CorvusisawidelydistributedgenusofbirdsinthefamilyCorvidae.Ranginginsizefromtherelativelysmallpigeon-sizejackdaws(EurasianandDaurian)tothecommonravenoftheHolarcticregionandthick-billedravenofthehighlandsofEthiopia,the40orsomembersofthisgenusoccuronalltemperatecontinentsexceptSouthAmerica,andseveralislands.InEurope,theword"crow"isusedtorefertothecarrioncroworthehoodedcrow,whileinNorthAmericaitisusedfortheAmericancroworthenorthwesterncrow.
ThecrowgenusmakesupathirdofthespeciesintheCorvidaefamily.ThemembersappeartohaveevolvedinAsiafromthecorvidstock,whichhadevolvedinAustralia.Thecollectivenameforagroupofcrowsisaflockoramurder.
Recentresearchhasfoundsomecrowspeciescapableofnotonlytoolusebutalsotoolconstruction.Crowsarenowconsideredtobeamongtheworld'smostintelligentanimalswithanencephalizationquotientapproachingthatofsomeapes.
Inmedievaltimes,thecrowwasthoughttoliveanabnormallylonglife.Theywerealsothoughttobemonogamousthroughouttheirlonglives.Itwasthoughtthatthecrowcouldpredictthefuture,inthatitwasthoughttopredictrainandrevealambushes.CrowswerealsothoughttoleadflocksofstorkswhiletheycrossedtheseatoAsia.
NorthAmericanurbancrowhistory
Crowsarefoundinmajorcitiesacrosstheworld,andtherehasbeenamajorincreaseinthenumberofcrowsinurbansettingssincethe1900s.HistoricalrecordssuggestthatthepopulationofAmericancrowsfoundinNorthAmericahasbeengrowingsteadilysincetheintroductionofEuropeancolonization,andspreadeasttowestwiththeopeningofthefrontier.CrowswereuncommoninthePacificNorthwestinthe1900s,exceptinriparianhabitats.Populationsinthewestincreasedsubstantiallyfromthelate1800stomid1900s.CrowsspreadalongwithagricultureandurbanizationintothewesternpartofNorthAmerica.