In the Pied Cuckoo campaign, MigrantWatchers have contributed 363 sightings of this wonderful species so far (until 15 July 2011). A summary of these sightings from places to where the Pied Cuckoo migrates shows that it does, by-and-large, arrive in advance of the monsoon, but the exact dates are variable.
To illustrate the general pattern of migration of this species, we have put together this animated map, which shows the progression of Pied Cuckoo migration across the country in advance of the monsoon.
This animation has been made by selecting March-to-July sightings from all Pied Cuckoo reports in the MigrantWatch database between 1 July 2007 and 15 July 2011. To compare these sightings with the onset of the monsoon, we have also added in lines depicting the normal onset of the monsoon (digitised from a map available from IMD Pune).
In March and April, almost all sightings are from southern India, where the species is known to be resident year-round. This remains so until the middle of May. In the third week of May, the first migrant sightings appear, in the West and the North-east. As the monsoon hits the Andamans, the first birds in northern India are seen. More and more birds are subsequently seen across the West, North and East. By the time the monsoon reaches Kerala (in the first week of June), Pied Cuckoos are everywhere, except perhaps the extreme West and North-West.
Where are the gaps in information? Do you see patterns that would be interesting to follow up? Do leave a comment below.
Thanks, of course, to all MigrantWatchers who have contributed their Pied Cuckoo sightings!