Proposal (31) to South American Classification Committee
Recognize
Micrastur mintoni
Effect on South American CL: This proposal would
add a newly described species to the list
Background: This cryptic species has been
overlooked and confused with M. gilvicollis; see Whittaker (2002)
for details.
New information: Whittaker (2002)
discovered this species by noting an unfamiliar vocalization and tracking it
down. This led to an analysis of specimens in Brazilian collections and some US
collections and to an analysis of Micrastur recordings from all over
Amazonia. He found that the new taxon differs strongly in voice (N = 42
recordings identified as mintoni) from other Micrastur, and is
diagnosable (N = 53 specimens) from the most similar species, M. gilvicollis,
in plumage pattern (tail barring; barring on underparts) and extent of
supraorbital bare skin. See Whittaker (2002) for details and other differences
that were statistically consistent but less than diagnostic. Although not
emphasized by Whittaker, mintoni, found from east of the Madeira and
south of the Amazon (as well, at least formerly in Atlantic forest of SE
Brazil) appears to be allopatric with gilvicollis; although resolution
of specimen sampling makes this less certain towards the Madeira, there seems
to be a sharp replacement at the Amazon. Presumably mintoni and gilvicollis
are sister taxa.
Recommendation: The plumage and
morphological data presented by Whittaker strongly support mintoni as
representing a diagnosable unit (subspecies or PSC species). Given the presumed
allopatry of gilvicollis and mintoni, it all comes down to, in my
opinion, voice in terms of species rank under BSC. Although I haven't compared
actual recordings, the sonagrams presented by Whittaker show impressive
differences between mintoni and gilvicollis, and even in the
absence of playback trials, would provide support for species rank for mintoni,
especially given the presumed importance of vocalizations in species
recognition in these "hidden" micrasturs. I see no reason not to add M.
mintoni to the list of species that we recognize.
Lit Cit:
WHITTAKER, A. 2002. A new species of
forest-falcon (Falconidae: Micrastur) from southeastern Amazonia and the
Atlantic rainforests of Brazil. Wilson Bulletin 114: 421-445.
Van Remsen, 26 June
2003
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Comments from Zimmer: " I have seen
and taped mintoni at several locations east of the Madeira, and can add
assurances that the vocal differences (from gilvicollis) described in
the paper are consistent and impressively distinct in the field. Just as an
aside, I experienced this taxon for the first time at Alta Floresta (Mato
Grosso, Brazil) in 1991. Ted Parker and I had our group on the road north of
town pre-dawn, and a pair of these birds was duetting back and forth. Ted
wasn't sure if it was a Micrastur or a frog, which should indicate just
how different it was from typical gilvicollis! I was on my first trip to
the Amazon, and had no experience with gilvicollis, so the difference in
voice didn't mean anything to me at the time. Ted was amazed when we taped the
birds in at first light and saw that they looked like gilvicollis. I've
got a copy of his notes from that trip, and in the gilvicollis account
he mentions the distinctiveness of the voice of the Alta Floresta birds and
says "check this". Years later, when Andy Whittaker went to Caxiuana
and heard/saw mintoni for the first time, he came back all excited and
told me about a new species of forest-falcon that he had found. He played me
the tape and I said "you know, I'm pretty sure that how gilvicollis
at Alta Floresta sounds." I dug out my tape, and sure enough, it was a
match. The morphological distinctions are sound too, but they are easily
obscured by the amount of age variation (in both gilvicollis and mintoni)
in specimens. I have no doubt that these are good species. It would be
interesting to hear the Atlantic Forest birds (which are either very rare or
already extinct), which Andy assumes are mintoni (probably so, but you
never know)."
Comments from Schulenberg: " My vote:
"Yes". I wish that Whittaker's paper had made more extensive
inter-specific comparisons of vocalizations *other* than the territorial
advertising song, but ... there it is."
Comments from Silva: "[YES.]
Whittaker presented very good evidence (morphology and song) to give a species
rank to mintoni."
Comments from Jaramillo: "YES. The paper
looks solid, and Kevin's notes were helpful. Amazing that a raptor can be out
there that was not recognized as being different for so long!
Comments from Nores: "[YES]. En este caso en particular yo estoy muy de acuerdo en que la diferencia de
voces con M. gilvicollis son tan marcadas como para separar las
especies."