The Scavenger is able to find many more objects when searching in the desert.The small spade (automatically) reduces the time required for each search in the desert... The chances of finding an object are also significantly increased.
How do I play as a Scavenger?
Your automatic searches take 30 minutes less than other citizens, therefore you can carry out more searches in a day! Your chances of finding something are also much better than those of normal citizens.
Furthermore, when you're in the World Beyond, your keen Scavenger's instinct lets you know in advance whether a neighbouring zone still contains objects or if it is depleted (this skill also allows you to discover buildings which contain objects)!