Five armed men broke into a zoo in Managua, Nicaragua, Friday and stole 15 endangered birds and a raccoon.

Police are investigating the robbery of the raccoon, five bi-colored toucans, nine parrots and a macaw kept in the zoo's rescue center, zoo director Marina Argüello told U.S. newswire The Associated Press.

The thieves managed to get past a security guard in the rear of the zoo and headed straight for the rescue center, she said.

The toucans had been prepared for mating, she added.

The loss was “incalculable,” said Argüello, but the birds can gross up to $1,000 each in the underground market.