It turns out that to tell the sex of a Galápagos penguin, all you need is a ruler.
In a paper published April 5 in the journal Endangered Species Research, scientists at the University of Washington announced that, for a Galápagos penguin, beak size is nearly a perfect indicator of whether a bird is male or female. Armed with this knowledge, researchers could determine the sex of a bird quickly and accurately in the wild without taking a blood sample — speeding up field studies of this unusual and endangered seabird.
It turns out that to tell the sex of a Galápagos penguin, all you need is a ruler.
In a paper published April 5 in the journal Endangered Species Research, scientists at the University of Washington announced that, for a Galápagos penguin, beak size is nearly a perfect indicator of whether a bird is male or female. Armed with this knowledge, researchers could determine the sex of a bird quickly and accurately in the wild without taking a blood sample — speeding up field studies of this unusual and endangered seabird.
“For Galápagos penguins, we really wanted to understand if there was a simple ‘rule’ we could employ to determine sex — a sign that would be fast and reliable,” said lead author Caroline Cappello, a UW doctoral student in biology.
Galápagos penguins are the only penguins to live in an equatorial region. Like all penguin species and most birds, they lack external genitalia. In addition, male and female Galápagos penguins look similar to one another and both share parenting duties, incubating eggs and rearing the offspring. Males do tend to be slightly larger than females, but the difference is slight. A DNA test is available to determine the sex of a Galápagos penguin, but that requires obtaining a blood sample from each individual — an invasive and time-consuming process.
Read more at University of Washington
Image: El Niño events can take a toll on Galápagos penguins. Boersma's team is studying whether these extreme weather events affect male and female penguins differently. (Credit: Caroline Cappello/University of Washington)
