Proposal (243) to South American Classification Committee
Change the name of Least Pygmy-Owl to Glaucidium sicki
Background: Silva et
al. (2002) described a new species of pygmy-owl (Glaucidium mooreorum)
from the Pernambuco area of northeastern Brazil. The description was based on
two specimens, but more importantly they demonstrated via spectrograph
comparisons that the voice was quite distinct from Glaucidium minutissimum and Glaucidium
hardyi. Morphologically, mooreorum and minutissimum are extremely similar in plumage pattern
and morphometrics, with overlap in both wing and tail measurements. Thus,
vocalizations are the key for distinguishing them and I believe Silva et al.
have demonstrated (albeit with very small sample sizes) that there are two
pygmy-owl species that our committee currently recognizes as one under the taxon
minutissimum. Until the distinctive voice of G.
hardyi was recognized,
it too was lumped under minutissimum (Vielliard 1989). All three of the above
species are allopatric, apparently with the São Francisco River in northeastern
Brazil separating mooreorum and minutissimum (see figure 5 in Silva et al. [2002]; I can
provide a pdf of this paper).
That was the rationale when our
committee voted to accept (proposal #32) mooreorum as a species.
New information: König and
Weick (2005) just published a paper that fully supports the recognition of the
Pernambuco birds as a separate species from birds in southeastern Brazil;
HOWEVER, they indicate that the holotype of minutissimum,
described by Wied in 1830, belongs to the Pernambuco species (=Silva et al.'s mooreorum). If König and Weick
are correct then the species that is found in southeastern Brazil was unnamed.
The following English translation (thanks to Arpad Nyári) from König &
Weick provides their rationale:
"In the 2002 edition of the
Brazilian journal Ararajuba,
a new species of pygmy owl, Glaucidium
mooreorum from the Brazilian
rainforests of Pernambuco was being named (Silva et al. 2002). The authors
reasoned the species status of this taxon mainly on the distinctive
vocalizations of G. minutissimum and G. mooreorum. The authors although,
have omitted the fact that in 1830, Maximilian zu Wied based his description of Strix minutissima on the similar locality of the Pernambuco
area ("hinterland of Bahia", where rainforests were still intact at
that time). Somewhat later, Otto Wucherer collected in the same region a few
more pygmy owls, of which two (an immature and an adult) were deposited at the
Natural History Museum in Tring (Sharpe 1875). One of these specimens was
loaned to us for comparison with the described Glaucidium mooreorum. Based on
this comparison we conclude that the specimen collected by Wucherer belongs to
the "new species". Because in the case of synonymy only the oldest
given name has validity, the "new species" of northeast Brazil must
be named Glaucidium minutissimum, whereas G. mooreorum represents its younger synonym. The
hitherto erroneously held pygmy-owl Glaucidium
minutissimum of southeast Brazil
was designated by us to a new scientific name."
They named
the southeastern Brazil birds G. sicki.
Apparently König and Weick did not
examine Wied's holotypes (the syntypes, an immature male and adult female, are
extant at AMNH; see below) and their interpretation of Wied's description is at
odds with what Arpad Nyári and I found when we examined Wied's (1830)
description. The following is verbatim from Wied's (1830) description for the
type locality: "im lunereu der Provinz Bahia" (translation = found in
the interior of Province Bahia). Note that this is precisely how it was
interpreted by Peters (1940). It is unclear how König and Weick turned
"hinterland of Bahia" into "Pernambuco area". Furthermore,
in Table 1 of König and Weick (2005) the locality of Wucherer's specimen, (the
Tring specimen that they borrowed, is simply listed as "Bahia".
Again, I am puzzled as to how this became "Pernambuco area".
Moreover, I emphasize that the provenance of the Wucherer specimens at Tring
that König and Weick used to support their conclusion is immaterial. Naturally,
the syntypes dictate the nomenclature.
If Wied's holotypes came from what
is now defined as the state of Bahia, then based on what we know about the
distributions of mooreorum and minutissimum
(again, see fig. 5 in Silva et al.) then it seems quite likely that Silva
et al. were correct in assuming that birds from the Pernambuco region were
unnamed and the moniker minutissimum applies to birds in southeastern
Brazil. However, if at the time when the above pygmy-owls were collected (1816)
and later described (Wied 1830), a much larger area of northeastern Brazil was
referred to as "Province Bahia", then there might be a question of
provenance and what name should be applied to these species. Consultation of
Paynter and Traylor (1991) does not reveal any change in the boundaries of the
state of Bahia. Perhaps one of our Brazilian colleagues can shed light on this
historical geographical question.
As mentioned above, based on both
Silva et al. (2002) and König and Weick (2005), it is extremely difficult to
tell these two species apart based solely on morphology. The number of
specimens of both taxa with precise locality, sex, and age data is very limited
(see Howell and Robbins 1995), thus one must be cautious in making definitive
statements about plumage characters. Nonetheless, both Silva et al. (2002) and
König and Weick (2005) indicate that the number of white tail bands differs
between Pernambuco (5 bands) and southeastern Brazil birds (4 bands) - note
that the number of white bands apparently includes the spots at the very tip of
the tail. Wied's (1830) description indicates that the male syntype had three
bands (=4 if the white tail tip is included). However, contrary to Wied's
description the two syntypes at AMNH (6345, 6345bis) both have five tail bands
(color photographs provided by P. Sweet, Sharon Kenney)! I suspect that Wied
did not count the spots at the tip of the tail nor the white band that is at
the base of the tail and hidden by the under tail coverts. At hand, I have a
Field Museum specimen (302417) that is labeled as a male (based on the presence
of spots on the crown it is an adult) from São Paulo and it has five white
bands (including the white tail tip spot & the white band at the very base
of the tail). Thus, based on this very limited amount of information it appears
that the number of white tail bands may not be diagnostic for distinguishing
these two species.
In summary, there is much
uncertainty involved with the nomenclature of these two taxa. It is indicated
clearly in Wied's (1830) description that the holotypes were from "the
interior of the province of Bahia" and the uncertainty in the value of the
number of white tail bands in separating these two taxa leaves me ambiguous
about what name should be applied to these taxa. Thus, given this uncertainty,
I believe the conservative action is to follow Silva et al. (2002) until there
are unambiguous data to suggest otherwise.
Taxonomic recommendation: I
recommend that we continue to recognize birds in southeastern Brazil as Glaucidium minutissimum and birds from the Pernambuco region of
Brazil as Glaucidium mooreorum.
Thus, I vote "NO" to accepting König and Weick's premise that birds
in southeastern Brazil (the former G. minutissimum) should be named G. sicki.
Acknowledgments: I thank
Arpad Nyári for the English translations of Wied's original description and
König and Weick's paper. Mary LeCroy, Paul Sweet, and Sharon Kenney provided
information on the Wied material at the American Museum of Natural History
(AMNH) and for photographs of the two G.
minutissimum syntypes.
References:
Howell, S. N. G., and M. B.
Robbins. 1995. Species limits of the Least Pygmy-Owl (Glaucidium minutissimum) complex.
Wilson Bull. 107:7-25.
König, C. & F. Weick. 2005. A
new Least Pygmy Owl (Aves: Strigidae) from southeastern Brazil. Stuttgarter
Beitr. Naturk. Ser. A. no. 688.
Paynter, R. A. & M. A. Traylor,
Jr. 1991. Ornithological gazetteer of Brazil, vol. 2. Museum of Comparative Zoology,
Cambridge, Massachusetts.
Peters, J. L. 1940. Check-list of
birds of the world, vol. IV. Museum of Comparative Zoology, Cambridge,
Massachusetts.
Silva, J. M. C. da, Coelho, G.
& Gonzaga, L.P. 2002. Discovered on the brink of extinction: a new species of pygmy-owl
(Strigidae: Glaucidium) from Atlantic
Forest of northeastern Brazil. Ararajuba 10:123-130.
Vielliard, J. 1989. Uma nova
espécie de Glaucidium (Aves, Strigidae) da Amazônia. Revista Brasileira de Zoologia
6:685-693.
Wied, M. zu 1830. Strix minutissima. Beiträge zur Naturgeschichte von Brasilien 3:242-246.
Mark B. Robbins, September 2006
_______________________________________________________________________________________________
Comments from Stiles: "NO.
Mark's discussion of a decidedly confusing situation persuades me that without
more and better locality information and genetic data, we are best off staying
with the status quo, which in any case seems more in accord with the type
material of minutissimum."
Comments from Zimmer: "NO.
I agree with Mark, that given the available evidence, this would be premature."
Comments from Stotz: "NO.
Unless the syntypes, which are available, can be shown to certainly refer to
the NE Brasil taxon, mooreorum,
we should maintain the current nomenclature."
Comments
from Jaramillo: "NO - The data are inconclusive at this point."
Comments from Pacheco: "NO.
Em minha experiência pessoal nas florestas
da Bahia por onde o Príncipe de Wied viajou e coletou espécimes -- a
vocalização de Glaucidium
minutissimum é equiparável /
inseparável daquela ouvida em vários partes do Sudeste do Brasil (Espírito
Santo, Rio de Janeiro, São Paulo etc) mas, claramente diferente daquela
atribuída a Glaucidium
mooreorum, a partir das gravações conhecidas. Os demais argumentos de König
e Weick igualmente não se sustentam, a partir do reexame dos síntipos de Wied."
Comments solicited from Vitor Piacentini: “In
a few words, here are the problems:
“- The authors equated southeastern
Bahia (where Wied had travelled) with Pernambuco (any map found by Google would
suffice here);
- They compared a specimen without
nomenclatural value (collected by Wucherer around present-day Salvador) to
determine the application of Wied's name - they have never seen the types of minutissimum or mooreorum (the only two known specimens of the species) to validate
their claim they are identical.
- Even if the specimens are ever found
to be identical, the voice of both species are quite distinctive and certainly
of much more taxonomic value than plumage. Yet the voice of Bahian Glaucidium minutissimum is identical to
those from Santa Catarina (the southernmost limit of minutissimum and type locality of G. sicki).
- The authors are evidently unfamiliar
with plumage alteration resulting from preparation: they defended that G. sicki (based on a stretched specimen)
have a large dark blotch on nape (the two false eyes), whereas their G. minutissimum (based on a shortened
specimen with the feathers greatly overlapping) does not! See the Figure 1 in
the original description of G. sicki.
- The authors showed the distribution of
their G. sicki going from Santa
Catarina all the way north up to ... Bahia! How can they say Bahia belongs to
Pernambuco and, later, include southeastern Bahia within the range of their G. sicki?
“I have examined most of the paratypes
of G. sicki, but unfortunately the
types of mooreorum were locked when I
went to Pernambuco to study the Phaethornis,
so for the time being I gave up publishing a formal rebuttal.”