Assertion: pelican's population | /r/CapableOf | undergo dramatic declines
Facets:
value: during the 1960s
type: TEMPORAL
value: during early 1970s
type: TEMPORAL
value: due to eggshell thinning
type: CAUSE
Source sentences:
text: N orth American populations underwent dramatic declines during the 1960s and early 1970s due to eggshell thinning induced by pesticides.