Great bustard (Otis tarda) populations in
Spain are located mostly in cultivated areas during winter.
The birds concentrate in large flocks and feed on
cultivated plants. This paper reports two types of
bustard-caused damage which occur in cereal, lucerne and
vetch crops in west-central Spain, as a
result of grazing and other bird activities such as
display. Field work was carried out between 1994
and 1995. Damage to cereal crops was caused during
germination and early seedling growth or to
young plants, although plants were able to recover from
this by regrowth and the overall yield was
not reduced. Vetch crops were damaged in localized areas,
but these recovered and were useful for
forage enrichment or as grain. However, the damage to
lucerne plots, although local, was extensive,
resulting in yield losses of 23–31% with respect
to the total production.