What do you do when you get hungry? You probably get up from whatever you’re doing and start raiding the kitchen, opening cabinets and the fridge until you find the perfect snack, right? Well for animals it is not always that easy. First of all, they have to find their food out in the wild, and it isn’t typically packaged up for them. To make things even harder, when the seasons change, it can change the amount of food that is available. Sometimes there is plenty of good food to eat, and sometimes there is not. This is a challenge that bamboo lemurs face in Madagascar, so what do they do?
Bamboo lemurs mainly feed on leaves, but they also enjoy fruits. A group of scientists wanted to see if these groups of lemurs had any sort of navigational strategy when it came to finding food to eat in a world where the amount of food available kept changing. To do this, they watched multiple groups of bamboo lemurs for a full year, taking note of their movements and behavior. The scientists found that the lemurs adjust how they navigate when the food changes. In times with a small amount of food available, lemurs stick to habitual routes, or commonly used paths. This suggests that lemurs are sticking to the easy routes when they don’t have as much food, which means that they are conserving their energy. But in times of food abundance, the lemurs will venture off course and move in straight lines. These straight lines can sometimes have more energetic cost, but they often will move directly to a large food source. In both of these strategies, the lemurs relied on certain markers in the environment in order to get around.
Basically, in times of little food, bamboo lemurs will prioritize saving their energy, and in times of lots of food, they will prioritize eating as much as possible. This change suggests that this traveling behavior is purposeful, rather than random. Patterns like this have only been shown before in chimpanzees and humans, so maybe these lemurs are not as different from us as they might seem. So just remember, the next time you want a snack, feel lucky that you won’t have to hike to get it!
Bethany Watkins, Miguel de Guinea, Stephanie A. Poindexter, Jörg U. Ganzhorn, Giuseppe Donati, Timothy M. Eppley, Routes matter: the effect of seasonality on bamboo lemur navigational strategies, Animal Behaviour, Volume 186, 2022, Pages 137-149, https://doi.org/10.1016/j.anbehav.2022.01.019
