Devibhagavatapurana 2.1.25

2.1.25

gacchantaṃ gaganaṃ śyenaṃ dhṛtvā cañcupuṭe puṭam |
tamapaśyadathāyāntaṃ khagaṃ śyenastathāparaḥ ||

Another falcon, seeing this one flying in the air with leaf in his beak, considered it to be some piece of flesh and fell upon him. Immediately a gallant fighting ensued between the two birds with their beaks.