Peter started birding in 2006, back when he was still in secondary school. In 2008, he joined the Kite Research Group of the Hong Kong Bird Watching Society. Beginning with monthly observations to record the number of kites all around Hong Kong, he has now become the Convener of the group. From 2009 onwards, Peter has been sharing his observations on his own Facebook page "My Black Kite Story". In addition to sharing photos on the Black Kites, he has also named 17 of them for easier tracking. During mating season, he would even draw out diagrams to analyse the “love triangle” romance between them (Black Kites are believed to be monogamous).

Siu Ying, in particular, is a Black Kite he has been observing in extreme detail for 13 years – he knows exactly how much trash it has taken to build nests; how many feathers have fallen. He suspects that Siu Ying and another Black Kite Tai Ma could recognise him. Out of many pedestrians who pass through their vicinity during mating season, Peter was the only person to be attacked by them. He isn’t discouraged: "Female birds may attack humans when they are nervous. Whenever this happens, I will leave as soon as possible to avoid disturbing their livelihood. Thankfully, Tai Ma only attacked me once so I was able to stay and observe until later in the night." While many have compared Peter’s observations on Black Kites to a soap opera, he would always cut in and say, "I am just recording what I observe!"