2016 Diamondback Terrapin Head Count Survey Methods
Coastal Bays: May 31-June 4
1)1-Way Water-based Survey methodology where the survey crew boats a long unbroken stretch of shoreline in just one direction with no constraints on time, counting all terrapins encountered, and again getting approximate GPS coordinates for where clusters of turtles are observed. No terrapins should be counted in areas you have already boated through. Please use the datasheet for water-based surveys.
2) Land-based Surveys from fixed shoreline points (based on VA methodology). These would preferably be areas where prior scouting have shown are good locations to record terrapins. Surveyors, using binoculars +/or spotting scopesto count all the terrapins in three 15 minute surveys from the same point (we will use maximum count).Multiple points can be surveyed on any given day, with lat-longs recorded at each survey point and terrapin count. Please use the datasheet for land-based surveys.
3) For terrapins sighted incidentally (not while participating in a survey) enter information at
Please plan your survey routes and shoreline points ahead of time and be safe! Also, for land-based surveyors, please make sure you have permission from landowners (if private property) for the shoreline points used.
Survey Methods for All Techniques
Any tide – just need to record tidal stage on the datasheet so we know what tide data was collected on.Use the DNR website to help figure this out: .
Clear Skies & Warm Temps - warmer temperatures means more surface basking behavior by terrapins. Based on past years efforts, best results are when cloud cover is <20% and air and water temperatureare ≥70° F. Please record all weather observations on the datasheet at the start and end of surveys for water-based surveys. Land-based surveys need only record this data when they begin at each survey point.Remember:significantly more terrapins are observed withwater temperatures of ≥70° F and low cloud cover. A good website to use for checking air and water temperatures, as well as other weather data, is:
Calm water – little wind or chop – this is variable depending on where you are – please do not go out in hazardous conditions or if high winds are forecast. Areas in the lee of land may still be possible to be surveyed in windy conditions. Estimate wind speed and direction (mph) on the datasheet – this information is readily available on i-phone weather apps. Note that land-based surveyors also need to be aware of wind conditions and its potential effect on the ability to observe terrapins.
Surveys will be conducted by creek, river or shoreline point, with latitude-longitude(NAD 83m Decimal Degrees) taken for surveyed sections. Remember to get lat-longs for start and stop points as well as some waypoints, if a water-based survey. Use waypoints when you have traveled for 5 or 10 minutes without sighting a terrapin. Please label these as “Waypoint”, “Start” or “Stop” under the “# Terps” column or in the Comments field on the datasheet. Waypoints are very important so we can map your boat routes; this is especially important for determining areas where terrapins are NOT seen. We can begin to better understand what is influencing where these aggregations occur if we also know where you have surveyed and not observed terrapins. If you move to another creek please start with a new datasheet.Land-based surveyors need only record GPS for each shoreline point from which they are surveying.
Examples of free GPS apps for smartphones.
Any app may be used as long as coordinates are reported in decimal degrees
"Coordinates" for iOS devices:
"GPS Coordinates" for Android devices:
Google Maps GPS Coordinates website. Can be used by someone who doesn't want to install an app but still has GPS enabled: (Be sure to allow location services the first time you visit the website, if it asks.)
"GPS Calculator" for Windows phones:
Boat driver plus 1or more observers, and 1 scribe- Please note on the datasheet who is acting in each capacity; it is OK if all on board act as observers but please note that on datasheet. It is best if there are a minimum of 3 people on a team. If kayaking try to have a team of 3 one-person kayaks, etc. if possible. Land-based surveys can be conducted by 1 person but it might be more fun (and accurate) to have 2 or more, plus one person can enter data while other(s) scan.
Note type of boat used – check the box on the datasheet.
0-6 knot boat speed -If you come upon anyterrapin aggregation, please stop the boat and count them, rather then flush them all underwater. Similarly, for land-based surveys you may want to wait 5 minutes upon arriving at a survey point before beginning data collection to give terrapins that may have submerged upon your arrival a chance to resurface.
Record # of terrapins on surface and on creek banks on all sides of boat including behind - Binoculars and digital camera could be used as tools to verify you are counting terrapins and not other objects (sticks, feathers, etc). Take a lat-long (NAD 83 m Decimal Degrees) of each terrapin aggregation and single turtles. If you can also get a photograph of terrapins and your survey team that would be great! The data sheets have columns for Ad F (adult females – very large) Ad M/Juv (adult male/juvenile, smaller) and undetermined. Please record all terrapins as undetermined unless you are certain they are large enough to be female. Also remember to tally the total number of terrapins observed by run in the appropriate box.Land-based surveyors should also attempt to count terrapins by sex/age category and tally them for each of three 15-minute survey periods. Scan right-to-left or left-to-right. Please check boxes on the datasheet if binoculars and/or spotting scopes were used.
Record all shoreline habitats present opposite where terrapin aggregations (or singles) are observed. Check the appropriate box(s) on the datasheet. If needed add comments in that field.Legend: MA=marsh, BE=beach, FO=forest, AG=agricultural lands, DE=developed. In comments please note if the shoreline is rip-rapped, bulk-headed, living-shoreline, etc. This is for water-based surveys only. However, land-based surveyors could note in comments field if the shoreline is stabilized (rip-rap, bulkhead, etc), and the surrounding land use (similar categories to water-based surveys).
Record any other reptile or amphibian species observed the same as you would for terrapins (please record lat-long and #) – put this in the comments field. If you can also photograph them that would be great!
Please not any other comments either in the section on “Overall Comments” or in the lower margin of the datasheet.
Lastly, please write legibly on the datasheets and PLEASE record your lat longs in NAD 83m DD (all GPS and i-phone apps can do this!!). Any questions please call Jen Rafter at 410-213-2297 x 105 or 443-783-9888 or email
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