DIAMOND-BACK TERRAPIN CULTURE 
65 
COPULATION, LAYING SEASON, AND INCUBATION PERIOD 
Copulation seldom has been observed. Males frequently persist in following 
certain females, however, and it is supposed that this indicates a desire to copulate 
and that copulation probably follows. If that be true, copulation may take place 
at any time during the period of activity. This sex activity is greatest in the spring, 
very soon after the animals emerge from hibernation, and it is probable that that is 
the chief “mating” season. 
The laying season begins in May, generally about the middle of the month, and 
it ends about the first of August. A female may lay only once during a season, or 
she may lay as many as four and, rarely, five times. 
The earliest date of hatching that has been noticed at Beaufort was July 28, but 
generally hatching does not occur before the middle of August, and the last eggs 
hatch during the first half of October. The length of the incubation period, of course, 
varies somewhat with the prevailing temperatures, being shortened by high tempera- 
tures and lengthened by low ones. Using the earliest dates (generally around May 
15) when laying was observed and the first dates (generally around August 15) 
when young terrapins emerged from the nests as a basis, the incubation period would 
appear to extend over about 90 days. Since newly hatched terrapins generally do 
not emerge from the nests immediately upon hatching, it may be assumed that the 
incubation period is somewhat short of 90 days. 
SPACE REQUIREMENTS 
It has been shown elsewhere (p. 53) that it seems practicable to confine as many 
as 100 recently hatched terrapins for winter feeding in a brooder house in a tank 
having a floor space of about 20 by 24 inches. To this statement there is little to add, 
except the caution that a high degree of cleanliness must be maintained. The tanks 
in which the animals were held at Beaufort under such crowded conditions were 
washed twice a day and scrubbed whenever it appeared necessary, and after each 
washing and scrubbing new and clean water was supplied. Care must be taken 
particularly to prevent the decay in the tanks of uneaten foods. 
The extent of crowding that terrapins can stand in outdoor pens is not well 
known. None of the experiments performed to date indicate that the different 
degrees of crowding that have been tried were deleterious. Certainly, much depends 
upon cleanliness and the free exchange of water; that is, much greater crowding will 
be possible when the pens are fairly free of decaying organic matter and when the 
tides and conditions are such that an almost complete exchange of water takes place 
twice daily and clean water is brought by each flood tide. The greatest crowding 
of growing and fairly large terrapins among the experiments under way at Beaufort 
is 198 in a pen 5 feet wide and 36 feet long. The length of the pen probably has 
little significance as the animals stay in the water, or at least very close to it nearly 
all of the time. Therefore, only about one to three fourths, depending upon the 
stage of the tide, of this particular pen generally is occupied by the animals. The 
rate of growth of the animals in this pen compares favorably with other less crowded 
lots, and from the standpoint of survival this lot is ahead of all others grown in 
captivity. 
