The gorillas were part of a family that originally had 12 individuals but now only has five. The lack of females is a major problem for the family's future, Ngobobo wrote on a blog on WildlifeDirect's Web site after the killings.
"It is a disaster that has shaken the global conservation community to its very foundations," Muir says. "We need to get on top of the situation fast, before any more gorillas are killed."
This is not the first execution of its kind in Virunga National Park, which spans the borders of the Democratic Republic of the Congo (DRC), Rwanda and Uganda. Since the beginning of 2007, seven gorillas—1 percent of their total population—have been found dead. The gorillas are listed as critically endangered.
Most of the killings occur from poaching by militias, government soldiers and villagers who rebel against the rangers protecting the park. DRC is ravaged by civil war, which has killed an estimated 4 million people, including 125 park rangers, since its onset in 1994.
In reaction to the latest killings, the Institut Congolais pour la Conservacion de la Nature, with funding from the Frankfurt Zoological Society and conservation group WildlifeDirect, has developed an emergency response plan.
The groups intend to organize gorilla-monitoring teams, set up anti-poaching patrols and make communities and authorities aware of the situation's magnitude.
"Our only hope now to save the gorillas lies in the success of the emergency plan," Muir says. "With the right support from the community and government, there is no reason we should not succeed."
Read more about DRC's mountain gorillas in the October issue of Smithsonian magazine.