The World's Largest Canary - Sao Tome Grosbeak

The São Tomé Grosbeak Neospiza concolor is a contender for being one of the most enigmatic bird species on the planet.

- Martim Melo

This Critically Endangered species is one of the rarest – or least observed – birds in the world, and its peculiar morphology resulted in it being placed in its own genus of uncertain affinities.

Based on the shape of its head and on its massive bill, the São Tomé Grosbeak was originally placed with the Thickbilled Weaver Amblyospiza albifrons. In 1903, other traits were used to place it in the true finches (Fringillidae), related to canaries and seedeaters (Serinus sensu lato). This is the current taxonomic view, but debate persisted throughout the 20th century about the true relationships of the species, with Ernest Moreau retaining the link to Amblyospiza in 1962. Genetic material was needed to confidently clarify the origins of Neospiza, but that is hard to come by for a bird that was not seen for close to a century. However, during his research on the origins of the endemic avifauna of the Gulf of Guinea, Martim Melo captured and bled four individuals between 2003 and 2011. These four samples provided sufficient material to infer the species’ evolutionary history.

In a recent paper published in Ibis (http://dx.doi.org/10.1111/ibi.12466), mitochondrial and nuclear sequences confidently identified Neospiza concolor as an Old World finch (Fringillidae: Carduelinae) within the Crithagra seedeater/ canary clade. This makes the São Tomé Grosbeak the world’s largest canary, 50 per cent heavier than the next largest species, the Thick-billed Seedeater Crith­