We describe a novel extension to the CONDENSATION algorithm for tracking multiple objects of the same type. Previous extensions for multiple object tracking do not scale effectively to large numbers of objects. The new approach -- subordinated CONDENSATION -- deals effectively with arbitrary numbers of objects in an efficient manner, providing a robust means of tracking individual objects across heavily populated and cluttered scenes. The key innovation is the introduction of bindings (subordination) amongst particles which enables multiple occlusions to be handled in a natural way within the standard CONDENSATION framework. The effectiveness of the approach is demonstrated by tracking multiple animals of the same species in cluttered wildlife footage.