Feeding performance, kinematics and skills change with age in a granivorous songbird

Changes in neuromuscular performance owing to maturation and ageing affect a wide range of motor behaviours in birds and mammals. The consequences may be especially pronounced during forceful and complex movements, such as feeding on seeds in songbirds, which require well-developed jaw muscles and fast, strongly coordinated beak and tongue movements. We investigated how feeding performance changes with age by filming juvenile and adult domestic canaries repeatedly over a span of two years with high-speed video. We extracted metrics of feeding performance, beak kinematics and seed handling skills of individuals during feeding on seeds with different characteristics. Age significantly affected several feeding metrics on the more challenging hemp seed, but not on the smaller and softer canary seed. Beak-opening frequency displayed a parabolic pattern, increasing early in life and slightly declining at old age, with no sex differences. Seed handling skills improved linearly with age and more strongly in males. The success rate of hemp seed husking also followed a parabolic pattern, improving in juveniles and declining in old age. Our results suggest that while learning and experience enhance feeding efficiency in early life, age-related declines may stem from reduced bite force or sensorimotor control deterioration.