vertical - crest penguin ( Eudyptes sclateri ) might be a little under the radar when it comes to the penguin reality . However , they have one fairly coolheaded and strange trick up their little penguin sleeves . These hoot lay fundamentally one and one-half eggs each yr in a bizarre training strategy .
The least studied of all the penguin mintage , they exist on just two island groups inNew Zealand : the Antipodes and Bounty Islands . They were nicknamed “ the forgotten penguin ” due the unavailability of these places by investigator Lloyd Davis , who is first author of a2022 study . The data in the study came from information collected in 1998 , and it ’s still the most detailed research uncommitted on their breeding behavior and hormones .
Erect - crestedpenguinsare within a group of seven species belonging to the genusEudyptes . All penguin in the genus consist clutch of two eggs in the rearing season . What makes the vertical - crested penguins special is that the first egg never seems to survive . The penguin have what is called “ extreme reversed egg - size dimorphism ” , where the first egg that they lay is much smaller than the 2d egg . What is even more unusual is that the first egg is turn a loss either before or on the 24-hour interval that the second egg is laid , and no first - repose ballock has been experience to survive longer than seven days after the second egg joined the nest .
The squad led by Davis see this while meditate a colony between September 29 and October 22 , 1998 . They watched the colony for up to 12 hr a day during this time , which cooccur with the courtship and lay periods . The squad was also able to measure theeggsizes of a survival of the fittest of both first - place eggs and second - laid eggs .
The team observed many illustration of the first - laid bollock being rolled out of the nest , either deliberately by the penguin or accidentally . Penguinnests are very simple with barely any nest material , so the squad fall up with an experiment to see if they could keep the first - laid egg in the nest for long by surrounding it with a ring of stones . This initially improved the numeral of eggs kept in the nests , but in the end all the first - laid ball were mislay , no matter of whether the nest had been phone in gem or not .
The squad think the penguin reject the first egg because it is formed while the birds are still transmigrate , and therefore is modest and less robust than the second egg , formed on the breeding island .
The researchers also discovered that around half of thepenguin pairsbarely bother to hatch the first - put down testicle and use much more time to incubate the bigger 2nd bollock . The independent reason for this is suggest to be that the penguins can not bring back enough food to feed twochicksand therefore invest much more in the larger egg size of the second - lay egg . The team think that vertical - cap penguins have the large departure in size of it of nut laid in the same period of any bird species .
“ The problem is that you ca n’t lay a 2d egg until you ’ve laid a first orchis , ” Davis toldBBC Discover Wildlife . “ So all you may do is reduce the investing in the first egg as much as you may . ”
