Grazing animals caused nest damage in ground-nests leading to a
9.8% loss of eggs, whereas roof-nests were damaged mostly by
intentional and unintentional human interference during building
construction, renovation or cleaning, resulting in an egg loss of
19.7%. Individual eggs remained unhatched in both nest-types. Loss
of eggs due to hatching failure was almost equal in ground- (2.3%)
and roof-nests (2.1%).