The rainbird and the 2009 monsoon

This entry was posted Tuesday, 6 October, 2009 at 5:39 pm

In several cultures and folklores across India, the Pied Cuckoo is believed to herald the onset of the southwest monsoon. In May 2009, MigrantWatch started a Pied Cuckoo Campaign, in which birders from all over India were asked to report first sightings of this species. Does the Pied Cuckoo arrive before the monsoon sets in in different parts of the country? Does the monsoon arrive at a consistent interval after the first Pied Cuckoo is seen? These are some of the questions the campaign set out to address.

The campaign was taken up enthusiastically by MigrantWatch participants, with over 100 Pied Cuckoo entries to the database for 2009, and additional records from previous years. (All data collected during this campaign can be accessed on the MigrantWatch website after you login to your account.)


So did the Pied Cuckoo announce the arrival of the monsoon in different parts of India in 2009? Here are two visual depictions of the arrival of the cuckoo and the monsoon.

The 2009 monsoon
The monsoon set in nine days early on the Kerala coast (on 23 May instead of the normal 1 June) and made a good start. A cyclone in the Bay of Bengal disturbed the normal pattern just after it set in. By 25 May the southwest monsoon had moved over entire Kerala and Tamil Nadu, parts of coastal Karnataka, northeastern states, and most parts of West Bengal. Despite an early beginning, the monsoon progressed slowly after the beginning of June.

About the map and graph
The map shows ‘isolines’ (connecting locations with similar monsoon arrival dates) that depict the approximate advance of the 2009 monsoon (redrawn from this map from IMD, Pune) and the first arrival dates of the Pied Cuckoo as reported by MigrantWatch participants from locations across India.

pc-monsoon2009-scatter-300x254-corrThe graph shows a scatterplot of monsoon arrival dates on the X-axis (horizontal) and first sightings of the pied cuckoo on the Y-axis (vertical). Each point corresponds to a location for which a Pied Cuckoo sighting was reported. The solid black line shows where one would expect the points to fall if each first sighting of was on exactly the day that the monsoon arrived at that location. The dashed black line indicates first sightings preceding the monsoon by five days, and the dotted black line 30 days.

Monsoon arrival dates were extracted from the isolines shown on the IMD Pune map.

For both the map and the scatter plot:

  • Only sightings before 15 July 2009 have been used.
  • Only the earliest sighting was used for locations with multiple sightings.
  • Because there is a resident population of Pied Cuckoos in southern India, we excluded all sightings south of 15°N latitude; but we made an exception for Rishi Valley, Andhra Pradesh (13.6°N), where the species is known to not be resident.<1>

What can we infer about Pied Cuckoo migration? Might the unusual monsoon this year have altered the typical pattern? Please do write down your interpretations as comments to this Blog. If you would like to look at all sightings of Pied Cuckoo in the 2009 season, you can download them here in excel, open document format, or as a comma-delimited text file. Please also read the notes accompanying these sightings.

1. It is still not clear where exactly in southern India this species is resident and where migrant. The various handbooks and field guides on Indian birds differ on this. You can help to resolve this issue by entering General Sightings of Pied Cuckoo from any time of the year into the MigrantWatch database.

This post was edited on 20 October 2009 to remove an erroneous May record of a Pied Cuckoo from Rajasthan. This record has been removed from the figures as well as the accompanying data files.

26 Comments to The rainbird and the 2009 monsoon

  1. Pankaj Sekhsaria says:

    October 11th, 2009 at 8:06 pm

    This posting has been an extremely interesting read. Wouldn’t hazard any kind of guess or analysis, but it is really exciting, particularly when one sees the potential of what this can achieve if data continues to be gathered for a few years.
    On another point, I was also checking the map on the site with the distribution of the participants. There seem to be no participants at all from other parts of South Asia? Have people here not been asked or is it just that no one from the neighbouring countries is interested. I would guess that at least in some places there would be considerable expertise and knowledge!

  2. Suhel Quader says:

    October 12th, 2009 at 11:24 am

    Thanks for your comment, Pankaj. So far, MigrantWatch has been publicised only in India (although it isn’t restricted to the country). I agree that it would be very valuable to gather information from other parts of South Asia; but perhaps we should wait for a year or two until the project is well-established within the country before attempting to broaden out?

  3. Aju Mukhopadhyay says:

    October 17th, 2009 at 10:16 pm

    The idea and the execution is certainly very interesting. One thing is observed that the pied cuckoos appeared earlier than the rains during the early part of the season and wherever the rains came later the cuckoos appeared simultaneously or may be later. More sightings would confirm this. And sightings from out of India would give an idea about the other parts of the globe. If anelaborate map with name places are given it would be easier to locate the exact places of the birds’ arrival and the on set of monsoon.

  4. karuna says:

    October 19th, 2009 at 3:53 pm

    Interesting, though a little late in the day for north India as for most of us,monsoons have ended. Hope to start this event in may in 2010.

  5. Snigdha Kar says:

    October 19th, 2009 at 6:58 pm

    Very interesting read indeed and I must thank Mr. Pankaj for his observation. I am sure in coming years more people would participate and therefore improve the data collection. Thanks to Migrant Watch also for this wonderful online survey.

  6. Suhel Quader says:

    October 19th, 2009 at 10:25 pm

    Thanks, Aju. In fact, it looks as though (for 2009 at least), the first sightings from most regions were in the second half of May, regardless of when the monsoon actually arrived. So in places where the monsoon first broke in the middle or end of June, the earliest Pied Cuckoo sightings preceded this by a month or more. About your comment on the map: it’s hard to make a readable map that also has lots of details, so we didn’t attempt to do this. But all the underlying information, including place names, is in the downloadable data files. If you’d like to create a more detailed map, we’d be very happy to post it here!

  7. Madhu says:

    October 19th, 2009 at 11:26 pm

    Cool data – and I look forward to more of it to build a better picture of this bird’s migration. I’m not sure if exactly coincidental arrival is what you would expect anyway – or would you? Spring migratory behavior is often driven by photoperiod, so the birds may be set to go at a certain point regardless of where the monsoon is. Or they could be starting with the early onset of monsoon-like wind patterns (from Indian Ocean towards the continent), which start well before the clouds reach India, I should think.

    Further, spring migration can also be under directional selection, with early birds reaping the greatest reproductive payoffs, so birds should be arriving as soon as they possibly can – which would mean at least some individuals are well ahead of the bulk of the population, and could arrive weeks before the monsoon. If the monsoon triggers ecosystem productivity resulting in favorable breeding conditions, then it should pay to be in place with breeding territories set up before the actual rains arrive. But then again, do these “normal” breeding considerations apply to these brood-parasitic cuckoos? They have to time their arrival to their (non-migratory?) hosts’ breeding cycle, which itself may be timed to anticipate/coincide with the monsoon.

    All of which reminds me of something I’ve been meaning to ask you, Suhel, for some time, but keep forgetting – even when we met in person!! Remember my “chasing the monsoon” hypothesis for autumn migrants? I had a similar (reverse) map in my paper (<a href=””PDF available here) on Greenish Warbler migration in the autumn, but based on location tags of specimens museum collections. I would like to test that hypothesis using the migrantwatch data on the greenish warbler and other wintering migrants. Have you / anyone else looked at that yet? If not, there’s a paper in there I’d like to work on…

  8. Madhu says:

    October 19th, 2009 at 11:32 pm

    Oops – sorry about the comment duplication. Also, I’m not sure how to add links in comments as normal html doesn’t seem to work. So here’s the url for my paper for anyone interested:

  9. Shyamal L. says:

    October 20th, 2009 at 8:29 pm

    Nice attempt to get people to see data. Just the way collaborative ornithology should go by way of inculcating a scientific temper (which would apparently also make folks realize their duty as Indian citizens).

    The pattern in Africa might be another part of the puzzle to look at.

  10. Shyamal L. says:

    October 20th, 2009 at 9:37 pm

    Here is a visualization on ManyEyes
    I have converted the date into a numeric form just to see if there is any clear trend, but it seems like the scaling of the spot sizes (on date) is not very visible.

  11. Deepa Mohan says:

    October 21st, 2009 at 12:59 am

    I too feel that since the 2009 summer monsoon is nearly over, perhaps data from the pre-monsoon period next year, as well as data from non-Indian sources, should be included before attempting to make a picture.

    But…what a fantastic effort. I think it’s slowly snowballing and will gain even more credibility as the database widens.

    One of the great problems we Indians have is that we are NOT used to recording data….”karNa paramparA” seems to be our way, the level of accuracy being remarkable when one realizes how unreliable a method it is…but like the whispering game, one does not know what is accurate and what is not. In this sense, having a recording program like MW is a pioneering effort, and it will take a while for everyone to get into the habit of reporting the sightings….certainly some of the birding egroups are propogating this message now.

    Thank you for a most interesting read! Obviously, since I am very ignorant of any but the sketchiest outlines, my comments cannot be anything but very general. :)

  12. Deepa Mohan says:

    October 21st, 2009 at 1:00 am

    Another very *general* comment…when I saw bar-headed in several countries, earlier I would look and be content…now I come and check if the sightings have been reported on MW! :)

  13. Uttara says:

    October 21st, 2009 at 11:47 am

    Dear Deepa and Karuna, just a quick clarification-– the data presented here are from the 2009 pre-monsoon and early monsoon period (May-June); only posted at the end of monsoon :-) . Yes, we are really looking forward to making this a yearly exercise and hope you will be able to join the 2010 campaign year (starting May 2010). General sightings will be good to collect through winter; we can use these to try and map the distribution of the resident population in southern India. Many thanks for your comments.

  14. ketki says:

    October 21st, 2009 at 3:27 pm

    makes wonderful reading.
    you have really taken a lot of effort to make it simple.

  15. vinaya kumar thimmappa says:

    October 21st, 2009 at 9:42 pm

    this is just superb…

  16. Suhel Quader says:

    October 27th, 2009 at 10:54 am

    Thanks, Shyamal. I submitted a comment on your ManyEyes page, but it doesn’t seem to have gone through. Just wanted to suggest that it might make sense to “reverse code” the symbols so that earlier sighting dates are represented by larger symbols.

    Madhu — thanks for your comments. Do use the MigrantWatch data for Greenish Warbler or any other species. Anyone is free to download and use this information! By the way, normal html does work — I think you forgot the closing ‘/a’ tag!

  17. Shyamal L. says:

    October 31st, 2009 at 11:15 am

    Hi Suhel, there was a second attempt I tried on that same site belonging to IBM

    Of course I realize that the data is far from good enough to do much, but I think part of the goal of such a system (which is not just about results but method as well) should be to inform contributors that the system can only be as good as the contributions allow it to be (just like Wikipedia) – and so another goal, should be to share the joy of scientific exploration and discovery and that is something that would be nice to see on the migrant watch system. Now that data access equity has been achieved, it would be great if the developers/maintainers of the system can be encouraged to set up a data analysis system in the style of ManyEyes – so as to make the methods of analysis available as well.

    Perhaps the R plugin for mediawiki (example here, which seems to have a glitch) is worth examining. Since users can then set up pages with their own ways of analysis of the data, the results of which are updated as data comes in.

    good luck

  18. Ravi Rajasingh says:

    November 5th, 2009 at 5:37 pm

    This is my first blog here, I joined this site just yesterday after seeing the website in the sunday Hindu.

    I live in the foot hills of the Shevroys in Tamil nadu and saw my first pied cuckoo 17 yrs ago when it heralded the pre monsoon rains .
    The books say , its locally and internationally migrant. And there is a resident population too.
    The resident popultion is a silent forager of berries durng winter.

    The Pied crested Cuckoo, lays its sapphire coloured eggs in the nests of the common babbler ( 7 sisters) in June and after being weened , the young adults group togther when they are independant ( thats when they get noisy again ) and fly away in Nov.

    I see that, the emigration part isnt discussed here. It may be worth observing that also, do these birds fly back to East Africa ?


  19. D.S.Dhadwal says:

    April 11th, 2010 at 10:00 am

    It is very nice to have such an idea/vision to check the migration pattern and it will have far reaching results if reporting will be authentic/systematic and also other factors(local and micro) effect have to be taken care in analysing the arrival and departure of birds.

  20. D.S.Dhadwal says:

    April 11th, 2010 at 10:05 am

    It is very nice to have such an idea/vision to check the migration pattern and it will have far reaching results if reporting will be authentic/systematic and also other factors(local and micro) effect have to be taken care in analysing the arrival and departure of birds.I am working in international RAMSAR site,PONG-LAKE,H.P.for the last 7 years and observing pied cuckoo since 2003 around Pong-Lake.Pong-Lake is home of 1.50 lac water fowls during winter season.This time i will try to send the arrivla dates and departure dates of Pied cuckoo.The migratory birds have left Pong-Lake and only 150 Bar Headed Goose,8 Tufted Ducks, 5 Common Coots are in Pong Lake.

  21. The Pied Cuckoo in 2010 – Mousumi Dutta @ the migrantwatch blog says:

    October 27th, 2010 at 7:15 am

    […] The Southwest monsoon normally sets in over Southeast Bay of Bengal on 20 May and then over Kerala on 1 June. An analysis of the first sighting dates of the Pied Cuckoo and the onset of the Southwest monsoon for the year 2010 (see figure below) shows a fairly systematic pattern. In general, the first sighting of this species in a State is 20-25 days in advance of the onset of the monsoon in that State. This appears to be earlier, relative to the monsoon, than reported for last year. […]

  22. Sunil Dubey says:

    June 24th, 2011 at 5:20 pm

    Its a good record for the bird. I am having an wye over the arrival of the bird in Jhunjhunu region (North-East Rajasthan) since five years and in the Udaipur region (South Rajasthan) since more than ten years.

    I found the pattern of arrival of the bird coinciding with the arrival of the south-west monsoon. I am releasing forecasts for the arrival of monsoon in Jhunjhunu region following the sightings of the bird and i have been fortunate to be accurate for that.

    I would advocate for more studies on bioindicator organisms. Most of the times modern technology remains fail for accurate predictions for the nature whilst the natural indicators come true.

  23. Saravanan says:

    March 23rd, 2015 at 11:16 am

    Hi, I am seeing Pied Crested Cuckoo for the past few days near our home in Madurai, TN, India. You may please take note. Date: 23 March 2015

  24. admin says:

    March 23rd, 2015 at 12:48 pm

    Thank you Sir. Would be grateful if you uploaded this either on MigrantWatch (www.migrantwatch) or eBird (

  25. Hitesh Oberoi says:

    June 7th, 2016 at 12:45 pm

    I spotted a pair of #Jacobin cuckoo in Ahmednagar ( Maharashtra ) outskirts
    This morning #07/06/2016 it’s the first soptted pair in my city…

  26. admin says:

    June 9th, 2016 at 11:46 am

    Thank you very much for this! If you could take a few moments to upload this sighting to, then it will remain on record into the future for others to see.

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