It may be holiday season for humans, but mountain gorillas find this time of year important too, buzzing with energy as they excitedly dine on one of their favorite foods – bamboo shoots!
Twice a year during Rwanda’s rainy seasons, bamboo takes the spotlight in the gorillas’ diet because it’s the season when bamboo shoots are growing. In contrast to the year-round herbaceous plants that make up most of their diet, the limited availability of bamboo leads to interesting behaviors among the gorilla groups, including competition for this highly desired plant. Here are some of the bamboo-related activities we often see:
Food stealing – Sometimes when the gorillas find a spot rich in bamboo shoots, they eagerly gather lots of extra pieces to consume later in a more isolated spot, ensuring they have a lot for themselves. But occasionally, a more-dominant gorilla may grab these collections from others, leading to food stealing and often resulting in loud reactions!
Bamboo salad – Even the way the gorillas prepare this prized food preparation is unique. Gorillas often mix them with drier leaves, showcasing their clever and adaptable eating habits. One of their favorite “bamboo salad” mixes includes bamboo shoots and leaves from the Droguetia plant, which belongs to the same plant family as nettles. We don’t know why they do this. It could be to counter the high water content of the shoots or to neutralize a compound in the shoots that could upset their digestive tract.
Youngsters learning – The interaction between bamboo and young gorillas is especially fascinating to watch as they are still learning how to handle bamboo shoots, which are sometimes hidden underground. It’s amusing to witness how they grab and pull with all their strength, occasionally rolling backwards in the process.
Extra energy – Bamboo shoots, being rich in calories, also turn the gorillas into bundles of energy. The bamboo zones become lively playgrounds where gorillas of all ages run, pull branches and climb, creating a show that echoes through the dense bamboo bushes. The young gorillas are often the most adventurous, climbing high up in the branches, which sometimes ends in trouble but never seems to deter them.
Venturing beyond the park – Gorillas are particularly drawn to eucalyptus, a species of tree planted outside the park with multiple uses by the local community. When in the bamboo zone, the gorillas get very close to the park’s edge, and the presence of eucalyptus’ sweet inner bark sometimes tempts them just beyond the park borders. This behavior, while natural, raises concerns about potential conflicts with nearby human communities. Protective measures, such as rangers lining up to keep the gorillas at a safe distance from humans, are taken to ensure a delicate balance between gorillas’ instincts and the needs of local communities.
This article is part of a series presented by the Fossey Fund’s gorilla program Senior Advisor Veronica Vecellio, focusing on the mountain gorillas the Fossey Fund protects and studies every day in Rwanda. Veronica has worked with these gorilla families for nearly 20 years and shares her deep knowledge and insights about their lives.