▁of ▁ 2 0 0 4 , ▁the ▁current ▁population ▁was ▁estimated ▁to ▁be ▁ 1 0 0 – 1 2 0 ▁individuals . ▁ ▁Conserv ation ▁▁ ▁The ▁major ▁threat ▁to ▁this ▁species ▁is ▁habitat ▁destruction . ▁The ▁grass land ▁W orth en ' s ▁sp arrow ▁is ▁specific ▁to ▁has ▁progress ively ▁been ▁pl ough ed ▁for ▁agricult ure ▁and ▁gra zing . ▁Currently ▁there ▁is ▁a ▁conservation ▁effort ▁being ▁coordin ated ▁by ▁the ▁Bird ▁Conserv ation ▁Alliance ▁and ▁other ▁organizations ▁to ▁protect ▁the ▁Sal til lo ▁Sav anna ▁in ▁Mexico . ▁The ▁program , ▁known ▁as ▁the ▁Mexican ▁Gr ass lands ▁App e al , ▁see ks ▁to ▁purchase ▁over ▁ ▁of ▁prime ▁grass land ▁habitat ▁to ▁protect ▁and ▁save ▁this ▁last ▁great ▁North ▁American ▁grass land . ▁By ▁protect ing ▁this ▁area , ▁the ▁appeal ▁will ▁con serve ▁habitat ▁for ▁the ▁W orth en ' s ▁sp arrow , ▁long - bil led ▁cur le w , ▁bur row ing ▁ow l , ▁mountain ▁p lo ver , ▁Sp rag ue ' s ▁pip it , ▁and ▁fer ru gin ous ▁ha w k . ▁ ▁References ▁ ▁Further ▁reading ▁▁ ▁National ▁Geographic ▁Field ▁Guide ▁to ▁the ▁Bird s ▁of ▁North ▁America ▁▁ ▁Z ink , ▁Robert ▁M . ▁and ▁Don na ▁L . ▁D itt man . ▁" Pop ulation ▁structure ▁and ▁gene ▁flow ▁in ▁the ▁Ch ipping ▁S par row ▁and ▁a ▁hypothesis ▁for ▁evolution ▁in ▁the ▁genus ▁Sp iz ella ." ▁ 1 9 9 3