Assertion: robin | /r/CapableOf | sing in winter flocks
Facets:
value: due to surging hormones
type: CAUSE
value: sometimes
type: TEMPORAL
Source sentences:
text: Sometimes robins even sing in winter flocks, due to surging hormones as the breeding season approaches.
text: We at Journey North consider a singing robin to be a spring bird, though we realize that sometimes surging hormones make robins sing even in winter flocks.