Author Institution: 2370 Club Road, Columbus 21, Ohi

Adler, Kraig K.

The Ohio Journal of Science

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EGG-LAYING IN THE SPOTTED TURTLE,CLEM MY S GUTTATA (SCHNEIDER)KRAIG K. ADLER2370 Club Road, Columbus 21, OhioLittle is known of the life history and nesting habits of the spotted turtle,Clemmys guttata (Carr, 1952). Babcock (1919) states that two to four eggs(averaging 30 x 17 mm) per clutch are laid in late afternoon or evening during theperiod June 10 to 25 in New England. In a later paper (1938), Babcock observedthat nests were found among damp logs or moss and noted that the intervalbetween deposition of the first two eggs was 15 min. Pope (1949) states that thehole is flask-shaped, near water, and that a clutch varies from one to four eggs.In the light of these scanty data, the following account should be of interest.The observations were made of two females of C. gutlata. The larger, measuring(straight-line) 5 in. carapace length, 3j^ in. carapace width, and 2 in. shell height,was collected by Tony and Peter Mars on June 7, 1960, at Lexington, Massachu-setts. I collected the smaller female (Kraig K. Adler n. 766), measuring3% x 2% x V/i in., respectively, on June 27, 1960, in the Venetian Village canals,adjacent to the southeastern corner of Lake Maxinkuckee, Marshall County,Indiana. Both were kept in a large outdoor turtle pond located on the CulverMilitary Academy grounds near Culver, Indiana. The enclosure was shared withabout 40 turtles of various local species of other genera.Both turtles laid eggs during the evening of July 11, 1960. Rain was notassociated with egg-laying; there was little moisture in the soil. The site selectedby both was in the sandy earth around the shaded perimeter of the pool, about ahalf foot from the water, although the terrain several feet from the water appearedjust as suitable. Ambient temperatures during the egg-laying period were 72° Fat 6:35 PM, 70° F at 10:30 PM, and 67° F at 12:20 AM.The larger turtle was first observed digging at 6:35 PM when the hole wasalready V/2 in. deep (all measurements are given along the slope of the hole,unless otherwise stated). The cylindrical hole was directed beneath the turtleand by 7 PM the lower end was slightly larger, thus making the cavity flask-shaped.The depth at this point was 2 in. At 8:18 PM, the hole was 3% in. deep (about2Y2 in. vertical depth, 2j^ in. diameter at the mouth). The hind legs were usedsuccessively, each one scraping the opposite side of the hole; after one leg hadbeen used for about six strokes, the other was used for a like number of times.Rests, about 30 sec long, between changes of legs became more frequent as diggingapproached termination; a 14 min rest occurred between termination of diggingand the deposition of the first egg at 9:14 PM. The egg was pushed around withthe hind legs in the enlarged cavity. The second egg (9:15 PM) was pulled andextracted from the cloaca with the aid of the hind feet. Then a little dirt waspushed into the hole. The next six eggs were laid at 9:20, 9:21, 9:24, 9:25, 9:29,and 9:41 PM, and were all pushed around with the hind legs. After adjusting theeggs and with few rests, the turtle started to fill in the hole at 9:45 PM. The lastegg disappeared beneath the soil at 9:49 PM (this egg was 1 in. below the surface ofthe ground on the slope). Both legs were used alternately to cover up, one ortwo strokes each. By 10:04 PM the hole was completely covered and the turtlesearched with only her hind legs for excess dirt; the loose dirt was then patteddown with the posterior portion of the plastron and the hind legs. The turtle'shead was completely withdrawn throughout the whole process following egg-laying.The animal entered the water at 10:14 PM and had considerable difficulty inTHE OHIO JOURNAL OF SCIENCE 61(3): 180, May, 1961.No. 3 EGG-LAYING IN THE SPOTTED TURTLE 181stabilizing herself; the anterior end was lower in the water than the posterior.She clawed at her tail by using both hind feet until well after 11 PM, when shecould swim almost normally.The smaller turtle began digging near a small clump of grass about three ftfrom the larger specimen. Her digging was first observed at 6:45 PM when thehole was 13^ in. deep. By 7:45 PM it was 2% in. in depth (1% in. diameter at themouth). Digging with the hind feet wTas essentially similar to that of the largerturtle, except that the right leg appeared to be employed more than the left. At8:11 PM a small rock was encountered and after attempts to dislodge it provedfutile, the course of the hole was altered slightly. By 10:30 PM the hole was 3 in.deep, and the rests between shifts of legs became more frequent, although theserests were not quite as long as in the larger female. The first two eggs, droppedat 11:28 and 11:32 PM, respectively, were pushed around with the hind legs. Thethird and last egg was laid, with apparent difficulty, at 11:37 PM; part of the cloacabecame extended and was pink in coloration. The turtle began covering the nestimmediately and the last egg disappeared from view at 11:55 PM (this egg was % in.from the surface on the slope). By 12:13 AM (July 12) the hole was completelycovered and the turtle reached out with the hind legs apparently in search ofexcess dirt. She then patted the loose dirt down in the same manner employedby the larger specimen. She entered the water at 12:45 AM and had less troublethan the larger female did in stabilizing herself. By 12:50 AM she too was pickingat her tail with the hind legs, an action which continued until after 1 AM.On July 14, 1960, both nests were opened and the eggs measured (table 1).TABLE 1Measurements of two clutches of Clemmys guttata eggs 3 days after deposition (in cm)Egg numberLarger female:lengthwidthSmaller female:lengthwidth12.51.62.61.621212.9.7.9.721213.5.6.9.743.01.753.11.763.01.873.11.883.11.7avg2.91.72.81.7In the clutch of the larger turtle, the eggs were in two levels of four each; in that ofthe smaller, one egg was in the lower level and two in the upper. Since mostaccounts list four as the maximum number of eggs per complement, it is of interestthat the larger specimen laid eight. However, Blake (1921) examined five speci-mens, three of which had oviducal egg counts of 9, 9, and 11. Perhaps due tothe dry, sandy soil in which the eggs were buried, all failed to hatch; one egg fromthe larger clutch was opened on August 10 and found to be fertile.It may be sheer coincidence, or it may be the result of response to some unknownfactor that both turtles laid their eggs on the same night, even though they hadbeen obtained from localities about 800 miles apart. My presence did not seemto affect the turtles in the nesting procedure; they did, however, withdraw theirheads with a faint hiss as a ruler was inserted into the hole to record depth. Therewas no cloacal discharge of urine by either turtle. Babcock (1938) states thatthere is a 15 min interval between the deposition of the first and second eggs; inthe two females observed here, the interval was 1 and 4 min, respectively. Through-out the whole process, neither turtle visually examined the hole or nesting site,even after egg-laying was completed. Clement (1958) found that Clemmysinsculpta turned around to examine its nesting site. This observation was madeunder unnatural conditions, however.182 KRAIG K. ADLER Vol. 61Pallas (1960) has also given an account of C. insculpta but under more naturalconditions than Clement. Most of her remarks are applicable to both species(and perhaps most turtles, for that matter), but there are a few differences.C. guitata rested occasionally in the digging process, insculpta did not. Bothspecies rested during the covering-up process. While digging, the spotted turtleextended the head only slightly; while covering the eggs, the head was completelywithdrawn. C. insculpta extended its head fully at both times (Clement, op. cit.,writes that his specimen frequently withdrew its head and snapped; however, thisspecimen was held in hand during egg-laying). C. guttata dug about six successivetimes with one leg before using the other; insculpta used each leg alternately.I should like to acknowledge the generous assistance of John L. Curry in takingnotes. I am also grateful to Clifford H. Pope, Norman E. Hartweg, Aubrey S.Bradshaw, and Robert E. Gordon for a critical reading of the manuscript.LITERATURE CITEDBabcock, H. L. 1919. The turtles of New England. Mem. Boston Soc. Nat. Hist. 8: 325-431.—. 1938. Field guide to New England turtles. New Engl. Mus. Nat. Hist., Nat. Hist.Guides, no. 2: 1-56.Blake, S. F. 1921. Sexual differences in coloration in the spotted turtle, Clemmys guttata.Proc. U. S. Natl. Mus. 59(2382): 463-469.Carr, A. 1952. Handbook of Turtles. Comstock Publ. Assoc, Ithaca, N. Y. 542 p.Clement, H. 1958. Observations on a captive specimen of Clemmys insculpta. Copeia 1958:336-338.Pallas, D. C. 1960. Observations on a nesting of the wood turtle, Clemmys insculpta. Copeia1960: 155-156.Pope, C. H. 1949. Turtles of the United States and Canada. Alfred A. Knopf, New York.343 p.

Egg-Laying in the Spotted Turtle, Clemmys Guttata (Schneider)

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Egg-Laying in the Spotted Turtle, Clemmys Guttata (Schneider)

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