。
She eagerly fed the little birds.
Literal
She [topic-は] [eagerly-熱心に] little-bird [to-に] feed [object-を] gave.
えさをやる is a stock phrase for feeding animals — literally 'give (animal-)feed.' Note the use of やる rather than あげる: as the rough/casual 'give,' it's appropriate when the recipient is non-human (animals, plants). With humans, it would feel too blunt.