- Scientists have resolved a long-standing mystery regarding the chicks of Great Auks
- Professor Tim Birkhead from the University of Sheffield has showed that Great Auk chicks fledged at around 20 days old
- The new research disproves previous theories about Great Auk chicks
Scientists at the University of Sheffield have resolved a long-standing mystery regarding the chicks of the extinct Great Auk.
The research has shown, contrary to what is popularly believed, that Great Auk chicks fledged at around 20 days old.
No one ever saw a Great Auk chick at their breeding colonies and until now it has been assumed that the chicks fledged just two days after hatching — which would explain why they were never seen.
This belief was based on an account from the 1690s giving the dates on which Great Auks arrived at and departed from their breeding colony on St Kilda. The birds were present for around seven weeks, which with an incubation period of 40 days, suggests that the chicks must have left soon after hatching.
The findings from this new research, published today (1 January 2021) in the journal British Birds, show that the idea of a two day fledgling period ignored the fact that people took every Great Auk egg that was laid and as result, the birds would have left the colony much sooner than if they had reared a chick.
The Great Auk’s extinction was caused by humans who hunted them for their meat, eggs, fat and feathers. The main reason that no one saw a Great Auk chick is that anyone who visited a Great Auk breeding colony took the eggs to eat.
Professor Tim Birkhead
Author of the research from the University of Sheffield
Professor Tim Birkhead, from the University of Sheffield’s Department of Animal and Plant Sciences, said: “The Great Auk’s extinction was caused by humans who hunted them for their meat, eggs, fat and feathers. The main reason that no one saw a Great Auk chick is that anyone who visited a Great Auk breeding colony took the eggs to eat.
“If the Great Auks on St Kilda abandoned their breeding colony soon after their eggs were taken, this explains their mere seven-week stay and destroys the foundation that these previous cases were based on.”
In order to figure out when Great Auk chicks fledged the team also looked at the closest living relatives of the bird, guillemots and razorbills.
The research showed that instead of fledging at just two days of age, it is much more likely that they fledged at about three weeks of age at around a quarter of their adult weight, similar to the chicks of their close cousins, the guillemot and the razorbill.
Professor Birkhead has become one of the most renowned seabird experts in the UK and has studied the behaviour of guillemots, puffins and razorbills on Skomer Island in Wales for almost 50 years. Professor Birkhead’s studies on Skomer Island have revealed fascinating and unprecedented insights into the ecology and behaviour of the 300,000 pairs of nesting seabirds in the region, such as how their populations have been affected by climate change.
The University of Sheffield’s Department of Animal and Plant Sciences is home to one of the biggest communities of whole-organism biologists in the UK, their research covers animals, plants, humans, microbes, evolution and ecosystems, in habitats ranging from the polar regions to the tropics. This work aims to shed new light on the fundamental processes that drive biological systems and help solve pressing environmental problems.
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