MIST NETS MAKE
THE DAY FOR GOT BIRDERS
Seven o’clock on a cold autumn morning by the River Tenes as it flows through the small country town of Bigues & Riells (pop. 8500). The ornithologists, in deep wellies, were already at work pitching mist nets, each 3 metres high and 12 metres long. Four nets were put up – two on the left bank, one on the right bank and one astride the 14-metre width of the river. Once over, it was a question of waiting. To lure the birds into the nets, a tape-recording of the songs and calls of a variety of birds played away.
Seven o’clock on a cold autumn morning by the River Tenes as it flows through the small country town of Bigues & Riells (pop. 8500). The ornithologists, in deep wellies, were already at work pitching mist nets, each 3 metres high and 12 metres long. Four nets were put up – two on the left bank, one on the right bank and one astride the 14-metre width of the river. Once over, it was a question of waiting. To lure the birds into the nets, a tape-recording of the songs and calls of a variety of birds played away.
Observing birds in the wild, even armed with the best binoculars, can be an activity fraught with frustration for the uninitiated birder. And to make matters worse, any large troop of expectant adults and excited kids crashing through thick undergrowth would make enough noise to put the most tranquil woodland bird to flight long before you get a glimpse of it.
This is where the ornithologists and their nets come in…
Lugging netting equipment, ornithologist Roger Sanmarti wades across the Tenes while his companion, Anna Dalmau, makes sure the mist net straddling the river is well secured.
Ornithologists only…
Made of nylon mesh and suspended between two poles, mist nets are widely-used to capture birds for ringing or banding for research purposes. The nets are virtually invisible, especially when deployed in wooded river banks. The bottom part of the net doubles up to form a pouch into which a bird would slip when it hits the net in flight. There is generally a low risk of injury to the birds, although disentangling them can be tricky and is left to trained ornithologists. In Spain, only certified ornithologists are allowed to use mist nets to capture birds for banding.
This male blackbird was the first to fly into the net and got entangled as it struggled to free itself. With care, patience and a lot of experience behind her, Anna went about the delicate task of extricating it. And in less than three minutes it was freed, none the worse for its experience.
Once freed, into a specially-designed bird bag it went. The bag is made of light opaque cloth and used for transporting birds from netting site to the "processing" area. Birds caught in any trapping technique are placed in such bags (one bird per bag) to prevent injury. Bags which contain birds are hung, never placed on a table or the ground.
Soon after the capture, the processing of this blackbird began. Processing involves identifying the species,taking measurements, figuring out age and sex, identifying the stages of moult (the periodic replacement of feathers by shedding old feathers while producing new ones), recording information on an official data sheet, banding the birds with a unique ring and, finally, releasing them safely.
A Kingfisher gets its ID…
Kingfisher (Alcedo atthis); Catalan: Blauet; Spanish: Martín pescador; German: Eisvogel ; French: Martin-pêcheur
Every bird band or ring is unique – one ring with one identification number for one bird. In Spain they are issued by the Ministry of Environment to accredited ornithology groups. The ones above were issued to the Catalan body, the Institut Català d’Ornitologia, based in Barcelona, and to which ornithologists Roger and Anna belong. The bands range from 2mm for passerines to 26 mm for large water birds, game birds and birds of prey. Size 10 on the right, above, carrying the ID number 17989 would be fitted on an Eagle owl [bubo bubo; Catalan: Duc; Spanish: Búho real; German: Uhu; French: Hibou grand-duc].
Duly ringed and registered, the kingfisher looked chirpy as it readied for the flight to freedom – and to the cheers of a delighted crowd who had been intently watching the ringers at work.
For these birdwatchers, the ringing session for birds caught in the mist nets was the real highlight of their birding morning at Bigues & Riells and more than made up for any disappointment at not spotting any bird in the trees. For both adults and the children who pursue birdwatching as a recreational activity this was probably their only chance to get a close look at birds of the wild. And for the young ones who were permitted by the ringers to stroke the birds gently before their release, it was a truly unforgettable experience. GOT’s regular “morning with nature” gatherings such as this one ensure that you don’t have to be an ornithologist to get near bird species ordinarily impossible to spot in the wild.
Robin (Erithacus rubecula); Catalan: Pit-roig; Spanish: Petirrojo; German:Rotkehlchen; French:Rougegorge
And, to round off an exhilarating session -- the ringing of this European robin, everyone’s favourite and undoubtedly the most easily recognisable passerine of all, with its orange breast and face lined with grey, its brown upper parts and its whitish belly. Both male and female are similar in colour.
With the closing of the ringing session came the second highlight of the day—the hands-on construction of nest boxes (below).
For the kids it was a noisy family affair, with Mums and Dads getting in on the action. All the material -- pre-cut wooden boards, nails, hammers and hooks -- were provided gratis by GOT. Nest-box experts were on hand to give practical advice.
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