When feeding birds on a large scale, beware of encouraging large numbers of parakeets to feed as they tend to gather on trees which they will damage. They strip the leaves and the bark leaving branches to die which poses a safety risk. Hammersmith & Fulham Council have been unable to prevent retired neighbour from feeding the parakeets which have caused this damage to a protected tree. It should be covered with leaves like the surrounding trees, not striped bare by over 50%.
6 Chestnut trees had to be felled in The Hague due to parakeet damage as they posed a safety risk to the area, Feb 2013
Reports of parkeet damage to Chestnuts + Oaks by the Arboricultural Advisory and Information Service, Dec 2011
Parakeets strip London Plane tree bare, June 2010