The other day I filmed a pair of Gadwall, and captured something interesting. The inter-specific interaction in this video is exciting (to me) and enlightening. Mallards are a larger Anas sp., and I assume they are more aggressive. Observing the Gadwall pair retreat in caution from the Mallard pair displays a “pecking” order between species. With birds such as waterfowl  that form massive multi-species flocks, it would be interesting to observe what other interactions portray the bullies and the submissive of the duck world.