Extensão da distribuição geográfica e zonas de contato entre Sturnella militaris e S. superciliaris e a integração entre biogeografia ecológica e a ciência cidadã

Abstract

Sturnella militaris and S. superciliaris are similar species whose diagnostic feature is the absence of a white eyebrow, in adult males of S. militaris, compared to S. superciliaris, during reproductive plumage or wear plumage. Past reports since 70’s decades confirm the expansion of its geographical distribution due to the transformation of natural landscapes into pastures or monoculture fields in Latin America. The review of the geographic distribution of these two species and the definition of a contact zone with possible hybridization events are objectives of this survey. The records were based on literature records for Peru and Bolivia, while photographic records for Brazil were taken originating from the Wikiaves portal. The total area of extension of occurrence of S. militaris was 1,483,876 km2, an increase of 39% in the species original area. In Brazil it was 1,233,079 km2 while in Bolivia it was 250,796 km2. For S. superciliaris the total of occurrence area was 1,188,087 km2, an increase equivalent to 16.5% of the total area of the known geographical distribution for the species. In Brazil it represents 1,120,031 km2, while in Peru it corresponded to 68,056 km2. The overlap between the species new geographic distributions indicated the existence of two distinct contact zones, in the South America central portion, following the Amazon-Cerrado ecotone limits in Brazil and Bolivia. Hybridization events were conjectured due to the detection of syntopic situations between the two species and also the identification of phenotypes supposedly compatible with hybrid individuals. Finally, it should be noted that the records available through virtual citizen science platforms can be remarkable sources to support studies with an approach related to ecological biogeography.