[BetterGeiger]

Do you think animals can only move a meter per minute!??

First of all, this part is not necessarily common knowledge but serious health effects does not mean incapacitated, and in the case of radiation it usually means effects that come on in the days/weeks following exposure, at least for humans. Animals can have different radio-sensitivity.

Regardless of that, a critter could easily travel a few hundred meters or more in a matter of minutes!! The search area then grows enormously. Total game changer.