the IUCN Red List threshold of a population decline of more than 30% in ten years or three generations. It is therefore evaluated as least concern. As reported by the Spanish researcher Félix Rodríguez de la Fuente in his "Fauna" series, the northwestern Spanish subspecies T. u. cantabricus—an Ice Age remnant—was threatened in the 1960s by commercial gathering of holly fruit-bearing branches for sale as Christmas ornaments—a practice imported from Anglo-Saxon or Germanic countries. In Scotland, the population has declined greatly since the 1960s because of deer fencing, predation and lack of suitable habitat (Caledonian Forest). The population plummeted from a high of 10,000 pairs in the 1960s to fewer than 1000 birds in 1999. It was even named as the bird most likely to become extinct in the UK by 2015, a survey then identified 1114 birds, occupying a reduced range of terrain. In mountainous skiing areas, poorly marked cables for ski-lifts have contributed to mortality. Their effects can be mitigated by proper coloring, sighting and height alterations. A study published in 2022 by NatureScot scientific advisory committee recommended 'renewed intensive measures' to maintain the population, especially steps to assist in the survival of eggs and chicks. Predators like crows, foxes and pine martens are blamed for the decline, as well as the deer fences, and increased human recreation in the territory which can injure adult birds.It was declared as 'extremely vulnerable' and requiring urgent action. Biodiversity Minister for Scotland, Lorna Slater, MSP described capercaillie as 'magnificent birds' and ' iconic' for Scotland and called for 'partnership working' to reverse the decline. Behaviour and ecology The western capercaillie is adapted to its original habitats—old coniferous forests with a rich interior structure and dense ground vegetation of Vaccinium species under a light canopy. They mainly feed on Vaccinium species, especially bilberry, find cover in young tree growth, and use the open spaces when flying. As habitat specialists, they hardly use any other forest types. Western capercaillies are not elegant fliers due to their body weight and short, rounded wings. While taking off they produce a sudden thundering noise that deters predators. Because of their body size and wingspan they avoid young and dense forests when flying. While flying they rest in short gliding phases. Their feathers produce a whistling sound. Western capercaillie, especially the hens with young chicks, require resources that should occur as parts of a small-scaled patchy mosaic: