How rare are Call of Earth, Call of the Predator?

[BarackObooma]

The Shardwurm Matriarch https://wiki.project1999.com/Shardwurm_matriarch drops all the level 50 Velious Spells including Call of Earth. She has a high drop rate of spells (I farmed her for awhile on my 60 shaman), like on average one per kill or two and has a quick respawn time (same as the ancient dragons in the same cave I think). She sometimes drops two spells. The spells are all considered common and sell for 50-150pp each. She can be a pain in the ass to solo for most classes as she fears (a 60 will resist most times), complete heals (that's the hardest part), etc.

Call of the Predator is much scarcer, mostly off 60+ WW dragons.