ajohn

I agree that some sort of 'bird index' is a very good idea for Hong Kong, to monitor the changes in population of certain bird species. Are Sooty-headed Bulbuls declining? Are Fork-tailed Sunbirds increasing? Is there any change in population levels for Common Tailorbird or Black Kite?

This would help to identify those species which may be in decline, so that conservation efforts can be made to protect them - the same way that the long-term decline in farmland birds in Europe was identified by regular surveying by volunteers.

So far in HK, the monthly waterfowl counts allow these assessments for a few species in a limited area, but there is no monitoring of other species, especially the commoner, widespread species.

I'm a bit confused, however, about the methodology involved with the proposed index. In particular, it is unclear whether there is a set area/time/frequency of surveys, or what species are being recorded. Simply recording the number of species and individuals seen on a birding trip does not give the replicable data required for an index of this type. Surveys also seem to be only at those sites which are known to be good for birds, which gives no indication of populations in the territory as a whole.

I feel that what is needed is something closer to the winter atlas methodology - where the location, duration, time of day, etc was pre-determined, and all birds were recorded to species.  Only a small sample of squares would need to be covered, but there should be a selection of sites in different habitats throughout the territory, which could be covered at a pre-determined frequency (even if this is only once/twice per year!)

If there are more details about how the surveys are carried out, it would be useful to post them on the forum and invite surveyors to join in with surveys, so that the surveys can be as thorough as possible.

ajohn

Following my previous post, I see data has now been entered for a number of sites.

Unfortunately, the data seems to me like no more than a series of numbers which seems to tell us nothing about the species involved and gives no data which can later be compared with other surveys (surely this should be the point of an index like this?)

Do we learn anything from the fact that at Kam Tin on 11 March, someone saw 876 birds of 59 species without knowing what those species were? Or that on the same day at Shing Mun there were 374 birds of 24 species?

We don't know about time involved, distance walked, species recorded, weather, etc, etc.

Perhaps I am misinterpreting the data somehow, but I still do not understand how this is helping to monitor bird populations in HK. Perhaps someone can clarify this for me?

I don't mean to seem critical of the work being done. I'm just concerned that this may be a missed opportunity to involve members of the HKBWS in collecting some really useful scientific data which could help in understanding and protecting the local bird community.