Why wildlife managers are coating raven eggs with nontoxic oil to protect sage-grouse

Egg oiling helps protect vulnerable Sage-Grouse by reducing raven numbers. Common ravens are among the most intelligent birds in the world. Over the years, raven numbers have increased in many places because they benefit from food and nesting sites linked to human activity. According to USGS research, from 1966 to 2018, raven numbers across North America rose by about 1.5% a year, with local densities doubling in under two decades in some western regions.That rise in raven populations has created problems for several vulnerable bird species. One of them is the greater sage-grouse, a ground-nesting bird found in the sagebrush ecosystems of western North America. Ravens prey on the bird's eggs and chicks.A new study has found that egg oiling can help reduce raven reproduction and inturn help sage-grouse survive. Researchers found that treating raven eggs with mineral oil reduced local raven numbers and also led to higher nesting success and population growth in sage-grouse.The findings were published in The Journal of Wildlife Management and reported by Science X. The researchers say the method works well on a local scale, but they also stress that it is not a complete solution becau...