Business travel or pleasure, it matters not. Two ducks go into my backpack, and one migrates to my pocket for easy access during the day.
Most of the time, the sight of "an adult" quickly pulling a rubber duck out of her pocket, placing it on a sign/person/prop, taking a picture and furtively retrieving the duck amuses folks. Occasionally, that sight prompts raised or wrinkled eyebrows.
That reaction doesn't occur often among birders. Thank you for your tolerance... and in some cases, your suggestions and enthusiastic participation.
Nor did any disapproval of my duck habit become visible during a recent vacation in Tuscany. The passersby on this cobblestone street in Cortona just smiled indulgently while my college roommate and I set up the shot outside a gelato shop.