Snipe taxonomy based on vocal and non-vocal sound displays: the South American Snipe is two species

MILLER EH; ARETA JI; JARAMILLO A; IMBERTI S; MATUS R

IBIS

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2020 vol. 162 p. 968 - 990

0019-1019

We provide the first analysis of vocal and non-vocal sounds in a species complex of snipe, a group of birds that lacks vocal learning, to investigate the species status of two geographically allopatric forms. The South American Snipe (Gallinago paraguaiae) consists of the subspecies paraguaiae and magellanica. The former occurs east of the Andes in much of South America north of Patagonia; the latter occurs in central and southern Chile and east of the Andes in Patagonia. We analyzed breeding-season acoustic displays from throughout South America: loud vocalizations when standing or perched; and the instrumental tail-generated Winnow sound produced in aerial display. Sounds of G. p. paraguaiae and G. p. magellanica differ qualitatively and quantitatively; the taxa can be identified from even brief recordings of ground calls or Winnows. Both taxa utter two kinds of ground call, but the calls differ greatly between the taxa. In G. p. paraguaiae, both call types are series of rhythmically repeated identical sound elements, but the types differ in how rapidly sound elements are repeated: slowly (about 5 elements per sec [Hz]) or rapidly (about 11 Hz). In contrast, the two call types in G. p. magellanica consist of series of slowly and rhythmically repeated (a) identical sound elements (repeated at about 3 Hz), or (b) sound couplets, each with two acoustically different kinds of element. The Winnow of G. p. paraguaiae comprises a rhythmical series of broadband sound elements that gradually increase in duration and energy, whereas that of G. p. magellanica possesses two or more kinds of sound elements that roughly alternate and are repeated as sets, imparting a stuttering quality. We included the related Puna Snipe (G. andina) in our study. Its sounds resemble but differ significantly from those of G. p. paraguaiae. Vocal and non-vocal acoustic differences between G. p. paraguaiae and G. p. magellanica are strong and consistent over their broad geographic distributions. On this basis, we consider that the two taxa to be different species. Relationships within the snipe clade (Gallinago plus Coenocorypha) have not been well-resolved through molecular analysis; the marked acoustic divergence within the South American Snipe suggests that acoustic display traits may be valuable in phylogenetic analysis of this clade.