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. ; 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 Nyari) 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 Nyari 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 Nyari 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.
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 brasiliera de Zoologia 6:685-693.
Wied, M. zu 1830. Strix minutissima.
Beiträge zur Naturgeschichte von
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."