New technology for tracking birds

A young osprey is ringed as pasrt of the The Tweed Valley Osprey Project.
A young osprey is ringed as pasrt of the The Tweed Valley Osprey Project.

Many of our wintering geese have very specific wintering and summering destinations.

The large and bold, black and white Barnacle Goose which winters at Caerlaverock in Dumfriesshire flies north to nest is Svalbard (Spitsbergen) whereas the population which overwinters on the Island of Islay nests in Greenland. The smaller Brent Goose which overwinters on the mud flats at Holy Island has a pale breast and nests in Svalbard whereas in the south of England there is a dark bellied race and they nest in Western Siberia.

Sometimes these geese will mix and intermingle when they overwinter here but in general they will return to their proper destinations to breed.

Male Shelducks do not take part in the raising of their offspring and leave that task to the female ducks. After egg laying most of our drake Shelducks fly across the North Sea and summer in Holland and in the Germany Bite where they moult. Goosanders have a similar strategy, here the males leave the females to raise the offspring and they depart to the fiords in northern Scandinavia.

For a long time bird ringing has been the principal method of finding out where our birds go when they migrated, but the chance of a ringed bird being recovered on its overwintering ground is very small. New technology in the form of tiny satellite transmitters has revolutionised the following of birds on their migration and turned up a number of surprises.

The small water bird, the Red-necked Phalarope, nests in very small numbers on some of our northern islands and it was assumed they wintered along the shores of the Indian Ocean and Persian Gulf where birds from Scandinavia are known to overwinter. Much to everyone’s surprise a Scottish bird with a tracking device flew the opposite direction and went via Iceland, Canada and the USA and overwintered on the Pacific coast in Ecuador.

Another amazing journey is that taken by Bar-tailed Godwits, some of the population of this wader breed in Alaska, from there they fly non-stop south, across the Pacific, all the way to New Zealand, a journey of some 7,700miles - flying non-stop for six days.

If you Google BTO Cuckoo tracking you can find a web site run by the British Trust for Ornithology and here you can follow the day by day movement of a number of Cuckoos with satellite tracking devices fitted to them when they were here in Scotland. Right now they have started their return journey and are just south of the Sahara. Similarly you can follow the migration of a number of Ospreys which fly to western Africa for the winter and are now returning back to Scotland to breed.

The next meeting of the Scottish Wildlife Trust in Duns Parish Church Hall is on Thursday, April 7, at 7.30pm. After a short AGM there will be talks by Myra Watson on some of the Hebridean Islands. David Long will talk on a region in France and Roger Manning will talk on ‘Recent Highlights’. Everyone is welcome.