What physical adaptation makes mergansers somewhat clumsy when walking on land?

Answer

Their leg placement is relatively far back on their body.

Specialized for diving, mergansers have their legs positioned further back on their bodies to provide excellent propulsion underwater, resulting in a somewhat awkward or hesitant movement when walking on land or ice.

What physical adaptation makes mergansers somewhat clumsy when walking on land?
birdfishDivingwaterfowlMerganser