[kuusisto]

Found it in the Results section:

> On average, 83% of captures were consumed by the cats (88% of invertebrates, 79% of reptiles and amphibians, 78% of mammals and 50% of birds) and the remaining items were left at the site of predation.

[dsr_]

Right. Feathers and bones don't digest well.

[im3w1l]

I think they meant the cat left 50% of birds completely alone. Not that they ate 50% of the mass of every bird. This is based on owning an outdoor cat and having it bring intact corpse trophies to the door.