Animals move for a variety of reasons. Some of these reasons include finding food, finding shelter, and avoiding predators and/or competitors. We are interested in not only what types of animals can be found in and around Statesville, but also when these animals move. We are really interested in exploring patterns of animal movement in Statesville compared with more rural areas of the county.
This past semester (Fall 2015), student research teams placed motion-activated trail cameras throughout the city to gather preliminary data. The figures below show animal activity patterns in greenway spaces throughout the city. Around 2000 pictures were analyzed for these figures.
Figure 1 shows the daily activity patterns of six animals. Some of these activity times were expected. For example, we expected to see high raccoon activity during the overnight hours and high grey squirrel activity during the daytime hours. We did detect several coyotes during the day, but they tended to be more active in the dark. This may be due to the fact that the cover of darkness provides better hunting opportunities and also allows them to avoid humans in the greenway areas. Even though opossums, red foxes, and grey foxes were not as abundant (on camera anyway), we did “catch” several.
If we delete raccoon and opossum activity (Figure 2), we can look at times of movement between three predators and one potential prey (squirrel). Even though both the sample size (2000 pictures) and the length of time (Aug.-Dec., 2015) are both too small to understand completely, figure 2 allows us to ask (and try to answer) some questions. For example, it looks as though squirrels do a really good job at avoiding times when coyotes are active. This makes sense. If you are a squirrel you would do well to avoid a major predator. It looks like red foxes and grey foxes are avoiding each other. Maybe this is because they are competitors. Among the competitors, coyotes were detected more often. Clearly, they are the dominant predator in this particular ecosystem.
One of our main objectives was to look at the white-tailed deer population in greenway areas. We can see interesting patterns develop when we compare doe vs. buck activity. Figure 3 shows activity levels from September through October, 2015. Notice how does are more active around sunrise (0700-0800) and sunset (1900). Secondary peaks of activity occur at 0100, 1100, 1700, and 2200. During these two months (Sept./Oct.), buck activity is minimal. However, the buck activity seems to follow along with the doe activity.
Now notice what happens when we look at doe vs. buck activity from October-November as shown in figure 4. Peak activity time for does are at 0800 and 1800, with secondary peaks at 0100, 0300, 2000, and 2200. Compared to figure 3, does are more active. The increase in buck activity may explain this. Notice again how the buck activity follows the doe activity. What explains this increase in buck activity during Oct.-Nov.? The rut. Females are entering estrus, and the bucks will only have 2-3 days to mate and pass their genes to the next generation. There is simply no time to lose.
We will continue to monitor animal activities during the spring and summer, and then set up more formal experiments. Below are some of the other interesting pictures we captured this semester.