sign in sign up
<<
Home , Ensatina

Society for the Study of and Reptiles

Patterns of Growth and Movements in a Population of Ensatina eschscholtzii platensis (Caudata: ) in the Sierra Nevada, Author(s): Nancy L. Staub, Charles W. Brown and David B. Wake Source: Journal of Herpetology, Vol. 29, No. 4 (Dec., 1995), pp. 593-599 Published by: Society for the Study of Amphibians and Reptiles Stable URL: http://www.jstor.org/stable/1564743 Accessed: 03-02-2016 23:13 UTC

REFERENCES Linked references are available on JSTOR for this article: http://www.jstor.org/stable/1564743?seq=1&cid=pdf-reference#references_tab_contents

You may need to log in to JSTOR to access the linked references.

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://www.jstor.org/page/ info/about/policies/terms.jsp

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected].

Society for the Study of Amphibians and Reptiles is collaborating with JSTOR to digitize, preserve and extend access to Journal of Herpetology. http://www.jstor.org

This content downloaded from 136.152.142.101 on Wed, 03 Feb 2016 23:13:43 UTC All use subject to JSTOR Terms and Conditions Journal of Herpetology, Vol. 29, No. 4, pp. 593-599, 1995 Copyright 1995 Society for the Study of Amphibians and Reptiles

Patterns of Growth and Movements in a Population of Ensatina eschscholtzii platensis (Caudata:Plethodontidae) in the Sierra Nevada, California

NANCY L. STAUB,1CHARLES W. BROWN,2AND DAVID B. WAKE3

'Departmentof Biology,Gonzaga University, Spokane, Washington 99258, USA, 2Departmentof Biology,Santa Rosa Junior College, Santa Rosa, California 95401, USA, and 3Departmentof IntegrativeBiology and Museum of VertebrateZoology, University of California, Berkeley,California 94720-3160, USA

ABSTRACT.- Movements and growth in a population of the terrestrialplethodontid salamanderEnsatina eschscholtzii platensis were investigated using mark-recapturemethods over a period of 1946 days at a mid-elevation site in the central Sierra Nevada of California. The study site included two plots of equal size, totaling 3.0 ha, in an old-growth pine-fir-incense cedar forest. Our sample included 925 captures,and 14%of the were recaptured at least once. Males were more active than females; recapture rates were significantly higher for males than for females, despite a 1:1 sex ratio. Variance in distance traveled was significantly greater for males than for females, and most long-range movements were by males, but mean distance traveled did not differ significantly between sexes. The maximum distance moved for males and females was 120.4 m and 60.6 m, respectively. These movement differences between sexes may explain differences in patterns of mtDNA and allozyme variation within the Ensatinaspecies complex. We suggest that terrestrialplethodontids routinely travel distances > 10 m and caution against calculating home-range sizes from studies conducted only on plots of small size.

Ensatinaeschscholtzii is a terrestrial - Park, Calaveras Co., California, at an average tid that is widespread in mesic elevation of 1400 m (see Fig. 1 in Wake et al., western North America. It passes its entire life 1989). Two 1.5 ha study plots were established cycle on land; there is no breeding migration, on either side of Moran Creek, a small perma- and avoid standing or flowing wa- nent stream. Each plot extended along the creek ter. Systematics and biogeography of the En- for 100 m, and up the respective creek bank for satina complex have been under study (cf. Wake 150 m. Grid lines from the plot perimeter were and Yanev, 1986; Moritz et al., 1992; Jackman laid every 10 m and numbered stations were and Wake, 1994), and ecological data are needed established at sites of intersecting lines. At each for estimating extent of gene flow and other of these sites a pitfall trap was established with- population genetic parameters. in 1 m of the point of intersection (trees, logs, In September, 1985, we initiated a long-term and rocks were avoided). Pitfall traps were used study of movement patterns in Ensatina esch- to minimize the amount of disturbance to the scholtzii platensis. Prior ecological studies had habitat (e.g., log turning). Traps were far more been conducted only for populations of E. e. effective than day-time or night-time searches eschscholtziiin southern California and E. e. xan- for salamanders (unpubl data). The traps were thoptica in the East Bay Region of central coastal round cans 18 cm deep and 16 cm in diameter. California (Stebbins, 1954). These taxa differ Each trap was provided with drain holes and a substantially in allozymes and mitochondrial bed of wet wood shavings and covered with DNA from the population studied (Wake and either a log or piece of bark. There were 176 Yanev, 1986; Moritz et al., 1992). The primary traps per plot. On the south plot an additional goal of our study was to compare movement pitfall trap was installed within 1 m of the cen- patterns of males and females, and estimate ter of each 10 x 10 m section. Thus, the south home range size. In addition, growth rates and plot contained 150 more traps than the north longevity were determined. plot. The north plot was flatter and received more sun than the south plot; the south plot MATERIALSAND METHODS was more densely vegetated at ground level. The study site is in old growth forest of pon- Both plots had nearly full canopy cover from derosa pine (Pinus ponderosa), sugar pine (Pinus towering old growth trees. lambertiana), incense cedar (Calocedrus decur- The central Sierra Nevada experiences sharp rens), white fir (Abies concolor) and black oak seasonality in climate that affects salamander (Quercus kelloggii) in Calaveras Big Trees State movements. Feeding and courting are restricted

This content downloaded from 136.152.142.101 on Wed, 03 Feb 2016 23:13:43 UTC All use subject to JSTOR Terms and Conditions 594 N. L. STAUB ET AL. to periods when the ground surface is moist Smirnov test compared the distributions for m (Stebbins, 1954). This site receives on average moved/day and cumulative m moved between 1500 mm precipitation per year, and rainfall males and females. The chi-square test was used occurs primarily from September or October to compare the number of captures and recap- through early May. Surface conditions become tures between the north and south plots and progressively drier from mid-April through the the frequency of movements >20 m between summer, and the habitat is too dry for surface males and females. We also tested the sex ratio activity for 4-5 mo. Snow falls on the site every of captures and recaptures using the chi-square year, usually between December and February, test. Statview 512+ was used for the above com- but the amount is highly variable. Snow cover parisons. We also tested for differences between persists for more than a month on only limited sexes in the variance of cumulative distance parts of the site. moved (log transformed) (Sokal and Rohlf, Traps were monitored every 1-4 wk during 1981). Individuals that matured during the study the wet season, from September, 1985, through were excluded from analyses unless otherwise March, 1988. Spacing of visits was dependent noted. on weather and was more frequent when con- RESULTS ditions were judged to be suitable for activity. A few specimens (<1% of the total) may have TrappingSuccess.--A total of 925 living sala- spent as long as 4 wk in a trap, but only during manders (including recaptures) were captured the coldest time of the year. Occasionally it was during the study (30 dead salamanders [nearly impossible to check all traps because of heavy all drowned] and 12 tails without bodies were snow. Tree falls necessitated the minor relo- also found in the traps). Successful traps typi- cation of a few traps. 1988 was a year of severe cally contained one , but from two to drought and surface salamander movements seven (a unique event) salamanders were found ceased by mid-March. The study was then sus- in a single trap. On 26-27 October 1985, 155 pended in anticipation of a controlled burn. animals were captured (389 empty traps, 90 with However, the burn was not conducted and one animal, 17 with two, four with three, one monitoring was reinitiated from early Novem- with four and one with seven). The second most ber, 1990, to January, 1991. successful trapping produced 77 animals (30 Individual E. e. platensishave a distinctive col- November 1990). On several trapping occasions or pattern, consisting of reddish orange dorsal no animals were found in any of the 502 traps. spots or blotches on a gray-brown background. We caught a lower proportion of juveniles than Salamanders retrieved from pitfall traps were observed by Stebbins (1954) for a population of photographed in color using a camera with a E. e. xanthoptica.In the laboratory we found that fixed focal length. Each salamander was sexed juveniles placed in traps are able to climb out, (juvenile, male, or female) and photographed while adults do so rarely. Thus, we suspect that against a centimeter grid with a label indicating juveniles escape traps more readily than do date, capture site, and the sequential number adults. of each captured salamander. Salamanders were One hundred eleven animals were recap- returned to cover objects within 1 m of their tured at least once (14% of total), including 25 site of capture. Following each trapping episode females, 65 males, six juveniles, and 15 small photographs were compared to all previous animals that we could not sex. One adult male prints to identify recaptures using individual was recaptured seven times over a period of 902 spotting patterns. From photographs, body size d, while 93 (84%) of the animals were recap- (tip of snout to tail base constriction, to nearest tured only once. While two females and 12 males mm) was measured for individuals with mul- were recaptured twice, only males were recap- tiple captures and tail length (tail base constric- tured three times or more. Recapture interval tion to tip, to nearest mm) was measured for varied from 14-1754 d (mean 197 ? 37.6 d). recaptured animals with regenerating tails. Body There was no significant difference in recapture size and tail regeneration growth rates were interval between males and females (Mann- calculated using these measurements. We be- Whitney U = 758.5, P = 0.63 for individuals (65 lieve the measurements from photographs were males, 25 females); Mann-Whitney U = 981, P accurate to within 1 mm, based on direct com- = 0.20 per episode (male episodes = 87, female parisons, for salamanders that were straight, but episodes = 27)). some inaccuracy may have arisen from mea- Trap density was 0.012 traps per m2 on the suring bent animals. north plot and 0.022 traps per m2 on the south The Mann-Whitney U test was used to com- plot. Assuming equal densities of salamanders pare recapture interval, m moved/day, m on both plots we expected the number of cap- moved/episode, cumulative m moved, and final tures to be proportional to trap density. Al- m from original capture site. The Kolmogorov- though we captured more salamanders on the

This content downloaded from 136.152.142.101 on Wed, 03 Feb 2016 23:13:43 UTC All use subject to JSTOR Terms and Conditions MOVEMENT PATTERNS IN ENSATINA SALAMANDERS 595 south plot than the north plot, numbers were 20- more numerous than expected on the north plot 18- and less numerous on the south 372 16 MALES (north: cap- 14- tures, south: 437 = P = captures; x2 42.0, 0.0001). Q 12- We expected higher recapture rates on the south 0 10- because of higher trap density, and this was the 8- case (north: 53 recaptures, south: 83 recaptures) (X2 0.907, = P = 0.34). - Because was on the south 2 trap density greater 0- . . . _ shorter movement distances were -U plot, expect- 10- ed. Mean distance per episode (males and fe- males combined) was significantly different be- 8 tween the two plots (south: 19.7 + 1.54 m, N = FEMALES 64; north: 26.5 + 2.68 m; N = 51; Mann-Whitney o 6 U = 1222.5, P = 0.02) but total distance traveled 4- did not differ between the plots (south: 27.4 + = (U 3.6 m, N 46; north: 30.7 + 3.9 m, N = 44; - ?4 2 Mann-Whitney U = 856.5, P = 0.21). Males and females were present in equal pro- u I If I iP I 0 portions in the total sample (discounting all re- 20 40 60 80 100 120 140 160 captures: 246 males, 243 adult females; X2= 0.02, Distance moved (m) P = 0.89). In contrast we recaptured signifi- FIG. 1. of cumulative dis- more males Frequency histogram cantly (65) than females (25); (X2= tance moved by recapturedindividuals. Therewas no = 17.8, P 0.0001). statisticaldifference between sexes in the percentage While the minimal distance moved was zero of individuals that moved more than 20 m per epi- for both males and females, nearly all individ- sode. uals moved between recaptures. Distance moved did not increase with duration of recapture in- Smirnov D = 0.23, P = 0.33), but males had a terval for males or females (males r2 = 0.001, P greater variance (test for equality of variances, = 0.74; females r2 = 0.15, P = 0.05 [b = -0.01]). P < 0.05). Individuals were recaptured in the same trap The mean distance traveled per day did not on only three occasions. An adult female, cap- differ significantly between sexes (by individ- tured twice, was found in the same trap on dates ual: males = 0.33 + 0.05 m/day; females = 0.21 separated by 1754 d (4.8 yr). An adult male was ? 0.04 m/day; Mann-Whitney U = 774, P = found at its original site after having been re- 0.54). Furthermore, there was no significant dif- captured 14.1 m away 29 d earlier. Another adult ference between the distributions of the values male was found in the same trap 70 d after its between sexes (Kolmogorov-Smirnov D = 0.18, first capture, but was recaptured three more P = 0.43). times in three different traps, the most distant The maximal movement per recapture epi- being 25.5 m from the site of first capture. sode was 120.4 m (406 d interval) by a mature Final distance from original site of capture male and 60.8 m (147 d interval) by a mature varied from 0 m (one male and one female) to female. One individual that was a juvenile at 120.4 m (a male). Mean final distance for males first capture but an adult female at the time of was 21.7 ? 2.1 m and for females was 22.2 ? recapture moved 82.5 m (218 d interval). Epi- 2.8 m, with no significant difference between sode distance did not differ significantly be- the means (Mann-Whitney U = 766.5, P = 0.68). tween sexes (Mann Whitney U = 1128, P = Final distances for seven juveniles ranged from 0.76). Furthermore, there was no significant dif- 10-86.3 m, including two stream crossings. ference between the percentages of males and The greatest cumulative movement was 150.4 females that moved greater than 20 m (recap- m over a 902 d period by the adult male recap- ture episode: X2 = 0.35, P = 0.55; individual: tured seven times; however, this individual X2= 0.82, P = 0.37) (Fig. 1). ended only 7.1 m (the minimal measurable dis- Although Moran Creek is permanent, it is tance) from the site of initial capture. The great- small (1 m or less in width), and even during est cumulative movement by an adult female times of high water there are at least 12 places was a single movement of 60.8 m, and the next in the 100 m stretch included in our study area greatest distance was 56.6 m. The mean cumu- that appeared to be suitable (large logs or piled lative distance traveled for males was 31.2 ? stones cross the creek) for crossing by terrestrial 3.5 m; for females, 23.3 ? 2.9 m. The means and salamanders. Yet, only three individuals were distributions did not differ between the sexes known to cross the stream, and two of these (Mann-Whitney U = 674, P = 0.21; Kolmogorov- were juveniles.

This content downloaded from 136.152.142.101 on Wed, 03 Feb 2016 23:13:43 UTC All use subject to JSTOR Terms and Conditions 596 N. L. STAUB ET AL.

75-

70-

65-

55-

0

50-

4-5 II ...... -200 0 200 400 600 800 1000 1200 1400 1600 1800 2000

Days since 9/14/85 FIG.2. Measuredgrowth of individual salamandersbetween recaptures.Only individuals with total re- captureintervals >1000 d were used.

Growth and Longevity.-Individual growth Because the variance around estimated growth patterns for animals with >1000 d recapture rates decreased with longer recapture intervals intervals are presented in Fig. 2. Mean growth (Fig. 3), we used animals with recapture inter- rates for males and females varied greatly (males: vals >1000 d to estimate age. The longest re- 0.005 + 0.0049 mm/day; females: 0.092 ? 0.0071 capture interval (which includes two recap- mm/day). Growth rates were computed with- tures) was 1859 d (5.09 yr). This adult male was out taking into account seasonal differences in 68 mm SVL at first capture and 70 mm SVL at activity. Thus, if salamanders experienced no final recapture (growth rate 0.0011 mm/d). This growth during part of the year, the growth rate recapture interval was not unusual; there were would be higher during periods of activity. 13 recapture intervals >1000 d (N = 11 males, Overall, growth rates decreased with increasing 2 females; x = 1367 ? 320 d). Ages of these body size (log growth rate in mm/day = 1.6- salamanders were calculated using estimated age 4.3 (log mean SVL in cm); P = 0.02; r2 = 0.10). at sexual maturity (Stebbins, 1954), average The tail was lost by 5.4%(N = 6) of recaptured growth rates, and length of recapture interval. animals during our study and several animals For example, a conservative age estimate for the had no tail when initially captured. The tail was animal recaptured after 1859 d is 15.2 yr (3 yr regrown by 9% (N = 10) of recaptures during to 55 mm (Stebbins, 1954), 7.12 yr to 68 mm the study. Rates of tail regeneration were vari- (using average male growth rate of 0.005 mm/ able (3 females: 0.0047 mm/day + 0.0023; 6 d), and 5.09 yr to 70 mm (actual recapture in- males: 0.0037 mm/day + 0.0009; 1 juvenile: terval)). The actual growth rate of this individ- 0.0012 mm/day). We recaptured one animal fre- ual was only 0.0011 mm/d, but we assumed the quently enough (N = 5) to document complete faster average rate from sexual maturity to time tail regeneration. The tail grew from 0.3 mm to of first capture, and thus our age estimate is 52 mm in 2 yr. conservative. Conservative age estimates for

This content downloaded from 136.152.142.101 on Wed, 03 Feb 2016 23:13:43 UTC All use subject to JSTOR Terms and Conditions m

MOVEMENT PATTERNS IN ENSATINA SALAMANDERS 597

0.15 - * MALE o FEMALE m

0- ?: 0.05- Im

0m Ib * O ._ _.., B(Oi mI ? L0 "SNO-n f4 1 .^q, m- 0 - *o - C mO

M.o . 0

v. -0.05 - mE U

0

I II X I I x | 5 x -0.15 18I I2 0 200 400 600 80080 I10001000 1200 1400 1600 1800 2000 Total recapture interval (days) FIG.3. Estimatedgrowth rate plotted as a function of the interval from first to last capture. Variance around the estimatesdecreases as recaptureinterval increases.Thus, only salamanderswith a total recapture interval > 1000 d were used in age calculations. those with >1000 d recapture intervals (N = lozymes was interpreted as a northward dis- 13) ranged from 5.5 yr to 14.9 yr (age: x = 9.6 persal of southern E. e. platensis, but the contact = + 2.8 yr, size: x 67.8 ? 3.6 mm). zones with northern populations for allozymes and for mtDNA did not DISCUSSION correspond (Jackman and Wake, 1994; Schneider and Wake, unpubl. Movement Patterns.--Because some males data). The allozymes, carried by both sexes, had traveled greater distances than females, the spread much farther than had the mtDNA, variance in total distance moved was signifi- which is transmitted only by the relatively sed- cantly greater in males than females. Conse- entary females. quently, over hundreds and thousands of years, RecaptureRates.-Because males and females males as a group disperse more than females, were present in equal numbers in the total sam- thus contributing disproportionately to gene ple, we expected equal numbers of recaptures. flow. Stebbins' (1954) studies on a different sub- The higher recapture rate for males has several support this conclusion; female E. e. possible interpretations: (1) females move off eschscholtziiwere more sedentary than males. A the plot more than males; (2) males have lower difference in movement patterns between males mortality rate than females; (3) females are bet- and females has been observed in Plethodonglu- ter at avoiding traps after being caught once; tinosus as well (Merchant, 1972). (4) males are more active on the surface than This result offers a possible explanation for females. Hypothesis 1 predicts higher vagility differences in patterns of allozyme and mtDNA for females than for males and our movement variation in E. eschscholtzii. Evidence from al- data do not support this prediction. Hypothesis

This content downloaded from 136.152.142.101 on Wed, 03 Feb 2016 23:13:43 UTC All use subject to JSTOR Terms and Conditions 598 N. L. STAUB ET AL.

TABLE1. Plot size, home range size, and maximumdistance traveled for terrestrialplethodontine sala- manders,listed in orderof increasingplot size. Note that home rangeestimates increase as plot size increases. N.A. = not available.

Max.dis. Plotsize Averagehome traveled (m) range (m2) (m) Sex Species Reference 3 x 3 0.163 N.A. male P. cinereus Mathis,1991 3 x 3 0.162 N.A. female P. cinereus Mathis,1991 10 x 10 0.49 N.A. male P. teyahalee Nishikawa,1990 10 x 10 1.03 N.A. female P. teyahalee Nishikawa,1990 10 x 10 0.6* N.A. N.A. P. hubrichti Krameret al., 1993 10 x 10 5.04 N.A. male P. jordani Nishikawa,1990 10 x 10 1.87 N.A. female P. jordani Nishikawa,1990 30.5 x 15.2 37.6 N.A. male P. jordani Merchant,1972 30.5 x 15.2 9.2 N.A. female P. jordani Merchant,1972 30.5 x 15.2 47.2 N.A. male P. glutinosus Merchant,1972 30.5 x 15.2 21.4 N.A. female P. glutinosus Merchant,1972 4.6 ha 10.78 N.A. male P. cinereus Kleebergerand Werner,1982 4.6 ha 19.85 N.A. female P. cinereus Kleebergerand Werner,1982 3.2 ha N.A. 91.5 N.A. P. glutinosus Wells and Wells, 1976 1.5 ha N.A. 120.4 male E. eschscholtzii presentstudy 1.5 ha N.A. 60 female E. eschscholtzii present study * Mediansize.

2 receives no support from our recapture data; There are a few reports of relatively long- there is no significant difference between male range movements in other terrestrial salaman- and female recapture intervals. We have no be- ders. Kleeberger and Werner (1982) suspected havioral data to address hypothesis 3, but it that some individuals of P. cinereuson their study seems unlikely. Hypothesis 4 is indirectly sup- site had moved off-site and later returned. An ported by movement data-the variation in cu- individual Plethodon glutinosus moved 91.5 m mulative distance traveled was greater for males (Wells and Wells, 1976), and some P. jordani than for females, suggesting that some males display homing behavior over a displacement move more often than females. Consequently, distance as great as 150 m (Madison, 1969). Our more males than females are recaptured. data suggest that such long range movements Home Rangeand TerritorySize. -Because of the occur regularly in Ensatina. difficulty in observing free-ranging terrestrial A study on small scale movements of Ensatina, salamanders without degrading habitat or in- comparable to the studies on Plethodon, would terfering with behavior, few studies have ex- yield valuable data regarding differences in amined movement patterns (but see Nishikawa, movement patterns and territory use. Further- 1990; Mathis, 1991). Our study focused on large more, studying the effects of season on move- scale movements (smallest measurable non-zero ment patterns may reveal that long range move- distance was 7.1 m) so we did not attempt to ments only occur at certain times of the year. estimate home range or territory size. Our For example, Mathis' (1991) study focused on movement data suggest that distance traveled movement patterns only in the non-breeding (and thus home range or territory size) may well season in order to avoid spacing or movement be correlated with size of the study plot (Table patterns related to breeding activity. 1). Capture disrupts normal activity patterns Estimated home range sizes for Plethodon ci- (possibly leading to loss of territory in some nereus range from 0.162 (Mathis, 1991) to 19.85 cases). A few individuals spent up to four weeks m2 (Kleeberger and Werner, 1982) for plots in the cans (always during the coldest time of ranging from 9 m2 to 4.6 ha. Studies using small the year when surface activity was minimal). plots may yield small home range sizes because Some long range movement might have been large movements are not detected. For example, induced. Photography was an additional inter- had we used a 10 by 10 m grid, the male we ference, but we assumed that the effects were recaptured 7 times would have been recaptured short-lived. within the 10 x 10 plot over the course of the Growthand Longevity.-Based on growth data study, but movements to more distant pitfall as well as time intervals between recaptures, traps would not have been detected. we estimate that animals approximately 68 mm

This content downloaded from 136.152.142.101 on Wed, 03 Feb 2016 23:13:43 UTC All use subject to JSTOR Terms and Conditions MOVEMENT PATTERNS IN ENSATINA SALAMANDERS 599

SVL are 9.6 yr old. Our estimates are slightly MADISON, D. M. 1969. Homing behaviour of the red- greater than those of Stebbins (1954), who es- cheeked salamander, Plethodon jordani. Anim. Be- timated the oldest marked individual (size of hav. 17:25-39. MATHIS,A. 1991. Territories of male and female ter- 72 mm) in his study to be at least population restrial salamanders: costs, benefits, and intersex- 81/2yr old. Growth rates for tail regeneration ual spatial associations. Oecologia (Berlin) 86:433- were consistent with Stebbins' (1954) estimates 440. of 2 for approximately yr complete regenera- MERCHANT,H. 1972. Estimated population size and tion. home range of the salamanders Plethodon jordani and was Plethodon glutinosus. J. Washington Acad. Sci. Acknowledgments.-This study undertak- 62:248-257. en as a research with the cooperative program MORITZ, C, C. J. SCHNEIDER,AND D. B. WAKE. 1992. California State Parks We Department. thank Evolutionary relationships within the Ensatina W. Harrison, J. Bolker, J. Camarillo, A. Collazo, eschscholtziicomplex confirm the ring species in- D. Good, T. Jackman, E. Jockusch, S. Marks, F. terpretation. Syst. Biol. 41:273-291. Mendez, G. Roderick, A-M. Tan and S. Scrog- NISHIKAWA, K. 1990. Intraspecific spatial relation- gins for assisting in various aspects of the study, ships of two species of terrestrial salamanders. Co- 1990:418-426. and we thank many others who helped check peia SOKAL, AND ROHLF. 1981. 2nd ed. W. the traps on occasion. M. Garcia Paris, E. Jock- R., J. Biometry, H. Freemanand Co., San Francisco. usch, D. Parks, C. Schneider, and R. Stebbins STEBBINS,R. C. 1954. Natural of the sala- offered comments on the Our field history manuscript. manders of the plethodontid genus Ensatina.Univ. studies were supported in part by NSF (to DBW), CaliforniaPubl. Zool. 54:47-124. Santa Rosa Junior College and the Murdock WAKE,D. B., AND K. P. YANEV. 1986. Geographic College Science Research Program (to NLS). variation in allozymes in a "ring species," the plethodontid salamander Ensatina eschscholtzii of LITERATURECITED western North America. Evolution 40:702-715. K. P. AND M. M. FRELOW. JACKMAN,T. R., ANDD. B. WAKE. 1994. Evolutionary , YANEV, 1989. Sym- and and historical analysis of protein variation in the patry hybridization in a "ring species": the blotched forms of salamanders of the Ensatinacom- plethodontid salamander Ensatina eschscholtzii. In D. and plex (Amphibia: Plethodontidae). Evolution 48: Otte J. A. Endler (eds.), Speciation and its 876-897. Consequences, pp. 134-157. Sinauer Associates, KLEEBERGER,S. R., AND J. K. WERNER.1982. Home Sunderland, Massachusetts. K. AND R. A. range and homing behavior of Plethodon cinereus WELLS, D., WELLS. 1976. Patterns of movement in a of in northern Michigan. Copeia 1982:409-415. population the slimy salaman- KRAMER, P., N. REICHENBACH,M. HAYSLETT,AND P. der, Plethodon glutinosus, with observations on ag- SATTLER.1993. Population dynamics and conser- gregations. Herpetologica 32:156-162. vation of the Peaks of Otter Salamander, Plethodon hubrichti.J. Herpetol. 27:431-435. Accepted: 28 July 1995.

This content downloaded from 136.152.142.101 on Wed, 03 Feb 2016 23:13:43 UTC All use subject to JSTOR Terms and Conditions