Commuting Storm Petrels and warblers

We recently received some interesting recoveries from the BTO, mostly of some pretty fascinating Storm Petrel movements. In the past we've traded quite a few birds with Ile Banneg, home to France's largest breeding population of Storm Petrels, but these reports were notable.

Over summer 2013 at Hot Point, Lizard, we only caught one French-ringed Storm Petrel (compared to four in 2012), but we've just heard that we had a great run of records of birds going the other way. In total five birds ringed at Hot Point in 2013 were recaught on Banneg later in the year, with a further bird ringed in 2012 unfortunately found predated there. This compares with just one going that way in 2012.

But what was interesting was when these birds were caught, with some making very quick movements over the 178km to Banneg. Birds ringed in June were recaught 35 days, 32 days and four days later, whilst a bird ringed in July was recaught three days later and one ringed in August was recaught the next day! I'm sure birds regularly commute backwards and forwards across the English Channel, but in theory non-breeding birds are more attracted to tape lures, but I bet these movements are of breeding birds...

We also just received details of a few movements from last autumn, including a Sedge Warbler ringed at Marazion and recaught in France five days later (but it did weigh 11g when ringed so was obviously getting ready for the off), a Spanish-ringed Reed Warbler recaught at Gunwalloe was ringed on spring migration (the first to be found in Cornwall), and a Chiffchaff we caught in November had been ringed in North Yorkshire a month earlier. This bird had come over 500km and was presumably on migration through the country when ringed.

The map below shows where these birds were ringed/recaught: Storm Petrels (red), Sedge Warbler (green), Reed Warbler (blue) and Chiffchaff (yellow). 

Mauritania Sedge Warbler and a Cormorant caught in the act

We recently received a whole bunch of reports back from BTO of birds we'd either ringed or recaught ourselves. The map below shows the spread of these reports and gives a good overview of where the birds we're ringing/seeing are coming from and going to. The map below shows birds ringed by us found elsewhere (in red) and birds ringed elsewhere recaught/seen by us (in blue), and you can zoom in to see more detail. Clicking on a line will also give you the full details for the movement: species, dates, places...

View Recent recoveries 2013 in a larger map

The furthest movements are a Sedge Warbler ringed at Gunwalloe recaught by French ringers 2400 miles away in Mauritania and a Polish-ringed Mediterranean Gull seen on the Hayle estuary (along with a Channel Islands Herring Gull). The movement to Mauritania is expected as this is where Sedge Warblers go, but is still only thew second from Cornwall to Mauritanis, with fewer than 25 BTO-ringed birds found there!

Other long-distance movements include Storm Petrels in all directions, with two birds to Skokholm Island (expect more from here as ringing has started a fresh here) and birds recaught from the Channel Islands and Co Wexford. We've also now got all the details back on the various colour-ringed Kittiwakes now breeding in Cornwall (more info on these here). These are all from the same French colony, but the interchanges are proving pretty fascinating!

View Recent recoveries 2013 in a larger map

A bit closer to home, a couple more of our colour-ringed Herring Gulls have been seen. Another bird from Falmouth visited Stithians Reservoir and a bird from Rinsey Cliffs was seen on the beach at Marazion. These birds all have a blue ring with code W:000 to W:999 so keep an eye out for these around the coast or at any gatherings of gulls. Another of our colour-ringed birds reported was a Cormorant caught in netting whilst stealing fish from an inland fishery, but was happily untangled and released unharmed. Wonder if it's learnt its lesson??

We don't have a photo of Cormorant TAH caught at the fish farm,
but here's TAB also ringed on Mullion Island

One final interesting movement is a Sedge Warbler ringed at Nanjizal and then recaught five days later at Gunwalloe, almost directly due east. We've also had recent reports of some of our Sedge Warblers moving north in autumn, so I wonder if these are actually heading out of the country somewhere further east and not directly or through the Isles of Scilly as expected...

Another Aquatic-less day, but perhaps an Estonian Arctic Tern instead?

With the wind hinting at turning to the east, we headed to Marazion this morning in the hope of a late Aquatic Warbler. But sadly still no luck, although 32 birds caught wasn't too bad considering how quiet the reedbed seemed. These were mostly Reed Warblers, though one of the driest net rides did catch this rather smart female Kingfisher (female by virtue of being greeny-blue instead of bluey-green) and almost caught a passing Common Sandpiper. Overnight the wind is proper easterly though, so maybe tomorrow will be the day...

A bit of extra interest for the morning came with the delivery, via RSPB, of a GPS data logger that was reported on an injured tern at Sennen Cove on Saturday. Unfortunately the bird died but the second finder only removed the data logger and not the ring, so we're still a bit in the dark as to what the bird was and where it was from! Rumour has it though that an Estonian-ringed Arctic Tern caught in Grampian recently also had a similar logger, so here's hoping...

 

 

We won't find out for a while though as the logger has to go back to the manufacturer (in Poland) to be downloaded to ID the bird. For info, the aerials allow the GPS data to be downloaded remotely to a radio base-station once the bird is back on its breeding grounds. So for those with 1107 € to spend, check out the technical specs here.

Thanks to Tony Mills for the Kingfisher photo and Terry George (Sennen Cove Birdwatching), Kester Wilson and Dave Flumm for eventually getting the logger to us.