Flexible search tactics and efficient foraging in saltatory searching animals

Area of Science:

• Animal behavior
• Ecology
• Zoology

Background:

• Foraging behavior is crucial for animal survival and has been extensively studied.
• Planktivorous fish are ideal models for foraging research due to frequent feeding and simple environments.
• Previous studies often assumed a cruise search strategy, overlooking alternative foraging patterns.

Purpose of the Study:

• To investigate the foraging strategy of white crappie (Pomoxis annularis) on zooplankton.
• To characterize the 'saltatory search' pattern observed in white crappie, where searching occurs only during pauses.
• To evaluate how alterations in the search cycle, in response to prey size, affect foraging efficiency.

Main Methods:

• Observed white crappie foraging behavior, noting their stop-and-go movement pattern.
• Defined and analyzed the 'saltatory search' cycle, including run length and pause duration.
• Developed a net energy gain simulation model to assess foraging efficiency based on prey size and search parameters.

Main Results:

• White crappie employ a saltatory search, not a continuous cruise search, while foraging on zooplankton.
• The duration of pauses and the length/speed of movement between pauses vary with prey size.
• The simulation model predicts optimal run lengths that maximize net energy gain, differing for small, large, or mixed prey.

Conclusions:

• White crappie adjust their saltatory search cycle components to optimize energy intake based on prey size.
• The model suggests that including small prey in a mixed diet may reduce net energy gain compared to focusing on larger prey.
• The saltatory search strategy and its adaptive modifications may be common in other foraging animals, including birds and lizards.