Volunteers from 808 Cleanups made both discoveries while cleaning and maintaining the area on Sunday and Monday.
The Department of Land and Natural Resources confirmed the birds are wedge-tailed shearwaters which are indigenous, but not endangered.
Officials say they are not sure who, or what, killed the birds, but volunteers say the deaths appear suspicious.
"We came out to find three dead birds, and (there are) probably more laid out," Volunteer Rich said over the weekend. "(It) didn't look like an animal killed them to me. No feathers, no bite marks, nothing ... I think it was a person. No doubt."
The mysterious deaths of the birds is concerning some who want the culprit to come forward.