10. By August 26, average length in a series collected was 42.9 mm.,
indicating an average gain of at least .35 mm. per day. One that may be
considered typical was marked on July 23, 1950, soon after hatching, and
it had a snout-vent length of 26.5 mm. and weighed .25 grams. It was
recaptured just a month later when it had grown to 36 mm. snout-vent
length, and weighed .8 grams. Potential growth rate under favorable
conditions is shown by the fact that some individuals have attained a
snout-vent length of 50 mm. by the third week of August, thus
approximately doubling their hatching length. A maximum growth rate of
about .5 mm. per day is indicated for these accelerated individuals, but
on the average, young are considerably less than 50 mm. in length even
when they enter hibernation. At the other extreme, representing retarded
growth, is an individual having a snout-vent length of only 34 mm. on
May 1. It must have been approximately nine months old on that date, but
of course had spent at least six months in hibernation. Even if it made
rapid growth subsequently, this yearling could scarcely have attained by
midsummer the pre-hibernation length of the most accelerated
individuals.
During the growing season following their first hibernation period, the
young grow to small adult size in most instances. After emerging from a
second hibernation they mature sexually and constitute an important part
of the breeding population.
Many of the skinks marked before their first hibernation, as hatchlings,
when they were a few days or a few weeks old, were subsequently
recaptured as well-grown yearlings or small adults, affording ample
information as to the usual growth rate and the extremes of acceleration
or retardation that occasionally occur. Records of selected individuals
in this group of skinks, marked early in life and recaptured after a
hibernation, are recorded below.
Table 8. Records of Individual Skinks Marked as Hatchlings (Before
the First Hibernation) and Recaptured the Following Year. Rapid
Rate of Early Growth Is Shown.
========+=================+==========+=====================+======+=============================
| |Snout-vent| |Weight|
| Date | length | Tail length | in |
| | in mm. | in mm. |grams | Remarks
--------+-----------------+----------+---------------------+------+-----------------------------
No. 1. |August 8, 1951| 23-1/2| 30-1/2 | .25 |Had just hatched when
|April 28, 1952| 39 | 55 + 1/2 | 1.3 |first recorded; second
|June 7, 1952| 48 | 69 + 1 | .... |capture was made soon
| | | | |after emergence from
| | | | |hibernation. All three
| | | | |captures within a 50-foot
| | | | |diameter.
| | | | |
No. 2. |July 8, 1952| 25 | 25 (broken stub) | .3 |
|April 23, 1953| 42 | 17 + 26 | .... |
|June 23, 1953| 56 | 22 + 36 | .... |
| | | | |
No. 3. |July 16, 1948| 26-1/2| 37 | .... |Caught at the same place
|July 5, 1949| 68 |101-1/2 | .... |on both occasions; in a
| | | | |little less than a year
| | | | |this female grew to
| | | | |small adult size.
| | | | |
No. 4. |August 23, 1950| 36 | 55 | .9 |The interval between
|May 19, 1951| 46 | 69-1/2 | 1.7 |captures included about
| | | | |two months of active
| | | | |life, plus the hibernation
| | | | |period; caught at the
| | | | |same place on both
| | | | |occasions.
| | | | |
No. 5. |September 2, 1950| 34-1/2| 33 (broken stub) | .... |Tail broken at first capture;
|June 12, 1951| 45 | 48 + 3 | 2.0 |recaptured 40 feet
| | | | |from original location.
| | | | |
No. 6. |July 28, 1949| 36 | 56 | .... |Recaptured 75 feet from
|April 21, 1950| 49 | 83 | 2.5 |original location.
| | | | |
No. 7. |August 31, 1951| 38 | 58 | .... |All three captures within
|May 25, 1952| 48 | 82 | .... |a 70-foot diameter.
|June 30, 1952| 63-1/2| 57 + 26 | .... |
| | | | |
No. 8. |August 23, 1950| 36 | 44 (broken stub) | .7 |Tail broken at first capture.
|July 23, 1951| 69 | 37 + 49 | .... |Capture sites 150
| | | | |feet apart.
| | | | |
No. 9. |August 23, 1949| 39 | 53-1/2 (regenerated)| .... |This male was retarded
|June 7, 1950| 46 | 70-1/2 (regenerated)| 2.1 |in growth, being still
|July 23, 1950| 58 | 88 (regenerated) | 3.7 |well short of small
|September 3, 1950| 62 | 91 (regenerated) | 4.9 |adult size as its second
| | | | |hibernation period
| | | | |approached; all four captures
| | | | |recorded within
| | | | |a few yards.
| | | | |
No. 10. |July 31, 1949| 38 | 23 (broken stub) | .... |Capture sites
|June 17, 1950| 58 | 43 + 36 | 3.6 |20 feet apart.
| | | | |
No. 11. |August 13, 1949| 40 | 66 | .... |Approximately a year
|August 8, 1950| 63 | 90 (regenerated) | 5.0 |after its original record
| | | | |this skink was recaptured
| | | | |80 feet away, still
| | | | |short of small adult
| | | | |size.
| | | | |
No. 12. |August 19, 1949| 42 | 40 (broken stub) | .... |All three captures within
|June 13, 1950| 58-1/2| 58 + 28 | 4.1 |a 50-foot diameter.
|July 5, 1950| 63 | 62 + 31 | 5.9 |
--------+-----------------+----------+---------------------+------+-----------------------------
Many other young were not caught and marked until the growing season
following their first hibernation, and were recaptured within this
second growing season weeks or months after they were originally marked,
and after they had made substantial growth. Those recaptured near the
end of this second growing season, when they were a year old, or a
little more, usually had attained small adult size or were nearing it.
Selected records of these yearlings are presented below.
Table 9. Selected Records of Individual Skinks Marked as Yearlings
(After Emergence From the First Hibernation) and Recaptured One
or More Times the Same Year. Rapid Growth Is Shown.
=======+==================+==========+=================+======+=================
| |Snout-vent| |Weight|
| Date | length | Tail length | in |
| | in mm. | in mm. | grams| Remarks
-------+------------------+----------+-----------------+------+-----------------
No. 1. |May 2, 1951| 38 | 53-1/2 | .... |Capture sites
|September 25, 1951| 62 | 25 + 31 | .... | 30 feet apart.
| | | | |
No. 2. |May 8, 1951| 39 | 57 | .... |Capture sites
|August 2, 1951| 60 | 67 + 25 | .... | 150 feet apart.
| | | | |
No. 3. |April 17, 1952| 39 | 55 | 1.1 |Capture sites
|June 23, 1952| 57 | 73 (regenerated)| .... | 30 feet apart.
| | | | |
No. 4. |May 20, 1952| 45 | 67 | .... |Capture sites
|May 28, 1952| 47 | 71 | .... | 15 feet apart.
|June 9, 1952| 53 | 82 | .... |
| | | | |
No. 5. |May 22, 1952| 48-1/2 | 77-1/2 | 2.0 |Capture sites
|July 20, 1952| 63 |106 | 5.3 | 10 feet apart.
| | | | |
No. 6. |June 11, 1950| 49 | 49 (broken stub)| 2.4 |Capture sites
|September 2, 1950| 63 | 63 + 31 | 4.9 | 20 feet apart.
| | | | |
No. 7. |April 14, 1950| 47 | 72 | 1.9 |Capture sites
|May 29, 1950| 50 | 82-1/2 | 2.5 | 50 feet apart.
| | | | |
No. 8. |May 12, 1952| 49 | 77 | .... |Capture sites
|June 18, 1952| 61-1/2 | 98 | .... | 60 feet apart.
| | | | |
No. 9. |June 4, 1950| 54 | 89 | 2.8 |Both captures at
|August 1, 1950| 64-1/2 |101 (broken stub)| 5.7 | same site.
| | | | |
No. 10.|June 11, 1950| 49 | 49 (broken stub)| 2.4 |Capture sites
|September 2, 1950| 63 | 63 + 31 | 4.9 | 20 feet apart.
| | | | |
No. 11.|June 13, 1949| 57 | 68 (regenerated)| .... |
|August 8, 1949| 70 | 37 + 11 | .... |
-------+------------------+----------+-----------------+------+-----------------
Adult skinks can be found in greatest numbers in the breeding season and
many of the young that were marked were recaptured as newly matured
breeding adults soon after their second hibernation, often still short
of average adult size. Selected records of such individuals are
presented below.
Table 10. Records of Individual Skinks Marked as Young and
Recaptured as Adults.
=======+===============+======+=====================+======+=========================
| |Snout-| | | |
| | vent | Tail length |Weight| Remarks
| Date |length| in mm. | in |
| |in mm.| |grams |
-------+---------------+------+---------------------+------+-------------------------
No. 1. |Male | | | |Probably less than a
|August 21, 1950|34 | 48 | .7 | month old at first
|May 30, 1952 |69 | 37 + 49 | .... | capture; at second
| | | | | capture 21 months
| | | | | later and 185 feet
| | | | | away, he had red
| | | | | facial suffusion
| | | | | already somewhat faded
| | | | | as the breeding season
| | | | | waned.
| | | | |
No. 2. |Male | | | |
|July 31, 1949 |39 | 64 | .... |All three captures
|August 22, 1949|47 | 75 | .... | within a 70-foot
|May 19, 1951 |73 | 69 (regenerated) | .... | diameter.
| | | | |
No. 3. |Male | | | |
|August 5, 1949 |36 | 57 | .... |Capture sites
|May 3, 1951 |67 |103 | 5.1 | 10 feet apart.
| | | | |
No. 4. |Male | | | |
|June 16, 1951 |44 | 41 (broken stub) | .... |Capture sites
|May 28, 1952 |63 | 77 (regenerated) | .... | 535 feet apart.
| | | | |
No. 5. |Male | | | |
|April 12, 1950 |45 | 73 | 1.9 |Capture sites
|May 1, 1951 |67 | 17 + 48 | .... | 100 feet apart.
| | | | |
No. 6. |Male | | | |This individual had
|April 12, 1950 |46 | 4 + 15 | 1.3 | attained approximately
|August 10, 1950|67 | 75 (regenerated) | 5.3 | average adult size by
|May 12, 1951 |71 | 77 (regenerated) | .... | the 1951 breeding
| | | | | season; all three
| | | | | captures were within a
| | | | | distance of 90 feet.
| | | | |
No. 7. |Male | | | |
|April 30, 1950 |48-1/2| 78-1/2 | 2.4 |
|June 15, 1950 |56 | 94 | 2.9 |
|May 19, 1951 |67 | 90 (broken stub) | .... |
| | | | |
No. 8. |Male | | | |
|May 3, 1950 |47 | 51 + 4 | 1.7 |Capture sites
|May 29, 1951 |75 |115 (regenerated) | .... | 450 feet apart.
| | | | |
No. 9. |Male | | | |
|June 2, 1949 |51 | 46 (broken stub) | .... |Capture sites
|May 2, 1950 |66-1/2| 31-1/2 + 51 | 7.0 | 90 feet apart.
| | | | |
No. 10.|Male | | | |
|May 20, 1950 |58 | 92-1/2 | 4.0 |Capture sites
|June 21, 1950 |61 | 95 | 4.7 | within 40 feet.
|August 21, 1950|70 |108 (broken stub) | 7.2 |
| | | | |
No. 11.|Male | | | |
|June 25, 1950 |62 |100 | 5.1 |
|May 1, 1951 |71 |113 | 7.1 |
| | | | |
No. 12.|Female | | | |
|April 15, 1950 |46-1/2| 73-1/2 | 1.5 |Capture sites
|May 20, 1951 |72 |113 | .... | 160 feet apart.
| | | | |
No. 13.|Female | | | |
|June 11, 1950 |51 | 69 | 2.5 |Capture sites
|May 25, 1951 |66 | 40 | .... | 20 feet apart.
| | | | |
No. 14.|Female | | | |
|June 6, 1949 |52 | 47 (regenerated) | .... |Capture sites
|May 20, 1950 |68-1/2| 69 (regenerated) | 7.5 | 20 feet apart.
|June 9, 1950 |71 | 71 (regenerated) | .... |
| | | | |
No. 15.|Female | | | |
|July 2, 1950 |60 |100 | 4.2 |Capture sites
|May 21, 1951 |74 | 33 + 35 | .... | 20 feet apart.
| | | | |
No. 16.|Female | | | |
|June 12, 1950 |57 | 83 | 3.1 |Capture sites
|May 1, 1951 |71-1/2| 53 (broken stub) | 6.4 | 35 feet apart.
| | | | |
No. 17.|Female | | | |This female probably
|June 22, 1949 |62 | 24 (broken stub) | .... | hatched in July 1948
|May 22, 1950 |72 | 27 + 7 | 9.0 | and was nearing adult
| | | | | size when first caught
| | | | | at an age of a little
| | | | | less than a year. By the |
| | | | | next breeding season it
| | | | | was an average sized
| | | | | adult; both captures at
| | | | | same site.
| | | | |
No. 18.|Female | | | |This female probably was
|July 4, 1950 |64 | 30 + 55 | 4.3 | Approximately a year
|May 23, 1951 |73 | 31 + 62 | .... | old when first caught,
| | | | | and she grew to average
| | | | | adult size by the
| | | | | next spring; both
| | | | | captures at same site. |
| | | | |
No. 19.|Female | | | |This female was about a
|July 5, 1950 |61-1/2| 92-1/2 (regenerated)| 4.7 | year old when first
|June 14, 1951 |73 |111 (regenerated) | 8.2 | captured; loss of weight
|June 29, 1951 |74 |106 (regenerated) | 5.0 | in July 1951 was caused
| | | | | by its laying a clutch
| | | | | of eggs. All three
| | | | | captures were within a
| | | | | 15-foot diameter. |
-------+---------------+------+---------------------+------+--------------------------
[Illustration: FIG. 12. Sizes of immature skinks of successive
annual broods, grouped in biweekly or monthly intervals, with mean,
standard error, standard deviation, and extremes shown for each
group.]
A certain small percentage fail to attain minimum adult size or breeding
maturity by the time of emergence from their second hibernation. Among
77 individuals marked as young either soon after hatching or in spring
and early summer, and recaptured the following spring, only one had
failed to grow to adult size. It was 46.5 mm. in length when marked on
June 13. When recaptured on April 25 of the following year, it had grown
to a length of 59 mm., still short of minimum adult length. During the
interval between captures it had maintained about the average growth
rate. Its failure to attain maturity was obviously the result of its
early retardation, and probably late hatching was primarily responsible.
Although this is the only individual with known history, which failed to
attain breeding maturity after its second hibernation, occasional
specimens are taken in spring which are somewhat below adult size but
seem too large to be young hatched the preceding summer. Obviously, the
incidence of such failure from year to year would be influenced by
weather conditions, and an unusually cool summer may result in such
delayed laying and hatching that an unusually large proportion of young
might fail to attain sexual maturity at the usual time. At more northern
localities, the percentage of such failures might be expected to
increase. At the northern edge of the range attainment of breeding
maturity may normally require more than two years. Such delayed
development would result in a drastic reduction of the reproductive
potential which might be critically limiting to the species, even in an
otherwise favorable environment, as the population would be unable to
replace rapidly enough the individuals eliminated by normal mortality
factors.
In contrast to the delayed development of those that have failed to
attain maturity at an age of two years, is the accelerated development
of those that have already more than doubled in length before the first
hibernation, and continue to grow rapidly after emergence. By late
spring they are already approaching adult size, perhaps even before
laying has occurred, and while breeding is still in progress. It is
certain that in northeastern Kansas there is no breeding by such
accelerated individuals approaching adult size at an age of nine or ten
months. Farther south in the species' range with a much longer growing
season, there is perhaps some possibility of such early breeding by
first-year individuals. This would reduce by more than half the length
of time required for a generation, and would tremendously increase the
reproductive potential. With such added impetus to its reproduction the
species might be able to withstand greatly increased predation pressure,
or other mortality factors.
[Illustration: FIG. 13. Growth curves of successive annual broods
(designated by the year of hatching), superimposed to bring out
differences in trends resulting from changes in weather from
year to year.]
Extremes of acceleration or retardation are relatively rare in the
population studied. Nevertheless, in April there are some individuals
between 50 and 60 mm. in snout-vent length which cannot be classified
with certainty as to their age group, and might be either accelerated
individuals about nine months old or retarded individuals about 21
months old.
The spread in size for any given age group is especially large, if data
from different years are combined. A typical individual, having a
snout-vent length of 25 mm. at hatching in mid-July may have attained 30
mm. by early August, 35 mm. by late August, and 45 mm. by the time it
hibernates late in September. Emerging shortly before the middle of
April it may grow to 50 mm. by the end of May, 58 mm. by the end of
June, and more than 60 mm. by the end of July when it is a little more
than a year old. By the time of its second hibernation it may have
attained a length of from 65 mm. to 70 mm., and emerges from this
hibernation as a breeding adult.
[Illustration: FIG. 14. Records of growth of immature individual
skinks, both hatchlings and yearlings, that were marked in one
year and recaptured the next.]
In reptiles in general there is a wide range in adult size, and the
extent and rapidity of continued growth after attainment of sexual
maturity and minimum adult size is still insufficiently understood.
Information bearing on this problem was obtained in the present study
from the recapture of marked skinks already measured as adults. It is
evident that the growth rate of the young, amounts to as much as 15 mm.
per month in snout-vent length in the late summer period from hatching
until hibernation, averages perhaps three or four mm. per month in the
summer after emergence from the first hibernation, and tapers off
rapidly as adult size is approached.
One hundred of the skinks marked as adults or subadults and recaptured
after intervals of months, including, in most instances, one or more
hibernation periods, represent in the aggregate, 87 years of growth.
These records show that after minimum adult size of 65 mm. is attained,
growth slows abruptly, and that by the time a length of approximately 75
mm. is attained in most instances growth has become extremely slow in
males and has virtually stopped in females. Males attain a maximum size
several millimeters larger than that of females. Individuals differ
greatly in their growth, however; some adults continue to grow rapidly
till they near the maximum size, whereas others apparently stop growing
when they are still below average adult size. Unusually large specimens
are not necessarily old, but may have attained their size only a year or
two after reaching maturity through the accelerated growth resulting
from abundant food and predisposing genetic factors. Likewise, unusually
old individuals are not necessarily the largest, but may be only a
little above average adult size. It may be assumed that no growth occurs
during the period of winter dormancy, which occupies approximately half
the year in the population studied. To compute growth rates, in those
recaptured after an intervening hibernation, periods of hibernation,
arbitrarily estimated as six months, were subtracted from the time
elapsed between captures.
Table 11. Average Growth Rate in a Selected Sample of Skinks
of Adult Size.
============+====================+====================
| Males | Females
|----------+---------+----------+---------
SIZE GROUP | Average | Number | Average | Number
|growth mm.|of skinks|growth mm.|of skinks
|per month |in sample|per month |in sample
------------+----------+---------+----------+---------
65-68 mm. | 1.4 | 11 | .8 | 12
69-72 mm. | .7 | 12 | .4 | 21
73-76 mm. | .7 | 13 | .3 | 21
77-80 mm. | .4 | 7 | .... | ....
------------+----------+---------+----------+---------
Opportunity to compare the rapid growth of young during their first year
of life with the relatively slow continued growth after attainment of
sexual maturity is afforded by the records of skinks caught and marked
while yet immature and recaptured in two or more successive years after
their attainment of sexual maturity. The records of selected individuals
of this group are presented below. With the exception of number three,
all in this series are of the 1949 brood, and probably all hatched
within a two-week period.
Table 12.--Records of Individual Skinks Marked as Young and
Recaptured Repeatedly After Attainment of Adult Size, Showing
Trend of Progressively Slowing Growth.
=======+==================+==========+=====================+======+============================
| |Snout-vent| |Weight|
| Date | length | Tail length | in |
| | in mm. | in mm. | grams| Remarks
-------+------------------+----------+---------------------+------+----------------------------
No. 1. |Male | | | |At an age of 33 months
|April 12, 1950| 43 | 71 | 1.5 | this male was far short
|August 30, 1950| 56 | 56 + 21 | 5.4 | of maximum size, and
|May 23, 1951| 68 | 59 + 32 | .... | smaller than some
|April 28, 1952| 73 | 62 + 38 | 6.6 | males a year younger;
| | | | | all four captures within
| | | | | a 65-foot diameter.
| | | | |
No. 2. |Male | | | |At an age of approximately
|July 5, 1950| 61 | 92-1/2 (regenerated)| 5.2 | one year this
|July 28, 1950| 64 | 97 (regenerated) | 5.4 | male was approaching
|May 3, 1951| 68 | 96 (broken stub) | 5.8 | small adult size; when
|June 21, 1951| 72 |101-1/2 (regenerated)| .... | last captured at an age
|May 1, 1952| 78 |101 (regenerated) | .... | of 34 months, he was a
| | | | | large adult. All five
| | | | | records within a 190-foot
| | | | | diameter.
| | | | |
No. 3. |Male | | | |This skink was nearly a
|June 22, 1949| 65 |111 | .... | year old and nearing
|May 4, 1950| 72-1/2 |115 | 7.3 | adult size when first
|June 17, 1950| 73 |116 | 7.8 | captured; recaptured
|May 15, 1951| 80 |125 | .... | in each of the four
|May 13, 1952| 82 |125 | .... | succeeding years, he
|April 6, 1953| 82 |104 (regenerated) | .... | showed slowing growth.
| | | | | He was near the maximum
| | | | | size at the time of his
| | | | | last capture when he
| | | | | was about 57 months
| | | | | old, and evidently had
| | | | | stopped growing (for
| | | | | movement see No. 2,
| | | | | p. 110).
| | | | |
No. 4. |Female | | | |This individual, marked
|July 13, 1949| 27 | 34-1/2 | .... | when less than two
|June 1, 1950| 54-1/2 | 93-1/2 | 3.1 | weeks old, had grown
|August 21, 1951| 74 |119 | .... | to nearly the maximum
|May 1, 1952| 76 |123 | 10.0 | female size at an age of
| | | | | 34 months; all four
| | | | | captures within a
| | | | | 175-foot diameter.
| | | | | (See Figure 24).
No. 5. |Female | | | |
|April 15, 1950| 43 | 70 | 1.4 |All six records within a
|June 5, 1950| 52-1/2 | 87 | 2.8 | 65-foot diameter (See
|May 25, 1951| 71 | 82 + 29 | .... | Figure 21).
|September 28, 1951| 73 |111 (regenerated) | .... |
|April 26, 1952| 74 |113 (regenerated) | 7.4 |
|April 24, 1953| 76 |114 (regenerated) | .... |
| | | | |
No. 6. |Female | | | |Hatched in July 1949,
|April 21, 1950| 46 | 75 | 2.1 | this skink had attained
|May 7, 1950| 48 | 15 (broken stub) | 2.0 | the maximum female
|May 3, 1951| 74 | 29 + 57 | 8.5 | size at an age of a little
|May 2, 1952| 78 | 25 + 64 | .... | more than three years;
|August 27, 1952| 79-1/2 | 95 (regenerated) | 8.3 | (for movement see
| | | | | Figure 25).
| | | | |
No. 7. |Female | | | |Hatched in July 1949,
|June 5, 1950| 51 | 82 | 2.5 | this skink was 11
|July 13, 1950| 59 | 93 | 3.9 | months old and about
|July 29, 1950| 64 | 98 | 4.4 | half-grown when it was
|August 21, 1951| 69 | 80 (broken stub) | 5.0 | marked. When last
|May 28, 1952| 73 | 83 + 9-1/2 | .... | caught at an age of 35
| | | | | months it was of average
| | | | | adult female size,
| | | | | having grown less than
| | | | | numbers 4 and 6 at the
| | | | | same age. All five captures
| | | | | were within a 60-foot
| | | | | diameter (Fig. 24).
| | | | |
No. 8. |Female | | | |Hatched in July 1949,
|April 26, 1950| 50-1/2 | 78-1/2 | 2.7 | this skink was of average
|May 24, 1951| 74 |107 (regenerated) | .... | adult female size
|April 28, 1952| 78 | 93 (regenerated) | 8.5 | and was breeding in
|April 23, 1953| 80 | 93 (regenerated) | .... | May 1951; it grew
| | | | | nearly to maximum female
| | | | | size in the next 11
| | | | | months. All captures
| | | | | within a 70-foot diameter.
No. 9. |Female | | | |
|July 5, 1950| 60 | 95 | 4.5 |All three captures at the
|August 6, 1951| 71 |106-1/2 | 5.6 | same site.
|May 28, 1952| 72 |110 | 8.5 |
| | | | |
No. 10.|Male | | | |Hatched in July 1949,
|April 23, 1950| 46-1/2 | 66 (regenerated) | 1.8 | this male grew less
|June 13, 1950| 52-1/2 | 26 + 3 | 2.7 | rapidly than most, and
|September 2, 1950| 66 | 32 + 51 | 6.2 | in the spring of 1953
|May 29, 1951| 67 | 33 + 58 | .... | was smaller than some
|August 3, 1951| 70 | 94 (regenerated) | .... | others that were a year
|March 27, 1953| 74 | 78 (regenerated) | 7.1 | younger, or even two
| | | | | years younger.
No. 11.|Female | | | |
|April 26, 1950| 50-1/2 | 78-1/2 | 2.7 |This skink had attained
|May 24, 1951| 74 | 87 | .... | maximum female size
|April 28, 1952| 78 | 72 + 21 | 8.5 | when she was a little
|April 23, 1953| 80 | 73 + 20 | .... | less than four years old.
-------+------------------+----------+---------------------+------+----------------------------
Differences in their growth rates therefore reflect differences in sex,
individual vigor, and local situation, in individuals living at the same
time and within the same general environment.