How to count porcupines
In kindergarten, we learn how to count to 10. We continue counting to 10 because it’s easy for us, whether it be counting birds, cars, or fingers. We might therefore assume that counting wildlife would be just as easy, but that isn’t the case. Wildlife are generally well hidden and tend to be active when humans are not. Seeing wildlife today has gotten harder because of the decrease in biodiversity. Going outside and counting wildlife is hard, not because we can’t count to 10, but because the wildlife is becoming harder to find.
Porcupines are not endangered or threatened, but their numbers are declining across much of their range in North America. This concern has led me to my independent research: trying to count the porcupines on the St. Lawrence University Kip tract, a forested property adjacent to campus that has sustained a porcupine population over the years. I am using game cameras to take pictures of porcupines as they walk by to estimate their population size.
Game cameras have been increasing in popularity for wildlife research. Compared to other methods like live trapping, game camera research is more cost-effective and requires less energy to set up and monitor. Game camera research is also less invasive, meaning camera traps have little effect on wildlife. “Camera trapping” is a wildlife monitoring approach that uses game cameras to do field research in a certain area. The cameras are motion activated so when a animal walks into the field of view it takes a picture. Camera traps are great for monitoring overall biodiversity in a region and can also be used for research on just one species. Camera traps can be left out for as long as needed but require a battery change after a few weeks. For my research, I placed 12 camera traps along the Kip tract, a forested property neighboring St. Lawrence University.
Image of a white tailed deer captured on a camera trap.
I broke up the Kip tract into 4 different habitat types: deciduous forest, evergreen forest, mixed deciduous forest, and floodplain and then I used specialized mapping software to create a set of random locations within each habitat type on the Kip Tract at which to deploy my cameras so there was no bias in my research. The bias I avoided was not putting cameras only in areas that had porcupine signs. That way, along with seeing how many porcupines there are, we can also see what habitats the porcupines are using. Porcupines prefer to live in coniferous and mixed-forest habitats. In the winter they nibble on evergreen leaves and the inner bark of different kinds of trees. Within the habitat types, we generated random points that were at least 50m apart. Why 50m? A porcupine’s home range has a radius of roughly 50m in the winter. Putting 50m in between cameras allows me to differentiate between individual porcupines and determine the population. Porcupines do not hibernate, so moving through the snow and staying warm is very energy-demanding resulting in a smaller home range during the winter.
After locating random points within each habitat zone and putting it all together on a map I headed into the field to establish my camera traps. I set up 12 cameras in total with three in each habitat type. As we know in the North Country, the weather can be quite cold in early February, and there is tons of snow! I had to use snowshoes to navigate the Kip tract to set up the cameras. I had never snowshoed before, but I was very grateful to have them! Snowshoes kept me on top of the several feet of snow, but some of my helpers had some trouble staying upright.
Falling in the snow while we fill out data sheets!
I followed a standard setup procedure for each camera that included facing the camera north so there is no glare from the sun. Once all 12 cameras were set, I returned every two to three weeks to collect the SD cards and analyze the pictures. How long to leave cameras in the forest is dependent on the researcher and the subject that is being researched. Some projects set up cameras and come back after a month to collect.
I brought SD cards back to the lab where I worked through a series of complicated steps such as renaming and resizing all the images to make analysis easier. I analyzed pictures for any kind of animal, bird, or person and how many there are. Some SD cards had as few as 6 pictures, 3 of me setting up and 3 of me checking the cameras, and others had up to 100!
Over the course of my semester research, I saw how the Kip tract changed from winter to spring. I started with snowshoes walking in a couple feet of snow and then switched to high boots to navigate the flooding and deep, thick mud on the Kip tract, a forested wetland. Towards the end of the semester, I checked cameras in a long-sleeved shirt and was sweating. The Kip tract provided me with many challenges. One of the cameras was difficult to retrieve because of the flooding. I was walking in a couple feet of water, which was very close to going over the top of my boots. Another one of my cameras I could not get because of the flooding from the melting snow. The camera location was so flooded that there were ducks swimming around the camera. When the water level lowered, I retrieved my camera.
Three wood ducks swimming in the flooded forest.
While out looking for porcupines I came across other wildlife. I was lucky enough to see a barred owl watching me check my cameras. After the owl determined I was not food, I got to see it fly and navigate through the trees. Red and gray squirrels were a common sighting, along with the sounds of black-capped chickadees. As the season progressed towards spring, it felt like the Kip tract was returning to life after a long, cold winter. What started with just chickadee chirps turned into a diverse number of songs and calls from the migratory bird species returning home. While admiring all the wildlife, I saw porcupine signs like tracks and chewings. I was not able to count the porcupines based on just signs alone, but that is why I have cameras scattered throughout the Kip tract. Although there is a growing concern about the decline of porcupines, it is reassuring to see signs of biodiversity in this forest.
As you are exploring the North Country in the coming seasons, remind yourself to count the wildlife. Is it hard? Is it easy? Hopefully one day it’s a challenge to count wildlife, not because they are hard to find, but because there are so many.
[Note to readers: This is the second installment of a series of 3 blogs shared by Peyton Schmitt '23, about research he conducted during the spring term of his senior year at St. Lawrence University. Read Part 1 or Part 3]