Around the time of the bird songs it seems some recent changes have been made to some creatures strength. For about a year now my 2 star wolves have never been killed by the low level necks and greylings in and around their compound. Recently I have been harvesting wolf parts from wolves that have died to necks. It could just be an anomaly, maybe multiple 2 star necks have spawned in and around my HQ, but even that would be a change as I've never come across 2 star necks in that area.