The wader census is carried out twice a week at Sungei Buloh during the migratory season. Why bother, some of you may ask. Well, you see, by having regular census in the Park, we can determine the important periods in which the birds arrive and depart during migration. This helps us to keep track of the population change as well as better understand the roles in which the mudflats here play in the migration routes of these shorebirds.

Wader census is usually carried out during high tide when the birds which are looking for a safe place to roost will find it in the form of one of the ponds with the water kept low through our sluice management programme. With our 'bionic eyes' (our telescope and binoculars actually), we comb the mudflats in search of the waders. To do a count requires some co-ordination between the staff. Each counting site is divided into two or more areas between the counters (usually 2 people to count and one to record).

Counts are usually estimated when the birds are in constant movement (flocks flying into a roost site), when the numbers are too large or when they are tightly packed together etc. This is done by estimating the number of birds (e.g., 50, 100 ..... ) in one field of vision in the telescope/binoculars before moving on to the next field and so on at the site. The counts are recorded on site into a field notebook and transferred into the database for storage and further assessment.

Sometimes disturbances to the birds, such as an inquisitive monitor lizard or a bird of prey circling above, can cause them to fidget and move. The worst scenario will be to double count birds which have flown in from areas that have already been covered. Fortunately, this is not common because waders do not move about much once they settle in nicely on a roost site. In most cases when they are disturbed, they may fidget and take flight. However, they will usually return to the same spot almost immediately and all that is required is a little patience for them to settle down again.

So you see, it is not easy counting our visiting friends after all.