ven ile ▁pl um age . ▁ ▁Th re ats ▁and ▁conservation ▁The ▁col la red ▁sp arrow h awk ▁is ▁not ▁glob ally ▁or ▁nation ally ▁threatened . ▁It ▁is ▁w ides p read ▁and ▁generally ▁un common , ▁but ▁may ▁be ▁common ▁in ▁for ests ▁in ▁the ▁trop ics ▁and ▁subt rop ics ; ▁it ▁is ▁also ▁secret ive ▁and ▁most ▁likely ▁under - record ed . ▁It ▁has ▁under g one ▁decl ines ▁in ▁extens ively ▁cleared ▁areas . ▁It ▁is ▁thought ▁that ▁their ▁loss ▁of ▁numbers ▁is ▁due ▁to ▁the ▁use ▁of ▁D DT ▁which ▁has ▁reduced ▁the ▁thick ness ▁of ▁col la red ▁sp arrow h aw ks ' ▁eggs ▁by ▁ 2 %, ▁and ▁the ▁increase ▁of ▁the ▁pied ▁cur raw ong ▁( St re per a ▁g rac ul ina ) ▁a ▁pred ator ▁and ▁compet itor ▁capable ▁of ▁ro bb ing ▁and ▁inj uring ▁adult s ▁and ▁killing ▁nest lings . ▁ ▁See ▁also ▁ ▁Hand book ▁of ▁Australian , ▁New ▁Zealand ▁and ▁Ant ar ctic ▁Bird s . ▁Vol , 2 : ▁R apt ors ▁to ▁Lap w ings . ▁March ant , ▁S .; ▁& ▁H igg ins , ▁P . J . ▁( Ed s ). ▁( 1 9 9 3 ). ▁ ▁Oxford ▁University ▁Press : ▁Melbourne . ▁ ▁References ▁ ▁External ▁links ▁▁ ▁Bird Life ▁Species ▁Fact sheet ▁ ▁col la red ▁sp arrow h aw ▁Category : B ird s ▁of ▁pre y ▁Category : B ird s ▁of