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Rice Creek Research Reports, 1998

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Title:
Rice Creek Research Reports, 1998
Series Title:
Rice Creek Research
Creator:
Valentino, David ( author )
Peavy, Samuel ( author )
Chepko-Sade, Diane ( author )
Weber, Peter ( author )
Weber, Nicholas ( author )
Nelson, Andrew ( author )
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English

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Rice Creek Field Station
SUNY Oswego

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Contains the Following Research Reports: Variability of Electrical Resistivity at Rice Creek Field Station, Oswego, New York: Implications for the Distribution of Groundwater; A Survey of Small Mammal Populations at Rice Creek Field Station (Year 3); Butterfly Populations at Rice Creek Field Station, The 1998 Season
General Note:
The summer of 1998 saw the continuation of the two long-term biological studies that initiated the Rice Creek Associates small grants program and the addition of a new project in the earth sciences. Rice Creek Associates was again joined by Oswego State's Division of Continuing Education and Office of Research and Sponsored Programs in support of the 1998 research efforts. Diane Chepko-Sade and Peter and Nick Weber indicate that the three years of data now available from their respective studies provide evidence of patterns of fluctuating population densities and environmentally related changes in habitat utilization that should lend significant insights into the dynamics of ecology at Rice Creek Field Station. Dave Valentino and Sam Peavy's explorations of innovative, non-invasive techniques for investigating conditions and structures beneath the surface of the earth open a whole new dimension to the natural history of the Field Station and the region. Diane is currently developing techniques of data management that will help her and her students track the fortunes of small mammal populations at Rice Creek in future years. Peter is well into the development of a monographic treatment of our butterfly populations. I am especially intrigued by Dave and Sam's suggestion that Lake Ontario, while receiving the surface runoff from a large part of north-central New York State, may at the same time be contributing water back into our subsurface aquifers. This year again I am left with the feeling that my enhanced understanding of the part of the world where I live and work is a significant return from the task of editing and formatting these reports. Andrew P. Nelson, Director Rice Creek Field Station June 19, 1999
General Note:
Submitted by Shannon Pritting (pritting@oswego.edu) on 2011-06-21.
General Note:
Made available in DSpace on 2011-06-21T14:00:07Z (GMT).
General Note:
SUNY Oswego Division of Continuing Education, SUNY Oswego Office of Research and Sponsored Programs, Rice Creek Associates

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SUNY Oswego
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SUNY Oswego
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All applicable rights reserved by the source institution and holding location.

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RICE CREEK RESEARCH REPORTS 1998 RICE CREEK FIELD STATION OSWEGO STATE UNIVERSITY OSWEGO, NEW YORK 13126 JUNE 21, 1999

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Rice Creek Research Reports 1998 The summer of 1998 saw the continuation of the two long-term biological studies that initiated the Rice Creek Associates small grants program and the addition of a new project in the earth sciences. Rice Creek Associates was again joined by Oswego State's Division of Continuing Education and Office of Research and Sponsored Programs in support of the 1998 research efforts. Diane Chepko-Sade and Peter and Nick Weber indicate that the three years of data now available from their respective studies provide evidence of patterns of fluctuating population densities and environmentally related changes in habitat utilization that should lend significant insights into the dynamics of ecology at Rice Creek Field Station. Dave Valentino and Sam Peavy's explorations of innovative, non-invasive techniques for investigating conditions and structures beneath the surface of the earth open a whole new dimension to the natural history of the Field Station and the region. Diane is currently developing techniques of data management that will help her and her students track the fortunes of small mammal populations at Rice Creek in future years. Peter is well into the development of a monographic treatment of our butterfly populations. I am especially intrigued by Dave and Sam's suggestion that Lake Ontario, while receiving the surface runoff from a large part of north-central New York State, may at the same time be contributing water back into our subsurface aquifers. This year again I am left with the feeling that my enhanced understanding of the part of the world where I live and work is a significant return from the task of editing and formatting these reports. Andrew P. Nelson, Director Rice Creek Field Station June 19, 1999 Contents Variability of Electrical Resistivity at Rice Creek Field Station, Oswego, New York: Implications for the Distribution of Groundwater. I A Survey of Small Mammal Populations at Rice Creek Field Station (Year 3) 20 Butterfly Populations at Rice Creek Field Station, The 1998 Season 25

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Variability of Electrical Resistivity at Rice Creek Field Station, Oswego, New York: Implications for the Distribution of Groundwater! David W. Valentino, Department of Earth Sciences, Oswego State University, Oswego, NY 13126 Samuel T. Peavy, Department of Geological Sciences Rutgers University, 195 University Ave., Newark, NJ 07102 Abstract: Electrical resistivity measurements were made to determine the variability of surficial deposits, the depth to bedrock and to characterize the distribution of groundwater at Rice Creek Field Station (RCFS) near Oswego, New York. The field station is underlain by drumlin deposits and ablation till associated with Pleistocene glaciation. These deposits reside on Ordovician quartz sandstone of the Oswego Formation that outcrops within 1500 m of the study site. Locally the Oswego Formation contains subvertical fractures with an average spacing of less than 0.5 m. Twenty offset Wenner electrical resistivity surveys were conducted in June and August of 1998 along trails and across an open field within the field station grounds. Analysis of pseudosections and simple 1-D modeling and 1-D least squares inversion indicate the following: 1) low resistivity zones associated with perched water tables within the chaotic drumlin deposits 2) highly variable and resistive near-surface measurements along Rice Creek were correlated with large (> 1 m diameter) glacial erratics as observed in the field 3) a transitional zone below -250 ft elevation of subcircular resistivity highs separated by relatively low resistivities that continue into the deepest portions of the data is coincident with the projected depth to bedrock beneath the field station and is interpreted to be an undersaturated zone within the fractured Oswego Sandstone 4) low resistivities below an elevation of-190ft are interpreted to be the top ofthe saturated domain within the fractured bedrock. Introduction: Geophysical methods have gained wide acceptance in recent years within the environmental industry as an important part of an overall program of investigation and/or remediation (Knight, 1997). The non-invasive nature of geophysical methods make them ideal for the purposes of the environmental industry, where boreholes give incomplete coverage and may allow contaminants to migrate vertically to potable water resources in the subsurface. Almost all geophysical methods have been used to image the shallow subsurface, from the more familiar seismic and magnetic methods, through newer methods such as ground penetrating radar (GPR) and controlled-source audio magnetotellurics (CSAMT). All of these methods, however, share a common purpose, to discover with the greatest possible resolution the distribution of various physical properties in the subsurface. I Financial support provided by Rice Creek Associates and by Oswego State University's Division of Continuing Education and Office of Research and Sponsored Programs.

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Many of the older methods have been adapted from their origins as petroleum or mining exploration tools. Electrical resistivity is one such method. The method is relatively simple: a low-frequency electrical current is introduced into the ground through a pair of current electrodes. A second pair of electrodes measures the potential difference allowing a determination of the electrical resistance. Knowing the geometry of the electrodes allows the determination of the lateral and vertical variation of the physical property resistivity in the subsurface (Telford et aI., 1990; Robinson and Coruh, 1988). For common earth materials, the value of resistivity (or conductivity) can vary widely, and is dependent on many factors, including: the type of material, porosity and permeability, temperature, water saturation, the chemical composition of dissolved ions in the water, and the concentration of those ions (Telford et aI., 1990). For the same material, the resistivity can vary by several orders of magnitude, and the cause of this variability can be attributed to the different types of electrical conduction that occur in the subsurface: ohmic conduction, electrolytic conduction and dielectric conduction (Robinson and <;oruh, 1988). Both ohmic and electrolytic conduction are important in the broad variation of resistivity observed in the subsurface. But, which of the factors listed above (material type, porosity and permeability, temperature, water saturation, chemical composition and concentration of dissolved ions in the water) are the most influential on the variation of resistivity in the long term? How are changes in temperature, for example, translated into measurable changes in resistivity? How does the type of earth material and its properties influence the final results? The exact nature of conductivity in the subsurface is complex, and dependent on many factors. Whereas much work has been done in the laboratory and the borehole environment to determine the relative importance of some factors such as temperature and ion content, little field work has been done using the surface methods most commonly employed in the environmental and engineering fields. This is especially true for the seasonal and longer term variability of subsurface conductivity. Water saturation is especially important in this regard, and resistivity values can vary widely in the same location during different seasons of the year. Wide seasonal variability has been demonstrated for natural potentials (Ernstson and Scherer, 1986; Quarto and Schiavone, 1996); similar variability in conductivity also exists. The measured values of resistivity are influenced by three main factors 1) the mineralogical composition of the subsurface materials 2) the degree of water saturation 3) the chemical composition of the groundwater Of the three factors above, (2) and (3) can be modified by the exchange of water between the atmosphere and the ground. Water saturation of the shallow subsurface is influenced by seasonal precipitation and location relative to bodies of surface and subsurface water (streams, ponds, perched aquifers, etc.). Theoretically, an increase in water saturation would overall decrease the range of resistivity as compared to a "dry" survey over the same area and within the same geological unit. Variations in the water saturation history and amounts of pore fluid have been shown to produce hysteresis in the measured resistivity during imbibition and drainage (Knight, 1991), suggesting that the history of saturation as well as the current state should be considered when interpreting electrical resistivity data. Due to the influence of moisture on electrical resistivity measurements, the use of resistivity as a groundwater exploration tool is highly effective. 2

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In the Summer of 1998 a grant from the Rice Creek Associates funded the first stages of a long term study of the seasonal impact on electrical resistivity measurement. The first stage of that project included regional mapping of the electrical resistivity variability at the field station grounds over a relatively short period of time (Figure 1). From that work we (Peavy and Valentino, 1998) delineated systematic variability in the subsurface materials and the distribution of regional and perched aquifers. The second stage of the project will examine the impact of particular environmental variables on electrical resistivity measurements. In a long term field experiment'the moisture input and output, and subsurface temperature at multiple sites will be monitored through one dry to wet season. The recent use of resistivity arrays to monitor leaks through landfill membranes (Frangos, 1997) and the potential for using this technology as an inexpensive method of monitoring conductive and non-conductive liquids in the subsurface makes understanding seasonal variations in resistivity all the more important, as the proper evaluation of the data requires that the detected anomalies be attributable to the expected target and not a seasonal effect. The purpose of this paper is to make available to interested scientists the geophysical data collected at the Rice Creek Field Station in the Summer of 1998. This paper will also discuss significant geological features identified in the subsurface at the Field Station. Geologic Setting: The geology of the Rice Creek Field'Station (Figure 1) is typical of much of the southern Lake Ontario plain. Bedrock in the area consists of sandstone, siltstone, and shale of the Ordovician Oswego Formation. Overlying the bedrock is an extensive drumlin field stretching between Syracuse and Rochester; cross-sections through the drumlins are nicely exposed along the lake shore southwest of Oswego. Drumlins are composed of massive diamictons (till) with stringers of sand, gravel, and silt, often showing evidence of soft sediment deformation and internal deformation fabrics (Menzies et aI., 1997). Intra-drumlin deposits consist of recent alluvium, varved pond deposits, sand and gravel filled channels, and beach deposits of ancestral Lake Ontario (Lake Iroquois). Bedrock exposures are rare but are encountered in stream cuts, along Lake Ontario, and often within 1D's of feet of the surface during drilling for domestic wells. The relief of drumlins ranges between -100 to 400 feet. Specifically, the terrain at RCFS consists of two drumlins divided by Rice Creek and a man-made pond (Rice Pond) and as such, the field station provides a good cross section of the types of glacial terrain available in north-central New York. Electrical Resistivty Data: Twenty (20) separate offset Wenner electrical resistivity surveys (Barker, 1981) using an offset of 5 m were conducted along trails and across open fields within the RCFS grounds during late June and late August, 1998. The data were collected using a 50-electrode system from Campus Geopulse and their automatic acquisition software. Data were automatically stored on a laptop computer for future analysis. Measurements for a particular electrode separation were repeated until a difference of less than 1% was obtained or until four complete cycles were attempted. Over 950/0 of the data collected were within the 1% tolerance; all other data were eliminated before the calculation of apparent resistivities. The average time for each completed survey was approximately 2.5 hours. Individual surveys along a given trail were designed to overlap slightly to provide some information on variations between surveys, to allow the creation of long 3

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pseudosections, and allow for the production of regional contour maps at various depths across much of the field station grounds. The locations of individual electrodes during the surveys was provided by a combination of exact measurement of the distance between each electrode using a 100 m tape and detailed field survey. Because the electrical resistivity lines were not perfectly straight, compass directions were used to determine the changes in the geometry of the line with respect to the electrode location. Distances between electrodes are accurate to less than 5 cm, and compass directions to approximately one degree. The distribution of data (Figure 1) was designed to give an overall coverage of the RCFS grounds without having to cut new pathways through the forest or fields. Data Processing Considerations: Calculation of apparent resistivity values from field measurements of electrical resistance can be done in most cases by multiplying by the appropriate geometric factor to give the value of apparent resistivity. For the Wenner array, the geometric factor is simply G=21ta where a is the electrode spacing for that particular electrode combination. Because the trails that the data were collected along contained non-straight segments, this simple geometric factor could not be used for our data sets. Therefore, the relative location of each electrode within a particular survey was determined, and the geometric factor calculated separately for each Wenner electrode combination using the standard equation for the four-electrode potential in a half-space. The equation is: -IG=21t (-l/d1 -I/d2 -I/d3 + I/d4 ) where G is the geometric factor, d1 is the distance from the source electrode to the first potential electrode, d2 is the distance from the sink electrode to the same potential electrode, d3 is the distance from the source electrode to the second potential electrode, and d4 is the distance from the sink electrode to the same potential electrode (Robinson and C;oruh, 1988). Individual geometric factors were then multiplied by the ratio of the measured potential to the current to obtain apparent resistivities. Depth values were assigned to each electrode separation using a value of one-half the spacing between the potential electrodes (Barker, 1989) adjusted for the elevation of the midpoint of those same potential electrodes. All data collected along individual trails were gathered together into a single pseudosection, resulting in the eight separate lines shown in Figure 1. Data collected during a four day period in June comprise Line 1 and Line 2; the rest of the data were collected during a similar period in August. Pseudosections of the all data are shown in Figures 2 and 3 (pages 9 17). An analysis of the overlapping survey data show that for most of the data, the differences in data values between surveys were less than 20 ohm-m, with the largest variations occurring for the closest electrode spacing. This was not the case for Line 2 and the Blue Trail surveys. The data for Line 2 were collected over a three day period. Data collected on the second day only a single survey did not match well with data collected the previous day. However, the data did match well with data collected the next day. The explanation probably lies in the weather, as a significant amount of rain fell overnight, saturating the ground between surveys. The three surveys comprising the Blue Trail pseudosection also have a similar problem, with two surveys 4

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being done on one day and the final one a day later after a thunderstorm that evening. All three surveys matched poorly in the near surface, with average differences as large as 800 ohm-m; below level 3, however, differences averaged less than 30 ohm-me In addition to the construction of pseudosections, data from the center of each electrode spread was used to construct a "sounding" from the surface to approximately 40 m depth. This information was used for I-D modeling as detailed later (Figure 4, page 18). Interpretation Of Pseudosectionsl The resistivity data collected at Rice Creek Field Station are shown in Figures 2 and 3. Both figures are plotted using the same spatial and apparent resistivity data scales. Depths in the pseudosections are with respect to the foot contour line on the map. Data collected in the northern portion of the field station display highly variable resistivity along the lower slope (K in Figures 2a and 2b), with some areas of lower resistivity in the near surface portion of the data along the upper slope (labeled P in Figure 2). Data collected across the southern end of the drumlin (Figure 3a) show some low apparent resistivity zones in the shallow subsurface along the upper slope, with subcircular high value zones separating low value zones (L in Figure 3) that continue into the deepest portions of the data sets (Figures 3a, 3b and 3c). There is some indication of similar zones in the northern data sets (Figures 2a and 2b), but these are not nearly as pronounced. Interpretation of the resistivity data was accomplished through correlation of resistivity trends visualized in pseudosections with near surface geologic features and modeling of the data using simple 1-D modeling and a two-dimensional least squares inversion code. The zones of low resistivity in the nearest surface are most likely an indication of perched aquifers within the drumlin deposits. This interpretation is supported by the location of a pond (Figure 1) parallel to the Red Trail line (Figure 2c), and the location of swampy areas adjacent to those regions in other data sets (Figures 2a, 2d, and 3a). These perched aquifers are most likely the result of local variations in the drumlin deposits, where fine-grained layers within the deposits hold the water in those zones. Surrounding those areas are regions of coarser deposits which drain well, allowing the water to percolate through the drumlin deposits to basement level or deeper. In order to confirm our interpretation, a I-D least squares inversion (Loke and Barker, 1995) was performed on the Red Trail data (Figure 2c). Results of the modeling are shown in Figure 4. They indicate that there are zones of extremely low electrical resistivity in the near surface, with larger values deeper in the section. The proximity of a pond and the very low values of resistivity can be best explained by a perched aquifer in the near surface with coarser and more resistive deposits at depth. A 1-D model of the same data using the method of Stefanescu (Stefanescu et aI., 1930) gave similar results. Zones of extremely high and variable resistivity in the near surface (labeled K in Figure 2) are indicative of large (>1 m diameter) glacial erratics as in the creek bed <30 m from the Lower Blue Trail survey (Figure 2b) and the lower portion of Line 2 (Figure 2a). An area along Thompson Road (Figure 3d) also shows similar large and variable resistivity anomalies. It is not certain what produces these anomalies, but similar erratics could be present in the upper portions of the drumlin in this area, although there are no indications of this on other data sets. 5

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Below approximately 250 ft elevation (-36 m in Figures 2 and 3), there are subcircular high value zones separated by relatively low resistivities along the lower slope of the drumlin. The lower resistivity zones appear to continue into the deepest portions of the data. These areas are best seen in Figures 2a, 2b, 3a, and 3b. The zones of relatively high resistivities match the depth to bedrock as projected from nearby Lake Ontario. The deeper zones of much lower resistivities may reflect a saturated domain within the bedrock controlled by the distribution of fracture zones that are documented in outcrops. Hence the transition from saturated to undersaturated fractures within the basement rock may explain these results (Peavy and Valentino, 1998). Based on the resistivity data, a depth of -55 meters (-190 ft elevation) seems appropriate. A resistivity "log" section created from apparent resistivity data collected along Line 2 is shown in Figure 5 (pg. 19). The horizontal, solid black line indicates the elevation of the Oswego Sandstone bedrock as observed at nearby Lake Ontario. The bold black lines 'are lines of equivalent resistivity value, and do not imply any geologic interpretation. One-dimensional models on two "logs" from Line 2 indicates a relatively high resistivity below -250 to 260 ft of elevation (-36 m depth on pseudosections), and lower apparent resistivities in the near surface. This high resistivity zone is roughly equivalent to the projected location of the Oswego Sandstone basement in this area. The dashed line at 170 foot elevation indicates the approximate level of the saturated zone within the bedrock. Conclusions: Electrical resistivity data were collected over the drumlin deposits at Rice Creek Field Station to determine the variability of the surficial deposits, the depth to bedrock, and to characterize the distribution of groundwater at the field station grounds. Offset Wenner electrical resistivity surveys were conducted in June and August of 1998 along trails and across open fields. Analysis of pseudosections and simple 1-0 modeling and 1-0 least squares inversion indicate low resistivity zones in the near surface interpreted to be perched water tables within the chaotic drumlin deposits and highly variable and resistive near-surface measurements along Rice Creek indicati ve oflarge(>1m diameter) glacial deposits. In addition, a transition zone below -250ft elevation (-36 meters depth) of subcircular highs separated by relatively low resistivities is interpreted to be the beginning of an undersaturated domain within the fractured Oswego Sandstone (Peavy and Valentino, 1998). Lower resistivities below an elevation of -180 ft are interpreted to be the top of saturated domain within the bedrock. It is interesting to note that the interpreted groundwater table in the bedrock at the field station is -75 feet below the surface elevation of Lake Ontario (265 feet), which is within 3000 feet of the survey area suggesting that the lake may feed the regional aquifer in the Oswego Formation. Acknowledgments: We would like to thank Rice Creek Associates for providing financial support for the field component of this project. We would also like to thank Dr. Andy Nelson, RCFS Director, and the field station staff for their help with field logistics, and K. Valentino for helping with field surveys. Dr. Cahit <;oruh of Virginia Tech provided the FORTRAN code for the 1-0 resistivity .modeling. RES2DINV was obtained from Advanced Geosciences, Inc. 6

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References: Barker, R. D., 1981, The offset system of electrical resistivity sounding and its use with a multicore cable, Geophysical Prospecting, vol. 29, p.128-143. Barker, R. D., 1989, Depth of investigation of collinear symmetrical four-electrode arrays, Geophysics, vol. 54, no. 8, 1031-1037. Loke, M. H. and Barker, R. D., 1995, Least-squares deconvolution of apparent resistivity pseudosection: Geophysics, vol. 60, no. 6, p. 1682-] 690. Menzies, J., Zaniewski, K., and Dreger, D., 1997, Evidence, from microstructures, of deformable bed conditions within drumlins, Chimney Bluffs, New York State, Sedimentary Geology, v. 111, p. 16]-]75. Peavy, S. T., and D. W. Valentino, 1998, Electrical resistivity variations at the Rice Creek Field Station, Oswego, New York, Geological Society of America Abstracts with Programs, vol. 30, p. A179. Robinson, E. S. and C;oruh, C., 1988, Basic Exploration Geophysics, John Wiley and Sons, New York, 562 p. Stefanescu, S. S., C. Schlumberger and M. Schlumberger, ] 930, Sur la distribution electrique potentielle autor d'une prix de terre ponctuelle dans un terrain a couche horizontales, homogenes et isotrope, Journal Physique et Radium, vol. ] 1, no. 1, p. 132-140. 7

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-----lkmScale Figure 1. Location of resistivity data at Rice Creek Field Station in Oswego, New York. The eight lines shown are composites of data from 20 individual surveys collected during June and August of 1998. Line locations are overlain on a topographic base (Contour Interval = 10 ft). 8

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"...., e....., .c.. eo Q \C .. -10 -20 -30 -40 -50 -60 100 200 300 400 SOO 600 800 900 E 150 200 250 300 350 100 400 4502A Distance (m::rs) Figure 2 (pages 9-13). Apparent resistivity pseudosections from the northern portion of Rice Creek Field Station as indicated in Figure 1. A) Blue trail line; B) Lower Blue Trail line; C) Red Trail line; and D) Bike trail line. Letters on each line indicate interpretations of perched aquifers within the drumlin till (P), highly resistive zones possibly due to large glacial erratics (K), and pronounced low resistivity zones which extend from deeper in the section to the near surface (L). Solid horizontal line is projected depth to bedrock basement; dashed line is projected depth to the top of saturated basement. All data are plotted using the same grayscale range and scale.

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B -.. Q tI'l N =" II g =" 10

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<=lI'lN II M <= <= <= In \C I I I (w) lfldaO 11 ..

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= l/) Q'Q Q l/) N II ,-. 6 '-' C'a= .rI).,. Q > = == Z = l/) U I I I I N(m) qlda(l 12

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-=II) ,..-lN II (m) qldaa 13

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W -101 -E -20 ,I:l. e -30 '-" .cQ. -40 Cl -50 -liOt;E-=, 50 100 150 200 250 Distance (m) 300 350 400 450 3A 100 200 Figure 3 (pages 14-17). Apparent resistivity pseudosections from the southern portion of the Rice Creek Field Station as indicated in Figure I: A) Brownell Road line; B) Green trail line; C) Field line; and D) Thompson Road line. Letters indications are the same as in Figure 2.

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00N 0 l.I) 0 0 z e '-' = .-Q .... 0 0 'C 0 0In 0 0 0 0 0 0 N 0 0 (ill) qldaO 15

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= N= = .=.r-... = It') = =N == I I I I (rn) qlda(l 16 It') = I

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= .Q 17 ..

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Red Trail Line PSZo o 40.0 80.0 120 200 240m 2.6 .,",' .......,I.",.l,....... ............. 12.8" 23.0 33.3 Measured Apparent Resistivity Pseudosection PsZ 0.0 40.0 80.0 120 160 200 240m 2.6 ,..................... ..........I.o..I.."""""""......&...I..................__'-'-..l-.l..........."""-"'-'-.&ooo.olo.................. 12.8 23.0; 33.3 Calculated Apparent Resistivity Pseudosection D h Iteration 3 RMS error =2.9% ept 0.0 40.0 80.0 120 160 200 240m 1.3' ., ., 10.8 21.7 38.7 Inverse Model Resistivity Section._..._....._..... 125 156 194 242 303 378 471 588 Resistivity (Ohm-m) Unit electrode spacing 5.0 m Inversion Completed Figure 4. Results of 2-D inversion of resistivity data along the Red Trial line. Compare with Figure 2C. 18

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I r:, ... I L.VYVI 80 .l[ t AM -x 3W 620 ..iIli II 150 I I o 100200300 ox" t- ht:H .jlJ\J 200 ..-.-100 XI) 500 ,...,..,.. .1420 t-. . 100 300 MJJ 200 lD Model Results ,t>CI --------------_.---------------.._-_.. I-D Model Results -----------------------------------------......9& .e: ., ,-..c::: '-" as Q,l CIS Q,l 00 ,g -< .-= o.... Q,l fiS .... \Q Figure 5. Cross -section along the line of Figure 2A, showing I-D model results and resistivity soundings. The results correlate well with the elevation of the top of basement projected from outcrops at nearby Lake Ontario. The results also support a transition in the data from undersaturated to saturated bedrock at approximately 180 feet.

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A Survey of Small Mammal Populations at Rice Creek Field Station (Year 3)1 B. Diane Chepko-Sade, Department of Biology Oswego State University During the spring, summer and fall of 1996, 1997, and 1998, I conducted a survey of small mammals at Rice Creek Field Station. The survey was conducted to see what small mammals were present, at what population densities, and how the populations compare with small mammal populations in similar environments mentioned in the literature, and at two other locations in northern New York. I have used repeated captures of marked individuals for each of the three years, in order to follow individuals through each breeding season, to begin to develop an estimate of age structure, reproductive rates, mortality, and turnover rates of the populations of different species. Work in 1996 and 1997 has been reported in previous issues of Rice Creek Research Reports (Chepko-Sade, 1997, 1998). The basic background information obtained from these studies will be useful in designing future research projects, and in designing field exercises to be used in undergraduate courses. Methods Used: Trapping grids were set up in four areas: one in an open field maintained by mowing, one in a conifer plantation, one in mature deciduous forest, and one in an area containing both open field and young, second growth woodland. The grids are 70 meters by 70 meters. Medium sized Sherman live traps (3"x3"x9") are placed 10 meters apart, for 64 traps for each grid, baited with sunflower seeds and set for one night and one day during each trapping session. o o 2 2 4 2 o 2 2 o 2 o o 2 3 2 5 3 1996 0 1997 2 1998 2 Small mammals trapped were identified, weighed and measured. Age was estimated (adult or juvenile, based on weight and reproductive status), and reproductive condition was recorded (Larson and Taber, 1980). Any mice and squirrels caught were marked with aluminum ear tags. All animals were released after data was collected. Trapping effort has varied over the three years of the study, depending on the number of field assistants available and project priorities. During 1996, when we were first setting up the grids, we only trapped a total of 10 times. In 1997 and 1998 we trapped 20 and 21 times respectively, though with trapping sessions were distributed more evenly over the summer in 1998 than in 1997 (Table 1). I Financial support provided by Rice Creek Associates and by Oswego State University's Division of Continuing Education and Office of Research and Sponsored Programs. 20

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The number of animals trapped during the field seasons of 1997 and 1998 are similar (Tables 2 and 3), as was their distribution between the four habitat grids. Blarina brevicauda and Tamias striatus continue to be found on all four grids, though only in or close to the wooded areas in the two fields. Microtus pennsylvanicus and Zapus hudsonius contunue to be found only in the fields, while Peromyscus leucopus, Tamiasciurus hudsonicus, Sciurus carolinensis and Glaucomys volans occur only in wooded areas. Since the trapping data for 1998 are very similar Table 2: Number of animals trapped per grid, by species, 1997 Deciduous Lower Field Pine Wood Upper Field Totals Blarina brevicauda 47 30 50 63 190 Peromyscus leucopus 8 22 -0 40 0 70 Sciurus carolinensis 2 1 0 3 Sorex cinereus 0 0 33 2 12 1 1 2 Tamias striatus 92 55 17 197 Tamiasciurus hudsonicus 2 2 0 6 Zapus hudsonius 0 1 24 37 Microtus pennsylvanicus 0 34 0 67 101 Glaucomys volans 1 0 1 0 2 Condylura cristata 0 0 1 0 1 unidentified bird 0 0 0 133 0 3 3 Mustela erminea 0 0 2 2 Totals 152 152 177 614 Table 3: Number of animals trapped per grid, by species, 1998 Deciduous Lower Field Pine Wood Upper Field Totals Blarina brevicauda 64 63 56 110 293 Peromyscusleucopus 29 23 53 2 107 Sorex cine reus 0 1 1 1 3 Tamias striatus 47 58 46 5 156 Tamiasciurus hudsonicus 0 3 6 0 9 Zapus hudsonius 0 27 2 35 64 Microtus pennsylvanicus 0 34 0 20 54 unidentified bird 0 0 0 1 1 Mustela erminea 1 0 1 0 2 Totals 141 209 165 174 689 in this regard to the data for 1997, it seems reasonable to assume that the data for these field seasons are representative censuses of the small mammal populations at Rice Creek Field Station. Species diversity and richness appear to be greatest in the Lower Field, which includes open field, deciduous woods and the ecotone between, and lowest in the mature deciduous woods. Number and identification of species trapped was similar for the two years, with the exception of 21

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two rarely trapped species, the star-nosed mole (Condy/ura cristata) and the southern flying squirrel (Glaucomys volans) which were trapped in 1997, but not in 1998. Both species are believed to have been present during both years, but seldom enter traps set on the ground. Flying Table 4: Number of animals trapped per number of trapping sessions for each two week trapping period, 1996 Mav June July August September October St.Av. Total 16-31 1-15 16-31 1-15 16-31 1-15 16-31 1-15 16-30 1-15 Dev. Blarina brevicauda 0.50 1.25 3.50 27.50 8.2 12.9 Sorex cinereus 0.00 0.00 0.00 0.50 0.1 0.3 Peromyscus leucopus 0.25 1.00 0.00 0.50 0.4 0.4 Zapus hudsonius 0.50 1.00 2.50 2.00 1.5 0.9 Tamiasciurus hudsonicus 0.00 0.00 0.00 1.00 0.3 0.5 Tamias striatus 0.50 3.00 2.00 11.00 4.1 4.7 Sciurus carolinensis 0.50 0.50 0.00 0.00 0.3 0.3 1998 Total Trap Success 9.5 42.5 1.5 6.0 14.9 18.7 Total Animals Trapped 24 19 0 0 0 85 0 0 3 0 14.9 26.5 131 Table 5: Number of animals trapped per number of trapping sessions for each two week trapping period, 1997 Mav July June August September October Ave. St. Dev. Total 16-30 16-31 1-15 16-3116-31 1-15 1-15 1-15 16-30 1-15 Blarina brevicauda 18.0 11.0 6.0 18.0 4.0 9.4 2.0 4.0 12.5 9.4 6.0 Sorex cinereus 0.0 0.0 0.0 0.0 0.0 0.3 0.0 0.2 0.0 0.1 0.1 Condylura cristata 0.0 0.0 0.0 0.0 0.0 0.0 0.2 0.0 0.0 0.0 0.1 Peromvscus leucopus 0.0 0.0 3.0 1.0 5.0 2.5 5.5 6.0 3.0 3.6 2.3 Microtus pennsvlvanicus 6.0 1.0 0.0 0.0 0.5 1.0 3.0 0.5 14.4 2.9 4.7 Zapus hudsonius 2.0 3.0 1.0 0.0 2.5 3.0 1.3 1.5 1.8 1.8 1.0 Tamiasciurus hudsonicus 0.0 1.0 0.0 0.0 0.0 0.0 0.0 0.8 0.5 0.3 0.4 Glaucomvs volans 0.0 0.0 0.0 1.0 0.0 0.0 0.3 0.0 0.0 0.1 0.3 Tamias striatus 12.5 5.0 6.0 7.0 4.5 7.5 5.5 12.5 16.2 8.5 4.2 Sciurus carolinensis 0.0 0.0 0.0 0.0 0.5 0.0 0.0 0.2 0.5 0.1 0.2 Mustela erminea 0.0 0.0 0.2 0.0 0.0 0.0 0.0 0.5 0.0 0.1 0.2 1997 Total Trap Success 27.5 12.0 32.0 19.0 16.0 36.0 28.8 18.5 47.0 26.3 11.1 Total Animals Trapped 32 72 37 235 55 12 19 32 115 0 67.7 70.2 609 Table 6: Number of animals trapped per number of trapping session for each two week trapping period 1998 May July August June September October St.Av. Total 16-30 1-15 16-31 1-15 16-31 Dev. Blarina brevicauda 16-31 1-15 1-15 16-30 1-15 15.7 16.0 27.0 3.5 5.3 10.5 21.5 11.5 17.0 14.2 7.5 Sorex cinereus 0.0 0.3 0.0 0.0 0.0 0.5 0.5 0.0 0.0 0.1 0.2 Peromyscus leucopus 2.0 3.3 4.7 5.3 8.0 2.0 7.0 7.5 6.5 5.1 2.3 Microtus pennsvlvanicus 1.0 3.7 2.7 2.7 1.5 2.0 2.5 3.5 3.0 2.5 0.9 Zapus hudsonius 2.0 1.7 0.3 2.0 7.5 5.5 8.0 2.5 0.5 3.3 2.9 Tamiasciurus hudsonicus 0.3 0.3 0.0 1.0 1.0 0.0 0.5 0.5 0.0 0.4 0.4 Tamias striatus 4.0 8.7 6.3 7.5 4.0 3.3 8.5 16.5 10.0 7.6 4.1 Mustela erminea 0.0 0.0 0.0 0.3 0.5 0.0 0.0 0.0 0.0 0.1 0.2 1998 Total Trap Success 13.5 32.3 33.3 52.5 24.0 18.3 48.5 42.0 37.0 33.5 13.2 Total Animals Trapped 48 27 55 97 100 105 97 0 84 74 70.3 11.6 687 22

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squirrels are more likely to enter a trap strapped to a tree trunk, while star nosed moles are more likely to be trapped in a pit trap. Trap Success for 1996,1997,1998 .1996 Trap Success 0 1997 Trap Success 1998 Trap Success 90 80 70 c o 'iii 60 fA C!) en 50C) c. c. cat= 40 fA "iii .5 30 c c:( 20 10 o ,.--,. ,.'-,.---r-,.rI----I---I-----I----' -----May 16-31 June 1-15 June 16-30 July 1-15 JUly 16-31 Aug. 1-15 Aug.16-31 Sept. 1-15 Sept. 16-30 Oct. 1-15 2-Week Periods Figure 1: Number of animnals caught per trapping session by two week periods. Seasonal Changes in Small Mammal Populations We had hoped to learn more about seasonal changes in population sizes of the small mammals at Rice Creek, and the data collected in 1997 and 1998 provide some information about this. Many small mammal populations go through seasonal changes in population size. Populations tend to grow from early Spring through the Summer months, but then suffer high mortality over the winter, rebuilding their numbers again the following summer (Tyron and Snyder, 1973). Longer-lived species show longer cycles. Some species have one litter of young per year, while others have two or more litters, depending on food availability, latitude, climate, and life history characteristics of the species. To get an idea of seasonal changes in population numbers at Rice Creek, I divided our samples into two week intervals, and then divided the number of animals trapped by the number of trapping sessions during each two week period (from table 1). Averaging the data in this way also reduces the effect of good trapping weather and poor trapping weather, which can affect trap success dramatically, but reduces representation of the total number of animals present (but not always trapped) at a site. These averages are presented in Tables 4, 5, and 6. 23 -"

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The data for 1996 imply that indeed populations were building over the summer, from a low of 1.5 animals/trapping to 42.5 animals/trapping. The pattern is less straightforward for 1997 and 1998, with both years showing more fluctuation (Figure I). This may represent the influence of cycles spanning more than a single year in some species. Trapping success is also influenced by many other variables, including temperature and humidity as well as food abundance and availability, reproductive cycles and time when young are maturing and dispersing. Trapping success increases on rainy nights, and is low on warm dry days. More male chipmunks are trapped than females during the breeding period (around the 4th of July) because they are traveling farther to encounter more females, and are more likely to encounter traps. More female chipmunks are trapped when they are lactating than males because females need more food to produce milk. The population fluctuations reported here are numbers of animals only, without taking sex or reproductive condition into consideration. More sensitive analyses will take age, sex, reproductive condition and individual identification into account (Davis and Winstead, 1980). Population measures can also take trappability into account by including marked individuals as part of the population if they were trapped both before and after a given trapping period. This more detailed examination of the trapping data will be the focus of the study during the summer of 1999. Literature Cited: Chepko-Sade, B. D., 1997. Survey of Small Mammal Populations at Rice Creek Field Station. In Rice Creek Research Reports 1996, Ed. A. P. Nelson, pp. 11-14. Rice Creek Field Station, Oswego, NY Chepko-Sade, B. D., 1997. A Survey of Small Mammal Populations at Rice Creek Field Station (Year 2)., In Rice Creek Research Reports 1997, Ed. A. P. Nelson, pp. 30-34. Rice Creek Field Station, Oswego, NY Davis, D. E. and R. L. Winstead, 1980. Estimating the Numbers of Wildlife Populations, In Wildlive Management Techniques Manual, Ed. S. D. Schemnitz, The Wildlife Society, Washington, D. C. Larson, J. S. and R. D. Taber, 1980. Criteria of Sex and Age, In Wildlife Management Techniques Manual, Ed. S. D. Schemnitz, The Wildlife Society, Washington, D. C. Tyron, C. A. and D. P. Snyder, 1973. Biology of the Eastern Chipmunk, Tamias striatus: Life Tables, Age Distributions, and Trends in Population Numbers. Journal ofMammalogy, Vol. 54, No, I. 24

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Butterfly Populations at Rice Creek Field Station The 1998 Season! Peter G. Weber, Department of Biology, Oswego State University Nicholas F. A. Weber, Box 359, West Lake Road, Oswego, NY Purpose of Project The purpose of the Rice Creek Butterfly Project is to characterize in detail the Station's butterfly community over the seasons, within habitats and between seasons. The 1998 season completed the third year of what we anticipate to be a five year study. We chose five years because it was the lower end given by Likens (1983) for long-term ecological studies. Methods and Materials We commenced sampling in 1998 on 24 April (nearly a month earlier than in the previous two years), at which time temperatures became suitable for butterfly flight. Sampling continued weekly until 1 Noverrlber (nearly two weeks beyond our previous latest sampling date). We maintained the sampling protocols established in the previous two years (Weber & Weber, 1998). However, sampling in 1998 was on a weekly basis, whereas in previous years it had been biweekly. To find out if weekly sampling might be a confounding factor, we compared the number of species/census hour in the three years by Analysis of Variance (Table 1) and found no statistical differences (5,86 =2.087, N.S.). A similar comparison of the count/census hour did yield significance (5,86 =3.135, 12 < 0.05). However, a Scheffe extension showed a difference only between 1996 and 1997, both years in which sampling had been biweekly. Thus it seemed unlikely that weekly sampling made a significant difference in estimates of either the number of species or individuals per sampling effort. To document the butterfly species occurring on the Station grounds, we photographed as many as we were able using a Table 1: Species per Census Hour and Count of Individuals per Census Hour for 1996 1998 (Mean STD). 1996 1997 1998 Species / Census Hr. 2.6 1.0 3.1 1.2 2.9 1.0 Count / Census Hr. 15.3 13.9 25.0 19.9 18.9 11.3 Canon EOS-Elan with an EF 100mm f/2.8 macro lens. We obtained 210 slide photos of 25 species in 1998. These slides have been archived at Rice Creek Field Station (RCFS). Additionally, we took 38 black and white habitat photos. Micrometeorological conditions were monitored at the same four locations exactly as in previous years (Weber & Weber, 1998). Additionally, the proportion of full sunlight was measured on eight dates (4/24,4/29,5/6,5/14,5/17,5/25,5/30 and 6/6), encompassing a period prior to leaf emergence until canopy closure. On each date the mean of six measurements, taken 1M above ground with a digital light meter (Model SLM-II0, A.W. Sperry Instruments Inc.), was taken at two locations within a stand of Beech-Maple Mesic (BMM) forest. This stand had been characterized by Weeks (1988), and more recently by Frank (1997), as to its canopy composition. These light measurements were compared to ones taken, within five minutes, I Financial support provided by Rice Creek Associates and by Oswego State University's Division of Continuing Education and Office of Research and Sponsored Programs. 25

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outside the forested stand in an open field. The ratio of the light in the forest to light in the field provided the proportion of full sunlight reaching the 1 M level in the forest stand. Since canopies composed of different species reduce overall light intensity differently (Brewer, 1994), as well as close at different rates (Ashby, 1971), the proportion of full light in the BMM stand could only be used as an index of canopy closure for all wooded areas on the Station grounds. We determined if a correlation was en 'vQ> -0-96 3S Q> ..Q. (f) 30 o '-2S Q> .c ___ 97E 20 :;:, ...... 98Z Q> 1S >.... .... 10 :;:, E :;:, S U o ......_........f-r.-r ............ ___ _................................................................ .... ........._........,I\l I\lNNeN eN mm 0--N eN eN m 0 00 eN eNeN m eN Apr. May June July August Sept. Oct. Nov. Day of Year Figure 1: Cumulative number of species per sampling day in each year. significantly different from zero by means of a Fisher's r to z transformation (Roth, Haycock, Gagnon, Soper & Calderone, 1995). In describing the degree of correlation, we used the informal interpretations given in Martin and Bateson (1986). Lastly, in order to compare abundances for each species between years, we calculated an index of percent change from the initial year the species was sampled on the Station grounds (Statistics Netherlands, 1997). For most species the initial year sampled was 1996. Table 2: Daily temperature, species richness, counts of individuals, and plant species in bloom (mean STD) in early season (days 114-175) compared to remainder of season, 1996-1998 Early Season Remainder of Season Davs 114-175. Apr 24-Jun 24 Davs 176-305. Jun 25-Nov 1 1996 1997 1998 1996 1997 1998 18.5 2.7 17.4.1 19.4.7 19.7.1 21.2 3.4 20.3 4.2 4.2 3.9 4.0 2.9 6.0 2.4 10.3 3.7 11.5 4.0 9.8 5.0 29.8 .0 14.2 20.1 36.8 35.6 59.9 44.3 101.2 76.8 65.7.1 13.2 5.5 27.7 10.2 31.5 11.6 31.6.3 40.5 11.0 39.7 12.2 Temperature (C) Number of Species Count of Individuals Plant Species in Bloom 26

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Results Overall Description ofthe RCFS Butterfly Community The 1998 season was different from the previous two. As shown in Table 2, early season County are denoted by a bold X (days 114-175) temperatures were warmer than usual. Consequently more Northern Cloudy Wing (Thorybes pylades) X species, and individuals, Checkered Skipper (Pyrgus communis) X were flying early. More nectar sources were Persius Dusky Wing (Erynnis persius) X doubtless available Xearlier than in the Least Skipper (Ancyloxypha numitor) XX X This was reflected in Little Glassywing (Pompeius verna) X early summer of 1998 individuals compared to the previous two years. bloom in the spring and Long Dash (Polites mystic) XX X X (Table 2). The balance of Delaware Skipper (Atrytone logan) X X the summer, however, Dun Skipper (Euphyes vestris) XX X was lacking in both Roadside Skipper (Amblyscirtes vialis) X numbers of species and Total 9 97 18 Table 3 : Skipper species at Rice Creek Field Station, 1996 1998, compared to total Oswego County species (from Shapiro, A.M. 1947. Butterflies and Skippers of New York State). Species new to Oswego Family Hesperiidae Silver-spotted Skipper (Epargyreus clarus) XX X X European Skipper (Thymelicus lineola) Northern Broken Dash (Wallengrenia egerement) New since 1974 Dreamy Dusky Wing (Erynnis icelus) X Common Dusky Wing (Gesta gesta) X Arctic Skipper (Carterocephalus palaemon ) X Hobomok Skipper (Poanes hobomok) X X X X Pepper and Salt Skipper (Amblyscirtes hegon) X Rice Creek Total 1996 1997 1998 Oswego Co. X X X previous two seasons. Leonard's Skipper (Hesperia leonardus) I ndian Skipper (Hesperia sassacus) X X X X X more plant species in Tawny-edged Skipper (Polites themistocles) Peck's Skipper (Polites peckius) X X XX X 3 0 0 Overall, the 1998 season was poorer in species by four (Figure 1), the early season peak in individuals was over a month early, and the late season peak was severely damped mainly due to low numbers of migrating monarchs (Danaus plexippus), and a decline in orange sulphurs (Colias eurytheme). Seven skipper (Hesperiidae) species were sampled on the Station grounds in 1998, in contrast to nine in each of the previous years (Table 3). No new skipper species were recorded in 1998. Moreover, 24 "true butterfly" species were sampled in comparison to 26 in each of the previous years (Table 4). We recorded one new "true butterfly" species, the painted lady (Vanessa cardui), giving the Station 37 species over the three years of sampling. Nearly half of the species on the Station grounds exhibited population declines from the previous year, whereas about a third did so in 1997 (Table 5). Four species (approximately 13% of species) became locally extinct, whereas two did so in 1997 (approximately 5% of species). Early Season Flights in Woodland Habitats The unusually warm early season allowed butterflies to be active before the leaves emerged on trees. A disproportionate number were observed flying in wooded areas, where few occurred 27

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during the balance of the Table 4: Butterfly species at Rice Creek Field Station, 1996 1998, season (Figure 2 A). In compared to total oswego County species (from Shapiro, A.M. 1947. contrast, once leaves were Butterflies and Skippers of New York State). Species new to Oswego out, most butterflies flew in open areas as the two years of data in Figure 2 B amply show. The early season appearance of butterflies in woods offered an opportunity to test the hypothesis of whether flights in woodlands were related to canopy closure, as reflected by a decreased proportion of full sunlight at the herb layer. Figure 3 A shows the proportion of full sunlight at two locations in the BMM stand. Before leaf appearance (on 4/23), about 50% 60% of full sunlight reached the herb layer. As the canopy closed, the percentage of sunlight reaching the forest floor declined to near O. Until spring 1998 no butterfly had been recorded within the BMM stand, and in 1998, none were recorded there after 6 May when the canopy was nearly closed. As the canopy closed, the proportion of all butterfly individuals flying in any wooded habitat declined from above 80% on 24 April to below 20% by 17 May (Figure 3 B). However, after that date the proportion of all individuals flying in woods increased somewhat, County are denoted by a bold X. Family Nymphalidae SUbfamily Satyrinae Northern Pearly Eye (Enodia anthedon) Appalachian Brown (Satyrodes appalachia) Eyed Brown (Sa tyroides eurydice) Little Wood-Satyr (Megisto cymela) Common Ringlet (Coenonympha tullia) Common Wood-Nymph (Cercyonis pegala) Subfamily Danainae Monarch (Danaus plexippus) Subfamily Heliconiinae Atlantis Fritillary (Speyeria atlantis) Great Spangled Fritillary (Speyeria cybele) Aphrodite Fritillary (Speyeria aphrodite) Silver-bordered Fritillary (Clossiana selene) Meadow Fritillary (Clossiana bellona) Subfamily Nymphalinae Baltimore Checkerspot (Euphydryas phaeton) Harris' Checkerspot (Charidryas harrisii) Silver Checkerspot (Charidryas nycteis) Tawny Crescent (Phyciodes batesii) Pearl Crescent (Phyciodes tharos) Question Mark (Polygonia interrogationis) Painted Lady (Vanessa cardui) American Lady (Vanessa virginiensis) Red Admiral (Vanessa atalanta) Eastern Comma (Polygonia comma) Gray Comma (Polygonia progne) Compton Tortoise Shell (Nymphalis vaualbum) Milbert Tortoise Shell (Nymphalis milberti) Mourning Cloak (Nymphalis antiopa) Subfamily Limenitidinae Viceroy (Basi/archia archippus) White Admira.l (Basi/archia arthemis) Family Lycaenidae Coral Hairstreak (Harkenclenus titus) Acadia Hairstreak (Satyrium acadicum) Banded Hairstreak (Satyrium calanus) Striped Hairstreak (Satyrium Iiparops) Brown Elfin (Incisalia augustinus) Eastem Pine Elfin (Incisalia niphon) American Copper (Lycaena phlaeas) Bronze Copper (Hyllolycaena thoe) Bog Copper (Epidemia epixanthe) Eastern Tailed-Blue (Everes comyntas) Spring Azure (Celastrina argiolus) Harvester (Feniseca tarquinius) Family Papilionidae Black Swallowtail (Papilio polyxenes) Tiger Swallowtail (Pterourus gfaucus) Spicebush Swallowtail (Pterourus troi/us) Family Pieridae Cabbage White (Pieris rapae) Clouded Sulphur (Colias philodice) Orange Sulphur (Colias eurytheme) Total New Since 1974 28 Rice Creek Total 1996 1997 1998 Oswego Co. X X XX X X X X XX X X X X X X XX X X X X X X X X X X XX X X X X X XX X X XX XX XXX X X X X X XXX X X X X X X X X X X XXX X X X X X X X X XX X X XX X X X X X X X X X X X X XX X X XX X X X X X X X X XX X X X XX X XXX X 2626 24 43 3 0 0

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reflecting the appearance of woodland or woodland edge species (e.g. red admiral (Vanessa atalanta), Eastern comma (Polygonia comma), and question mark (Polygonia interrogationis)). Correlation analysis between the proportion of individuals of all species flying in woods and the proportion of full sunlight, yielded a "marked", significant relationship (r = 0.79, =2.393, Q < 0.05). If only field inhabiting species (e.g. cabbage white (Pieris rapae) and clouded sulphur (Colias philodice) were considered in the analysis, the proportion of individuals flying in woods declined in a pattern nearly reflecting canopy closure (Figures 3c & 3a), although the data were sparse. Correlation analysis revealed a "very high" relationship (r =0.89), and a high degree of significance 3.142, Q < 0.002). Table 5: Species (percent) that increased, decreased or showed no change in abundance over the previous year. Locally extinct are included in the decreased category. 1997 1998 54.00% 43.20% 33.10 % 48.60% 10.80% 8.10 % 5.40% 13.50% Increased Decreased No Change Locally Extinct Provisionally, then, it appears that before canopy closure the amount of sunlight filtering in warms the interior of woods sufficiently to make them suitable early season habitats for even field inhabiting species. Curtis (1959) points out that on clear days temperatures in Wisconsin deciduous forest litter may reach abnormally high levels (49 -54C) before leaves emerge. No doubt the suitability of woodland habitats to butterflies before canopy closure is also enhanced by protection from wind. Curtis (1959) states that wind velocities within Wisconsin mesic forests were less than 1/10 those outside. And with spring ephemerals in bloom at this time, the interior of woods may also provide a ready source of nectar (although we observed no butterfly nectaring a sprIng ephemeral). As the canopy closes, woodland habi tats become too cool for butterfl ies, at which time the warmer, albeit windier, open habitats are preferred. While the trends in Figures 2 and 3 are encouraging, the data base needs to be expanded (e.g. the correlations were based on only 18 16 14 tn 12 'iij j "0 10 .E '0!8 E j z6 2 o+--------,--------.-Conifer Hardwood Mesophytic Successional Gardens Shallow Old Fields Wood Stream Bank Plantation Swamp Forest Hardwood Emergent Opening Forest Marsh Figure 2 (A): Total 1998 count in station habitats before canopy closure (4/24-5/6). Count Before Canopy Closure by Habitat (April 24, April 29, and May 6, 1998) 29

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I I I eight and five points) before firm conclusions may be reached regarding flights in woodlands in relation to canopy closure. Butterflies and Plants in Bloom Butterflies and plants are intimately related, in fact coevolved (Ehrlich & Raven, 1964). It should not be surprising, then, that the number of species, and individuals, in flight should be related to the number of plants in bloom. The three years of data given in Figure 4 A shows a "marked relationship" between the number of butterfly species in flight and plant species in bloom (r = 0.72, =8.11, n< 0.0001). Moreover, 51 % of the variation in butterfly species is accounted for by variation in plant species in bloom. In contrast, the number of butterfly individuals in ui fI) + (,) i >:I c Plantation Swamp Forest Hardwood Emergent Opening Forest Marsh Conifer Hardwood Mesophytic Successional Gardens Shallow Old Fields Wood Stream Bank Mean Yearly Count by Habitat for 1996 and 1997 o250 500 2000 1750 2250 1500 1250 1000 750 Figure 2 (B): Mean yearly count (+ SE) by habitat for 1996 and 1997. flight (Le. total count) shows only a "definite but small" relationship with the number of plant species in bloom (r =0.33, =3.08, n< 0.005) (Figure 4 B). Only 11 % of the variation in number of individuals flying is accounted for by number of plant species in bloom. Between Year Comparisons of Abundance In order to describe yearly variation in relative abundance we calculated indices of change from the first year that the species was sampled for all species recorded on the Station grounds. As examples, Table 6 gives such indices for a species with 0.70 0.60 0.50 3 0.40 0.30 o Q.e 0.20 0. 0.10 Proportion of Full Sunlight at 1 Meter 0 o Trail Location B-3 o Trail Location R-2 0 4/30 5/7 0 5/14 Date 5/21 5/28 6/4 Figure 3 (A): Proportion of full sunlight at 1 M measured at a Blue Trail (B-3) and a Red Trail (R-2) location within the BMM stand, from prior to leaf emergence until canopy closure. 30 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I

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relatively constant abundance over the years, the silver-spotted skipper, one that declined, the orange sulphur, and one that increased, the pearl crescent. B. Proportion of All Individuals Flying in Woodlands 1.0 0.9 n= 7 0.8 Pr oP.0.7 art. on of 0.6 Ind ivi du 0.5 als 0.4 0.3 0.2 0.1 0.0 4/24 4/29 5/6 5/14 5/17 5/25 5/30 Date 6/6 c. Proportion of Individuals of Field Inhabiting Species Flying in Woodlands 0.6 n= 2 0.5 U) 0.4'ii :J 'tJ.:; :c .5 '0 0.3 c 0 t: 0 a.. 0 Q: 0.2 0.1 0.0 4/24 4/29 5/6 5/14 Date 5/17 n = 19 5/25 n = 37 5/30 n = 10 6/6 Figure 3: (8) Proportion of all individuals and (C) Proportion of individuals of field inhabiting species flying in woodlands prior to canopy closure. 31

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o o 0 .CII 0 oo Y=O.414+0.254X o O-l--.................. Within Year Abundances: Phenograms We continued to monitor the seasonal abundance of each species as shown in the example for three species of Satyrs (Figure 5). The unusually warm early season (Table 2) had a pronounced influence on the phenology of nearly all species. Twenty eight of the 31 species flew on earlier dates than in the previous two years. Only black swallowtails and orange sulphurs appeared later. Flying earlier also meant that the species ceased flying earlier: about 65% of the 31 species ceased flying earlier than in the previous two years. ....-__ A. Butterfly Species / Plant Species 22 20 en 18 CUo'u 16 14 o 96 >-12 (I) 97.... 98't 10 CIJ 8 ..... 6 4 2 o 10 20 3040 so 60 Plant Species in Bloom Although the season was overall early for nearly all species, the general phenological pattern for each seemed to be retained much as in previous years. Table 7 summarizes the number and percent of species recorded in 1998 with different number of flight period patterns over the three seasons of the study. A species which has a peak flight once during a season is referred to B. Butterfly Individuals / Plant Species350 300 250 ..... C Y=15.857+1.552X 0 200 o 96 U 97.... 6 98..... '50 o 0 0 I-6o 100 50 0 La ......... OJII 6iJ1 o o 0 10 20 30 40 SO60 Plant Species in Bloom as univoltine. Most Figure 4: (A) Butterfly species vs plant species in bloom and (B) Butterfly count species exhibited a vs plant species in bloom; 1996, 1997, 1998. univoltine flight 32

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pattern in each of the three years. Shapiro (1974) states that 63% of Tug Hill species are univoltine (Table 7 gives about 68% for ReFS). Peck's skippers (Polites peckius) black swallowtails, banded (Satyrium calanus) and striped (Satyrium liparops) hairstreaks, although scarce on the Station grounds (and therefore their flight patterns uncertain), were scored as univoltine. The Eastern Tailed-Blue (Everes comyntas) seemed bivoltine in two of the three years and the Viceroy (Basilarchia archippus) seemed to be bivoltine in each year. More long term data is 'evidently needed to characterize their flight period pattern on the Station grounds. The Pierids were clearly trivoltine in each year, excepting orange sulphurs. This species, in a 7 Appalachian Brown 1998 N = 18 6 Eyed Brown 1998 n=8 6 4 4 5/16/98 5/30/98 6/13/98 6/27/98 7/11/98 7/25/98 8/8/98 8/22/98 Date 8 7 Appalachian Brown 1997 N =16 6 O+------r---r------,----.L...--..........,L....a..--...,..-------..,---,--5/16/97 5/30/97 6/13/97 6/27/97 7/11/97 7/25/97 8/8/97 8/22/97 Date 5/16/98 5/30/98 6/13/98 6/27/98 7/11/98 7/25/98 8/8/98 8/22/98 Date 6 Eyed Brown 1997 n=5 (I) 4 -; ::J 3 :0 .E #2 5/16/97 5/30/97 6/13/97 6/27/97 7/11/97 7/25/97 8/8/97 8/22/97 Date Appalachian Brown 1996 8 N =20 7 6 4 O+------r---r------,------...&.......j........... 5/16/96 5/30/96 6/13/96 6/27/96 7/11/96 7/25/96 8/8/96 8/22/96 Date Eyed Brown 19966 n=3 4 3 O+-----r---r------,-----1I--1L-...I\-----..,----r5/16/96 5/30/96 6/13/96 6/27/96 7/11/96 7/25/96 8/8/96 8/22/96 Date Figure 5: Yearly phenograms for Satyrinae (A) Appalachian Brown and (B) Eyed Brown. 33

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steady population decline since 1996, was trivoltine in 1996, bivoltine in 1997 and univoltine in 1998. Least skippers (Ancyloxypha numitor) and pearl crescents, bivoltine in previous years, were trivoltine in 1998. Lastly, great spangled fritillarys (Speyeria cybele) and spring azures (Celastrina argiolus), univoltine in previous years, were bivoltine in 1998. That sonle species exhibit a variety of voltinisms and others do not is well known. The adaptive nature of this difference, however, is not known (e.g. Shapiro, 1974; Glassberg, 1993). Table 6: Index of abundance (percent of total count in 1996) for declining, and increasing species from 50 Little Wood-Satyr 1998 45 n =108 40 35 en 30 25 20 # 15 10 5 0+-----4-------.......-------fl----r------,-------r-----,5/16/98 5/30/98 6/13/98 6/27/98 7/11/98 7/25/98 8/8/98 8/22/98 Date 1996 1998. 1996 1997 1998 Silver-spotted Skipper (Epargyreus c1arus) 100 77.1 82.9 Orange Sulphur (Colias eurytheme) 100 45.9 12 Pearl Crescent (Phycoides tharos) 100 176.9 301.3 Table 7: Number and percent of species with different seasonal flight peaks. Number Percent Univoltine in Each Year (1996-98) 21 67.7 Bivoltine in Each Year (1996-98) 2 6.5 Trivoltine in Each Year (1996-98) 2 6.5 50 Little Wood-Satyr 1997 45 n= 5340 35 30 25 Bivoltine in 1998 and Univoltine in 1996 or 97 2 6.5 Trivoltine in 1998 and Bivoltine in 1996 or 97 2 6.5 Different Voltinism Each Year 1 3.2 New in 1998 1 3.2 20 Future Work 15 10 We would like to continue monitoring the 5 ReFS butterfly community for another two O+-----.--------+--------..------------fl---.----,---, 5/16/97 5/30/97 6/13/97 6/27/97 7/11/97 7/25/97 8/8/97 8/22/97 years at least. The five years of data, then, Date should be adequate in describing, for each species, its within year, between year, and between habitat patterns of abundance. Our 50 Little Wood-Satyr 1996 accumulated data will also allow us to 45 n =70 determine the influence of mowing on40 35 butterfly populations, as many of the Station'sen 30 open habitats sampled by us are maintained on 25 20 a mowing schedule (Weeks, 1988). We hope # 15 to involve one or two undergraduate students 10 in this problem. Our data also allows us to 5 determine how various aspects of habitat 5/16/96 5/30/96 6/13/96 6/27/96 7/11/96 7/25/96 8/8/96 8/22/96 patches influence butterfly populations on the Date Station grounds. One of us (PGW) has begun Figure 5: Yearly phenograms for Satyrinae: to analyze the existing data from this point of (C) Little Wood-Satyr. view. For example, some of the relationships we will explore include butterfly diversity, 34

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------------------------------------------population size, immigration and extinction rates in relation to habitat patch size. Lastly, the effects of micrometeorology on butterfly movements and habitat preferences, as described above in "Early Season flights in Woodland Habitats", seems to be a promising area to pursue. References Ashby, M. (1971). An Introduction to Plant Ecology, (2nd Edit), London, U. K.: MacMillan. Brewer, R. (1994). The Science ofEcology, (2nd Edit), Philadelphia, PA: Saunders. Curtis, J. T. (1959). The Vegetation ofWisconsin, Madison, WI. The University of Wisconsin Press. Ehrlich, P. R. ,and P. H. Raven (1964). Butterflies and plants: A study in coevolution, Evolution, .lli, 586-608. Frank, J. A. (1998). Survey of the amphibian and earthworm species at Rice Creek Field Station. In Rice Creek Research Reports 1997. Ed. A. P. Nelson, pp 16-20. Rice Creek Field Station, Oswego, NY. Glassberg, J. (1993). Butterflies through binoculars. NY: Oxford University Press. Martin, P. & Bateson, P. (1986). Measuring Behavior, Cambridge, U.K.: Cambridge University Press. Likens, G. E. (1983). A priority for ecological research. Bulletin ofthe Ecological Society of America, 64,234-243. Roth, J., Haycock, K., Gagnon, J., Soper, C., & Calderone, J. (1996). Abacus Concepts, Using StatView. 466 pp., Berkeley, CA: Abacus Concepts, Inc. Shapiro, A. M. (1974). The butterflies and skippers of New York (Lepidoptera: Papilionoidea, Hesperioidea), Search: Agriculture, Entomology,11, 1-60. Statistics Netherlands, Environment Sector (1997), Butterfly Monitoring Project [online]. Available: http/neon.vb.cbs.nl.sec_lmi_e/f1ofau/butterfly/mno 0068i.htm [1997, November 25]. Weber, N.F.A and P.G. Weber (1998). Butterfly populations at Rice Creek Field Station: The 1997 season. In Rice Creek Research Reports 1997. Ed. A. P. Nelson, pp 1-15. Rice Creek Field Station, Oswego, NY. Weeks, J. A. (1988). Guidelines for Environmental Management at Rice Creek Field Station, Bulletin No.6. Rice Creek Field Station, Oswego, NY. 35

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Research Related Publications from Rice Creek Field Station Bulletins: Shearer, R. I. (ed.)* 1974 Rice Creek Biological Field Station Bulletin. Vol 1. No.1. SUNY Oswego. Contents: Limnological Data Collected From Little Sodus Bay-----------------------------------------------------------------4 Kundell, J. E. A Chemical and Physical Comparison ofLittle Sodus Bay, Port Bay, Socius Bay, an{1 Irondequoit Bay ---------------------------------------------------------------------------------------------------------7 Spafford, R. A. The Distribution ofMicrocrustaceans at the Mud-Water Interface ofLittle Sodus Bay32 Del Prete, K. Phosphate and Nitrate Study ofLittle Sodus Bay During Ice Cover and Early Spring, J972 -----------------------------------------------------------------------------------------------------------45 Tritman, N. D. Chlorophyll and Phaeophytin Determination ofa Phytoplankton Comlnunity During and After Ice Cover --------------------------------------------------------------------------------------------52 Shearer, R. I. An Investigation ofthe Vertical Distribution ofthe Meiiobenthos ofLittle Sodus Bay----59 Bocsor, J. G. Seasonal and Vertical Distribution ofZooplankton in Little Sodus Bay----------------------66 Hickey, John T. 1971. The Flora ofthe Vascular Plants ofthe Rice Creek Biological Field Station. IN: Shearer, Robert I. (ed.) 1974. Rice Creek Biological Field Station Bulletin Vol. 1 No.2. SUNY Oswego. Maxwell, George R., Gerald A. Smith, Patricia A. Ruta, and Thomas L. Carrolan.... 1976. Preliminary Bird and Associated Vegatational Studies for Navigation Season Extension on the St. Lawrence River. IN: Shearer, Robert I. (ed.) 1974. Rice Creek Biological Field Station Bulletin Vol. 3. SUNY Oswego. Smith, Gerald S., Andrew Bieber, Michael K. Bollenbacher, Joseph D. Brown, Theresa A. Dillon, Deborah Dosch, Carol J. Elliott, Angelo Giordano, and Paul T. Meier. 1977. Habitat and Wildlife Inventory: Guide to Coastal Zone Lands, Oswego County, New York. Rice Creek Biological Field Station Bulletin Vol. 4. SUNY Oswego. Smith, Gerald A. and James M. Ryan. 1978. Annotated Checklist ofthe Birds ofOswego County andNorthern Cayuga County, New York.. Rice Creek Biological Field Station Bulletin No.5. SUNY Oswego. Weeks, John A. 1988 Guidelines to Environmental Management at Rice Creek Field Station. Rice Creek Field Station Bulletin No.6. SUNY Oswego Fosdick, Craig. R. 1995. The Birds ofOswego County: An Annotated Checklist. Rice Creek Field Slation Bullelin No.7. SUNY Oswego Check Lists.{Pocket Format): Maxwell, George C. (undated), Birds ofCentral New York, Daily Field Check-List. Rice Creek Biological Field Station. SUNY Oswego. Weber, Nicholas. 1997. Field Check List ofButterflies. Rice Creek Field Station, SUNY Oswego. Research Reports: Nelson, Andrew P. (ed). 1997. Rice Creek Research Reports: 1996. Rice Creek Field Station. SUNY Oswego. Contents: Weber, N. F. A. and P. G. Weber. Butterfly Populations at Rice Creek Field Station: A Progress Report -----------I Chepko-Sade, B. D. Survey ofSmall Mammal Populations at Rice Creek Field Station ---------------------------------II Nelson, A. P. Flora ofRice Creek Field Station ---------------------------------------------------------------------------------15 Rosenbaum, P. A. Overview ofRecent Herpetological Research at RCFS -------------------------------------------------J6 Nelson, Andrew P. (ed). 1998. Rice Creek Research Reports: 1997. Rice Creek Field Station. SUNY Oswego. Contents: Weber, N. F. A. and P. G. Weber. Butterfly Populations at Rice Creek Field Station: The /997 Season --------------1 Frank, J. A. Survey ofthe Amphibian and Earthworm Species at Rice Creek Field Station -----------------------------16 Nelson, A. P. Flora ofRice Creek Field Station ---------------------------------------------------------------------------------20 Weeks, J. A. A Study ofBird Nesting on Rice Pond and Adjoining Habitats, Spring and SUl1l1ller /997 --------------21 Chepko-Sade, B. D. A Survey ofSmall Mammal Populations at Rice Creek Field Station (Year 2) ------------------30 Publication is out of print. Photocopies may be available on request. A fee will be charged.