▁inside ▁the ▁parent ' s ▁territory ▁and ▁ 3 ▁eggs ▁are ▁laid . ▁These ▁eggs ▁are ▁inc ub ated ▁for ▁a ▁month . ▁The ▁ch icks , ▁once ▁h atch ed , ▁remain ▁inside ▁the ▁territory ▁until ▁they ▁have ▁fled ged . ▁Ch icks ▁st ray ing ▁into ▁the ▁territory ▁of ▁another ▁g ull ▁are ▁li able ▁to ▁be ▁killed ▁by ▁that ▁territory ' s ▁pair . ▁Ch ick ▁mort ality ▁is ▁high , ▁with ▁on ▁average ▁one ▁ch ick ▁surv iving ▁to ▁fled ging . ▁On ▁occasion , ▁abandoned ▁ch icks ▁will ▁be ▁adopted ▁by ▁other ▁g ull s . ▁ ▁Hy brid ization ▁In ▁Washington ▁state , ▁the ▁western ▁g ull ▁hy brid izes ▁frequently ▁with ▁the ▁gla uc ous - wing ed ▁g ull , ▁and ▁may ▁closely ▁res emble ▁a ▁Th ayer ' s ▁g ull . ▁The ▁hy br ids ▁have ▁a ▁fl atter ▁and ▁larger ▁head ▁and ▁a ▁th icker ▁bill ▁with ▁a ▁pron ounced ▁angle ▁on ▁the ▁lower ▁part ▁of ▁the ▁bill , ▁which ▁distingu ishes ▁it ▁from ▁the ▁smaller ▁Th ayer ' s ▁g ull . ▁ ▁Western ▁g ull s ▁and ▁humans ▁ ▁The ▁western ▁g ull ▁is ▁currently ▁not ▁considered ▁threatened . ▁However , ▁they ▁have , ▁for ▁a ▁g ull , ▁a ▁restricted ▁range . ▁Num bers ▁were ▁greatly ▁reduced ▁in ▁the ▁ 1 9 th ▁century ▁by ▁the ▁taking ▁of ▁se ab ird ▁eggs ▁for ▁the ▁growing ▁city ▁of ▁San ▁Francisco . ▁Western ▁g ull ▁colon ies ▁also ▁suffered ▁from ▁disturb