Vital breakthrough may rescue one of the world’s rarest penguin species from extinction

The hoiho, a species of penguin endemic to New Zealand

New Zealand is known for its biodiversity, including unique bird species. For example, there is the kiwi, the emblem of the country and which is a species which belongs to the ratites, that is to say the birds which are incapable of flight.

But another species of rare, flightless birds can be seen on New Zealand lands. Indeed, the hoiho, also known as the yellow-eyed penguin (yellow-eyed penguin in English) is endemic to this Oceanian country.

Elected bird of the year in New Zealand twice, this penguin stands out on the one hand with its physique and its bright orange-yellow eyes, and on the other hand with a shrill and powerful cry, which it is used to uttering to communicate with other individuals of its species, whether to defend its territory or to signal danger.

A very rare species… because it is threatened

The hoiho is considered one of the rarest penguin species on the planet, with a population decline clearly visible over the past 30 years. Specialists now estimate that there are only 2,600 to 3,000 adult individuals left in the wild, and fewer than 150 breeding pairs.

The reason for this decline may arise from several factors, including habitat loss and incidental take mortality. Additionally, a new disease, known as respiratory distress syndrome (RDS), has been affecting hoiho chicks since 2019.

To provide the best conservation measures for this penguin species, researchers from the University of Otago – Ōtākou Whakaihu Waka, Department of Conservation and Ngāi Tahu, analyzed whole genome sequencing of approximately 250 penguins from across mainland New Zealand and the sub-Antarctic Enderby and Campbell Islands. What they discovered was enough to shake up their knowledge of hoiho.

There are actually three subspecies of hoiho

Indeed, the results obtained revealed that this species is in fact composed of three distinct subspecies. A comparison of the genome with those of two extinct penguin species allowed the researchers to discover that these three subspecies were “deeply divergent lineages”, having separated from each other between 5,000 and 16,000 years ago.

Having discovered the existence of these subspecies will allow conservation organizations to better adapt their efforts according to the population they will have in front of them. This also addresses the fact that the southern hoiho population shows no signs of RDS, compared to northern populations.

“This is a turning point for hoiho conservation. Each group has a unique evolutionary heritage, specifically adapted to its environment, and without rapid, targeted action, we could lose one forever,” Jemma Geoghegan, from Otago's Department of Microbiology and Immunology, said in a statement, referring to the northern population.

Source: IFLScience