Friday, November 20, 2009

Retrieving data-loggers

Processing station - Manawatu Estuary

About to release a banded godwit
A couple of weeks back now an important catch took place down at Foxton Beach, at the Manawatu Estuary. The main purpose of the catch was to retrieve as many of the 24 data-loggers back off birds that had been carrying them around the globe. Data-loggers record data on hours of light/dark while attached to a bird. From this data longitude and latitude can be calculated, giving the migration journey of the birds. However, to retrieve this data the device needs to be removed from the birds leg, where it has been sitting for a year (or in some cases 2 years). Of the 24 birds that had dataloggers placed on them all 24 had been sighted back in New Zealand, 23 of those in Foxton and 1 in Christchurch. A 100% survival indicating no adverse effects on these datalogger birds. We were able to join with a number of NZ birders and DOC staff to catch birds with cannon-nets, the dream goal being to retrieve all 23 data-loggers from the birds present. Radio NZ was also there, recording the action and seeking insights from participants as the day unfolded. A touch of careful movement of birds from down the end of the beach found them roosting in the catching zone, so then 3,2,1 fire! Off went the cannons, firing the nets over the birds. We raced to the shore to release the birds and within 10 minutes all birds had been placed safely in bird boxes, thankfully with no casualties! In the end, amongst the catch, were 17 birds with data-loggers. A good result, though still leaving the question of how to get the other 6 or 7?

1 comment:

Bronwyn McKee said...

Hi Craig,

Someone at Freyberg suggested I look up your blog. I have quite a good Godwits shot that they thought you might like. You can drop me a message on the school's e-mail system if you like, with an e-mail address I can send it too.