Soren Series
The planet that the series takes place on isn't Earth.
- The planet that the owls live on is known to have once had Humans, called the "others" by the owl civilizations. It is also known to have both an "endless sea" and the Sea of Hoolemere. The latter sea is a large round ocean with a single island in the center - and it's remarkably similar to the massive crater on the northern pole of Mars. The books "imply" that the planet is earth, but this troper believes that to be nothing more than a red herring. The planet is Mars, tilted at an angle and abandoned by humanity after being terraformed and given a moon (which is likely what led to the tilt). That would also explain how the owls were able to grow large enough brains to achieve sentience, despite their brains being too heavy for them to be able to fly if they were on earth. It could also explain why the planet seems so cold compared to earth.
The Hagsfiends were created in a lab.
- They were artificial creations in the waning days of humanity, to see if one could recreate dinosaurs. However, these first few Hagsfiends, called Strigivids (Strigidae+Corvid) were failing, due to their bodies trying to tear themselves apart from the incompatible genetics. Then one of them, a Strigivid who had inherited the intelligence of her Corvid relatives, called out for help. Something answered, and she was granted both full sapience, and magic to fight back against her cruel creators. So the Strigivids rose up, and turned on humanity. (On humans and humans alone, the Fyngrot cripples them and forces them to relive the pain of their creations.) They escaped and began to spread, forcing humans off of Earth and into space. As sapience spread among other avians, the Strigivids' origins were forgotten: all that they remember is that they were not natural species, and turned against them. So after decades, if not centuries, of being treated like unholy hellspawn, the Strigivids-or Hagsfiends, as they were being called-accepted this depiction, and became the Demonic avians that the other avians saw them as.
- This can also explain, to an extent, why the owls can see color: genetic engineering of Strigiformes shortly before the Strigivid Uprising.
Humanity fell to Nuclear War.
- Because, while magic is all well and good, it would just make sense for humanity to destroy itself before the Avians rose to sapience. Maybe they were experimenting with genetic engineering, maybe not. Maybe some got to space, maybe not. But either way, they were responsible for their own downfall, and all that remains are ruins.
Alternatvely, Ga'Hoole is an Alternate Continuity to Splatoon.
- Namely, (SPOILERS FOR SPLATOON 3), instead of spewing into the water, the Liquid Crystals of Alternia that contained "humanity's essence" were vaporized and spewed into the air, where it then boosted the intelligence of land and sky-based animals, and ensued that mammals were still around-albeit not as transformed as Inklings were, and instead getting minor changes to biology and becoming far more intelligent.
Coryn Series
- The Dire Wolves are the descendants of large dog breeds brought to Mars by humans. The "cold" that the first Fengo survived was actually cryo-sleep or similar, and the Sacred Ring is a giant Planetary Heating Device powered by the Ember, which is a relic of the Others once used as a power source and now accessible by anyone who contacts it. Just a theory of this proper.
- As an addendum to both above theories, human's aren't extinct. The whole series is an experiment to see if non-human life would develop along similar lines to humans if granted sapience. Before leaving for the stars, humans genetically engineered a lot of species (Owls included) and planted them on a terraformed Mars to see how they'd develop, monitoring them closely for thousands of years. The Ga'Hoole tree is a sign that the experiment is succeeding: the Owls have written language and work in groups, and have reverse-engineered some of the technology from a long-defunct Martian Colony. (Specifically, a Printing Press and Barometer. The blueprints were planted there for the sake of the experiment.) Once the Owls of Ga'Hoole have developed the capability to reach space, the humans will reveal themselves, and welcome their creations to the stars.
