Funnily enough, as I was writing my last comment, a young guy in grey hoodie was walking round in the nature reserve. Now I'd be happy for young people to take such a super-keen interest in the nature around them on a beautiful day like today, but somehow I'm kinda doubtful that's what he was doing. May be a perfectly innocent walk-around/teenager seeking a bit of solitude, but as the reserve is closed off, he'd have jumped the fence somewhere at least? Or are Lewisham conservation officers going incognito in grey hoodies now?? (I should mention that I work from home and my home-office looks out onto the reserve, I'm not the new self-appointed neighbourhood-watch-militia or anything, promise! No, really! )