Assertion: dove's call | /r/HasProperty | soft purring
Facets:
Source sentences:
text: Identification from African collared dove is very difficult with silent birds, with the African species being marginally smaller and paler, but the calls are very distinct, a soft purring in African collared dove quite unlike the Eurasian collared dove's cooing.
text: Their call is a soft cooing wha-up.