The eagle owl lays eggs after 23 years is thought to be male

The eagle owl shocked the whole sanctuary in England by laying an egg for more than 20 years, it has always been like a bull.

An eagle named Kaln is said to be a male during 23 years living in the Gloucester reserve, England. However, on June 23, Kaln laid an egg, surprising its caregivers, according to Vincent Jones, founder of the reserve.

Kaln's egg has not been fertilized and will not hatch into a baby.(Photo: BBC).

The egg has not yet been fertilized, so Kaln will not have a baby."I think it's as shocking as we are , " Jones said.

Sex discrimination in owls is quite complicated because males and females have a very similar appearance, according to research published on January 24, 2008 in Heredity magazine. Unlike mammals and many species, owls do not have distinct distinguishing characteristics even in the genitalia . Jones also shared a sanctuary with little attention to the gender of the birds they received because most were rescued from their owners.

According to National Aviary zoo, the Eurasian eagle owl lays 6 eggs for a month in the late winter. Kahn never laid eggs for 23 years in the reserve. Jones says it always shows signs of a male bird.

Even genetic testing cannot always identify males and females in many owl species, according to a study in 2008. The female had Z and W chromosomes while the male had two Z chromosomes. But the two types of chromosomes are so similar that it is difficult to identify. The study group tried to differentiate the genes of male and female eagle owl but failed.

Around the time of spawning, Kaln is upset and has some health problems. However, it became more vigorous and stronger yesterday, according to Jones.