The widespread declines of songbirds in rural Britain do not correlate with the spread of their avian predators

摘要: During the last 30 years, there have been marked declines in populations of many British songbirds breeding on farmland, while two their main predators, sparrowhawk ( Accipiter nisus ) and magpie Pica pica ), spread back into areas from which they had disappeared. The causes songbird remain unclear but given coincidence timing, it might appear that increased predation could be responsible. Although studies failed to find links between changes mortality avian previous work has, with few exceptions, involved only short–term small spatial scales. Here we use large–scale, long–term data a national bird census scheme examine whether magpies sparrowhawks depressed rates year–to–year population change 23 species. Our results indicate are unlikely caused because patterns did not differ sites without these predators.