The great eastern rainforest of Equatorial Loxodia has returned to its former glory, stretching from the estuarine wetlands of Abelox to the foothills of the mid-Loxodian ridge. It is one of Apterra's greatest centers of biodiversity, hosting hundreds of vertebrate species and thousands of endemic plants. The canopy is a dangerous home; hordes of trigger-happy Scansoriarthriform woodlice won't hesitate to attack any creature they deem a threat to their home, while their ever-present Plague cousins periodically launch their attacks. Though Pestilarthrids are herbivorous, their powerful jaws can easily tear apart small animals that get in their way. Arboreal birds must also keep an eye out for tree-dwelling predators like terror kiwi chicks, some species of which live in the treetops until around their first birthday, and glirrels, which are almost impossible to spot until they launch their attack. Despite all this, there are many opportunities for small kiwis that call the trees their home. Two clades have thus far stepped up to the challenge.

Several species of downlings survived into the Arthrocene. The sugarcreeper was one of them; though they died out across Panapterra during the early Ice Age, a small population survived on the Gecko Isles. Although most species of sugarcreepers still live on the island continent, one group rafted back to the mainland about two million years ago, and its descendants found their way to the rainforest soon after. One of the most common species is the Blossombird (Flornis fistulognathus). This ten-centimeter-tall, sixty-gram kiwi spends its time scurrying along the thick branches of older hybrid trees. It doesn't waste its time with younger palm-grasses, as branchblooms - its preferred food - are rarely found on trees less than fifteen years old. The blossombird's long, straight beak can reach the nectar deep within each floret without disturbing the plant, though it does not pollinate the flower. This sometimes draws the attention of arboreal isopods, which have evolved to recognize this species as a parasite, at which point the bird makes a hasty retreat to another tree.

Not all sugarcreepers steal without giving anything in return. The Corollette (Flornis penicillops) is a dainty, grey-and-yellow bird that also has a taste for nectar. Less picky than its relative, it also feeds on the sugary secretions of the trees themselves. This is permitted by pill bug colonies because the corollette provides a much-needed service. The base of its bill has a ring of soft, golden feathers perfect for carrying pollen. Not only does it pollinate the branchbloom, but it even goes out of its way to pick up pollen from the tree, despite palm-grasses providing no nectar reward in their flowers. Consequently, many species of woodlice have evolved to see the corollette as a welcome species in their territory, granting them safe passage through the canopy, even protecting it from predators and Plague attacks. In return, if a corollette sees a dying tree, or one in the midst of losing a battle against Plague woodlice, it will allow newborn Scansoriarthriforms to hitch a ride on its facial feathers, transporting them to a sapling without a colony of its own. Though they aren't conscious of the ways in which their efforts bolster the health of their companions, their instincts to provide these services nonetheless improve the birds' long-term survival. Corollettes have an exceptional lifespan for birds of their size - up to 35 years if they aren't picked off by carnivores - so helping their mutualistic partners is a worthwhile investment. A population of healthy trees in a corollette's territory ensures more food will be available years down the line, and a thriving Scansoriarthriform community decreases the rate of predation by an order of magnitude.

By far the largest climbing bird in the forest is a different type of downling, this one from the zipperbill lineage. While its carrion-eating habits are still common among many of its descendants, this particular offshoot has found a new use for its knife-like beak. A notorious pest of palm-grasses, the Girdlebill (Secarostris balteocisor) tears through the trees' soft outer skin to reach the sweet flesh within. This is the largest of Apterra's climbing birds, clocking in at 3-5 kilograms and standing well over half a meter tall. It shuffles along branches sideways, never picking its feet up to avoid losing its balance. Like all zipperbills, the girdlebill has a patch of bare skin on its face, a trait that originally evolved as a way of keeping clean around carcasses, but which serves a new purpose: resisting counterattacks from sheriff and flipbug woodlice. This thick, wrinkled layer of grey flesh is nearly impossible to bite through, allowing the girdlebill to feed freely for minutes at a time. Eventually, though, the isopods force it to move on to a new target, so it rarely stays long enough to cause serious damage to any one tree. 

Forming the sister taxon to the pillbirds, skeeter-snappers (Muscivorapterygidae) are another speciose clade of avian climbers. With long, grasping digits and lightweight bodies, they move through the trees faster than any other bird. One widely-distributed genus of Muscivorapterygids is called Muscapiorostris, or Tweezerbeaks. This group has a uniquely proportioned beak: long and needle-like, its bill may be 150% the length of the rest of its body. The head can swivel more than 225 degrees in either direction, letting the bird catch prey approaching from any angle. Its strikes are faster than the blink of an eye, and the thin profile of its beak avoids creating any air currents that could alert mosquitoes to its presence. Despite its unwieldy appearance, the beak is so heavily pneumatized that it weighs almost nothing, so the tweezerbeak can jump and skitter along branches with surprising agility.