I spent $80 and 37 cents to find out when birds visit my home

#iot #python #showdev #sideprojects

I had one question: when do birds actually show up at my bird feeder?

Not a startup idea. Not a product pitch. Just curiosity.

The Setup ($80)

The Code (93 lines)

A Python script that runs in a loop. Every 60 seconds: capture a 1280x720 frame with fswebcam, post-process with ImageMagick (-auto-level -auto-gamma) for outdoor lighting, upload to Supabase Storage with exponential backoff retry.

The design philosophy: never crash. If WiFi drops, retry. If all retries fail, skip and move on. 99%+ upload success rate from a $16 computer on a windowsill.

The Analysis ($0.37)

After 3 days and 1,500 images, I ran every photo through Qwen 2.5 VL 7B via the OpenRouter API. 996 input tokens per 1280x720 image, ~34 output tokens. Total cost: thirty-seven cents.

What I Found

433 birds across 3 days. Peak hour: 3 PM — not dawn. The afternoon window (12-5 PM) accounts for 70% of all bird activity.

The growth curve was wild: Day 1 had 55 birds. Day 2 had 51. Day 3 exploded to 327. A Bird Net Promoter Score of 100 — someone told the flock.

Species breakdown: House Sparrows dominate, House Finches (the red-headed ones) are everywhere, occasional pigeons photobombing, and one frame with something that might be a hawk.