A new genus for three species of tyrant flycatchers (Passeriformes: Tyrannidae), formerly placed in Myiophobus
Author
Ohlson, Jan I.
Author
Fjeldså, Jon
Author
Ericson, Per G. P.
text
Zootaxa
2009
2290
36
40
journal article
10.5281/zenodo.191390
9e573dc9-5b22-4767-8933-3cc698872a19
1175-5326
191390
Nephelomyias
,
gen. nov.
Ohlson, Fjeldså & Ericson
Type
species
:
Mitrephorus ochraceiventris
Cabanis, 1873
.
Included species:
Nephelomyias pulcher
(P. L. Sclater, 1861)
comb. nov.
, Handsome Flycatcher;
Nephelomyias ochraceiventris
(
Cabanis, 1873
)
comb. nov.
, Ochraceous-breasted Flycatcher;
Nephelomyias lintoni
(Meyer de Schauensee, 1951) comb. nov. Orange-banded Flycatcher.
Diagnosis
:
External morphology
—Small passerine birds similar in proportions to several “contopine” flycatcher genera (clade F
4 in
Ohlson et al. 2008
; Contopini in
Tello et al. 2009
), e.g.
Lathrotriccus
and
Empidonax
, but bill flatter and relatively shorter, barely longer then the surrounding rictal bristles, and with a much smaller distal hook. Distinguished from other species traditionally included in
Myiophobus
by the combination of contrasting wing bars and pale panel on the distal two thirds of the secondaries, rich yellow to ochraceous underparts, and lack of streaking or flammulated pattern on chest and flanks. They are markedly distinct from other members of Hirundineinae, being less derived in both proportions and plumage pattern. They lack the unique colour pattern of
Myiotriccus
and the long wings, weak tarsi and predominantly rufous plumage of
Pyrrhomyias
and
Hirundinea
.
The total length is 12.5-
14 cm
(
lintoni
and
ochraceiventris
) or 9.5–
11 cm
(
pulcher
). Plumage predominantly olive above and yellow below, with orange ochre breast in
ochraceiventris
and
pulcher
; head with prominent yellow to orange-red coronal patch (most prominent in males) and pale arched supraloral line and inconspicuous eye ring; wings and tail dusky to blackish with broad pale ochre to bright cinnamon tips of greater and median secondary coverts, forming two conspicuous wing bars; tertials and remiges edged whitish to pale ochre, except on the inner third of the secondaries, which forms a distinct blackish patch in the closed wing.
Nephelomyias pulcher
differs from the other two by being smaller with a proportionally shorter tail. Interspecific variation in plumage coloration involves tone and richness in colour of underparts and wing markings, colour of the supraloral stripe and eye ring and degree of grey tinge on the head. Apart from this variation,
N. ochraceiventris
has the ochre colour of the underparts extending over the sides of the head, and an all black bill (yellowish lower mandible in the other two);
N. lintoni
has pale iris (dark in the other two species).
FIGURE 1
. Simplified phylogenetic tree of
Tyrannidae
modified from Ohlson et al. (2008). Nodes supported by Bayesian posterior probabilities <0.95 are collapsed. Clades with several genera have in most cases been condensed and are indicated by arrows at the tip of the branch. All species traditionally placed in
Myiophobus
are in bold type. The three species in
Nephelomyias
form a strongly supported clade with
Myiotriccus
,
Pyrrhomyias
and
Hirundinea
(Hirundineinae)
, whereas the other
Myiophobus
species belong in
Fluvicolinae
.
Anatomical characters
—
Cranial and syringeal material is only known for one species (
N. ochraceiventris
), so a full evaluation of anatomical characters cannot be made for the genus. Furthermore, cranial and syringeal morphology in
Tyrannidae
has been shown to be highly homoplastic (
Birdsley 2002
;
Ericson et al. 2006
;
Ohlson et al. 2008
) and any of the individual character states below are found in some other tyrant flycatcher clade. However, at least
N. ochraceiventris
shares with
Myiotriccus
,
Hirundinea
and
Pyrrhomyias
the following unique combination of characters (
Lanyon, 1986
,
1988a
,
1988b
):
1) Superior interorbital fenestrae obliterated by ossification (found in many members of
Elaeniinae
and
Rhynchocyclidae
, but not in
Tyranninae
or
Fluvicolinae
other than
Myiophobus flavicans
,
M. inornatus
and
M. fasciatus
);
2) Lack of a fork at the posterior end of the trabecular plate in the nasal septum (characteristic for non-
fluvicoline tyrant flycatchers, in
Fluvicolinae
only found in
Myiophobus phoenicomitra
and some
specimens of
M. roraimae
);
3) 1–2 A elements form completely ossified rings around each bronchus in the syrinx (found in most
tyrannids, absent in
Ochthoeca
,
Tumbezia
,
Colorhamphus
,
Fluvicola
,
Arundinicola
and
Alectrurus
in
Fluvicolinae
, in the tody-tyrants and
Cnipodectes
in
Rhynchocyclidae
, and in all members of
Elaeniinae
except
Inezia
and
Zimmerius
);
4) Bronchi separated by a calcified pessulus (found in many members of
Rhynchocyclidae
, but absent
in all other tyrant flycatchers, except
Sublegatus
,
Colonia
,
Machetornis
,
Zimmerius
,
Inezia
,
Pseudelaenia
,
Myiophobus flavicans
,
M. inornatus
and
M. fasciatus
.
Nephelomyias ochraceiventris
further shares with
Myiotriccus
a slightly elevated trabecular plate, resulting in a sagittal ridge at the ventral end of the nasal septum (typical of elaeniines) and the lack of a notch at the anterior end of the nasal septum. Neither of these character states is found in
Hirundinea
,
Pyrrhomyias
or any member of
Fluvicolinae
, except
Myiophobus phoenicomitra
and
M. roraimae
.
Habitat and behaviour:
Distinguished behaviorally both from the other members of Hirundineinae and from their former congeners in
Myiophobus
by being more arboreal, inhabiting the canopy and subcanopy of humid montane forest. They forage for small arthropods (and possibly some fruit) by short sallies to air or foliage and by perch gleaning. Unlike other members of Hirundineinae, they usually travel in small groups which often accompany mixed foraging parties (
Poulsen 1996
), a behaviour that sets them apart from most tyrant flycatchers outside
Elaeniinae
(
Ohlson et al. 2008
).
Distribution:
All three species are restricted to humid forest in the Andes.
Nephelomyias pulcher
has a disjunct range, with populations in the Andean cloud forests (
1500-2600 m
) of
Colombia
and northern
Ecuador
and in the yungas of
Bolivia
and southern
Peru
.
Nephelomyias lintoni
and
N. ochraceiventris
are sandwiched between the two populations of
N. pulcher
, replacing each other in the upper montane and elfin forest (
2200-3500 m
) north and south of the North
Peru
Low.
Molecular data
: Phylogenetic analyses based on DNA sequence data from three nuclear introns of 126 species of
Tyrannidae
and allies show that
Nephelomyias
species do not belong to
Fluvicolinae
, where species of
Myiophobus
are placed (
Fig. 1
;
Ohlson et al. 2008
). Instead, they group with
Myiotriccus
,
Pyrrhomyias
and
Hirundinea
, forming the small clade Hirundineinae that constitutes an independent deep lineage in
Tyrannidae
. The relationship of this clade to
Elaeniinae
,
Tyranninae
and
Fluvicolinae
is currently unresolved.
Etymology
: The genus name
Nephelomyias
(from Gr.
Nephéle
=cloud, mod. L.
myias
= a flycatcher) highlights the restricted Andean cloud forest canopy habitat of all three species. The name is masculine in gender.