Download Camera Trap Animal Diversity and Census Lab

Camera Traps Used to Determine Species Diversity and Animal
Behaviors in an Urban Setting
Emma Kandrac
Westfield State University
April 10, 2014
Introduction
Camera traps are often used to determine which kinds of organisms live in a given location and
the behavior of these organisms. The way they work is by capturing a photo every 30 seconds the camera
detects movement. With these photos we are able to tell what kind of and how many organisms we are
dealing with and what time of day and temperature takes place while they roam.
This lab took place in Westfield, Massachusetts around the corridor between the Little River and
Westfield State University’s campus. We kept our hopes low and expected to catch a couple of squirrels
and raccoon, or possibly a deer or two. It was early spring and we figured most organisms were still
hibernating from the past winter.
Methods
This lab took place over a total of 1 week, 24 hours a day. This way we could see what time of day
the organisms traveled while having a broad length of time to catch as many organisms as possible. We
divided the 24 hour day into 4 different periods: Morning (6AM-9AM), Day (9AM-4PM), Evening (4PM-7PM),
and Night (7PM-6AM).
The materials we used in this lab consisted of 8 cameras, fastening ropes to hold the cameras in
their position, locks to keep the cameras from getting tempered with, and peanuts to attract organisms
passing through the area. The 8 cameras were placed in different spots around the corridor that we
thought would capture a lot of movement. In order to find the best location to place the cameras, we
searched for tracks of organisms to find their natural route of travel. We searched for tracks in areas where
substances were favorable for track detection, such as along trails, near river banks, and deep and
secreted in the woods (McCain and Childs 3). We chose locations near and far away from the river where
there were tracks located and the cameras couldn’t be easily seen to the general public. The cameras
were positioned at about the height of our hips and pointed towards the ground so it could pick up small
organisms in the area. Peanuts were generously scattered around the field of view that the camera was
facing. Peanuts were chosen as bait because salt attracts most animals.
The cameras were programmed to capture movement in 30 second intervals so that the same
organism wasn’t captured twice. We borrowed this camera-based encounter rate from Masatoshi
Yasuda’s study, “Monitoring Diversity and Abundance of Mammals with Camera Traps: A Case Study on
Mount Tsukuba, Central Japan”. Species-appearances were counted independently if the time between
two consecutive photographs of the same species was at least 30 seconds (Yasuda 39). This was to assure
that the same organism wasn’t captured twice and then counted as another individual.
Results
What we discovered was that there was actually a fairly large abundance of species in our urban
setting. We captured a total of 7 different species and 82 different organisms (Table 2). The species found
were Black Bears (Ursus americanus), Raccoons (Procyon lotors), Gray Squirrels (Sciurus carolinensis),
Coyotes (Canis latrans), Gray Foxes (Urcyon cinereoargenteus), Rabbits (Sylvilagus floridanus), and Bobcats
(Lynx rufus) (Table 1). The most common species we found were Gray Squirrels with 55 sightings, and the
least common species found were Rabbits and Bobcats with 1 sighting for each species (Figure 1).
Table 1: The species observed on the 8 different camera traps used along with each’s scientific name.
Taxa
Scientific Name
Black Bear
Raccoon
Gray
Squirrel
Coyote
Gray Fox
Rabbit
Bobcat
Ursus americanus
Procyon lotor
Sciurus carolinensis
Canis latrans
Urcyon cinereoargenteus
Sylvilagus floridanus
Lynx rufus
Table 2: The various species captured on the 8 different camera traps along with how many of each
species were sighted.
Frequency
Black Bear
Raccoon
Gray Squirrel
Coyote
Gray Fox
Rabbit
Bobcat
7
8
55
4
6
1
1
Number of Sightings
60
50
40
30
20
10
0
Black Bear Raccoon
Gray
Squirrel
Coyote
Gray Fox
Rabbit
Bobcat
Species
Figure 1: The various species found by the 8 cameras in the corridor along with the number of times the
species was captured. The Gray Squirrel was the most commonly seen species with a total of 55 sightings
while the Eastern Rabbit and Bobcat were the least common seen species with a total of 1 sighting each.
Organisms were captured mostly around night time (7PM-6AM) and hardly any organisms were
found during the day (9AM-4PM), except squirrels (Table 3 and Figure 2).
Table 3: The species found by the 8 different cameras along with the time of day each organism was seen:
Morning (6AM-9AM), Day (9AM-4PM), Evening (4PM-7PM), and Night (7PM-6AM).
Temporal Behavior
Black Bear
Raccoon
Gray Squirrel
Coyote
Gray Fox
Rabbit
Bobcat
Morning Day Evening Night
2
2
4
8
19
28
6
2
4
6
1
1
Number of Sightings
30
25
20
Morning
15
Day
10
Evening
5
Night
0
Black Raccoon Gray Coyote
Bear
Squirrel
Gray
Fox
Rabbit Bobcat
Species
Figure 2: The different species captured by the 8 different camera traps along with the time of day the
organisms were seen. Blue represents the organisms spotted in the morning (6AM-9AM), red represents the
organisms spotted during the day (9AM-4PM), green represents the organisms spotted in the evening (4PM7PM), and purple represents the organisms spotted at night (7PM-6AM).
With our groups’ specific camera, we captured 2 Gray Squirrels, 2 Black Bears, and 1 Bobcat. We
noticed that the temperature of the days the animals were found averaged at around 37.8 (F) and the
average precipitation was around 0.12 (In) (Table 4).
Table 4: The species found on our groups’ specific camera along with the date seen, the average
temperature of the day, and the amount of precipitation fallen that day.
Taxa
Gray
Squirrel
Gray
Squirrel
Black Bear
Black Bear
Bobcat
Date
Seen
Average
Temperature
Of Day (F)
Precipitation
(Inches)
3/20/2014
47
0.5
3/20/2014
3/22/2014
3/24/2014
3/27/2014
47
40
22.5
32.5
0
0.04
0
0.02
Discussion
The results of this camera trap lab show us that there is a wide variety of animals
found in this particular urban setting. We can see how important these corridors are: for
what seems like a small, secluded area during the day is really a home for many
animals big and small at night. Without wildlife corridors, biodiversity would increase
greatly as these corridors provide shelters and a method of moving from one location
to another for small, often vulnerable animals. Therefore if they were removed, only
those animals which could survive in the open and escape predation easily would
remain (McCain and Childs 5).
Using camera traps is a great way of documenting wildlife without disturbing it.
Although with them we know that not every species living in the area was captured on
film, we get a brief view of what life is like for the organisms with and without human
presence. We see that during the day, only small, quick organisms are found roaming
around with humans. At night, we have species ranging from bears to coyotes which
opens our view of the food chain taking place in the area. We see that squirrels are
abundant while larger mammals have much smaller populations.
Camera traps are a very effective way to determine a location’s species
diversity and animal behaviors 24 hours a day for as long as needed and with minimal
effort. We are able to “capture” the living organisms in their natural environment
without disturbing or disrupting them. The only human effort used is setting up the
camera and changing the batteries from time to time, which is much easier than
waiting around hoping an animal will approach us. Most animals avoid humans so
being able to see them without having them see us is a great benefit in camera traps.