Friday, April 23, 2010
This was our last day together in Nova Scotia, tomorrow we'll all get on a plane and go back to our homes. So that got me thinking about what makes a good home. We've been learning about the different habitats of animals we see here and that some of them are extremely vulnerable when their environment changes. People often make the mistake of thinking that other animals can make do wherever they are, the way that people can. Humans have managed to be successful at living in almost every corner of the planet. We can make clothes, build shelters, and trade with each other for what we need. Sometimes we even get so clever that we forget how much we still depend on our environment for survival. I don't grow or gather my food, or go to the river for water, or make my clothes, or build my home, but I could. I would spend all of my time doing it, but I could do it. Instead, I can rely on other people to help me get these things from the earth so I can spend my time working, playing, or thinking. On the other hand, most animals are spending all of their time trying to meet their basic needs of food and shelter. Mammals sometimes live alone or in groups, but they are very territorial. They may need a small or a large territory to survive in the wild, which they will defend. We as humans can understand the need to protect our home, but again we have to remember that people are not like other animals. Animals defend their territory because there is only enough food and room to raise babies for a certain number of animals. Only the strongest animals, which have found enough food to be healthy, will be able to defend their home. Being able to keep a territory means that animal or group of animals can secure food and shelter. This really sunk in for me this week when we captured a meadow vole. It was a female that had a long black strip of fur on her back. Fur can grow back black from an injury, and from the look of it, she was probably attacked by a bird of prey but then managed to escape. We caught her again in the same trap a few hours later, but when we opened the trap she was dead. Although we were sad, it was probably just her time. She had made it through the winter and had survived an attack, which is more than most voles can say. But Christina also suggested that maybe when she was attacked by the bird, she had been carried a bit and landed outside of her territory. She would have survived for the moment but then would have no home or stockpile of food. If it was a good place for a vole to live, other voles would be living there and keep her out. So she would have been in a tough situation. When we put our trap out we could have been saving her life! The trap is warm, nothing else lives in it, and it's full of food - perfect if you don't have your own home or food. Maybe that's why she was so eager to go back in once we released her. This is another reason why you never release an animal into a place it is not familiar with. Other animals are as connected to their homes as we are! And I am happy to be going back to mine :)
Thursday, April 22, 2010
I celebrated the Earth today by cutting down some trees! I prefer to say, though, that I spent today creating more grassland habitat. It is really important to remember that different animals may have very different kinds of habitat. If there was only forest at Cook's Lake, there would be many fewer species able to live there. Chris and Christina are trying to keep the 350 acres of land they manage as diverse as possible, providing homes for species that are losing habitat everywhere else. Forests are wonderful too, and planting trees in other places might be the right thing to do. People can take forest for granted here since there seems to be so much of it, but it turns out that not all forest is the same. Certain trees are suited to certain conditions. Tamarack is a native tree here and likes boggy wet land, and Red Oak grows in dry soil, so unless you knew the land pretty well you could plant a tree where it wouldn't survive. Even though it is true that much of Nova Scotia is forest, not as much of it is healthy and strong. If we take from the land, we have to be thoughtful about the ways that we try to give back. That means really observing the environment that you are in; the weather, the animals and the people that use it, and what it looked like in the past. What may be best in the long term may not be the easiest solution at the moment, like cutting a few pine trees down.
Last night we headed to a nearby lake to observe a family of beavers at their lodge. I'm borrowing pictures taken by Sue who has a great camera, since it was dusk and hard for me to get a good shot. Christina told us before we went out that beavers are sensitive to movement and will warn other beavers of potential danger by slapping their large tail on the water and diving underwater. This tells predators that the beaver has seen them and not to bother trying to hunt it. So, we all lined up along the water's edge and sat perfectly still and quiet to see what would happen. At first I saw a red-winged blackbird sitting on the lodge. Then out of the corner of my eye I saw something in the water. Since beavers swim with their feet, not their tail, it left a V shaped trail of water behind it. There was also a muskrat that came around, which is smaller, but they swim mostly with their tails and leave a kind of zig-zag trail of water behind them. The beavers would swim back and forth to a little island of sticks that they had piled up. We could even hear them gnawing on the bark! Sometimes they would bite of a branch to carry over to the lodge. Through my binoculars I got a really good look at them!
Tuesday, April 20, 2010
Last night we sat down with Chris to have a look at the data we have collected so far. They set out with a question they wanted to answer, developed a method that would give them reliable results, and we are helping them collect data. Answering their question can only happen after data has been collected over a long period of time. Once you collect enough data, the problem is to find out what it tells you. The data doesn't mean anything until you have examined it. He explained their methodology for doing this. One way is called Capture-Mark-Recapture or CMR. This means they count the number of recaptured animals after a few days to estimate how many animals are in an area. There was a very useful math formula we could plug our data into and come up with an estimate: based on the fact that we caught 7 voles, and recaptured 5 of them over 5 days, we can estimate that there are 13 voles in 1 hectare (100m x 100m square) at last week's location. Very cool! Here is Anne checking the new traps we set yesterday. There is some grassland, some forest, and also some hard brush. Malakai, here's what the red fox scat looks like! They are rare around here because they compete with coyote for the same food, and the coyote is much bigger. They also leave scat as a way of marking their territory. They leave it on top of prominent places like big rocks. Can you see all the fur and bones twisted up in it? We only caught one mammal so far at Cooks Lake, it's a meadow vole, as opposed to the red-backed voles we caught last week. Do you see any differences? We saw a rotted tree stump on a walk today, but the core of the tree had decomposed before the branches, so you can see how the branches leave their mark inside of the tree as it grows.
Monday, April 19, 2010
We started setting new traps in a new location today. Christina's family bought some property near Cook's Lake and they have been maintaining it for almost 20 years as a nature preserve. There is a lot of work involved in helping the land stay healthy for many types of plants and animals, as well as keeping it safe and easy for volunteers to walk around in the forest. Parts of this land get very wet in the spring and create large puddles that will dry up by the summertime. But while they exist, they are extremely important habitat for amphibians, such as frogs. They lay their eggs in the pond and if they time it right, it will be a pond long enough for the eggs to hatch and for the tadpoles to grow enough to leave the water. One project volunteers can help with is building pathways over the ponds so people don't step on these eggs! There's also a beaver at the lake. Beavers are very territorial and there will usually be only one pair of beavers and their kits on the lake. Most beavers here don't build dams because the lakes are already deep enough to build their lodges. We saw some evidence of someone's handiwork! Remember our weevil study? Weevils are a problem here for conifers, not deciduous trees. They lay their eggs in the bark. Well, it's only a problem if you are a forester trying to grow straight trees. It causes a new trunk to grow out of the spot where the old truk was damaged by the weevil, so the tree can look quite bushy after some time. It's great if you're a bear or a porcupine looking for a place to nap. Here's an example of an old white pine with weevils:
Sunday, April 18, 2010
Kejimkujik in the Mi'kmaq language means "land of the spirits." There are old growth hemlocks here, one of which they have dated to 500 years old. Look closely at this tree, can you think of how this happened? It rained a bit for the first time today, but it was still beautiful: Of course, we also looked for more scat. Here is a nice shiny pile from a deer!
So how does keeping trap of mice and voles, counting snowshoe hare scat, and mapping damaged tree bark help us understand climate change? Well, that is an interesting question with an interesting answer. Chris spent some time explaining his professional work and the science behind climate change. He did his best to put some very complicated data into terms that we could understand, since we haven't studied it before. First of all, it is important to call it climate change rather than global warming, since temperatures on the earth have always been changing throughout history. Actually, the average temperature at the moment is even a bit cooler than it has been in the past. What is alarming is the rate of change. Animals can be very good at adapting to their environment but they can't do it very quickly. When temperatures change faster than they can adapt, many of them will die off, especially the ones that have specific requirements for food and shelter. Let's take the snowshoe hare for example. It is an important source of food for birds of prey and large mammals such as coyote. Incredibly, when the days get short in the winter time, signals in their brain start to turn their fur from brown to white. This makes sense, since usually there will be snow in the winter and white fur will help it camouflage. But, if there is no snow and the hare turns white, it will be very easy for predators to see it. On the other hand, if it snows in the spring when the longer days trigger the fur to turn brown, the hare will be brown on a background of white and again very easy for predators to see. Winter weather here can change a lot anyways, and with increasing unpredictability due to rapid climate change, Chris and Christina are interested to see if this will eventually hurt their population. This is just one example, can you think of others? I should also explain what "rapid" means in terms of earth's history. Scientists have a way of measuring temperatures on earth even millions of years ago. Over a 20,000 year period of time, there was a 6ºC change. This caused a mass extinction of plants and animals. Humans have made a big impact in the last 200 years. Don't you think this must have some lasting effects?
Friday, April 16, 2010
You might be surprised to find out the kind of day to day work that being a scientist involves. So far, we have been collecting data in a transect, or line. But today we collected data in a quadrat. A quadrat is a 10 meter by 10 meter square that we set out in the woods using 4 poles as the corners. Then we got down on our hands and knees and tried to count every single snowshoe-hare scat that we could find inside the square. Each one looks a little like a coco-puff. In 5 different quadrats, we collected a total of 5,000 scat! This may sound a little crazy, but it's actually important work. We can learn from this data an estimate of how may snowshoe-hare there are in that area, even though we can't see them all. This is also an animal that is sensitive to climate change, so Chris and Christina are interested in seeing if their population may change depending on climate conditions. More on climate change to come!
Thursday, April 15, 2010
Today was varied as usual. We started the morning by checking our traps, and it turned out we had caught 4, all of which had been caught yesterday as well. Then we released the voles and reset the traps with new food. Before lunch we did a survey of porcupine damage along the road. Remember that porcupines eat bark in the winter and early spring before there are greener things to eat. And remember how we looked at the layers of a tree cookie? The layer close to the bark is responsible for bringing nutrients to the growing tree. Those same nutrients are tasty for the porcupine as well. They seem to prefer birch trees and spruce trees here. What do you think will happen to the tree if the porcupine eats too much of the bark? That's right, the tree will die. The clever animal usually eats patches of bark only on one side of the tree, so the tree will be around to munch on later! The real problem is that one of the big industries around here is forestry. Farms that grow and sell spruce trees for Christmas think of porcupines as pests and will kill them in order to protect their source of income. Chris and Christina are working on collecting data so they can offer solutions to people in order to keep the porcupines from being killed. One idea is to simply plant birch trees, which are extremely common and not used by people here, around their spruce farms. They are much easier for the porcupine to eat and so they won't be tempted to nibble on the spruce as well. It is important to keep in mind how much of an impact people have on the survival of animals, even in ways you wouldn't think of at first. So, today I helped save the porcupine!
Wednesday, April 14, 2010
Today we checked our traps once in the morning and once in the afternoon. We trapped and released a total of 7 red-backed voles. 5 of them had markings on their fur which meant that they had already been caught by a previous team in September. This is good news, because it means those voles have survived the winter with enough food and without being caught by a predator. 2 of them had not been caught before, and Christina cut the tips of a bit of hair on their sides in order to leave a mark (this does not hurt the vole). Why do you think it is important to know which mice have been caught before and which ones are new? Here's a picture of Christina weighing a deer mouse, it weighed about 23g: We also took a walk to look for field signs and came across a lot of coyote scat on the trail. Since they are carnivores, their scat has lots of fur and bones in it which they cannot digest. This is a close up of what it can look like!
Tuesday, April 13, 2010
We set 100 small mammal traps today in an area called a hectare, which is 100 by 100 meters. Tomorrow we'll check on the traps. We make sure to put enough hay and food inside the traps so the animals will survive until we collect them several hours later. At this point in the year, Chris told us that if 5 traps have a mammal in them out of the 100 we put out, that would be a good day. After we measure them they are released unharmed. Our goal is to be able to estimate how many animals there are in a certain area. Because small mammals are so important to the food chain, if they have a healthy population, chances are that the rest of the animals in the environment are doing well also. Christina and Chris are ecologists, meaning they study ecology. Do you have ideas about what ecology is? Please look up this word in a dictionary and tell me what definition you find. I look forward to reading your responses!
Monday, April 12, 2010
Here's a picture from where we took a walk this afternoon. The woods are right along the rocky coast, and dotted with small lakes and ponds that can also have salt water in them from the ocean. This is a red squirrel who was eating from a pine cone. They like to find one spot where they always eat. Like squirrels, chipmunks will also eat the seeds from pine cones, but sit in different places to eat. Chipmunks are more likely to leave a pile in a more exposed place like this rock which was near our path. Can you guess which animal left behind these prints in the mud? It has five toes. Look below for a further clue. The same animal that left those prints left this piece of scat as well. In it you can see grasses and seeds but also sand. Can you think of why this mammal would have eaten sand? Well, it didn't eat the sand on purpose, but was eating something else that ate sand! Something tasty in the ground...hmmm. Tell me your ideas and I'll reveal what it is on tomorrow's post! More field signs! What happened to this tree? Can you see the teeth marks on the trunk of this tree? Who would eat bark? Look for more clues below. What a find! This animal's scat looks like a "string of pearls" and is kind of yellow in color. It's a porcupine! They sleep in trees during the day and come out at night but can cause a lot of damage to trees since eating the bark can kill the tree. Unfortunately, some people consider them pests for this reason. They rely on their quills to scare predators away and don't try to run away from threats, even people. He was very cute!
Sunday, April 11, 2010
Hi everyone! I left from JFK airport this morning and arrived in Halifax, Nova Scotia to meet the other members of my research team. It was a beautiful sunny afternoon, but a bit colder than in New York. We drove two hours south to a small town called Cherry Hill where we will be staying. There are 7 other women, you can check out their blogs too! Some of them are also teachers, and we all have something different to share with the group. We are all interested in the environment and learning about wild animals, even if that means getting our hands dirty! We met the scientists, Chris and Christina, who are really interesting and know a lot about the animals that live around here. They also have a dog named Lycos (which means wolf). They said we may see river otters, deer, porcupine, mink, and hare. We will learn tomorrow about how to look for signs of animals in the field. I'm excited to give you news soon!