Brian Zimmerman is chief curator at ZSL London Zoo
‘Our most famous ghost is The Whistler: one of the engineers working on the aquarium in the early twentieth century who was famous for whistling while he worked. I’ve encountered him once – 19 years ago, not long after I first started working at the zoo. I was alone in the building on a Saturday morning before we opened, waiting for a volunteer to join me, when I heard this melodious whistling getting closer to the door. I assumed the volunteer would walk in, but it suddenly stopped. I went to check it out but there was nobody there, and when my workmate turned up she had no idea what I was talking about.
‘Initially, I put it down to a weird experience or me just imagining things, but when I casually mentioned it to a colleague later, they told me about the story of The Whistler. That was when I freaked out. Prior to that, I was never a believer, but when you have an experience like that it does make you question things. Every time I work in that part of the aquarium I think about what I heard. A few of my co-workers have heard his whistling or footsteps when they’ve been alone. Sometimes we have volunteers refuse to go to certain parts of the aquarium by themselves as they feel strange things such as sudden cold draughts. I don’t think he’s a malevolent spirit, though. He was the caretaker of the building and I like to think he’s still looking after it today.’