Proposal (844) to South American Classification Committee

Recognize Mionectes roraimae as a species distinct from Mionectes macconnelli

Effect on South American checklist: This would split an existing species on the list (M. macconnelli) into two species M. macconnelli and M. roraimae.

Background: The taxonomic history of M. macconnelli follows a tortured path, now comprising two subspecies in northeastern South America and two isolated subspecies in southwestern Amazonia. This proposal deals only with the two northern forms, nominate macconnelli, a small lowland flycatcher ranging across southeastern Venezuela, the Guianas and the eastern half of Amazonian Brazil, and a highland form, roraimae, found in the tepuis of southeastern Venezuela and adjacent highlands of western Guyana and northern Brazil.

On 7 March 2001 we (Hilty and Ascanio) first noted that the vocalizations of highland roraimae differed dramatically from lowland macconnelli. Surprised by this we began a series of playback experiments and observations of these two taxa that were obtained during six different months over a five-year span, ending in Aug of 2005.

Analysis:

Distribution. Based on available date the two forms are allopatric, essentially elevational replacements, similar to many species in the Andes and elsewhere. Records of lowland macconnelli range up to c. 500 m; those of roraimae c. 600-1900 m with the single exception of one at 335 m on Serra do Tapirapeco in northern Brazil and two in Venezuela at 500 m, these latter two records in areas where lowland macconnelli has not been recorded. Voice: Display songs of the two forms show no audible similarity to human ears. Sonograms clearly depict these differences and readers can listen to these songs to appreciate just how dramatically different they are. Recordings by S. L. Hilty, D. Ascanio, and M. B. Robbins can be accessed at the Macaulay Library of Natural Sounds, Cornell University; those of A. Whittaker are deposited at the British library of Wildlife Sounds. Habitat: Both species occur in lower levels inside humid to wet forest, macconnelli in more seasonal lowlands and foothills; roraimae in wetter premontane and montane forest, often on white sandy soil. Song playback trials: We presented the results of 16 sets of playback trials. Not a single macconnelli showed any response to roraimae songs and vice versa. On the other hand, responses of roraimae to its own display calls were strong (=immediate) Dec-June but declined to none by Sept.; macconnelli responded strongly to its own songs in Feb but did not respond to any display calls or songs in June when the display area appeared deserted. Displays: macconnelli displays low (c. 0.3-2.5 m up), often around buttresses, and in fairly tight groups, some individuals just a few meters apart. Display vocalizations are often accompanied by little sallies and wing flicking. On the other hand, roraimae display perches were higher (c. 2.5-7 m up), consisted of single birds or well-separated twos, only occasionally 3-4 individuals, and always with individuals at least 15-60 m apart. Their calling never reached the frantic activity associated with macconnelli and behavioral movements, unlike macconnelli, were minimal. Measurements: wing and tail measurements between the two forms differed significantly (t-test, p<0.001); other measurements did not; plumage differences are diagnosable in hand but likely not in the field.

Recommendation: Based on field experience with both forms including 1) utterly different display songs, 2) field playback trial experiments, 3) numerous differences in display behavior; 4) differences in their leks, and 5) elevational differences in distribution, we recommend that these two forms be treated as separate species. The mensural differences (above) and minor plumage distinctions, although insufficient for separation alone, lend minor support for the strong behavioral and distributional differences that we document.

As regards an English name, there are few obvious morphological differences between these two taxa, but it is helpful to have an English name that also reflects a scientific name, in this case, e.g. McConnell’s Flycatcher, Mionectes macconnelli so we would suggest retaining this name and inventing a new name for M. roraimae. With this in mind, and the fact that there is already a Roraiman Flycatcher in existence, as well as several species prefixed by the name “Tepui”, we thought simply highlighting the region, by calling it Sierra de Lema Flycatcher, where we first noted the song and behavioral differences of roraimae would provide distinction and historical perspective for future observers or taxonomists.

References:

Hilty, S. L. and D. Ascanio. 2014. McConnell’s Flycatcher Mionectes macconnelli is more than one species. Bull. B. O. C. 134 (2): 270-279.

Hilty, S. L. Birds of Venezuela. 2003. Princeton Univ. Press, Princeton, NJ.

Macaulay Library of Natural Sounds, Cornell University, Ithaca, NY. https://www.macaulaylibrary.org/

Link (example) for lowland M. m. macconnelli: https://search.macaulaylibrary.org/catalog?taxonCode=mccfly1&q=McConnell%27s%20Flycatcher%20-%20Mionectes%20macconnelli

Link (example) for M. m. roraimae:

https://search.macaulaylibrary.org/catalog?taxonCode=mccfly3&q=McConnell%27s%20Flycatcher%20(Sierra%20de%20Lema)%20-%20Mionectes%20macconnelli%20roraimae

Steven L. Hilty, 1 Jan. 2020

Comments from Areta: “YES. The differences in vocalizations and morphology coupled to their narrowly parapatric distributions provide incontrovertible species-rank evidence for M. roraimae. The reciprocal playback experiments, indicating response to homotaxon vocalizations and no-response to heterotaxon ones during the breeding season, seals the deal beyond doubt. Regarding the English name, I am fine with Sierra de Lema Flycatcher, to escape from the Tepui/Roraiman monikers.”

Comments from Stiles: “YES to the Mionectes split proposed by Steve and agree with his E-name as well. I consider that the evidence presented (ecological behavioral, and especially vocal - including the reciprocal playback results - make a strong case.”

Comments from Jaramillo: “YES – separate Mionectes macconnelli into two species, based on differing vocalizations, lack of response to heterospecific vocalizations, and differing elevational distribution (habitat). YES – to Sierra de Lema Flycatcher for M. roraimae.”

Comments from Bonaccorso: “YES. Plumage and mensural differences are imperceptible in the field, which will confuse non-taxonomist, but differences in song and, especially, the results of playback experiments are very convincing.”

Comments from Zimmer: “ “YES. In February of 2004, alerted to the pending work on these flycatchers by Hilty & Ascanio, I had the opportunity to observe and tape record multiple lekking individuals of M. roraimae in the Sierra de Lema, and found the vocal, behavioral (with respect to display height and spacing on leks and less frenetic physical behavior as regards wing-flicking, etc) and ecological distinctions from nominate macconnelli (with which I was familiar from the Brazilian Amazon) to be exactly as portrayed by Hilty & Ascanio (2014). I also performed some informal playback trials of recordings of nominate macconnelli to those displaying roraimae, and, as expected (given the rather extreme differences in vocalizations), failed to elicit any response. These are truly cryptic taxa from a morphological standpoint, but the vocal, behavioral and ecological distinctions first brought to light by Hilty & Ascanio provide a slam-dunk rationale for treating these two taxa as specifically distinct. I would also voice support for the authors’ choice of “Sierra de Lema Flycatcher” as an appropriate English name for roraimae.”

Comments from Robbins: “YES. It has been clear for some time (in part based on our work in Guyana; audio and specimens) that this represents an unrecognized species.”

Comments from Pacheco: “YES. The distinctive characteristics of the taxa with respect to the display song and display behavior are sufficient, in my opinion, to accept the recommendation.”

Comments from Remsen: “YES. Technically the two may be allopatric, but barely. Perhaps there is a gap in their elevational distribution, but without any true barrier, I wonder if more thorough sampling would reveal parapatry. Therefore, as long as the plumage differences are diagnostic, and there is no sign of gene flow through intermediate plumages, then these two taxa are species by any definition. The behavioral, vocal, and habitat differences reveal the mechanism by which gene flow is minimized or prevented. Congrats to Steve and David for sleuthing this out. Note also that the differences between widespread macconnelli and oleagineus are really pretty small, so treating roraimae as a species is not conspicuously divergent from taxa already ranked as separate species a century ago because of sympatry. With geographic variation within them, one wonders if there are other taxa that are actually species out there.

“As for the English name, I am reluctant to use the proposed name without a separate proposal, especially because it is basically Spanish. However, “Sierra de Lema” is the official geographic name used on all maps (i.e. there are no “Lema Mountains”, the name is published, all comments above are favorable or neutral, and l suspect that trying to concoct a novel name would be an ordeal.”

Comments from Stotz: “YES I am not thrilled with the suggested English name, but I have no alternative. I am okay with using Sierra de Lema Flycatcher for the new species.”