Livestock Guardian Calculator

The calculator uses a lookup table where the head-per-guardian ratio tightens from 100 head under low pressure to 75 under medium and 50 under high pressure — meaning a high-predator-pressure setting roughly doubles the recommended guardian count for the same herd size compared to low pressure. This reflects that a single guardian can realistically only confront and deter so many simultaneous or repeated predator incursions before coverage breaks down.

Terrain applies a multiplier on top of the base ratio: 1.0 for open pasture, 1.3 for mixed brush and timber, and 1.6 for rugged canyon country. The reasoning is visibility and coverage — a guardian in open pasture can see and respond to threats across a wide area, while broken or heavily vegetated terrain blocks sightlines and slows response, so more guardians are needed to cover the same acreage effectively.

The calculator assigns each guardian type a flat annual cost estimate ($1,500 for a dog, $800 for a llama, $600 for a donkey, covering feed and veterinary care) and a baseline effectiveness score (9, 7, and 6 out of 10 respectively) before any predator-pressure adjustment. Dogs cost more to keep but are rated most effective and versatile against a wider range of predators, while llamas and donkeys are cheaper to maintain but score lower, reflecting their more limited effectiveness against serious threats like wolves or bears.

No — it's derived entirely from fixed lookup tables (a per-species baseline adjusted down for higher predator pressure and nudged for whether the recommended guardian count meets or falls short of raw demand), not from any data on actual predation outcomes. Real-world effectiveness depends heavily on individual animal training, whether guardians work in a bonded pack or alone, and how well they've bonded with the specific herd, none of which this model can capture.