Dodos and spotted green pigeons are descendants of an island hopping bird
According to scientists, the mysterious spotted green pigeon (Caloenas maculata) was a relative of the dodo. Scientists have examined the spotted green pigeon’s genetic make up and their findings have been published in the open access journal BMC Evolutionary Biology. Their results support the theory that both birds are descended from ‘island hopping’ ancestors.
The only known example of the spotted green pigeon is the Liverpool pigeon, which is currently residing in the World Museum, Liverpool. Unfortunately the only other known specimen has been lost, and there are no records of the bird in the wild. There is no record of where the pigeon was found, and it wasn’t even known if the spotted green pigeon was a species, or just an unusual form of the Nicobar pigeon from around Indonesia.
The scientists took DNA from two feathers of the spotted green pigeon. Due to the age of the specimen, the DNA was highly fragmented, so the team had to focus in on three DNA ‘mini barcodes’-small sections of DNA which are unique for most bird species. They looked at these sections of the pigeon’s DNA, and compared it to other species.
This confirmed that the spotted green pigeon is indeed a separate species, showing a unique DNA barcode compared to other pigeons. The pigeon’s closest genetic relation is the Nicobar pigeon, along with the dodo and Rodrigues solitaire, both extinct birds from the islands near Madagascar. The green spotted pigeon shows signs of a semi-terrestrial island lifestyle and the ability to fly. The close relation, the Nicobar pigeon, also shows similar habits and has a preference for travelling between small islands.
The scientists say this lifestyle, together with the relationship of both pigeon to the dodo and Rodrigues solitaire, supports an evolutionary theory that the ancestors of these birds were ‘island hoppers’, travelling between islands around India and Southeast Asia. The birds that settled on particular islands proceeded to evolve into the individual species. The dodo’s ancestor managed to hop as far as the island of Mauritius near Madagascar where it famously lost the ability to fly.
Dr. Tim Heupink, Griffith University Australia: “This study improves our ability to identify novel species from historic remains, and also those that are not novel after all. Ultimately this will help us to measure and understand the extinction of local populations and entire species.”
Clemency Fisher, Curator of Vertebrate Zoology at the World Museum says: “We are very pleased that the extinct spotted green pigeon has its correct place in the world of birds after more than 230 years. Tim Heupink’s groundbreaking genetic research, analysing small fragments of DNA from tiny pieces of feather, proves the spotted green pigeon is unique and a distant relation to the Nicobar pigeon, the Rodrigues solitaire and the dodo of Mauritius”.
Header Image Source: BioMed Central