MIST-NETTING: HOW MUCH OF AN INJURY HAZARD DOES IT POSE TO WILD BIRDS?

  

 Setting up a mistnet (photo: Júlio Reis via Wikimedia Commons)

TO what extent are wild birds stressed when they are trapped in mist-nets prior to ringing or other scientific research?

Some year ago, the issue was raised by naturalist-author Richard Mabey after a Siberian blue robin - the first record for Europe - had  been trapped in a mist-net on October 27, 1975, on Sark in the Channel Islands.

He noted: "It was 4,000 miles off track, tired, hungry, terrified and hung up by its feet for God knows how many hours.

"I am bothered by the attitudes towards birds of supposed bird lovers who desire to trap birds at the moment of their greatest exhaustion and insecurity,  then to process them as if they were so many pieces of baggage. 

"It seems to me inexcusably degrading to both birds and handlers when the outcome is likely to be nothing more than another species on the British list."

He widened his concern with a reference to birders destroy who were reported to have "destroyed a clutch of bearded tits by chucking a piece of concrete into a reedbed to try to flush a bittern".

In its latest review of the potential hazard of mist-netting, the BTO  says: "Any effect of capturing wild birds on their individual welfare, or that of their wider populations, is an important ethical consideration.

"It also has significant implications for the integrity of the data collected as biases may be introduced if capture and handling bring about changes in behaviour or survival.

"Ultimately, the benefit of the information accrued when capturing wild birds for study needs to outweigh the potential risk to individuals that are caught."

The report continues: "While the potential effect of fitting rings or other devices to birds has been assessed  through a series of  studies, the direct effects of the capture methods themselves have received less attention.

"We undertook an assessment of the impacts of mist-netting for birds as part of the British and Irish Ringing Scheme.

"Overall mortality rates were low with most fatalities reported to have occurred before individuals had been extracted from the nets.

"We will use the results from this study to help to refine guidelines for those trapping and handling wild birds and to identify additional opportunities to secure information that could be used better to understand risk factors and associated mortality."

The BTO says the results were published in an edition of the open access journal, Ecology & Evolution, and shared with operators of other European ringing schemes to help ensure they have the widest benefit.


See also:  

https://en.wikipedia.org/wiki/Mist_net

https://onlinelibrary.wiley.com/doi/10.1002/ece3.4032
          
http://www.socsercq.sark.gg/siberianbluerobin.html

https://sora.unm.edu/sites/default/files/journals/nabb/v007n01/p0002-p0014.pdf