How safe is mist netting? First large-scale study into bird capture technique evaluates the risks

Jun 30, 2011
This is a Wilson's warbler in a mist net. Credit: Renee Cormier

Capturing birds using mist nets to study behaviour, movement or the demographics of a species is one of the most common research techniques in ornithology, yet until now there have been no large scale studies into the risks mist nets pose to birds. Writing in the British Ecological Society's Methods in Ecology and Evolution researchers from California used a dataset of over 345,000 records to evaluate the risks of mist netting.

The research, led by Erica Spotswood from the University of California at Berkeley, used data from organisations across the United States and Canada to assess the which could increase rates of injury or mortality including bird size, age, frequency of capture and the role of .

The results revealed that are rarely injured or killed by mist nets. Of 620,997 captures the percentage of incidents of injury amounting to 0.59% while only 0.23% of captures resulted in . The authors then began to analyse risk factors which could lead to increased incidents.

Spotswood first discovered the lack of research into mist netting while applying to study the Gray-green Fruit Dove in French Polynesia. When concerned officials denied her permit and questioned the safety of capturing birds with mist nets Spotswood realised that no comprehensive study quantifying the frequency of bird injuries during mist netting existed.

"I was very surprised to find that no study of this kind existed, because mist netting has been around since the 1950s and is an extremely widely used and common technique for monitoring ," said Spotswood. "In the United States at least one million new birds are banded each year at several hundred bird observatories around the country."

The authors compiled a dataset of documented bird injuries and mortalities from 22 bird banding organisations across the and Canada, resulting in a dataset of over 345,000 records of capture, spanning more than 20 years of research and featuring 188 species of birds.

"Using this enormous dataset we could consider not only the rate of injuries, but could ask which species are most at risk and what kinds of incident are most common," said Spotswood. "What began as an inquiry for a permit application ended up evolving into something we feel will be of value to the scientific community."

The team also analysed how repeated capture can affect the likelihood of incident and were surprised to discover that birds which were captured more frequently were less at risk than birds which were only captured once. The team suggest this is because frequently captured birds are more likely to be established adults with territories, which are commonly in better condition than birds that don't have territories.

Finally the team found that birds which were released with an injury were just as likely to be recaptured as birds without, meaning that injured birds continue to survive in similar numbers to uninjured birds, meaning the long term impact of mist netting is minimal.

"A lot of wildlife research requires that animals are captured and handled in order to study populations, , behaviour or movement, yet the process can be stressful to animals. For both ethical reasons and the sake of the research, it is important to make absolutely sure any risks are minimized," concluded Spotswood.

"Our study fills in an important gap in understanding by evaluating one of the most commonly used methods in ornithological research. We have shown that when banders follow good practices, incidents are rare. We hope that the results of this paper will be widely read by the banding community and that it will help researchers minimize any risk of incident."

Explore further: Study finds tropical fish moving into temperate waters

add to favorites email to friend print save as pdf

Related Stories

Birds quarantined at Texas pet stores

Mar 01, 2006

PetSmart Inc. has reportedly offered to quarantine birds at its Texas stores after two of them began showing signs of a bacterial infection.

Bird flu outbreak reported in Russia

Oct 01, 2007

Hundreds of thousands of birds at a poultry farm in Russia's southern Krasnodar Terroritory are being destroyed following an outbreak of bird flu.

Recommended for you

Study finds tropical fish moving into temperate waters

34 minutes ago

Tropical herbivorous fish are beginning to expand their range into temperate waters – likely as a result of climate change – and a new international study documents the dramatic impact of the intrusion ...

Warming leads to more run-ins with polar bears

3 hours ago

Word spread quickly: a polar bear, then two, were spotted near this remote Inuit village on the shores of Hudson Bay, about 1,800 kilometers (1,120 miles) north of Montreal.

Stranded pilot whale rescued in Cape Verde

22 hours ago

The archipelago nation of Cape Verde is widely recognised as a marine biodiversity hotspot, not least because of the abundance of marine mammals found in its waters.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.