A visual encounter survey is simply a systematic survey of wildlife, by following a predefined transect and relying on visual contact. Often, visual encounter surveys involve audio encounters, particularly with vocalizing birds or amphibians. Examples of Visual Encounter Surveys:
- Following a predefined trail and noting any reptiles or amphibians you encounter.
- Creating a straight line through a field and marking any plants that fall within 3 meters of that line.
- Following a predefined path, and spotting birds using binoculars for 5 minutes every 200 meters.
Some general best practices for VES:
- Avoid back tracking on your survey or you may end up double counting.
- Design your survey to be a loop
- Depending on your study, consider randomizing:
- The direction you start down a loop trail
- The times you start
- Which transects you sample
- Plan with your target species and study goals in mind
- General surveys should randomize more and be more general
- Surveys for specific taxa should be planned with their activity levels in mind
- Be aware of these biases in your results!
- Not everyone is as skilled of a searcher. Ensure your team has a diversity of talents.
- Record the number of people you survey with and start+end times for your surveys. You'll use this to calculate people hours you surveyed.
- Be intentional about what data you collect. It may not be feasible to stop for measurements every time you spot a lizard. Also, you have to carry everything.
- Some organisms can be collected, measured, and released a later time.
- General data that dont require an organism are great (temperature, humidity, weather, canopy coverage, habitat type etc.)
- Some data can be collected from date, time, or GPS coordinates after the survey period
- Distance from water
- Lunar cycle
- Habitat type (if predefined)