Saturday, 15 September 2012

Tracking the Cuckoos.

The 'Red Listed' Cuckoo is one of the UK's fastest declining migrants, and until recently was one of the least known about species once it left the UK. 

Cuckoo. Courtesy of the BTO.

This is 115589 who was to become known as John and who was to play his part in what has developed into a sad episode in the story of the BTO's 'Tracking Cuckoos Project'.

During the summers of 2011/12 a total of seventeen Cuckoos were satellite tagged in a project by the BTO to try and get some data on the movements of the species. Last year I sponsored a bird called Clement who was unfortunate to have perished after he had successfully migrated back to his wintering grounds in Africa. This year I sponsored John who sadly has - for some unknown reason - suffered the same fate as Clement did in 2011 though John appears to have got no further than north-eastern Spain when - faced with the result of recent wildfires and ensuing chronic drought - feeding would have been made difficult if not impossible, and he behaved very oddly in that he made an oblique re-crossing of the Pyrenees. Another Cuckoo name Reacher 'disappeared' and is presumed dead in exactly the same area where the recent fires had been reported. Temperature data taken from the tags of the Cuckoos seem to suggest that the birds body temperature wasn't influencing the tags temperature which unfortunately supports the idea they may have perished.    

Yet another Cuckoo named Lyster who has become a particularly sad story in that he was the one who was successfully tracked for 15 months following his tagging in the summer of 2011, his epic journey was tracked all the way to Africa and to the delight of all concerned made it back to England the following spring this year. How sad then that Lysters tag failed to transmit after having received the information that his position was in the Mauritanian Desert. He had passed through Catalonia where the fires had been reported and had stopped off in an area thought not likely to have been able to provide the feeding opportunities to put on enough weight for a successful crossing of the desert in Africa. 

As it stands today, just one Cuckoo out of eight tagged in England in 2011/12 still survives and is transmitting, his name is Chris. He is in Chad in an area he visited last year before continuing into the Congo Rainforest, all eyes are now on how closely his activities this year match those of last year from here on.

Given the trials and tribulations of migration, I don't think anyone would have expected every Cuckoo to make it from the UK to Africa, but you can't help but feel a sadness that so many have been lost from one regional group, but this appears to reflect the trends that Cuckoos in England have declined by much more than populations in Scotland and Wales....All very sad given a Red Listed and fast declining migrant bird, with a long way to go to discover some of the reasons why.

 Cuckoo Marc Heath

Thanks for the brilliant image of the juvenile Cuckoo Marc....I know this is last years photograph - taken 23 July 2011 - but you have to wonder where this bird might be today.


Warren Baker said...

All very sad Pete,
Just one Cuckoo from eight left, an appalling ratio of losses if extrapolated through the Cuckoo population :-(

Brian Rafferty said...

Pete.Thanks for all of the very interesting but very sad cuckoo information..Let's hope Chris makes it back again next summer. Take care.

Ana Mínguez Corella said...

Hi Peter!!!.. I love cukoos!!!.. Greetings..

Noushka said...

Brilliant shots, I envy you the last one!
Sad to learn it is in such decline in the UK...
This summer, I have seen one perched 12 meters from me as I was taking pictures of dragonflies with the macro lens... :( I was sooooo angry and frustrated!!
I hope we manage to preserve our nature for the future, seems bleak though...

Pete Woodruff said...

Warren/Brian/Ana/Noushka....Thanks for you comments, I have noted them all with interest.