Feral pigeons are a man-made bird that lands on every roof in the city. Put a 15-gram solar LoRa node on an owned club pigeon and you get a rooftop sensor and relay that never needs a cell plan, a tower, or a permit to dig. Three thousand of them cover a city for the price of one traffic light.
Racing and homing pigeons from a local club, with the owner's consent. They roost in the same loft every night, so every node comes home to be checked, weighed and recharged. Wild birds are never touched.
LoRa radio, a solar patch, a 150 mAh cell, temperature / humidity / pressure, a 3-axis compass and motion sensor. Standard ornithology backpack mount: no glue, no collar. Beacons every 15-30 minutes; logs every minute; dumps the log at the loft.
A $10.90 Wi-Fi LoRa kit in a printed weatherproof box, screwed to a chimney or snapped onto a base plate. Fifty per city. Everything the birds hear lands on the map within seconds, on the roof's own Wi-Fi.
Every node relays for every other. A cat in a storm drain reaches a cat on a fence; a pigeon on the ledge hears both; a drone parked at 400 ft hears the whole district. Pigeons are the roof layer: the densest, cheapest, highest nodes a city can have, sitting exactly where cats cannot go and where the gateways already are.
Their own budgets: New York's shelter contract averages $53.7M a year; Miami-Dade Animal Services is $39.7M and holds 500,000 stray cats "steady"; Chicago spends $12.5-14.9M a year on rats and its own audit says the plan is unlikely to work. A full Cat City program with 3,000 pigeon nodes and 1,000 tracked cats is about $600,000 a year including a warehouse where we hold, train and neuter on site, priced to finish instead of continue; a city that lends an unused building pays $520,000.
Sources on the studies page: NYC Comptroller 2025, Miami-Dade FY23-24 adopted budget, Block Club Chicago / The Center Square, SF Chronicle, Pimentel 2005, Loss et al. 2013.
You keep your birds and your loft. We supply the tags, the loft dock and the map. Your birds' data pays for their feed. Owned birds only, consent in writing, payload under 5 % of body weight.
Kittens, friendly strays and owner surrenders are held at the hub, neutered, vaccinated, chipped and socialized, then adopted through the partner shelter. Working cats go to businesses. Adoption page →
A shoebox-sized weatherproof receiver on your chimney or wall, on your Wi-Fi, drawing less than a phone charger. You see the dashboard for your block. Warehouses, breweries and logistics yards first.
$25,000: twenty tracked cats, a hundred pigeon nodes, five gateways, one neighborhood, and a report the council can vote on. Then a city program priced to end the stray problem, not manage it forever. Have an unused building? Lend it as the hold-and-train warehouse and clinic room (vet students under a supervising DVM neuter on site; basic shots, flea and worm treatment for every animal) and the program price drops.