Entre Ríos Seedeater (Sporophila zelichi): a species that never was

Abstract

Entre Ríos Seedeaters (Sporophila zelichi), also called Zelich's Seedeaters, White‐collared Seedeaters, and Narosky's Seedeaters, are one of the rarest birds in the Neotropics. However, doubts have been raised about the validity of this species. Therefore, I evaluated the systematic status of Entre Ríos Seedeaters based on analysis of previously unpublished vocal and habitat data. I tested four hypotheses regarding the systematic status of S. zelichi: Good Species Hypothesis (valid species), Hybridization Hypothesis (hybrid S. palustris×S. cinnamomea), Color Morph Hypothesis I (morph of S. cinnamomea), and Color Morph Hypothesis II (morph of S. palustris). The songs and preferred habitat of S. zelichi are indistinguishable from those of Marsh Seedeaters (S. palustris), and the songs of both forms have exhibited similar changes from the early 1990s to 2003–2007. In contrast, the songs and preferred habitat of Chestnut Seedeaters (S. cinnamomea) differ from those of S. zelichi. Therefore, the Good Species Hypothesis is rejected by vocalization and habitat data, the Hybrid Hypothesis is undermined by the absence of shared vocal characters and limited habitat overlap of the proposed parental forms S. cinnamomea/S. palustris, and Color Morph Hypothesis I is rejected by both song and habitat data. However, Color Morph Hypothesis II is supported by both song and habitat data. Thus, I propose that S. zelichi be considered a color morph of S. palustris.

Another color morph of Sporophila Seedeater from the capuchinos group (Aves, Emberizidae)

“…Studies on voice and behavior, for example, although still insufficiently used for this group, have been contributing effectively to solving taxonomic difficulties in the genus (SCHWARTZ, 1975;ARETA, 2008;ARETA et al, 2011). On the other hand, molecular approaches have revealed shallow genetic divergence among several species, as is the case for the ten species that form the "Southern Capuchinos group" (LIJTMAER et al, 2004;CAMPAGNA et al, 2009).…”

“…Important advances in the general understanding of the capuchinos have been gained, especially in the identification of new color morphs to several species, as well as of this group's natural history (ARETA, 2008(ARETA, , 2009FACCHINETTI et al, 2008;LIMA, 2008;ARETA et al, 2011). Sporophila zelichi (Narosky, 1977), for example, was proposed as a color morph of Sporophila palustris (Barrows, 1883), which invalidates the species status of the former (ARETA, 2008).…”

“…Sporophila zelichi (Narosky, 1977), for example, was proposed as a color morph of Sporophila palustris (Barrows, 1883), which invalidates the species status of the former (ARETA, 2008). Likewise, "caraguata" was suggested to be a color morph for Sporophila ruficollis (Cabanis, 1851), and a color morph is presently being described for Sporophila hypoxantha Cabanis, 1851 (Juan I. Areta, pers.…”

“…obs.). The descriptions of these new forms have been based mainly on studies of vocalization and habitat preference (ARETA, 2008;ARETA et al, 2011).…”

“…Aiming to provide useful new information for diagnosis of South American capuchinos, we describe herein this new, identifiable plumage type and discuss its taxonomic status based on habitat use characteristics, voice and behavior. In view of recent studies that proposed color morphs for capuchinos (ARETA, 2008;ARETA et al, 2011), we evaluated whether the specimens found are (1) individuals of Sporophila melanogaster with intra-specific variation in their plumage (color morph); or (2) a new species, sympatric with S. melanogaster.…”