Action: Control predators not on islands for cranes
A single trial from the USA found that greater sandhill cranes Grus canadensis tabida had higher hatching and fledging success in years with predator control, compared to years without control.
Supporting evidence from individual studies
A trial in southeast Oregon, USA, between 1966 and 1989 (Littlefield 2003), found that greater sandhill crane Grus canadensis tabida hatching success and fledging success were both higher in ten years when predators were controlled than in nine years without predator control (average hatching/fledging success of 55% and 9.1% for 662 clutches in predator control years vs. 42% and 5.1% for 434 in non-control years). Coyotes Canis latrans and ravens Corvus corax were controlled by poisoning and shooting. The main nest predators were coyotes (predating 17% of clutches in predator control years and 27% in non-control years), ravens (14% and 20%) and raccoons Procyon lotor (11% and 8%, the increase possibly related to a reduction in coyote numbers).