New research shows rise in predators is threatening red-listed birds with extinction

A survey of ground nesting birds on around 3,000 acres of moorland in north Northumberland has shown dramatic declines of iconic threatened species 10 years after predation management ceased as part of a controlled experiment spanning two decades.

A recently published scientific paper based on the study found golden plover dropped by 81 %, snipe by 76 %, red grouse by 71 %, lapwing by 49 %, curlew by 24 %, while black grouse and grey partridge went locally extinct.

Ground-nesting birds are particularly susceptible to predators and their populations can recover when predation pressure is relieved during the breeding season. Experimental legal removal of predators between 2001 and 2008 on the same experimental plots demonstrated a three-fold improvement in breeding success amongst ground-nesting birds, with subsequent increases in their abundance.

Dr Andrew Hoodless director of research at the Game & Wildlife Conservation Trust (GWCT), which carried out the experiment said: “The declines occurred in spite of the fact that habitat remained the same, and they are part of a bigger picture mirroring downward trends among these species across the UK.

“In the long-term, habitat manipulation could make breeding grounds less predator friendly, but in the meantime, without lethal control of predators at landscape scales, we will see continued rapid declines and local extinctions.”

There are growing concerns that increases in generalist predators in the UK over the last few decades have contributed to declines in ground-nesting birds. National populations of carrion crows and foxes are either the highest, or among the highest, in any European country. These high densities are linked to a range of factors including an absence of apex predators, intensive agriculture, the availability of food waste in urban areas and expansion of non-native woodland, which provides protection and breeding places.

When predator numbers were surveyed in 2019, 10 years after the Otterburn Upland Predation Experiment ended, they showed fox abundance had increased by 78% and carrion crows by 127%, resulting in dramatic losses of ground nesting birds.

Previous research by the GWCT shows that legal predation control undertaken by grouse moor keepers to protect red grouse sustains a range of red-listed species. A paper published last year showed curlew raise four times as many chicks on areas managed for red grouse and 96 % of UK’s remaining black grouse live on the fringes of grouse moors where predator control is carried out.

Dr Hoodless continued: “We face some difficult choices. Human activity has upset the natural balance of species across all UK landscapes.  I can understand that people are uncomfortable about the idea of controlling one species to protect another, but it’s¬ important that the wider public and policymakers understand the reality of the situation. Without habitat management, and the continuation of effective lethal predator control on a landscape scale, the science clearly shows that many much-loved iconic species will be lost from large parts of the UK.

“If we fail to acknowledge the threat and to invest in effective solutions, we risk denying generations to come the magical experiences of the curlew’s cry, a black grouse lek or a wing of golden plover skimming over heather moorland.”

Summary of the paper: The role of predation management: Ten years on from a predator removal experiment