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'Ile study reporled here was designed to documert the initi^l responses of Par pond
alligalors to the drawdown of P:rr Pond. By using census procedurcs and other telhniques
similar to those employcd in earlier studies of this Populalion and by taking advanlage of the
numerous individuals in the population thal hrd beeo previously marked, all efforl was made to
present thc responses observed in the conlext of previous information available for this
populalion (Murphy 1977, 1981i Brandt 1989, 1991). Reserch efforts were focussed on three
areas: (l) population rumbers ^nd sprtirl dislribulion, using stard:lrdized census tcchniques, (2)
behaviour and movemenl prtlerns of individurls within the population, using r^dio telemetry
techniques, and (3) reproductive biolog/. With thc exccption ot :rerialcensusuweys which
continued through July 1992, all asPecls of the study reported here wetc conducted between July
1991 and March 199.
The SRS is locnted along the northweslernmost limits of the nlligators' inland range in
lhe southeastern Udted States, and this study Provided an opporluniry ro document various
aq)ccts of ihe alligafors' posldrawdown wintering ecology, nnd lo prcsenl a comparison with the
results of earlier p.e-dr.wdown studies of the wintering ecolog/ of:rlligators in this same
reservoir system (Brisbin.l al. 1982).
MATERIALS AND METHODS
Studv area:
The Par Pond reservoir is located on the U.S. Depnrtment of Energy's Sav:rnnah River
Site (SRS). This 750 km: sile was closed to public rccess in rhe early 1950s and since that time
has been uscd for varjous nuclcat industrial aclivities. The SRS is located aloog the northern
shorc of the Savannah River ^nd occupies portions of Aiken, Allendale and Barnwell Counlies
of South Carolina. The area is located in the Upper Atlantic Coast,tl Plnin. Brisbin e, dl.
(1982) report that winler tempcratures in lhis area avcraged 4.9, 4.6 and 4.9'C for December,
January rnd February, rcspectively, for the poriod 1971_1981. Extreme lows for these same
monlhs during thh pedod wer€ -8.9,-15.6 and'10.0'C, respectively Further descriptions of the
climate, topography, flora and fauna of the SRS have been Provided by Jenkins and Provost
(1964), Murphy (1981) and Hilesrad and Bcnnett (1982).
The Par Pond rese,voir was constructed in 1958 by impounding an area that included
the confluence of several nnturnl stream watercourses. This qeated a rcserr'oir with three major
exteosions which bavc become known as the Hot Arm, North Arm and West tum (Figure 1).
The Par Pond reservoir system also includes two smaller reservoirs; Pond B (81 ha) and Pond
C (67 h:r), which have, along wilh Par Pond itself, rcceived the cooling water effluents of one or
two operating nuclear reaclors. The thermal gradients and early history of reactor oPerations at
the site have been described by Parker e, al (1973), Gibbons rnd Sh.ritz (1974) and Brandt
(1989), and the responses of P:rr Pond nlligators to .hese.hcrmal inputs have been described by
MuQhy (197, 1981) and Murphy and Brisbin (1974). All thermal inlut to tbe Par Pond system
ceased in Auglst 198?, and bolh of the associaled reacors have been inoperative sincc that
trnre.