Episodic-like memory during cache recovery by scrub jays

Area of Science:

• Cognitive Ethology
• Animal Behavior
• Neuroscience

Background:

• Episodic memory, recalling specific past events (what, where, when), is considered uniquely human.
• Food-storing birds exhibit spatial memory for caches and adapt strategies based on food perishability, suggesting temporal sensitivity.

Purpose of the Study:

• To investigate whether scrub jays possess episodic-like memory, specifically the ability to recall 'when' food items were cached.
• To determine if scrub jays' caching and recovery behaviors reflect temporal awareness of stored food's condition.

Main Methods:

• Scrub jays cached perishable wax worms and non-perishable peanuts in distinct locations.
• Researchers assessed recovery preferences at different time intervals after caching to observe behavioral responses to food decay.

Main Results:

• Jays preferentially searched for fresh wax worms shortly after caching.
• Jays learned to avoid searching for wax worms after a delay, indicating awareness of their decayed state.
• The observed recovery preferences support memory of both the location and the time of caching.

Conclusions:

• Scrub jays exhibit behavioral criteria for episodic-like memory in non-human animals.
• This study provides evidence that scrub jays remember not only where but also when they cached specific food items.