Biologically inspired collective construction with visual landmarks

We describe our research in using environmental visual landmarks as the basis for completing simple robot construction tasks.Inspired by honeybee visual navigation behavior,a visual template mechanism is proposed in which a natural landmark serves as a visual reference or template for distance determination as well as for navigation during collective construction.To validate our proposed mechanism,a wall construction problem is investigated and a minimalist solution is given.Experimental results show that,using the mechanism of a visual template,a collective robotic system can successfully build the desired structure in a decentralized fashion using only local sensing and no direct communication.In addition,a particular variable,which defines tolerance for alignment of the structure,is found to impact the system performance.By decreasing the value of the variable,system performance is improved at the expense of a longer construction time.The visual template mechanism is appealing in that it can use a reference point or salient object in a natural environment that is new or unexplored and it could be adapted to facilitate more complicated building tasks.

Visual landmark-directed scatter-hoarding of Siberian chipmunks Tamias sibiricus

Spatial memory of cached food items plays an important role in cache recovery by scatter-hoarding animals.However,whether scatter-hoarding animals intentionally select cache sites with respect to visual landmarks in the environment and then rely on them to recover their cached seeds for later use has not been extensively explored.Furthermore,there is a lack of evidence on whether there are sex differences in visual landmark-based food-hoarding behaviors in small rodents even though male and female animals exhibit different spatial abilities.In the present study,we used a scatter-hoarding animal,the Siberian chipmunk,Tamias sibiricus to explore these questions in semi-natural enclosures.Our results showed that T.sibiricus preferred to establish caches in the shallow pits labeled with visual landmarks(branches of Pinus sylvestris,leaves of Athyrium brevifrons and PVC tubes).In addition,visual landmarks of P.sylvestris facilitated cache recovery by T.sibiricus.We also found significant sex differences in visual landmark-based food-hoarding strategies in Siberian chipmunks.Males,rather than females,chipmunks tended to establish their caches with respect to the visual landmarks.Our studies show that T.sibiricus rely on visual landmarks to establish and recover their caches,and that sex differences exist in visual landmark-based food hoarding in Siberian chipmunks.