Sandhill crane nesting success and productivity in relation to predator removal in southeastern Oregon

I reviewed Greater Sandhil Crane (Grus canadensis tabida) reproductive success at Malheur National Wildlife Refuge in southeastern Oregon, 1966-1989, during which time predators were removed in 12 years and not removed in 12 years. Of 1,024 comparable crane nests found in those years, compared to those during nonremoval years, nests during years when some predators were removed had greater nesting success, more young fledged/100 pairs, lower mortality rates of young, and higher annual recruitment rates. The most important limiting factor for cranes at Malheur NWR was low annual recruitment resulting primarily from predation on eggs and prefledged young. Coyotes (Canis latrans) were the primary predator on eggs and young, but in some years Common Ravens (Corvus corax) and raccoons (Procyon lotor) took a large number of eggs.