atypicalsizeis 12 by 20 inchesinwhichanywherefromone
tofivelayersarehoused.Spaceavailableperbirdvariesfrom
240 to 48 squareinchesdependingonthenumberofbirdsper
cage. There is a tendency to crowd the layers to reduce
building and equipment costs per bird.^36
Obviouslythissizeistoosmallforevenonebirdtostretch
herwingsfully,letalonefivebirdsinthesamecage—andas
thelastlineofthequotedpassagehints,fourorfivebirds,not
one or two, is the industry standard.
Since the first edition of this book was published, the
conditionsunderwhichhensarehousedinmodernintensive
farminghavebeenthesubjectofnumerousstudies,bothby
scientificandgovernmentalcommittees.In 1981 theBritish
HouseofCommonsAgricultureCommitteeissuedareporton
animalwelfareinwhichitsaid“wehaveseenforourselves
battery cages, both experimental and commercial, and we
greatlydislikewhatwesaw.”Thecommitteerecommended
that the British government should take the initiative in
having battery cages phased out within five years.^37 Still
more telling, however, was a study conducted at the
Houghton Poultry Research Station in Britain on
thespacerequiredbyhensforvariousactivities.Thisstudy
foundthatthetypicalhenatrestphysicallyoccupiesanarea
of 637 squarecentimeters,butifabirdistobeabletoturn
around at ease, she would need a space of 1,681 square
centimetersifkeptinasinglecage.Inafive-birdcage,the
studyconcludedthatthesizeofthecageshouldallowroomat
thefrontforallbirds,andthereforeneededtobenotlessthan
106.5centimeterslongand 41 centimetersdeep,givingeach
bird 873 square centimeters (approximately 42 by 16
inches).^38 The 48 squareinchesnotedaboveinthePoultry