Winter has been unusually warm in Kyiv this year, but the day I visited the sprawling parkland at Babyn Yar the temperature was a biting -7C. Despite this, and the fact that it was midweek and mid-morning, the park was busy enough. Dog walkers hurried across the frozen ground. Mothers with pushchairs stopped periodically to check on their warmly bundled infants. An elderly couple marched along a broad path using walking poles to steady themselves where snow had warmed and refrozen into ice. The phrase babyn yar translates as “old woman’s ravine”, yar being of Turkic origin. In September 1941, when the Nazis and their collaborators began their murderous extermination of Kyiv’s Jews here, the ravine was set in open ground on the fringes of the city. The poet Yevgeny Yevtushenko discovered it had become a suburban waste tip in 1961, when he wrote his famous poem, later set to music by Shostakovich. “Here all things scream silently,” Yevtushenko wrote. Now the park is manicured and thronged with trees – two-tone poplars, monochrome against the snow, gnarled weeping willows and black locusts (or false acacias), their bark crevassed like glaciers. To Yevtushenko, the trees at Babyn Yar looked ominous, “like judges”. That much hasn’t changed. Despite the cold, these frozen trees were filled with chatter: the squeaky bark of a woodpecker, the rapid-fire piping of a nuthatch and the seesaw of great tits. Most obvious was a busy group of hooded crows. A pair broke off and flew overhead, one of them flipping on to its back momentarily, exposing a gap in its left wing where it had lost a couple of primary feathers. Two more were hopping towards a patch of grain spread on the path ahead of me. Each winter, flocks of these sharp-witted birds arrive from their breeding grounds in the countryside to gather in the city. It’s safer here and there’s more to eat. Research also suggests that these crows share knowledge about sources of food: a corvid information exchange. At Babyn Yar, you can’t help but wonder what the crows are telling each other about us.