Enter what you know about a colony and your trapping capacity. The chart projects the colony's size over five years with your current effort, compared to doing nothing. Use it to plan, and to show funders why sustained TNR works.
Five-year projection
No TNR
Your current effort
How the model works
- Half the unsterilized adults are female; each raises about 1.5 litters a year with 4 kittens per litter.
- Three of four outdoor-born kittens do not survive their first year. The survivors join the colony as breeding adults.
- About 15% of cats leave the colony each year (death, adoption, dispersal).
- Trapping targets unsterilized cats first, which is standard TNR practice.
- This is a planning estimate, not a guarantee. Real colonies vary. Parameters follow commonly published feline population figures.