I have had the "SPCA conversation" with several people who manage Burnaby Wildlife Rescue, and they all told me the same thing: They rely heavily on the BCSPCA to bring them injured wildlife, as they don't have the manpower to do it themselves since they are 100% volunteer run.
Yes, the public does bring them birds and easy-to-handle animals who are sick or injured, but it is the SPCA who they rely on to get the more difficult animals into their facility so they can help. It should not be up to the SPCA, who has little knowledge about wildlife, to determine if an animal should be killed or saved.