Even though they lived alongside humans for more than a century, scientists know precious little about the flightless birds known as the dodo, but a new analysis of the species’ bones could shed new light on the creature’s life cycle, including how quickly it grew to adulthood.
“Before our study the only things we knew about the ecology of these birds was that they were a big pigeon [with a body mass of] about 10 kilos,” lead author Delphine Angst, a paleontologist at the University of Cape Town in South Africa, said in an interview with The Guardian.
Now, however, she and her colleagues were able to analyze leg and wing bones belonging to 22 unique dodo specimens kept in museums around the world. Among other things, they discovered that dodo chicks tended to hatch in August and grew very quickly, according to BBC News.
“Using the bone histology for the first time,” Dr. Angst explained, “we managed to describe that this bird was actually breeding at a certain time of the year and was molting just after that.” Once they hatched, the dodos rapidly grew to adult size, she explained, and by March, they molted and revealed the fluffy grey plumage attributed to them in historical eyewitness accounts.
Technique allowed age, gender of specimens to be identified
Furthermore, the research, which was detailed in the latest issue of the journal Scientific Reports, made it possible to differentiate between adult and juvenile dodos, and male and female ones, for the first time, according to CNN. This was accomplished by studying the number of layers found each specimen’s bones, as well as finding a tissue produced only by ovulating females.
That special tissue, Dr. Angst told The Guardian, provides a supply of calcium which is used in the production of eggs. The presence of this bone tissue, she said, allowed them to tell for certain that a specimen “is a female during ovulation, which is quite cool.” However, without that tissue, she said it would be impossible to identify the sex of any given dodo specimen.
Based on their analysis, the study authors determined that the chicks hatched in August and grew rather quickly. This would enable them to be prepared when cyclones and other severe storms hit their home island between November and March, limiting the availability of food. In late March, the birds would begin to molt, starting with the wing and tail feathers, and by the end of July, all of their juvenile feathers would be completely replaced – just in time for mating season.
“For the first time, we have some evidence of the reproduction and the molting,” Dr. Angst told CNN, “but on top of that, we can say when these events happen[ed] during the year. Our results show that there is still a lot of things which have to be discovered about the dodo.”
“The authors of this study have done a wonderful job filling important gaps in our understanding of how the dodo lived over 300 years after the last dodo died,” avian paleobiologist Daniel Field, a researcher from the University of Bath who was not involved in the newly-published analysis, told The Guardian.
Image credit: Julian Hume