Francis Heatherley, The Peregrine Falcon at the Eyrie… (1913)
“ Peregrine— Adult— Alarm cry, 7 An aristocrat, 2 Castings, 57 Dominance of female, 2, 63 Female—see Falcon Flight, 1, 7 Food cry, 14 General appearance, 1, 20, 64 Head movements, 10 Language, 66 Male—see Tiercel Perverted voles, 2, 23, 63 Size, 1, 2 Special senses, 65, 66 Eggs— Date when laid, 7 Incubation period, 7 Number in clutch, 4, 5, 7 Sexual difference, 7, 65 Young—- At different ages— Two days, 7 Four days, 8, 10 Five days, 20 Seven days, 24 Eight days, 26, 28 Nine days, 34 Peregrine—Young (continued) . ”
