The dry grasslands of Ailuropia contain a patchwork of environmental conditions, ranging from temperate prairies to cold steppes to seasonal "savannas". The physical landscape is very uniform, consisting mostly of hilly lowlands stretching for hundreds of kilometers in every direction. The climate of any given point within this expanse is determined by the two great mountain ranges found north and south of this region. They create a double rain shadow effect: at the foothills of each range is a dry, savanna-like environment, and deserts exist in the central region where the shadows overlap. More hospitable grasslands exist at either end of the continent, where modest quantities of rain arrive from the seas to the east and west. This web of geographically interconnected but environmentally distinct regions has been very conducive to speciation, and the region as a whole boasts levels of biodiversity not seen in the temperate areas of other continents. One species, though, patrols the entire Ailuropian interior, crossing biome boundaries and dominating its ecosystem.
Apteryx grandis is the descendant of kiwis that emigrated from Loxodia just a few thousand years after the Dawn Muricene concluded. This migration numbered only in the hundreds, and it was not the only kiwi lineage in its new home. By pure chance, a very interesting founder effect occurred here, one that would change the course of this group's history. A rare gene variant responsible for increased body size, present in less than 0.1% of other Apteryx populations, just so happened to be found in over a quarter of these migrants. As they spread across Ailuropia, their larger-than-average body size set them apart from their cousins. Indeed, the differences only became more pronounced over time; niche partitioning took place, resulting in the giant kiwis becoming more and more distinct from the smaller forms over time.
Other novel traits now separate this species from its various smaller counterparts. In addition to weighing well in excess of 10 kilograms, A. grandis' bill has become shorter, deeper, and stronger. This permits several lifestyle changes; the giant kiwi incorporates modest amounts of grass in its diet and is better than its cousins at rooting through the soil for hidden isopod prey. Its capacity to defend its young from predators is also much improved - angry parents can often be seen throwing would-be nest raiders several meters into the air.
This species's adaptability allows it to easily traverse the various habitats across its range. The inland savannas have their wet season during early spring, when meltwater flows into the valleys from the massive glaciers atop the mountains. During this period, massive A. grandis herds congregate along the foothills, which are briefly almost as productive as the rest of the interior grasslands combined. By the time these areas dry up, the kiwis will have already migrated to the continent's west coast, where the summer heat causes an increase in evaporation from waters off the subtropical coast, resulting in several months of near-constant rainfall. When winter finally arrives, the birds take refuge in pockets of less-seasonal prairie to incubate their eggs, which hatch just in time to join their parents in the yearly springtime feast.