One of the decisions that must be made by a searcher or a waiter is how long to remain in one place

As in all choices it is a balance of cost versus benefit. The searcher or even the waiter must decide how much energy will be spent by staying in one area versus moving to a new one with the amount of benefit each will obtain in the same area vs. a new area. It is a basic cost/benefit analysis of energy utilized versus energy or resource gained.

2. A search image is a distinctive attribute that the animal has that it identifies with a specific benefit. For example it might be a flower shape or berry color that it identifies as being beneficial to consume. It facilitates short-term specialization by maximizing recognition of a specific item in a localized environment. If the search image is specific (say the only edible berries are red ones then the animals with the red search image for berries will maximize their specialization and benefit) it can lead to more rapid specialization to maximize resource utilization.

For more information on search image and specialization see http://www.elasmo-research.org/education/white_shark/cognition.htm http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15118915&dopt=Abstract.