Teddy Warner created Avian Visitors, a bird monitoring system that uses a Raspberry Pi with USB microphone to detect and identify bird species passing by. The project began as a simple afternoon experiment after Warner mounted a microphone on his apartment balcony to listen for birds, but gained attention on Twitter, prompting him to document the build.

The system costs approximately $80 in hardware including a Raspberry Pi, microSD card, USB microphone, and power supply. It runs BirdNET-Pi software with Cornell's BirdNET acoustic classifier to identify species. Installation takes 20-40 minutes via a simple installer script that configures the system, though users need to set up their own Gemini and eBird API keys for full functionality.

Avian Visitors creates a collage of bird illustrations generated through Gemini's image model in Edo-period Japanese kachō-e style. The system offers multiple extension options including Cloudflare Tunnel for public access, Home Assistant integration, and MQTT bridge capabilities, allowing users to build automations or integrate with existing smart home systems.