of spaceper chicken—or less thanthe area of a sheet of
standardtypingpaper. (Inmetricterms,this is 450 square
centimetersforahenweighingmorethantwokilos.)Under
theseconditions,whenthereisnormallighting,thestressof
crowding and the absence ofnatural outlets for the birds’
energiesleadtooutbreaksoffighting,withbirdspeckingat
eachother’s feathersand sometimeskilling and eatingone
another. Verydim lightinghas beenfound to reduce such
behaviorandsothebirdsarelikelytoliveouttheirlastweeks
in near-darkness.
Feather-peckingandcannibalismare,inthebroilerproducer’s
language,“vices.”Theyarenotnaturalvices,however;they
aretheresultof thestressand crowdingto which modern
broiler producers subject their birds. Chickens are highly
socialanimals,andinthefarmyardtheydevelopahierarchy,
sometimescalleda“peckingorder.”Everybirdyields,atthe
food trough or elsewhere, to those who are higherin the
pecking order, and takes precedence over those who are
below.Theremaybeafewconfrontationsbeforetheorderis
established,butmoreoftenthannotashowofforce,rather
thatactualphysicalcontact,isenough.AsKonradLorenz,a
renowned observer of animal behavior, wrote in the days
when flocks were still small:
Doanimals thusknoweachotheramongthemselves?They
certainly do.... Every poultry farmer knows that ... there
existsa verydefiniteorder, inwhicheachbird isafraidof
those thatareaboveherin rank. Aftersome fewdisputes,
whichneednotnecessarilycometoblows,eachbirdknows
which ofthe othersshe has tofear andwhich must show
respecttoher.Notonlyphysicalstrength,butalsopersonal
courage, energy, and even the self-assurance of every