Introduction To Net Checks

Jon Van Arragon

Beaverhill Bird Observatory

Introduction to Net Checks

• Checking the mist nets at a banding station is a critical role to ensure the station runs smoothly and safely
• When you are running net checks, it is your responsibility to ensure the safety and wellbeing of the birds being captured and that the nets are properly set
• The added responsibility of this role can be intimidating at first, but we will ease you into things and make sure you have all the help you need
• You will always have an experienced staff member with you on a net check to guide you through things until you’re approved to go on net checks solo

Mist Net Setup

• Mist nets need to be opened and set properly to ensure they can capture birds both safely and effectively
• The trammels of the net should be spaced relatively evenly
• The trammels are the horizontal lines of thicker material holding the mesh up
• If these are too close together, birds can get caught in multiple panels of mesh at the same time

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These should be spaced evenly

Mist Net Setup

• Open the nets but pushing the top trammel up about one foot to start unrolling the net
• When spacing the trammels, don’t just pull on the top one. Instead, push all of them upwards together, leaving the lowest trammel once it is in position
• Opening the nets stepwise like this increases their longevity
• Don’t push the top trammel over the top of the net’s pole!

These should be spaced evenly

Mist Net Setup

• The bottom trammel of the net should be around knee height to ensure larger birds don’t end up on the ground if they are caught in the bottom pocket
• There must be adequate tension on the net
• If it is drooping or sagging in the middle, tighten the guy lines on either end of the net by sliding the knot further up the pole

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Slide this knot upwards to tighten the net

This line should be roughly knee height

What Do You Bring on a Net Check?

• Bird bags – these hold the birds and keep them calm while transporting them back to the station. Bring 1-2 sacks of bird bags, these can be found in Rubbermaid bins in the lab
• Extraction kit – these contain scissors and a crochet hook for dealing with difficult bird extractions, as well as some net repair supplies. They are the flamingo fanny packs hanging on the wall behind the banding bench
• Radio – lets you communicate with the banders if things get busy, or call for assistance if needed
• A net stick – to raise or lower sections of the net as needed. These are usually leaning against the north side of the deck
• Leave backpacks behind – these can get caught in the net easily and potentially tear a hole in it!

Net Check Basics

• When mist nets are open, they should be checked every 30 minutes at minimum
• Nets should be checked more frequently in some situations
• On busy days with lots of birds being caught
• If the weather is poor or borderline (covered on a later slide)
• If a predator was sighted near one of the nets (based on the discretion of the bander in charge)
• Often during a net check, one person heads forwards along the net loop while the other heads backwards. They meet somewhere in the middle of the loop before heading back

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Net Check Basics

• When checking a net for birds, always walk along its entire length and check it from top to bottom
• Remove any leaves, sticks, insects, or other debris from the net as you check it
• If you need to lower part of the net to reach a bird, pull down on the loops or elastics using a net stick
• Be careful not to get any birds caught in multiple pockets when you do this
• Don’t forget to raise the net back up when you’re done!

Get all these leaves out of the net, don’t just leaf them there!

Net Check Basics

• Birds should be put in bird bags right away once extracted from the net
• Once a bird is bagged, grab a clothespin from the net you took it out of and attach it to the string of the bird bag
• Multiple bags can be flagged with the same clothespin
• These clothespins have the number for that net written on them and are found on the ropes at either end of the net

Clothespins are on these ropes

Closing Nets

• In some situations, you will need to close some or all nets to ensure the birds we study are safe
• Days where extremely high numbers of birds are being caught and the banders cannot keep up (this will be a mutual decision between both you and the banders and requires communication)
• If the net is damaged and cannot be repaired quickly (eg a broken trammel)
• In poor weather conditions (specifics covered on a later slide)
• If you close a net for any reason, make sure you let the banders know when and why a net was closed. This lets us track our banding effort and make repairs to nets as needed.

Closing Nets

• Before closing a net, be absolutely certain that there are no birds caught in it
• To close a net, we roll the bottom 4 panels of mesh into the top pocket of the net, then secure the rolled net with ties cloth ties
• We’ll show you how to do this in the field!
• Nets should be cleared of all debris before closing to avoid damaging them
• Leaves or sticks getting rolled into the net can rip or tear it, and our nets cost $300 each! Please be nice to them!

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This is a properly closed mist net, note the long blue ties securing it shut

Weather Conditions

• To ensure the birds we study are safe, mist nets are only opened in favorable weather
• The nets should be closed in the following conditions
• Temperatures below 0°C or above 25°C
• Note that during owl banding nets can remain open down to -20°C
• If it is raining or snowing
• If wind speed exceeds 17 km/h
• If the net is in direct sunlight on a warm day
• Weather calls can be tricky and subjective, don’t be afraid to ask for a second opinion
• Be proactive about weather – if a thunderstorm is looming, don’t wait until it starts raining to close nets!

Priority Birds

• In addition to wooden clothespins with the net number on them, there are also colored plastic clothespins to indicate priority birds
• A bird is a priority bird if:
• It has a brood patch – check birds for a bare, wrinkly patch of skin on their chest
• It is very young (head is covered in fuzz, flight feathers not fully grown in)
• It is a sensitive species (a list of these can be found on the wall of the banding lab, includes species like hummingbirds)
• Let the banders know if you have any priority birds when you arrive back at the lab

Transporting Birds

• Always carry bags containing birds by the string, and take care not to swing them or bump them
• Do not cup the bird in the bag as this can restrict their breathing
• Never put more than one bird in a single bag
• If you need put bagged birds down to extract more birds, hang them by the string on the wooden crosses located next to each net
• Be absolutely certain that you do not forget any birds!

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Back at the Lab…

• When you arrive back at the lab with your birds, hang them on the hooks behind the banding bench
• If you have several bird bags that are held together with a clothespin, don’t just hang all of them by the loop of one bag. Make sure the loop of every bag is looped over the hook individually so that no birds fall off the hook.
• There are little cards on rings with times listed on them hanging on the hooks to keep track of which birds were caught on which net check
• Hand birds to the right of the time tag
• Remember that the capture time for your birds is the time you started the net check it was caught on!

Final Notes

• Going on net checks might seem intimidating at first due to the added responsibilities involved, but it is also one of the most rewarding parts of running a banding station
• Communication with the banders and any other extractors will help each net check go smoothly
• Remember that bird safety always comes first!

Red-tailed Hawk

• His name is Keith
• He is the goodest, most precious, and most special boy ever
• He is kind of derpy, but we love him

That’s All!

• Contact information if you have questions:
• Jana Teefy, Head Biologist: biologist@beaverhillbirds.com
• Jon Van Arragon, Assistant Biologist: assistant.biologist@beaverhillbirds.com