You counted activity near a garden path yesterday and want to compare it with today. Before collecting more numbers, write down exactly what counted as an observation and how the session was conducted.
Define the event
For a harmless practice exercise, you might count visible crossings of an imaginary line from a fixed public viewpoint. State that crossings are being counted, not unique animals. The same individual may cross more than once.
Choose a fixed observation window and record its start and end. Do not disturb animals, handle specimens or enter restricted areas for the exercise.
Record the conditions you can describe
Note the location, weather impression and any interruption. Keep observations separate from explanations. A lower count on one day does not, by itself, establish why activity changed.
If you alter the viewpoint or counting rule, record the change. Otherwise the comparison may mix different procedures while appearing to measure the same thing.
Review the method before the result
Ask whether both sessions were completed under the stated rules. Mark incomplete sessions rather than quietly treating them as equivalent.
Our guide to separating observation from explanation supports the notebook. Even a small exercise benefits from a protocol that lets future you understand what the numbers actually represent.