Kiwi Bird DNA Reveals the Unusual Genome that Evolved to Adapt to the Dark

First Posted: Jul 24, 2015 07:16 AM EDT

Kiwi birds are a bit unusual. These small, flightless, endangered birds are nocturnal and can be found foraging on the ground. Now, scientists have sequenced the genome of this bird and have identified several sequence changes that underlie the kiwi's adaption to a nocturnal lifestyle.

The kiwi has a number of unusual features. It has only rudimentary wings, no tail, and a very long beak with nostrils. These birds are mainly nocturnal with a low basal metabolic rate and the lowest body temperature to be found among birds. To date, there has been very little genetic information available for this species that might help scientists to understand their unusual biology better.

In this latest study, the researchers sequenced the genome of the brown kiwi, Apteryx mantelli. This revealed that genetic changes likely adapted them to nocturnal life. For example, mutations have inactivated some of the key genes involved in color vision, and the number of odorant receptor genes expanded. This suggests that a kiwi's sense of smell is highly developed.

With that said, the findings also show that there is very little genetic variability in the population. This could further endanger the survival of this species, and has to be taken into account when designing breeding programs in the future.

"The genome of the kiwi is an important resource for future comparative analyses with other extinct and living flightless birds," said Janet Keslo, computational biologist, in a news release.

The findings reveal a bit more about the kiwi, and could help with conservation efforts moving forward.

The findings are published in the journal Genome Biology.