The status of Tawny Owls is threatened. It is estimated that there are only about 50,000 breading pairs in the wild, even with only this many left very little is being done to revive their population.
One impact of Tawny Owls going extinct would be a spike in the mice and vole population. This would cause a major imbalance in the ecosystem; with more mice and vole there would be less of the food that they eat, which would effect the other animals that eat those plants, that would mean a decline in the population of the animals that eat those animals, and so on.