Differences in hippocampal volume among food storing corvids

Area of Science:

• Comparative neuroanatomy
• Avian cognition
• Behavioral ecology

Background:

• The hippocampal complex (hippocampus and parahippocampalis) is crucial for spatial memory in birds.
• Previous research indicates larger hippocampal volumes in food-storing birds compared to non-storing species.

Purpose of the Study:

• To investigate the relative volume of the hippocampal complex in four food-storing corvid species.
• To correlate hippocampal volume with spatial memory performance and reliance on food stores in the wild.

Main Methods:

• Comparative analysis of hippocampal complex volume relative to body and brain size in gray-breasted jays, scrub jays, pinyon jays, and Clark's nutcrackers.
• Assessment of cache recovery and operant tests of spatial memory.

Main Results:

• Clark's nutcrackers exhibited a significantly larger hippocampal complex relative to body and brain size compared to the other three species.
• Clark's nutcrackers demonstrated superior performance in spatial memory tests and greater reliance on stored food in their natural habitat.

Conclusions:

• A larger hippocampal complex volume in corvids is associated with enhanced spatial memory capabilities.
• Increased reliance on food caching behaviors in the wild correlates with greater hippocampal volume in these bird species.