Valmiki Ramayana Aranya Kanda Sarga 69 Shloka 23

परमदारुणः extremely dreadful, वञ्चुलको नाम by name Vanchulaka, एषः पक्षी this bird, युद्धे in strife, आवयोः both of us, विजयम् triumph, शंसन्निव as though telling, विनर्दति cries loudly.

This vanchulaka bird's loud and dreadful screams suggest our triumph in war.