The Copenhagen Zoo faced worldwide criticism last month for euthanizing a healthy giraffe named Marius in an effort to prevent inbreeding.
Now, the zoo has euthanized four healthy lions — two adults and their two 10-month-old cubs, according to news reports.
The zoo is introducing a male lion and cited in a statement the need to not disrupt the "pride's natural structure and behavior," according to the Associated Press.
On Feb. 9, Marius the giraffe was shot in the head, dissected in public, and then fed to the zoo's lions.
The public backlash over Marius has not dissuaded the Copenhagen Zoo from putting down animals.
"Marius hasn't made us the least bit afraid, because what we are doing is the most correct thing to do," Steffen Stræde, the zoo's chief, told Ritzau, a Danish news agency, The Copenhagen Post reports.
"I think people are more enlightened after Marius," Stræde said in the interview.
According to the zoo, the lions will not be publicly dissected, The Telegraph reports.
Accredited American zoos do not euthanize healthy animals because these zoos use contraceptive techniques to prevent inbreeding and overpopulation.
European zoos prefer to let animals "perform behaviors naturally," Gerald Dick, executive director of the World Association of Zoos and Aquariums, said in an interview last month with USA TODAY Network.
The Copenhagen Zoo typically puts down 20 to 30 animals a year.