Assessing the Extinction Probability of the Purple-winged Ground Dove, an Enigmatic Bamboo Specialist

Abstract

The continued loss, fragmentation, and degradation of forest habitats are driving an extinction crisis for tropical and subtropical bird species. This loss is particularly acute in the Atlantic Forest of South America, where it is unclear whether several endemic bird species are extinct or extant. We collate and model spatiotemporal distributional data for one such “lost” species, the Purple-winged Ground Dove Paraclaravis geoffroyi, a Critically Endangered endemic of the Atlantic Forest biome, which is nomadic and apparently dependent on masting bamboo stands. We compared its patterns of occurrence with that of a rare “control” forest pigeon, the Violaceous Quail-Dove Geotrygon violacea, which occurs in regional sympatry. We also solicit information from aviculturists who formerly kept the species. We find that the two species share a similar historical recording rate but can find no documentary evidence (i.e., specimens, photos, video, sound recordings) for the persistence of Purple-winged Ground Dove in the wild after the 1980s, despite periodic sighting records, and after which time citizen scientists frequently documented the control species in the wild. Assessments of the probability that the species is extant are sensitive to the method of analysis, and whether records lacking documentary evidence are considered credible. Analysis of the temporal sequence of past records reveals the extent of the historical range contraction of the Purple-winged Ground Dove, while our species distribution model highlights the geographic search priorities for field ornithologists hoping to rediscover the species—aided by the first recording of the species vocalizations which we obtained from interviews with aviculturists. Our interviews also revealed that the species persisted in captivity from the 1970s until the 1990s (up to 150 birds), until a law was passed obstructing captive breeding efforts by private individuals, putting an end to perhaps the best chance we had to save the species from extinction.

Biodiversity of vertebrates in Argentina: patterns of richness, endemism and conservation status

“…Among mammals, Pteronura brasiliensis has not been recorded in the country since 1980 but a solitary specimen has recently been observed in Chaco and Formosa provinces. Among birds, the extinct Primolius maracana was last recorded in the 1990’s ( Bodrati et al 2006 ) and Paraclaravis geoffroyi , a Critically Endangered species, is possibly Extinct ( Lees et al 2021 ). Richness patterns for threatened and endemic species do not show a relationship to latitude and differed in terms of overall richness, which differ substantially among taxa, as observed at the Neotropical/Andean and global scale ( Loyola et al 2009 ; Jenkins et al 2013 ).…”

Bird Extinctions in Brazil’s Atlantic Forest and How They Can Be Prevented

“…Seven Brazilian birds are now listed as globally Extinct, Extinct in the Wild, or Critically Endangered (Possibly Extinct), of which five were from the Atlantic Forest (Table 1). For a further two species, both Atlantic Forest endemics, there are no documented records (i.e., with photos, sound recordings, or other concrete evidence) from this century, and they too may be extinct (Pacheco and Fonseca, 2001;Butchart et al, 2018;Lees et al, 2021). Of this total of seven to nine lost species, two have been saved through captive breeding programmes (ICMBio, 2018;Francisco et al, 2020).…”

“…In the case of Marsh Antwren, research is ongoing on it and its sister species, Paraná Antwren Formicivora acutirostris, to understand its genetic structure and habitat needs. Passive acoustic recorders are being used to search for Purple-winged Ground-dove (Lees et al, 2021).…”

Threatened neotropical birds are big, ecologically specialized, and found in less humanized refuge areas

“…Here we present a comprehensive analysis evaluating the individual and combined effects of multiple intrinsic and extrinsic factors on the extinction risk of neotropical birds. Extinction risk or conservation status of neotropical birds have been studied before, but previous work primarily focused on specific species or groups (e.g., Olah et al 2016, Lees et al 2021, localities (e.g., Stouffer et al 2006, Lees and Peres 2008, Devenish et al 2020, or a few traits and factors (e.g., Lees and Peres 2008, Ferretti 2019, Prieto-Torres et al 2021. Collectively, previous work has provided useful insights, but only by expanding the taxonomic and geographic scales and testing diverse intrinsic and extrinsic factors can we hope to gain a more holistic picture of generalized patterns.…”