Lactation was studied in red deer Cervus elaphus Linnaeus, 1758 hinds
from the Slowinski National Park during years 1990-1994. Yearling hind
s did not participate in breeding. It was only 2.5 years old and older
hinds that lactated. Lactation was prolonged until December and Janua
ry when 52% of hinds were still lactating. Physical condition of hinds
as measured with body weight, KFI, and visceral fat content did not d
iffer significantly between lactating and not lactating hinds. The pro
portion of lactating hinds was declining until 1993 and increased in 1
994. This was accompanied by a drop in the index of recruitment, ie th
e number of calves per 100 hinds.