He and his colleagues observed more than 1,800 falcon attacks on wild pigeons in an open field near Davis over seven years.
But some residents of the building have long been known to consider the huge hawks, which prey on pigeons and rats, a nuisance.
Perhaps the Forsaken had to depend on pigeons and eyes-and-ears just like anyone else, but being too sure could be fatal.
Moreover, experiments on pigeons have been thought to rule out that possibility.
Robin Baker has recently challenged whether the observations on pigeons require any true navigating skill at all.
He has subsequently become one of the world's few experts on feral pigeons.
"He was good on pigeons," his wife said.
I have the greatest possible objection to experimenting upon living animals, but he described to me an experiment on pigeons.
Andris went there to die; do you think I wanted to wait on couriers, or pigeons!
He has said that earning the degree had helped him create addictive games by using the same techniques originally used on pigeons.