According to the National Veterinary Institute (Statens veterinärmedicinska anstalt, SVA), it was emaciated when it died.
Why the antelope starved to death is unclear. Parken Zoo director Helena Olsson believes that the bongo antelope may have been driven away from the feed by the other animals and the remaining bongo antelopes are now being fed by other means.
Henrik Uhler, assistant state veterinarian at SVA, told news agency TT that if the animal was emaciated when it died, there may have been several reasons behind its state, including illness, but also starvation.
There are about a hundred bongo antelopes left in the wild in Africa and somewhat more live in zoos around the world.
Two of Parken Zoo's cheetahs were also found to be too skinny. They caught the attention of a visitor who alerted the county administration board. Officials later learned the cheetahs' condition due to an illness.
"It is really good that we were made aware of this," the zoo's veterinarian consultant Göran Sjöström told the newspaper.
The species' legal status is described as "near threatened." Bongos have been observed to live up to 19 and are one of the largest of the forest antelopes.
In addition to the deep chestnut colour of their coats, they have bright white stripes on their sides to help camouflage them from their enemies. Because of their bright colour, they are very popular in zoos and private collections.