Bird Extraction

Around this time last year I first spoke about my new experience with mist nets and bird banding.  I volunteered again this year as well, though my car troubles did set me back a bit in terms of time.  However, when I was finally able to go and assist I was told that since I was a consistent volunteer they’d like to train me in mist net extraction, if I was interested.  I definitely was!

Given my limited time this fall, I had limited chances to learn the extraction technique, but I volunteered for their spring banding project too.  The reason they do these projects is to learn which species both live in and use the Albany Pine Bush Preserve as a stop-over during migration.  Showing that the Preserve serves as an important place for food and breeding to various species aids the Preserve in funding and research ability.  Each banded bird has a unique number on their band and this is added to a federal database.  If another area catches the same bird during their own banding projects they can put this number into the system to see where it came from.  This allows some general tracking for migration routes and survival.

What I learned right away is that different species react to the net and extraction in different ways.  Some species hit the net and just chill.  Other species try to escape by rolling around like crazy and getting themselves much more tangled.  Some species will allow you to extract them from the net while doing nothing but casting a suspicious eye toward you.  Others will scream and flap and bite, which actually doesn’t help in getting them out, but let’s face it, from their perspective some huge animal is grabbing at them and likely preparing them for a small, feathery snack.  Woodpeckers and blue jays, for instance, are all too willing to peck you to death if they can, while titmice scream.  And scream.  And scream.  Keeping all of this in mind, I opted for the calmer birds for my first extractions.  A thrush fit this nicely.

It is possible that the birds can get injured while extracting them, but the percentage of injuries is pretty low.  Banders at the Preserve are all trained and new extractors, such as myself, are walked through the procedure with an experienced member of the team right there and ready to help.

The first step of the extraction process is to figure out which side of the net the birds came in at, and to do this you have to identify un-netted portions of bird.  I didn’t think that was too difficult, at least on the birds I worked with.  The more difficult part, in my opinion, was trying to find the initial hole they went through.  If they went into one hole they should be pulled out of the same hole.  But it’s a net with thin little netting and sometimes it was difficult to see it hiding in the feathers of the birds.    In general it’s easier to pull it off the head if you have it off the wings first, and it’s also easier if the birds themselves would stop grabbing a hold of the net with their feet after you untangled their feet to begin with.  Woodpeckers and blue jays especially like to do this, and those are some strong little toes.

Little sticks or, surprisingly, crochet hooks can actually be helpful sometimes in grabbing a piece of net string.  And a firm grip on the bird’s legs/thigh area helps prevent leg injuries while you are trying to untangle the limbs.

As I mentioned in my last post on the subject, which talked about what sort of data we collect from the birds while we band them, weight is one of the things we check.  A fat bird is a well-fed bird, especially if they’re migrating.  Getting the weight of the birds is now done at the Preserve using a new technique.  Before, what we would do is weigh the bird in their carrying bags, and then weigh the bag alone, and figure out the bird’s weight.  Now they use a flat scale with a can and cone.  The scale is zeroed out so that the weights of these items are not included.  The bird is put head first into the cone and then the cone is put in the can for the weighing process.  It actually works pretty well.  The cone allows for a snug fit of variously sized birds while being safe.  Once the weight is taken, usually the last thing to get, the birds are then safely released, no harm done.

It’s been quite a while since my ornithology course and the bird species I learned at the time were often the ones that came to my feeders.  While assisting in this banding project I realize that my bird species recognition is woefully inadequate so I asked, and received, a list of all of the resident and migratory species that come into the Preserve.  My goal is to study this list over the next several months so that I am more prepared for the spring banding.  Also, I need to brush up on my bird body part lingo, such as primaries and coverts.

Mist Nets and Banding, the Life of a Birder

After my herpetofaunal survey was complete I recalled that the Albany Pine Bush Preserve often does bird banding in the fall.  I had come into this information at the same time I heard about the possible opportunity with the herps back in the spring; while networking at a local natural history conference.  Good stuff!  So, I reached out and contacted the Pine Bush staff once again.  As it turned out, they had started their banding in August, but I was able to come in for the second half of the project.

I love birds.  I think you have to in order to get up well before the sun and trek out into the inky morning to put up mist nets.  Now, normally I have to be to work at 8:30 and the banding didn’t start until 6 or 6:30 A.M. and then usually went until 11 A.M. (depending on when they decided to put the nets up).  However, I have a great boss and co-workers; they didn’t mind me coming in a little late once in a while.  The banding was generally held twice a week and was dependent on weather.  It was not dependent on the activity level of swarming mosquitoes, which had become rejuvenated after all the wet weather in August.  Needless to say most of us were covered in bug spray or wearing bug-resistant clothing.  Like with the herps, we tried to keep our hands clean as we didn’t want to handle birds and coat them with chemicals.

I’ll start off by saying I have very little experience with birds.  Last year, when I attended the Northeastern chapter of The Wildlife Society’s wildlife techniques course we did bird surveys through call, and I had taken an Ornithology course in school where we learned about the behavior, evolution, anatomy, and call of more birds, but I had never actually had hands-on experience in this field.  Due to that I had decided to be more of an assistant and observer.  I let the experienced handlers remove the birds from the net while I observed their techniques and asked questions.  I wasn’t about to risk bird injuries by jumping into a situation unprepared.

We had ten mist nets set up at various locations around the Pine Bush’s educational center.  Before I get ahead of myself, some of you might be wondering what the heck a mist net is and what that has to do with bird banding.  Basically these are long, mesh nets strung out between two poles.  They can vary in length and height depending on target species.  Birds, or bats, can’t see these nets very well and end up flying into them and getting tangled.  Now that may seem a little mean but this technique is pretty safe.  Trained extractors (people doing the removing) can safely and gently remove the animal from the net.

Mist net dangers include the animal getting too hot or too cold while trapped in the net; predators finding the entangled birds; injury while being removed.  To reduce the chances of these occurring we based our rounds on the weather.  If it was hot or cold we’d check the nets every half an hour; if the weather was mild we would check them every hour.  The extractors all had experience and when a volunteer was ready to take the leap and try to remove a bird, it was with the supervision of an experienced person there to guide them.  Dangers to the handlers: bird poop.

Once removed from the net the birds were put in small bags.  This made transporting the birds easier while making the rounds, instead of trying to hold several angry birds.  They were then brought back to the banding station and hung up on a little line.  Hanging their bags up was because there were often many more birds than banders.  Smaller birds were often done first in order to reduce their stress.

What sort of data is being collected likely depends on the organization conducting the project.  We took down the name of the species, the sex and age if distinguishable (some bird species have marked sex differences all year round while others often look the same outside of the mating season; age can sometimes be told by looking at select feathers on the bird’s wings and tail as well as checking their skull for lines or shadows that may indicate a not-yet-sealed skull, similar to a human baby’s soft spot), fat levels, wing length, weight, wing and body molting, and on select species a feather was taken for DNA analysis.  After all the data was recorded a small aluminum band was selected based on the size of the bird’s leg, the unique numbers on the band were recorded in order to identify the bird, and then they were safely released to fly away and scream out their insults at the indignity of it all.

I was able to assist in releasing the birds as well as holding them for their photographs, carrying the bagged birds, and generally just asking questions.  I had the pleasure of being bit by several species.  Some of them were fierce little things!  And I thought the blue jays were quite funny because they would clasp their feet together, so when it was time to release them they wouldn’t at first take advantage of the freedom because they were too busy holding their own feet.  They would flop over in my hands and look around for a few minutes before finally taking off.  I also had several small species that seemed to think my hand was quite comfortable.  I actually had to nudge them before they stood up and flew away.  One bird decided that he wanted to take refuge in the jacket of the bander, slip under his arm, literally hang upside down for a few minutes, gently land on the ground under the chair, and then seemed to decide it was safe to leave.

I enjoyed my first experience with birds.  They are very cute, of course, and I liked the relatively harmless way they were handled.  Next time the project starts perhaps I will take the next step and learn how to extract them from the mist nets.