Well, thanks mainly to Shaun Martin (and the many sponsors and the many citizen scientists) we can answer that question....as we (Hong Kong) took part in the City Nature Challenge.
Using the very brilliant APP (if you do not have it, download it now! its great for ID and recording your own observations)
called iNaturalist 1,128 people in Hong Kong set off on a mission to record as many species as they could.
And we recorded an amazing 3,596 species! WOW.
To put that in perspective, out of the 159 cities that participated, we ranked 2nd for number of species, which is an incredible result. It shows how biodiverse this territory is - and also how little old Hong Kong often punches above its weight, due to its great citizens and their organisational and motivational skills.
Here is the blurb from the organiser, and the full results.
"City Nature Challenge Update: 6/5. RESULTS ARE IN!!!
At 9am this morning (the cut-off time), our final results were (with global position out of 159 cities):
Observations: 31,144 (10th). (Last year: 20,268) Species Logged: 3,596 (2nd). (Last year: 2,932) Observers: 1,128 (9th). (Last year, 755)
To say, I am proud of all of you is a massive understatement. Hong Kong's biodiversity is well and truly on the global stage and I wish to thank every single one of you; participants, promoters and to those organisations that created specific activities or integrated the CNC into usual activities.
Also, a MASSIVE thanks to all of you that offered identifications to these observations. Our participants are now much more informed about the biodiversity that's on their own doorstep and that is our ultimate aim.
I urge you all to continue this journey. Although the CNC is over, there is still so much to see in Hong Kong and we need your help to log it. Who knows? You could be the next person to discover something new".
If you see this man, shake his hand and thank him....better yet, buy him a beer! This is Shaun Martin, the inspirational chap behind getting the citizen scientists of Hong Kong organised.
Full disclosure: www.wildcreatureshongkong.org is very proud to be a sponsor of the City Nature Challenge.