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Don Lewis, Massachusetts Audubon Society,
Fox Island Wildlife Management Area

May Day — 1 May 2001

Warm, clear and beautiful — summer arrived in the Land of Ooze.  Water temperatures over the tidal flats rose to 72 degrees by late morning.  A glorious way to celebrate May Day.

Terrapins took full advantage of the moment and criss-crossed Blackfish Creek with the tide.  While not quite low enough to allow easy capture as they slipped through the rip, still visibility was awfully good and if turtles happened to swim within a few feet, water clarity made it impossible for them to disappear into the muck.  And five terrapins, three females and two males, made that bad choice of approaching too closely.

Two of the females were recaptures (#322 and #844), while the others were all seen for the first time.  And very interesting recaptures they proved to be.  Last May 30th, at 3:30 in the afternoon, these same two turtles were captured in the same location during the same tide.  Now inpidual recaptures are not a rarity, but to capture the same two turtles on the identical tide one year apart is a coincidence that stretches odds to the breaking. 

These two terrapins look alike, too.  Terrapin 322, on the left, is 18.95 centimeters long and weighs 1150 grams; Terrapin 844, on the right, is 18.80 centimeters and 1136 grams.  Even the shape of their scutes and the shade of their carapaces are similar.

  

Except for the fact that they nest on opposite banks of Blackfish Creek, one on Indian Neck and the other on Lieutenant Island, they could be twins.  It starts you wondering about the social life of our brackish friends.

Terrapin 1055, a six-year-old turtle, demonstrates all the identifying characteristics of a typical mature male.  And he was kind enough to pose for the camera to illustrate those traits: the smallish “pin head” compared with the broader headed female, and the large thick tail compared with the female’s smaller, thinner tail.  Of course, gender dimorphism with males half the size of mature females is a good indicator, too.  The challenge comes, though, with distinguishing between mature males and pre-pubescent females of roughly the same size.