units three () and five () are upland broadleaved mixed and yew woodland. The units were assessed in 2012 and 2013, when all units were adjudged unfavourable and recovering, except unit 4 which was favourable. Plans for management of units 1 and 2 were in place, and recovery was expected. That left woodland units 3 and 5 still with problems. Woodland from unit 3 was encroaching onto unit 1 (supposed to be heath). Unit 3 had not enough ground flora, although it did have naturally regenerating trees. The problem with woodland unit 5 is that there was almost no understorey, and not enough ground cover plants, although it did have some new saplings. Both wood units 3 and 5 had some encroaching bracken. Unit 4, the visitor attraction with the rocks, was considered favourable because visitor damage did not appear noticeable, and there were not too many plants concealing the geology. The trees which conceal views from the rocks were not mentioned. Nevertheless, the rocky part of the site receives more than 175,000 people including families, climbers, naturalists and others every year, and this does affect the biodiversity of the rocky section. On 17 February 2018 at Brimham Rocks the Police, the North Yorkshire National Parks and the RSPB launched Operation Owl, "an initiative to tackle the illegal persecution of birds of prey in the county. This was because North Yorkshire had the highest raptor persecution record in the country, and they wanted to do "random swoops" in places where they believed this might be happening. They were also asking the public to report "illegal pole traps, poisoned bait and habitat disturbance, associated with "shooting interests." Pole traps are "spring-loaded traps fixed to the top of posts which have been outlawed since Victorian times." The traps themselves are legal for catching vermin (e.g. rats) if used low on the ground and in tunnels, but are illegal on poles where birds will be killed. In September 2018 a group of climbers assisted the National Trust in "to return many of the locations between Cubic Block and Titfield Thunderbolt at Brimham to their previous airy and open state," that is, they removed large trees and other growth which had caused obstructions to the climbing experience at Brimham Rocks. At 8.45 pm on 1 June 2018, in "an act of mindless destruction," five youths were observed destroying one of Brimham Rocks' balancing stones