Wednesday, June 27, 2007

A Tale of Two Boat Trips: no. 1, Nighttime

For several years now, we have wondered whether its possible to catch storm petrels at sea...

This would allow us to test a whole set of new hypotheses about the lives of these highly pelagic birds on the open ocean.
Others have certainly managed it in other parts of the world, including the New Zealanders studying the recently rediscovered New Zealand storm petrel, who have caught several of these remarkable birds at sea, in order to take genetic samples and fit radio-tracking devices in the hope of discovering the birds' breeding colonies.

Most successful have been Gill, Sladen & Huntington, who published a paper in 1970 describing how they caught 117 Wilson's and 13 Leach's petrels (plus 120 assorted shearwaters) using a hoop net hand-thrown from the back of a boat during daylight in the Bay of Fundy, Canada. (Bird-Banding, April 1970, pages 111-113).

This has never yet worked for us off Portugal and after a series of daytime pelagic trips spent half-heartedly waving various prototype nets rather pathetically over the sides of boats, we decided to take another tack.
Preparing yet another unsuccessful version of Gill et al.'s hoop net on a dytime pelagic trip in 2006

A chance encounter with Jose Xavier of Cambridge University at a schoolteacher's climate change seminar in Lagos (organised by A Rocha's own Paula Banza/Felgueiras), led us to Daniel Machado -a marine biology graduate with an 11m catamaran which he has fitted out for a marine ecotourism business venture. Renata, Patricia and Rob went to take a look and realised that it would be perfect for running 9m mist nets along the two hulls! Clearly this needed to be done at night on the open ocean -what could possibly go wrong?

A trial run fitting the mist nets during daylight -note the confident grins!

And so it came to pass that one not too stormy night, Rob, Mark, Colin & Jez, captained by Daniel and crewed by Andre, set sail from Portimao out onto the trackless ocean. Once we had reached about 10km offshore, Daniel and Andre furled the sails and we set two mist nets along each hull of the catamaran. We were very pleased with the result -two absolutely taut and rigid mist nets, floating on an artificial "island"!

Oh captain, our captain! Daniel at the wheel, sailing out from Portimao at dusk

Colin was "volunteered" to tie off the mist net at the far end of the hull.

We turned on a tape-lure, hung a bag of mashed up mackerel chum over the side, and waited...
Two chums preparing the chum
There then followed a slightly disappointing couple of hours of swaying around, with no birds attracted to the tapes. In desperation, we shone some torches over the sea, to see if we could spot any passing stormies. To our surprise, the sea was alive with petrels, some of which seemed to change direction in response to the torch beams and could be "steered" towards the nets! Suddenly there was a storm petrel flying in an arc over Colin's torch, over our heads... and... it tumbled into the mist net right next to Rob! Rob held onto the bird, Jez grabbed Rob and Mark grabbed Jez. The surprised bird was safely weighed, measured and released, amid scenes of great rejoicing!
...The first European storm petrel to be mist-netted at sea (I suppose).
Ringing inside the cabin
Some time later, another bird was landed on the deck next to Mark, who calmly picked it up and appeared from behind the cabin exclaiming "I've got one in my hand!" More measurements ensued, and we continued trying to catch more birds until our torch batteries gave out and the strengthening wind forced us to move closer inshore.
And so we arrived back at Portimao at dawn, after an exhilarating night of scientific adventures, and looking forward to having another go next year! (I speak for myself, clearly -Rob). Thanks to Daniel and Andre for looking after us -if you'd like to contact Daniel about boat hire etc, click here.
Colin reflecting on a very interesting experience (or is he just asleep?)

Saturday, June 16, 2007

2007 catches

May 22-23: 6 stormies, 1 carrying a Spanish ring
May 23-24: 15 stormies, 1 UK ring
May 24-25: 3 stormies
May 25-26: 6 stormies, 1 UK ring
May 26-27: 5 stormies, 1 UK ring, 1 Italian ring (first one ever!)
May 27-28: 4 stormies
May 28-29: 3 stormies
May 29-30: 6 stormies
May 30-31: full night off -Dave having set a new world record of 8 consecutive stormie nights!
May 31-June 1st: 3 stormies, 1 UK ring
June 1st-2nd: 1 stormie
June 2nd-3rd: 9 stormies
June 3rd-4th: 5 stormies
June 4th-5th: 7 stormies
June 5th-6th: 14 stormies
June 6th-7th: Night off
June 7th-8th: 46 stormies, 4 UK rings
June 8th-9th: 40 stormies, 1 "big petrel" seen and heard but not caught!
June 9th-10th: 62 stormies, 1UK ring
June 10th-11th: 45 stormies, 1 UK ring
June 11th-12th: 43 stormies, taking us to a grand total of 3,999
June 12th-13th: 39 stormies on land & 2 caught at sea during the night!
June 13th-14th: 67 stormies, 1UK ring, 1 Norwegian ring
June 14th-15th: 32 stormies, 2 UK rings
June 15th-16th: Phew, a much needed night off!
June 16th-17th: 18 stormies, 1 Spanish ring
June 17th-18th: 32 stormies, 1 Norwegian ring
June 18th-19th: 6 stormies -last night of the season
June 19th: End of season party!
June 20th: sleeeeeeeeep

Final 2007 total: 25 nights, 518 stormies, 18 international rings
Grand total 1990-2007: just over 4,000 stormies

The 2nd bird of the year -a Spanish-ringed storm petrel!

Vomit news

Renata's PhD project focuses on the diet of storm petrels during their long-distance migrations, and we have managed to collect some excellent samples of vomit (which mist-netted storm petrels occasionally produce) and faeces. You may particularly enjoy this fine sample, featuring various bits of fish and (just above the centre of the paper disk) three tiny isopods.

Vomit samples are quite rare from migrating stormies, and each one is received with great rejoicing from Rob. Perhaps he should get out more...

Quite how storm petrels manage to feed on isopods at night is a bit of a mystery -see our recent paper:
Thomas, R.J., Pollard, A.L. & Medeiros, R. Evidence for intertidal foraging by European Storm Setrels Hydrobates pelagicus during migration. Atlantic Seabirds, in press.

New light was shed on this mystery last night, when Earthwatchers Sherri and Karen discovered that isopods can find and attach themselves to dead fish floating in the surf zone -so perhaps stormies eat isopods by "accident" when eating bits of fish, rather than by actively hunting isopods in the dark.

South coast 67: West coast 0

A trip was organised to the west coast, to try to catch stormies. Earthwatch team 1 in 2005 had caught 4 birds there that were unusually lightweight. We wanted to try to confirm whether stormies really are lighter on the west coast. The trip was coordinated by Manuela Nunes of ICN, assisted by Carlos, Colin & Mark.
By all accounts it was an exciting night of dodging large waves and jumping across large boulders but unfortunately no stormies were seen or caught.

Mark and Colin setting out for the west coast

The following night, Manuela and Carlos joined us on the south coast, where we were much more successful.

Our 4,000th storm petrel

Well done us -we have reached 4,000 storm petrels caught and measured by the A Rocha Portugal field centre. We had a party in the garden to celebrate this milestone in our project, as well as the recent promotion of our very own Nicola Marples to senior lecturer at Trinity College Dublin.

Monday, June 11, 2007

Updates on the Italian wanderer

A storm petrel caught on the night of 26-27th June was carrying an Italian ring. The Mediterranean storm petrel population is genetically divergent from the Atlantic population, and is generally assumed to be dispersive but not to migrate long distances. As far as we know, this is the first time a stormie from the Mediterranean breeding range has been caught in Atlantic waters (though do let us know if you know of other instances!). We will have to wait to find out the details of its genetics and of where and when this bird was ringed in Italy, but this movement provides evidence that there is at least some exchange of storm petrels between Mediterranean and Atlantic waters.

Magnus Robb, who is completing a book about storm petrels for publication in the autumn, has emailed to say that there are 2 records of stormies ringed on Malta and found dead in Altlantic waters:
1. 15/09/1989: A bird found dead on Ameland, one of the Frisian islands strung along the northern coast of the Netherlands. Ringed in a colony in Malta on 10/07/1971.
2. 02/02/1990: A bird found dead on the Côte Sauvage, La Tremblade, Charente-Maritime on the Atlantic coast of France. Ringed on Malta on 24/05/1986.

The new book 'Petrels night and day' by Magnus Robb, Killian Mullarney & The Sound Approach, will be out in the autumn. If you'd like to order a copy, email Magnus on:

Renzo Ientile has been in touch from Italy to say that this bird was ringed in Marettimo, Italy, as a chick in the nest on 16/07/04, thereby confirming that it was Italian by birth -apparently the first definite record of a Mediterranean storm petrel (Hydrobates pelagicus melitensis) in Atlantic waters!
These details will all be formally confirmed in due course via the EURING bird ringing database.

Saturday, June 09, 2007

Migration season

Two great nights in a row, with catches of 46 and 40 birds. This takes us to a 2007 total of 173 stormies -already more than the 2006 total of 136 birds. Our next challenge is to reach the all-time total of 4,000 Portuguese storm petrels -just a couple of hundred to go but 10 or so nights to do it!
Here is the team with the 100th bird of 2007.
Left to right: Jose Xavier, Patricia, Dave, Claudio, Jez & Leila.

Each petrel was examined by a committee of experts.
L-R: Sara, Patricia, Leila, Jez

Friday night was family night -here are Rosie and Ben Simonson about to release a petrel.

Thursday, June 07, 2007

101 things to do when not catching stormies

No. 2: build a tarpaulin shelter. Here are a few of the award-winning designs from 2007.

"The concorde" -modelled by some exhausted petrellers after it had initially collapsed. This is also rare photographic evidence of Dr Jo Lello on fieldwork.

"The Sierra", prior to the installation of the Jo Lello memorial picnic blanket

The "Al Fresco", before or after the shelter had collapsed on a sleeping Jez!

Friday, June 01, 2007

101 things to do when not catching stormies

No. 1: Comedy photos

Unidentified flying objects

Full moon with werewolves