2a. Scan Sampling
The purpose of this exercise is to discover differences in behaviors and frequency of behaviors among different age/sex categories. You can also use this kind of data to compare different species.
In this exercise you will scan your group every 20 seconds. This means that you will look at what all animals in the enclosure are doing at the same moment by scanning the area from left to right and taking a “mental snapshot” of each individual’s behavior. Mark a “1” in the appropriate behavior row under each animal in the scan sample table: A “1” is marked for each scan for each animal doing that behavior. Do a scan every 20 seconds, at exactly the 20-second mark, and note the behavior you saw each individual engaging in. Then stop until the next 20-second mark. Any behavior that occurs before or after the 20-second mark is ignored.
You score one behavior for each animal during each scan. If a particular animal cannot be seen, you still need to account for it. Include the behavior “out of sight” on your scan sample table, where you can mark this type of occurrence. If during a scan a particular animal is engaged in more than one behavior, note the priority behavior, as you determined in the ethogram section. With our limited ethogram, it is likely an animal will do something that does not fit any of your listed behaviors. In such instances, include the behavior “other” on your scan sample table.
The point of a scan sample is to gain a general sense of how a group spends its time. It usually focuses on a limited number of behaviors and, as you will see, it fails to record a great deal of what actually occurs. Think about the types of behaviors best captured via this method and the types of behaviors that should not be studied using a scan sample.
Below is a small example of a scan sample with only 10 scans. The behavior observed for each animal during a scan has been marked by a “1.” Each column adds up to 10.
| Behavior |
Adult Male |
Adult Female 1 |
Adult Female 2 |
Juvenile Male |
| Walk |
11 |
1 |
11 |
11 |
| Feed |
1111 |
1111 |
11111 |
111 |
| Auto-groom |
11 |
111 |
111 |
|
| Solitary play |
11 |
11 |
|
11111 |
| Total |
10 |
10 |
10 |
10 |
Each behavior for each animal can then be calculated: # of observed scans/ # of total scans*100. This will tell you the percent of scans spent doing each behavior. In the first box, 2 marks = 2/10 scans*100 = 20%. The adult male spent 20% of his observation time walking. This can be compared to the Adult Female 1 who has 1 mark in that first row = 1/10 scans*100 = 10% of her observation time spent walking.
2b. Continuous Focal Animal Follow
In the scan sample data, you recorded a series of “snapshots” of activity across a whole group. This can generate a lot of data about many individuals. However, it also fails to record a great deal of detail about the sequence of behaviors leading up to, and following from, a single event that you record in your scan.
Continuous focal animal follows represent the other end of the data collection spectrum. In this method you continuously monitor the activities and interactions of a single animal—your focal animal—for a set period of time. At the end of that time period you begin a new sample on a different focal animal. By continuously following the activities of one individual, you record much more detail than in a scan sample, but you only have details about one individual and those it interacts with. It also takes a lot more time to gather enough data because you are watching only one animal at a time. See the example below.
