Don't look down!

Me coming down from a 40-spotted Pardalote nest in Tasmania, Australia

Within 24 hours of landing in Tasmania, Australia, I was 20 feet up a tree. Climbing trees I have found, is quite fun. Not that I didn't already know this, having climbed trees in my backyard growing up like most kids, but now I use ropes and feel safe about it. Why do I climb trees? To look into bird nests of course! In Tasmania, I was studying an extremely endangered species called the 40-spotted Pardalote, and hardly anything was known about its natural history.

Whenever studying birds, especially endangered species, it is important to know their nesting success. To have a successful nest means a pair of birds raises their young from eggs all the way until the jump out of the nest and fly off on their own. Bad weather, predators, parasites, or disease are a some of the reasons why a nest might fail. To study this aspect of their lives, it means finding nests, and then monitoring them so you know how many young birds survive their childhood and leave the nest as juveniles. For birds that nest in a classic bird's nest (called an open cup nest, usually made out of woven fibers and sticks into the shape of a small bowl) monitoring them can be easy - you can look inside! But for cavity-nesting birds, like woodpeckers in North America or the Pardalotes in Tasmania, things get a little more difficult. You can't simply see into the nest if it is in a hole in a tree trunk! This is where climbing comes in.

Using the camera to look inside a nest cavity

As seen in the picture above, there are cameras we can use that have a bendable extension. This extension can be slid into a cavity, and using small lights on the tip, you can see the contents of a nest on the inside. Using this, we can monitor nests to see how many eggs are laid, how many nestlings hatch out, and watch their development as they grow up. Of course, getting high enough in the tree to use the camera is often the hardest (and most enjoyable) part).

Marika heading up to a nest

To climb the trees we use a single rope technique, the Texas kick. We ascenders to climb the rope instead of the tree itself. An ascender is a metal device with a handle that slides along the rope in only one direction. For our method, you tie your harness to 2 ascenders, which are attached to the rope you are going to climb. The lower of these also has a length of rope coming from it which has a loop for one of your feet. To climb, you stand up in the loop and push the top ascender higher up the rope. Then you sit down (letting the higher ascender hold you by your harness) and push the lower ascender and footloop higher on the rope. Then you once again stand up in the foot loop and raise the upper ascender. Sit down, raise the lower one. Stand up. And repeat loads of times. Too easy. Well not as easy as flying right up there like the pardalotes do, but still not bad.

view looking up while climbing - an ascender can be seen on the rope

Amanda climbing to a cavity

On one particular instance, Marika, one of my coworkers, came along so we could climb and put up cameras at a few of the nest cavities. We hoped to find out what predators were eating some of the nests we were monitoring. First we had to 'string' a couple of trees, which is not always an easy feat. Stringing a tree means sending a small line high in the tree over a branch that you want to use to support your climbing rope. To get the string over the tree branch we use a fishing rod with all but the bottom segment and reel removed, and tie a sinker on the end of the line. A think rubber strip on a slingshot post is attached to the handle below the reel, and this becomes the slingshot to send the line up in the tree! You simply shoot the fishing line with the sinker over a limb, tie a string to it, and reel it back in. Then you can tie a rope to the string when you need to climb, and pull it up and over the branch.  

Marika up a tree

It seems simple until all the little twigs, branches, and other trees become involved in the process. Often it takes many shots, and as anyone who has fished on a wooded bank knows, it is not easy getting the line out of a tree once tangled. Sometimes once the line is in the tree, and the string pulled through, you need to re-route where the string goes (sometimes you can only shoot it over from a certain distant angle, but you really want the rope to go straight down or something like that). This can involve tying rocks or water bottles to the string and pulling those over pesky branches before dropping it down the correct way. Check out the video for an example of me and some crew members using a much bigger sling shot to string a tree in Hawai'i.

Marika coming down from a cavity.
This 40-spotted Pardalote cavity was later taken over by a Green Rosella parrot.

Me checking the battery and memory card of a camera

The next tricky thing Marika and I had to overcome was getting the cameras attached to the tree in a way that they could take pictures of the entrance of the nest. As they say, duck tape can fix anything. We have now developed a method of using a couple sticks and taping those to the cameras, and taping the sticks to the tree, allowing us to more easily point the camera at the nest, as well as replace batteries and memory cards without moving the camera's position. But alas, the trickiness does not end there. Unfortunately we did not realize at first that the batteries in these cameras pop out easily, and need to be taped in place. So when Marika came back a month later to help me check the cameras we had put up, only 1 of 4 had recorded any useful pictures. 

Me up a tree!

No predation was witnessed on camera this year, but a Green Rosella decided to excavate a hollow right with a 40-spotted Pardalote, and unsurprisingly this pair of 40-spots has failed twice since. But, we have almost 1000 pictures of a Green Rosella digging out its own (unused as of yet) cavity. Also, when climbing to a Striated Pardalote nest, Marika found a possum in the same hollow in the trunk! Clearly this guy could not get in to the actual cavity or there is no way the striated pair could have fledged chicks, which they did! 

40-spotted Pardalote at its nest

view from 40-spotted nest #18, looking south to the isthmus across the bridge on Maria Island

view from the last nest I climbed to in Tasmania

Fittingly enough, on my last day in Tasmania I also went skyward. I climbed up a neat tree with a high nest (maybe 60 feet), but no low branches on the tree. I had climbed this one before, but it has some great views, and just hanging out in the canopy of any forest is neat. You see birds below you flying from twig to twig, and maybe a Grey Shrike-thrush flying up to a perch just below and belting out its song. Just a little taste of what it would be like to live as the Pardalotes do. 

view on the way back down - I looked!