Extra food provisioning does not affect behavioral lateralization in nestling lesser kestrels.

Area of Science:

• Behavioral Ecology
• Neuroscience
• Animal Behavior

Background:

• Brain lateralization, or functional asymmetry, is adaptively shaped by early-life environmental conditions.
• Early food availability may influence brain lateralization, but this effect is understudied.
• Lesser kestrels (Falco naumanni) are sexually dimorphic raptors, making them a suitable model for studying lateralization.

Purpose of the Study:

• To investigate the modulatory effect of early food availability on brain lateralization in lesser kestrels.
• To test the hypothesis that reduced intra-brood competition due to increased food supply would decrease lateralization strength.

Main Methods:

• A wild population of lesser kestrels was subjected to increased food supply from egg laying to nestling rearing.
• The lateralization of preening behavior (head turning direction) was quantified in nestlings.
• Maternal body condition was also assessed as a potential factor influencing lateralization.

Main Results:

• Extra food provisioning significantly improved nestling growth.
• Nestling lateralization strength and direction were not significantly affected by the extra food.
• Maternal body condition did not explain variation in nestling lateralization.
• Sex-specific differences in lateralization direction were observed, with females showing more rightward turns.

Conclusions:

• Early food availability does not appear to modulate behavioral lateralization in a motor task in lesser kestrels.
• The findings suggest limited phenotypic plasticity in brain lateralization in response to early nutritional conditions.
• Sex-specific lateralization patterns exist independently of early food availability.