Assertion: mallard's range | /r/CapableOf | overlap in the primorsky krai
Facets:
value: due to the spotbill's northward expansion
type: CAUSE
Source sentences:
text: The present species is known to produce fertile hybrids with the Pacific Black Duck and the Philippine Duck in captivity (Carboneras 1996), and naturally hybridizes with the Mallard as their ranges now overlap in the Primorsky Krai due to the Spotbill's northward expansion (Kulikova et al. 2004).