The announcement made by the fox queen Malora triggered an event that should have happened way later into the invasion.
The two other invading continents sped up their progress using the resources they had just gotten from capturing the basic villages of the other tribes that lived in their parts.
Each seasonal part had its own special resources that the humans had a use for, so with a little bit of bribing and trading, the spiders, kangaroos, and ravens got their hands on some special tailor-made technology that was useful against their enemies, thus leading to the conquering of the whole continent.
There were still places that no one set their foot in on the Sparron continent, and that's where the others were currently laying their eyes on.