Four decades after Belton: a review of records and evidences on the avifauna of Rio Grande do Sul, Brazil

Ismael Franz,Rafael Antunes Dias,Glayson Ariel Bencke,Leandro Bugoni,Carlos Eduardo Agne

doi:10.1590/1678-4766e2018005

Abstract

ABSTRACT We present a new update of the list of birds of the state of Rio Grande do Sul, Brazil, based on a thorough review of new records and evidences accumulated from February 2011 to July 2017. This is the fifth update since the first compilation based on a reasonably complete geographic coverage of the state, published by William Belton in 1978, and the second produced by a regional (informal) committee. It is also the first to widely use citizen science contributions available on shared portals and digital databases on the internet. Forty-three taxa were added, resulting in a final list with 704 species, 6.5% more than in the previous assessment in 2010. Two species were replaced due to taxonomic changes. Documentation for inclusions based on unpublished records is indicated or published here. We also updated the documentation of another 20 species previously included in the list. Inclusions represent mainly migrants recorded in the state as vagrants or irregular visitors (22), but also cases of recent range expansion (especially from the north) and previously overlooked resident or migratory taxa. The average rate of additions (over six species per year) was 30% higher than in the previous period and is expected to accelerate. The percentage of accepted species without documented records in the state decreased from 1.8% in 2010 to 0.7% in the current list. We attribute these results to a better spatial and temporal coverage of the state in recent years, mainly due to the increasing contribution of amateurs, who accounted for 60% of the new occurrences. In contrast, the percentage of species documented by museum specimens has decreased steadily over time (currently at 84%). Investment in scientific research and collection of voucher specimens in the state should keep pace with the growing interest birds arouse in society, due to the importance and usefulness of museum specimens.

Highlights

Apresentamos uma nova atualização da lista das aves do estado do Rio Grande do Sul, Brasil, a partir da revisão de novos registros e evidências acumuladas no período de fevereiro/2011 a julho/2017
For new occurrences and documentation updates compiled from the scientific literature, we provide only basic metadata for each record in summary tables
The remaining are mostly migratory birds recorded as vagrants or irregular visitors (22 species), along with previously overlooked migratory or resident taxa present at low densities or with marginal occurrence in the state (7–11 species). This points to a better coverage – both spatial and temporal – of the state by amateur and professional birders in recent years, leading to an increased detection of unusual species (“rarities”). This greater observer coverage is due in large part to the increasing contribution of citizen science to knowledge on bird occurrence and distribution in RGS

Summary

Introduction

Since the first comprehensive assessment (i.e., Belton, 1978), almost 100 new species have been added to the state list (Bencke et al, 2010) Comparing their data with the results of previous reviews, Bencke et al (2010) detected an accelerated increase in the number of species recorded in RGS (over four new species per year in 2001–2010). A large proportion of these records are accompanied by documentation in the form of sound recordings or, more frequently, digital photographs, which enable the confirmation of the identifications by experts In addition to this greater involvement of amateurs, a significant increase in the number of professional ornithologists working in the state is evident in the last three decades Besides being powerful tools for environmental education (Farias, 2007), these hobbies have great potential for generating large volumes of useful data (see Dickinson et al, 2010), for example, by nourishing national databases of bird records, which are key for spatial and temporal analysis, as well as for careful conservation planning (Giorgi et al, 2014; Lees & Martin, 2014; Pegas & Castley, 2014; Callaghan & Gawlik, 2015)

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