For the last three decades, residents of GLMZ's mid-tier districts have been treated to an unexpected amenity: pigeons that glow. The birds — common rock doves, Columba livia, the same species that has infested human cities for millennia — emit a faint blue-green bioluminescence along their breast feathers, visible at dusk and in darkened alleyways. The effect is subtle but unmistakable. In certain lighting conditions, a roosting flock looks like a constellation that decided to nest on a fire escape.

The source of the glow has been traced to geneware contamination in the municipal water supply. Specifically, a luminescence modification originally developed by Helix Biosystems for cosmetic pet applications entered the groundwater table through improperly disposed biowaste sometime around 2190. The modification codes for a variant of green fluorescent protein that integrates into feather keratin during molt. The pigeons drink the water. The pigeons grow new feathers. The feathers glow. It is, in the clinical language of the environmental impact assessment, "an uncontrolled transspecies cosmetic expression event."

Residents of the Shelf have largely embraced the glowing pigeons. Night market vendors in the Circuit sell pigeon-watching tours. Children name the birds. A Shelf community board in Block 14 voted to designate them "neighborhood wildlife ambassadors," which carries no legal weight but was accompanied by a very nice ceremony. The pigeons attended. They did not appear to care.

Biologists at the Great Lakes Metropolitan Zone Environmental Monitoring Station are less charmed. Dr. Yuki Andersen-Okafor, lead ornithologist, describes the contamination as "a multi-generational genetic alteration affecting a wild population numbering in the hundreds of thousands, with no containment strategy and no reversibility pathway." The bioluminescence itself is cosmetically harmless, but it indicates that geneware agents are actively incorporating into wild genomes — and luminescence is the modification that happens to be visible. What other modifications are expressing silently?

Perhaps most unsettling is the navigation shift. Andersen-Okafor's team has documented that GLMZ's pigeons no longer navigate primarily by the Earth's magnetic field, as their ancestors did. Instead, they orient by BCI signal strength gradients — the invisible topology of neural interface broadcasts that saturate the city. They fly toward signal density. They roost near relay nodes. They have, without anyone designing it or intending it, rewired their migratory instincts to treat the city's digital infrastructure as terrain. They've been doing this for at least thirty years. Nobody noticed until someone thought to check.