▁fallen ▁con es ▁are ▁also ▁for aged ▁on ▁as ▁well . ▁The ▁cross b ill ▁will ▁use ▁its ▁be ak ▁to ▁pr y ▁the ▁cone ▁open ▁and ▁then ▁it ▁will ▁use ▁its ▁tongue ▁to ▁obtain ▁the ▁seed . ▁The ▁cross b ill ▁will ▁then ▁use ▁a ▁gro ove ▁inside ▁its ▁mouth ▁to ▁shell ▁the ▁seed ▁to ▁eventually ▁eat ▁it . ▁ ▁V ocal izations ▁As ▁mentioned ▁previously , ▁the ▁red ▁cross b ill ▁had ▁ 1 0 ▁different ▁call ▁types ▁and ▁the ▁Cass ia ▁cross b ill ▁was ▁call ▁type ▁ 9 . ▁The ▁Cass ia ▁Cross b ill ▁fled g ling ▁initially ▁im it ates ▁its ▁parents ’ ▁flight ▁calls ▁and ▁eventually ▁will ▁modify ▁its ▁call ▁to ▁im itate ▁their ▁mate . ▁Comp ared ▁to ▁the ▁other ▁call ▁types , ▁the ▁Cass ia ▁cross b ills ▁songs ▁will ▁be ▁more ▁repet itive ▁while ▁using ▁fewer ▁sy ll ables . ▁The ▁individual ▁notes ▁of ▁the ▁song ▁are ▁typically ▁bu zz ier ▁and ▁will ▁have ▁multiple ▁instances ▁of ▁silence ▁in ▁between ▁call ▁phr ases . ▁Their ▁song ▁consists ▁of ▁stra ined ▁and ▁sharp ▁chip ▁and ▁k ip ▁calls . ▁Occ asion ally ▁when ▁red ▁cross b ills ▁for age , ▁there ▁will ▁be ▁overlap ▁between ▁different ▁call ▁types . ▁It ▁is ▁believed ▁that ▁cross b ills ▁used ▁the ▁public ▁information ▁of ▁different ▁calls ▁to ▁for age . ▁This ▁eventually ▁led ▁to ▁ass ort ative ▁f lock ing ▁when ▁cross b ills ▁would ▁follow ▁vocal izations ▁that ▁would ▁provide ▁them ▁the ▁easiest ▁route ▁to ▁food