brewood ringers

Results of a Ringing Expedition to the Parque Ambientale, Vilamoura, Portugal

5^th-13^thOctober 2012

Colin McShane (A); Dave Clifton (A); Paul James (A); Chris Hughes (A); John Hodson (A); Glynn Middleton(C); Scott Petrek (C); Lloyd Park (C); Michelle Househam (T); Howard Morgan (T); Charlie Sargent (T)

Introduction:

This expedition builds on the five very successful trips since 2007.

Although fewer new birds were ringed than for any previous trip, the trip was successful in that the third highest range of species was caught, and a very important new species was added to the list of species caught at the site ( see below). The main disappointments were the inaccessible ‘tip’ site; poor roost numbers; the poor response of birds to our sound systems, and the lack of an influx of ‘new’ birds to replace migrants which left early in the week.

Two new species were added to the overall species list, with a couple of unexpected surprises finding their way in to the nets, in the form of two Wrens ( Troglodytes troglodytes) and a magnificent Aquatic warbler ( Acrocephalus paludicola), which is a globally threatened species with only a handful of ringing records in Portugal.

Our roost netting efforts were very disappointing. Most of the hirundines moved on early in the week, and although our sound systems brought many Corn buntings ( Emberiza calandra) into the trees reeds and bushes near the nets, very few actually entered the netting area on their way to roost.

No sessions were lost due to adverse weather, the conditions being hot and settled during the whole period. However, bright sunshine and strong onshore winds reduced the daily catch by increasing net visibility.The absence of any periods of overnight rain, or heavy cloud cover certainly reduced the number of birds ‘grounded’ on migration. Although the data show arrivals of certain species during the week, there were no obvious ‘falls’ of migrants. There was a general ‘clear out’ of many migrant species during the week which was not replenished by equal numbers of incoming birds.

Once again, our visit was well supported during the planning and implementation stages by our friends and contacts in Portugal; Nuno Grade, Ana Luisa Quarema; Vitor Encarnacao, Michael Armelin, to whom we owe, as always, an immense debt of gratitude. The provision of a heavy duty undergrowth ‘strimmer’ by the Parque authorities, was particularly useful in quickly opening up traditional net rides.

Methodology:  

Catching used on average 13 Japanese/Polish mist nets, set at fixed positions, practically identical to those set in previous years. The site is close to the observation hide and has become the main core area for the operation, and therefore provides some good comparative data.

The northern edge of the marsh, ( aka the ‘Tip’) which has been netted in all previous years except 2010, proved impossible to get into due to dense growth of bramble in particular.

However the interesting area we opened up for ringing in 2011; an area of scrub and young olive bushes adjacent to the water treatment works proved a useful additional ringing site, producing a third of the catch on most days. Although access is tricky, we put in place a wooden ‘bridge’ and a rope for hauling up the side of the ditch. Visiting Sylvia and Phylloscopus warblers in particular were caught in good numbers and we are still of the opinion that as the season develops this site would get even better for Blackcaps and Song Thrush because of the available small olives.

 Extra nets were set in the fields to target groups like finches, wagtails, pipits, and hirundines but these proved very disappointing compared to previous years, for which we have no plausible explanation. One evening trip to dazzle Red Necked Nightjars ( C. ruficollis) was also unsuccessful and special efforts to catch raptors resulted in only one Kestrel ( F.tinnunculus). The usually abundant raptors were much less obvious this year.

Nets were erected around 07.00 hrs each day, with sunrise around 07.20 hrs.  They were manned continuously and checked every 20 – 30 minutes.  Weather conditions were generally good and ringing carried on continuously, with nets being furled around 18.30 hrs for the first three days. However, as the week wore on the afternoon conditions deteriorated into gale force onshore winds so ringing was halted around 13.00. Only two attempts at roost netting were attempted with very modest results. The Hirundine species had largely moved on before we tried to net them them at roost, and of the hundreds of Corn Buntings in the area and roosting in the reedbeds, very few could be attracted using sound lures. 

All birds were ringed using CEMPA rings and all were processed to record; age, sex, weight and maximum-chord wing length.  Migrant species were scored for fat, using the 5-point Euring scale.

Results: