie W ebb (Dusky-capped), and slight in three others (Nutting’s, Brown-crested, and Yucatan). The 1. Ash-throated Flycatcher M. cinerascens; bills of Mexican Myiarchus flycatchers are 2. Dusky-capped Flycatcher M. tuberculifer; blackish with some pale flesh colour at the (a: olivascens, western Mexico; base of the lower mandible; the legs and feet b: lawrencei, south-eastern Mexico); are blackish. 3. Yucatan Flycatcher M. yucatanensis; Myiarchus flycatchers inhabit forested and (a: yucatanensis, Yucatan Peninsula; scrubby habitats. Generally they do not perch b: lanyoni, Isla Cozumel); conspicuously, and they can sit still and qui­ 4. Nutting’s Flycatcher M. nuttingi; etly for long periods. They are vocal mostly in 5. Brown-crested Flycatcher M. tyrannulus; early morning and, although common in many (a: magister, western Mexico; areas, all species can be overlooked easily. b: cooperi, eastern Mexico); 6. Great Crested Flycatcher M. crinitus; The problem 7. Flammulated Flycatcher Deltarhynchus The Mexican and Central American flammulatus (7a: worn plumage); Myiarchus flycatchers appear remarkably 8. Piratic Flycatcher Legatus leucophaius; uniform overall, and up to four species are 9. Sulphur-bellied Flycatcher Myiodynastes sympatric in some areas (to the extent that luteiventris (9a: variation in throat pattern); they can occur together in a single fruiting 10. Streaked Flycatcher Myiodynastes tree!). In general there are two main problem m aculatus; areas: west coast taxa and east coast taxa. In 11. Bright-rumped Attila Attila spadiceus; western Mexico, Ash-throated, Nutting’s, (a: mexicanus, West Mexico; Brown-crested and Dusky-capped flycatchers b: gaum eri, Yucatan Peninsula). all occur sympatrically; Flammulated Fly­ 21 COTINGA 2 Myiarchus flycatchers catcher is also found in much of this region. voice, tail pattern (some intermediate pat­ In eastern Mexico, Brown-crested, Great terns occur), strong contrast between rufous Crested, Dusky-capped and Yucatan flycatch­ edges of primaries and whitish to pale lemon ers occur sympatrically. Maps 1–7 show the edges of secondaries. Also note Ash-throated’s distributions of Myiarchus and Flammulated more peaked nape and slightly larger bill, and flycatchers in Mexico and northern Central that the grey from its throat extends up into America. its face. In fresh plumage, the underparts of Specific identifications of Myiarchus are Ash-throated are paler overall than Nutting’s, best based on diagnostic call notes, with due without such a contrasting or bright yellow attention paid to relative bill size, and tail pat­ belly. Separated from the larger and rangier terns. Face pattern and wing pattern are also Brown-crested Flycatcher by voice, tail pat­ useful. Note that the pattern of rufous on the tern, and its proportionately smaller bill. outer rectrices can often be seen in the field by looking at the underside of the closed tail. 2. Dusky-capped Flycatcher M. tuberculifer Songs are given in the nesting season only, (6.3–7.3"; 16–18.5 cm). Widespread resident in often at or before dawn, and are of limited wooded and forested habitats, riparian groves, identification value when it’s too dark to see etc. (Map 2). Diagnostic call notes are a plain­ the singing bird. Fortunately, the Mexican tive, drawn-out wheeeeu or peeeu (but beware Myiarchus flycatchers all have diagnostic call very similar call of Yucatan Flycatcher), and notes which are given fairly frequently. In ad­ a shorter note followed by a rolled whistle, dition, all species have a varied repertoire of whee peeerrr-rr. Occasionally gives a soft whit “generic” chattering and bickering calls, or pip call not unlike Ash-throated (K. harder to transcribe and generally less useful Kaufman in litt. 1994). Note dull wingbars and for specific identification. little or no rufous in tail. 2a. M. t. olivascens The following species accounts and Table (typical of western Mexico); 2b. M. t. lawrencei summarize the identification features of the (typical of south-eastern Mexico). Mexican Myiarchus flycatchers and the super­ Western birds are separated readily from ficially similar Flammulated Flycatcher. sympatric species by voice, relatively slender There are three main identification problems: (but proportionately long) bill, dull wingbars, Ash-throated, Nutting’s, and Brown-crested and tail pattern. Eastern birds are separated (overall pallid, medium to large, with distinct from Yucatan Flycatcher by voice, darker head pale wingbars and obvious rufous in their (lacking paler grey lores and eyering), and pale tails); Brown-crested and Great Crested (large lemon to pale cinnamon edges to tertials. Also and large-billed with pale wingbars and obvi­ note more peaked nape and dull rufous to grey- ous rufous in their tails); and Dusky-capped brown wingbars. and Yucatan (small, relatively small-billed, with dull wingbars and little or no rufous in 3. Yucatan Flycatcher M. yucatanensis (7– their tails). Numbers with the following spe­ 7.5"; 17.5–19 cm). Resident in thorn forest and cies accounts correspond to those on Plate woodland in Yucatan Peninsula (Map 3), but p. 20, and those of Maps 1–7. generally less common there than Dusky- capped Flycatcher. Diagnostic call notes are a 1. Ash-throated Flycatcher M. cinerascens plaintive, drawn-out, slurred whee-ee-eu or (7.5–8"; 19–20.5 cm). Breeds in deserts of north­ hoooooo-eu, rising then falling, and a drawn- ern Mexico, wintering in scrub on Pacific slope out, plaintive whistle followed by a bright, and in adjacent interior south into Central upward-inflected whistle, wheeeer hweep. America (Map 1). Diagnostic call notes are a Note dull wingbars and reduced rufous in tail, wet to slightly sharp, single-syllable pip or pic, separating this species from all except Dusky- often quite soft, and a rolled prreeer, suggest­ capped Flycatcher. 3a. M. y. yucatanensis ing a referee’s whistle, and a soft kabrick or (Yucatan Peninsula); 3b. M. y. lanyoni (Isla habrik, not as loud as a similar call of Brown- Cozumel, darker overall than mainland birds). crested Flycatcher. Note extensive rufous in Distinguished from Dusky-capped Flycatcher outer rectrices with dark area typically by voice, lack of dark-headed look, paler grey­ spreading across tip. ish lores and often a broad, almond-shaped Separated from Nutting’s Flycatcher by eyering, and whitish edging to tertials. Also 22 COTINGA 2 Myiarchus flycatchers note less peaked nape and dull grey-brown tern with Ash-throated and note pale grey face wingbars. (unlike Nutting’s). Separated from migrant Great Crested by its overall paler and greyer 4. Nutting’s Flycatcher M. nuttingi (7–7.5"; 18– plumage, the brownish cap contrasting with 19 cm). Resident in thorn forest on Pacific the paler grey face, and less contrast between slope and in interior valleys (Map 4). Diag­ pale grey chest and pale lemon belly. Also note nostic call notes are a sharp wheek! or wheep, an extensively pale base to the lower mandi­ suggesting Great Crested Flycatcher but ble on many Great Crested Flycatchers. shorter and more emphatic, and a doubled kwee-week! These calls have a piping or lightly 6. Great Crested Flycatcher M. crinitus (8– whiny quality that may suggest an American 8.8"; 20.5–22 cm). Migrant and winter visitor Oystercatcher Haematopus palliatus, unlike to humid forest and woodland in E and S the fuller-toned call of Great Crested Fly­ (breeds NE Mexico) (Map 6). Diagnostic call catcher. Note extensive rufous in rectrices note a rising, slightly drawn-out, single-syl­ with dark area typically not expanding across lable wheep or wheeep, most like Nutting’s tip. Flycatcher but less emphatic (although possi­ Separated from Ash-throated Flycatcher