Netherlands,G.CroninobtainedaPh.D. forastudyofthe
behaviorof confinedsows. Here ishis descriptionof how
they behave when first put in a stall with a tether:
The sows threw themselves violently backwards, straining
againstthetether. Sowsthrashedtheirheads aboutasthey
twistedandturnedintheirstruggletofreethemselves.Often
loud screams were emitted and occasionally individuals
crashedbodilyagainstthesideboardsofthetetherstalls.This
sometimes resulted in sows collapsing to the floor.^88
Theseviolentattemptstoescapecanlastuptothreehours.
Whentheysubside,Croninreports,thesowsliestillforlong
periods,oftenwiththeirsnoutsthrustunderthebars,making
occasionalquietgroansandwhiningnoises.After afurther
period,thesowsshowothersignsofstress,suchasgnawing
the bars of their stalls, chewingwhen there is nothing to
chew,wavingtheirheadsbackandforth,andsoon.Thisis
knownasstereotypicalbehavior.Anyonewhohasbeentoa
zoo that keeps lions, tigers, or bears in barren concrete
enclosureswillhaveseenstereotypicalbehavior—theanimals
paceendlesslyupanddownthefencesoftheircages.The
sowdoesnothaveeventhisopportunity.Aswehaveseen,in
naturalconditionsthesowisahighlyactiveanimal,spending
severalhoursaday findingfood,eating, andexploringher
environment.Now,gnawingatthebarsofthestallis,asa
veterinarianhasnoted,“oneofthefewphysicalexpressions
available to her in her barren environment.”^89
In 1986 the ScottishFarm BuildingsInvestigation Unit, a
government-supported research organization, published a
reviewofthescientificevidenceonthequestion:“Doesclose
confinementcausedistressinsows?”Afterdiscussingmore