hasdonejustthat,andherworkprovidesyetmorescientific
backingforwhathasalreadybeensaid.Givenachoice,hens
familiarwithbothgrassedrunsandcageswillgototherun.
Infact,mostofthemwillpreferarunwithnofoodonittoa
cage that does have food in it.^58
Ultimatelythemostconvincingwayahencanindicatethat
her conditions are inadequate is by dying. Ahigh rate of
mortalitywilloccuronlyunderthemostextremeconditions,
sincethenormallifespanofachickenisfarlongerthanthe
eighteenmonthstotwoyearsthatlayinghensareallowedto
live. Hens,likehumans in concentration camps,will cling
tenaciouslytolifeunderthemostmiserableconditions.Yetit
iscommonplaceforaneggfarmtolosebetween 10 and 15
percentofitshensinoneyear,manyofthemclearlydyingof
stressfromovercrowdingandrelatedproblems.Hereisone
example:
Accordingtothemanagerof a50,000bird eggranchnear
Cucamonga,California,fivetotenofhishenssuccumbdaily
toconfinementstress.(That’sbetweentwoandfourthousand
peryear.)“Thesebirds,”hesays,“don’tdieofanydisease.
They just can’t take the stress of crowded living.”^59
Acarefullycontrolledstudybymembersofthedepartmentof
poultry science at Cornell University confirmed that crowding
increases death rates. Over a period of less than a year,
mortalityamonglayershousedthreetoatwelve-by-eighteen-
inchcagewas9.6percent;whenfourbirdswereputinthe
samecage,mortalityjumpedto16.4percent;withfivebirds
in the cage, 23 percent died. Despite these findings, the
researchers advised that “under most conditions Leghorn
layersshouldbehousedatfourbirdsper 12 by 18 inchcage,”