Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations

1978 Effects of snowmobile activity on wintering pheasants and vegetation in northern Iowa Richard Sojda Jr. Iowa State University

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Recommended Citation Sojda, Richard Jr., "Effects of snowmobile activity on wintering pheasants and wetland vegetation in northern Iowa marshes" (1978). Retrospective Theses and Dissertations. 16905. https://lib.dr.iastate.edu/rtd/16905

This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Effects of snowmobile activity on wintering pheasants and wetland vegetation in northern Iowa marshes

by

Richard Sojda, Jr.

A Thesis Submitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of MASTER OF SCIENCE

Department: Animal Ecology Major: Wildlife Biology

Signatures have been redacted for privacy

Iowa State University Ames, Iowa 1978 ii

TABLE OF CONTENTS Page ABSTRACT iv INTRODUCTION 1 PART I. EFFECTS OF SNOWMOBILE ACTIVITY ON RING-NECKED PHEASANTS 4 STUDY AREA 5 METHODS 6 Capturing and Marking Pheasants 6 Snowmobile Treatments 6 Telemetry 7 RESULTS 12 DISCUSSION 18 PART II. EFFECTS OF SNOWMOBILE ACTIVITY ON WETLAND VEGETATION 21 STUDY AREA 22 METHODS 24 Snowmobile Treatments 24 Vegetation Measurements 26 RESULTS 29 General Observations 29 Measured Effects 33 DISCUSSION 37 Plant Response 37 Snowmobiling and Habitat Management in Cattail Sloughs 39 iii

Page

CONCLUSIONS AND IMPLICATIONS 41 LITERATURE CITED 43

ACKNOWLEDGEMENTS 46 APPENDIX A 47

APPENDIX B 58 iv

ABSTRACT

Local movements of nine, female ring-necked pheasants (Phasianus colchicus) in response to snowmobile activity were monitored by radio­ telemetry in a cattail (Typha spp.) in northwest Iowa during February 1978. Snowmobiling was confined to six trails, each about 1120 m long and 160 m apart through a section of a large marsh used by pheasants as winter cover. No radio-equipped birds left the area traversed by snow­ mobile trails during snowmobile treatment, and no changes in roost-site location or daily behavior patterns were observed. Movement by a pheasant during snowmobiling \Alas detected with certainty only once in 24 instances, and in this case the bird moved toward rather than away from the trail area. In cattail marshes similar to the one studied, snowmobiling probably would have little or no effect on pheasant populations if traffic could be confined to a few, widely-spaced trails. Effects of snowmobiling on wet­ land vegetation also were examined from December 1976 to June 1978. No differences (f > 0.10) in densities of cattail, Carex, or bur reed (Sparganium eurycarpum) resulted from trail grooming without subsequent snowmobiling, but a 12 cm decrease (f < 0.01) in cattail height did occur. Trail grooming with snowmobiling caused a 23 percent decrease in cattail density, 12 percent (12 cm) decrease in cattail height, and a 44 percent increase in Carex density (f < 0.005). Snowmobiling had no effect on bluejoint (Calamagrostis canadensis) density or Carex height (~> 0.75). No difference was detected between trails with 440 snowmobile trips and v

those with 180 trips per season. Vegetation changes observed in this study would not result in a serious alteration of wildlife habitat if snow­ mobiling were to be confined to dispersed trails •. 1

INTRODUCTION

Snowmobiling, as a mechanized form of recreation, has been examined from both aesthetic and ecological perspectives (Doan 1971; U.S. Congress, Senate Committee on Interior and Insular Affairs, Subcommittee on Parks and Recreation 1971; Bury 1978). The aesthetic aspects obviously involve personal interpretation of one's own values and beliefs relative to the utilization of a public resource. On the other hand, an evaluation of the ecological effects of outdoor recreation activities should have a factual basis. Several attempts have been made to study these effects (Bury et al. 1976; Bury 1978). White-tailed deer (Odocoileus virginianus) did not significantly change the size of their home ranges during three weekends of snowmobiling (Sollinger et ale 1972). In other studies, deer temporarily moved away from trails in response to initial snowmobiling until they became habituated to the traffic (Dorrance et al. 1975; Lavigne 1976). Once accustomed to snowmobile traffic, deer may also use trails to their advantage in travelling when adverse snow conditions otherwise hinder them (Lavigne 1976). Eastern cottontails (Sylvilagus floridanus) may increase nighttime activity and sizes of their home ranges in response to snowmobiling (Bollinger et al. 1972); however, these results were based on only 3 days of testing. In comparin~ the numbers of animal tracks on and off sno\\llnobi 1e tra i 1s, snowshoe hares (Lepus americanus) tended to avoid travelling on trails, but activity of red faxes (Vulpes fu1va) increased near the same trails (Newman and Merriam 2

1972). High-intensity snowmobiling adversely alters the microclimate of subnivean habitats for small mammals (Schmid 1971). Other anecdotal observations on the possible effects of snowmobiling on wildlife have been summarized by Bury et al. (1976) and Bury (1978). The possible effects of snowmobile activity on birds have not been documented. However, Hume (1976) noted that goldeneyes (Bucephala clangula) avoided motor and sail boats, and Wright and Speake (1975) have preliminary evidence that nesting wild turkeys (Meleagris gallapavo) may be adversely affected by trail bikes. In Iowa, where an average of 1.5 million ring"necked pheasants

(Phasianus ~olchicus) has been harvested annually since 1963 (Farris et al. 1977), the Iowa Conservation Commission has not allowed snowmobiling. on some of its game management areas due to suspected detrimental effects on wildlife populations. Pheasants concentrate during winter in the wet­ lands of northern Iowa. It has been postulated that snowmobile activity might force pheasants to leave favorable cover of the marsh for unsuitable cover in surrounding areas such as plowed fields, grain-stubble fields, and road ditches. In such unsuitable habitat, pheasants would be more vulnerable to predation, blizzards, hunting, and other mortality factors. To test this hypothesis, Part I of this study was designed to monitor movements of radio-marked hen pheasants in response to snowmobile activity. These marshes also provide important habitat for waterfowl, nongame birds, and furbearers (Weller and Spatcher 1965). It was also postulated that snowmobiling might affect summer growth of wetland vegetation and 3

therefore adversely affect important wildlife habitat. Woody vegetation can be stunted or deformed by snowmobiling under certain snow depth and packing conditions because of damage to apical meristematic tissue (Newman and Merriam 1972). Domestic forage grasses seem very resistant to snowmobile travel (Walejko et al. 1972). However, effects on alfalfa seem related to snow depth and packing conditions and the resultant change in soil temperatures (Walejko et al. 1973). Effects of snow­ mobiling on wetland vegetation is unknown. Nelson and Deitz (1966) described techniques for killing and reducing growth of cattails (Typha spp.) by cutting growing stems below water level. Weller (1975) modified this technique by cutting cattails with a tractor-mower during winter. Aquatic species of Carex, on the other hand, increase growth as a response to litter removal (Personal communi­ cation, A. van der Valk, Department of Botany and Plant Pathology, Iowa State University, Ames). Part II of this study was designed to test the hypothesis that density and height of cattails would be decreased by snowmobile activity, and that density and height of Carex would be increased by snowmobile activity. Additionally, the effect of snowmobiling on plant species growing on was examined during the drought of 1976-77. 4

PART I. EFFECTS OF SNOWMOBILE ACTIVITY ON RING-NECKED PHEASANTS 5

STUDY AREA

Ba rri nger Game Management Area, Cl ay County, Iowa, is a semipermanent, slightly owned and managed by the Iowa Conservation Commission. Barringer Slough can be classified as a IV-B-2 wetland according to the system of Stewart and Kantrud (1971). Hayden (1943) and Glover (1949) give a detailed description of the area. The study area was confined to the most southerly 200 ha of the Game Manage­ ment Area. About 65 percent was dense cattails, 20 percent was not vegetated with emergents and during winter was bare ice, and 15 percent was equally divided among sedge meadow, upland prairie, and corn-stubble fields. Adjacent private land was intensively farmed and had almost no winter coyer for pheasants. Corn and soybean crops comprised more than 80 percent of the farmland and much was fall plowed. This study was done during February 1978. The average temperature for that month recorded at the U.S. Weather Bureau Station at Spencer, Iowa (approximately 27 km west) was -12.1 C, 5.1 C below normal. Average precipitation for the month was 0.7 cm, 1.7 cm less than normal (Environmental Data Service 1978). 6

METHODS

Capturing and Marking Pheasants

During October 1977, one juvenile hen pheasant weighing 840 g and

: nine adult hens weighing 900 ± 22 g SE were captured by nightlighting in prairie and sedge-meadow vegetation bordering Barringer Slough. From

18 January to 1 February 1978, seven juvenile hens weighing 951 ± 18 g

and five adult hens weighing 966 ± 47 g were captured in clover-leaf traps batted with corn that were placed at the edge of a corn-stubble field about 75 m from the slough. All 22 hens were equipped with com­ mercially manufactured radio transmitters that operated at 164+ MHz and weighed approximately 29 g. The radios were attached with plastic tubing to the hens with a harness having neck and body loops similar to the harness described for ducks by Dwver (1972). Radio contact was lost with 13 of the 22 pheasants due to transmitter failure or predation prior to experimentation with snowmobiles. All nine hens with functioning transmitters were flushed before and after experi­ mentation and seemed to be flying with no appreciable interference from the radio package.

Snowmobile Treatments

Six parallel trails, each approximately 1120 m long and 160 m apart, were established with a Bombardier Skidozer SV 200 trail groomer on the 7

first day of snowmobiling (Fig.l). These trails crossed the area of slough most frequently used by the radio-equipped pheasants as determined for several days prior to trail establishment. Four different snowmobile treatments were used: (1) one snowmobile travelled one trail once, (2) one snowmobile travelled all trails once, (3) two or three snowmobiles in a group travelled all trails once, and (4) one snowmobile travelled all trails two or three times in succession. About 35 minutes were required to travel all trails once (Table 1). A 1977 Massey-Ferguson Whirlwind 340 snowmobile was used in all treatments. John Deere snowmobiles were the supplementary vehicles used in treatment 3. It was obvious to an observer in the marsh that vehicle noise rapidly dissipated with increasing distance from the snowmobile. The sound may have been muffled by the standing vegetation. A General Radio Co. Type 1565-B sound level meter was used to measure the noise level of the Massey-Ferguson snowmobile being driven at treatment speed, approximately

16 km per hr. The noise level on the ground 10 rrl from the snowmobile was 64.2 ± 0.9 dbA; at 25 m the noise level was 54.5 ± 0.4 dbA. A 10 dbA increase is equivalent to about twice the level of perceived noise (Bugliarello et ale 1976:142). These tests were done on a clear night at the conclusion of the snowmobile testing period in a cattail stand that could be classified as hemi-marsh (Weller and Spatcher 1965).

Telemetry

After pheasants had been equipped with radio-transmitters, shifts occurred in transmitter pulse rate, receiver frp.quency, transmitter 8a Figure 1. Locations of cover types, snowmobile trails, and antenna masts, Barringer Slough, Iowa. 8b

BARRINGER SLOUGH o lkm I , 9

Table 1. Snowmobile treatments conducted and pheasants monitored during February 1978 in Barringer Slough, Iowa. On 10 February only one section of trail was travelled. The entire trail system was travelled on all other days. Only birds that were located by triangulation both before and after snowmobiling are listed.

Date Time of No. of No. of Pheasant snowmobiling trips snowmobiles identification nos.

Feb. 10 2100-2130 1 1 1-3, 2-10 Feb. 11 1710-1755 1 1 2-10

Feb. 12 2140~2210 1 1 1-3 Feb. 13 2015-2047 1 1 2-10, 2-12 Feb. 14 1618-1648 1 1 1-1, 1-3 Feb. 15 1630-1705 1 3 1-3 Feb. 16 2050-2122 1 1 1-3, 2-10, 2-12 Feb. 17 1450-1518 1 1 1-3, 2-12 Feb. 19 2133-2208 1 1 1-6, 1-10, 2-10 Feb. 20 1655-1820 3 1 1-3, 2-10 Feb. 21 2205-2325 3 1 1-3, 1-6, 2-12 Feb. 23 1854-1955 3 1 2-10, 2-12

frequency, or a combination of these. Therefore, it was not possible to assign a signal to a particular bird identified at time of capture. Durin9 the 2-week experimental period, signals could always be separated from each other" althouqh it \~as still not known to which captured bird they should be assigned. 10

A dual-yagi antenna approximately 6 m above ground level was used in conjunction with a null-peak receiving system. Locations of pheasants were monitored from each of three antenna masts (Fig. 1) before and after running the snowmobile on the trails. Two observers concurrently took readings at each of two antennas. Then, one observer moved to a third antenna and again monitored the signals in the same sequence. Thus, a time interval of about 1 hour elapsed among the group of three bearings for each bird. The stationary observer repeatedly monitored signal locations of all birds during the entire interval. Approximately 2 hours elapsed between the readings taken before and after treatment. All treatments except one were conducted when pheasants were assumed to be roosting. Based on observation of radio-marked birds prior to any snowmobiling, birds did not move while roosting. One treatment was conducted between

1400-1600 hours, five between 1600~2000 hours, and six between 2000-0000 hours (Table 1). This was believed to coincide with the timing of most

public sno~~obiling.

While attempting to qua~tify system error and reading error (Heezen and Tester 1967), it was determined that a stationary transmitter (not

attached to a bird) could be located within a 1.4 ± 0.4 ha triangle. However, the mean size of a triangle representing the location of live

pheasants was larger, 2.4 ± 0.4 ha. Due to the large variability in mean size of the triangulated locations, the error information determined from the stationary transmitter was not used to correct pheasant locations. This discrepancy, as well as the large variability, resulted from many factors (Heezen and Tester 1967, Brander and Cochran 1972). 11

It was believed that the following were major factors contributing to the inaccuracies of the telemetry system: (1) receiving stations being too distant (0.4 - 2.4 km) from the radio-equipped birds, (2) inadequate quality of transmitter manufacture~ (3) severe signal attenuation by the dense cattail vegetation, and (4) comfort movements of the birds. There­ fore, the triangulated areas representing pheasant locations before and after snowmobile treatment (Appendix A) were judged subjectively in regards to pheasant movement. This was done by examining the amount of overlap between triangulated locations when plotted at a scale of 1:4,800. When no overlap occurred and when triangle centers were at least 200 m apart, the birds were judged to have moved. Sets of triangulated locations were judged to represent no movement when overlap was approxi­ mately 50 percent or greater and (or) separation of triangle centers was less than 100 m. Also, extremely imprecise triangulations were judged to represent no movement when the bearings from a single antenna site were different, but bearings from the other two antenna sites were similar before and after snowmobiling. Intermediate instances were categorized as representing possible movement. 12

RESULTS

An attempt was made to locate the nine birds that had functioning transmitters both before and after snowmobile treatment on 12 different days, resulting in 108 potential sets of triangulations. In 84 instances (78%) it was not possible to triangulate bearings for the same bird both before and after snowmobiling because a signal was not received at one or more antenna sites. From signals received at only one or two antennas, it was determined that pheasants had not left the marsh as a result of snowmobiling. However their exact locations could not be determined (Appendix B). Thus, before and after triangulations were completed for only six of nine radio-equipped pheasants. Based upon the subjective review of 24 usable sets of triangulations, pheasant movement in response to snowmobile activity was minimal (Table 2). No difference in pheasant movement was found among treatments, time of treatments, or date of treatments. As pheasants tended to remain station­ ary during all snowmobile treatments, weather conditions did not affect movement. On 17 February, pheasant No. 1-3 exhibited the only clear-cut instance of movement during a snowmobile treatment (Fig. 2). It moved approximately 915 m from an area of dense cattails situated off the trails to an area of dense cattails situated on the trails. This change of location probably represented normal movement from diurnal cover to its usual roosting habitat, rather than response to snowmobiling. The 13a Figure 2. Locations of pheasant No. 1-3 observed by radio-telemetry before (wide, broken line) and after (solid line) snowmo­ biling as an example of obvious movement on 14 February, Barringer Slough, Iowa. Dotted lines represent snowmobile trails. 13b

- I

N~

......

...... o 100 m ...... ~. '- -' .... 1""········· ...... 14

Table 2. Number of times individual radio-equipped pheasants moved in response to snowmobiles in Barringer Slough. Categorization is based upon subjective inspection of triangulations plotted at a scale of 1:4,800.

Bird Definite Possible No Percentage of times no number movement movement movement movement occurred

1-1 ' 0 0 1 100 1-3 0 1 6 86 1-6 0 0 2 100

1-10 0 0 1 100 2-10 0 2 5 71 2-12 0 0 5 100

Total 0 3 20

Percentage of Total 0 13 87

area of diurnal activity was outside the usual home range of any of the radio-marked pheasants, although other pheasants were known to be winter­ ing in that section of slough. In 20 instances (87%) no movement was observed in response to any of the snowmobile treatments (Fig. '3)". In three instances (13%), it was unclear whether the birds were moving in response to snowmobile activity due to the large telemetry error observed (Fig. 4). These 15a Figure 3. Locations of pileasant No. 1-1 observed by radio-telemetry before (wide, broken line) and after (solid line) snowmobiling as an example of no movement on 17 February, Barringer Slough, Iowa. Dotted lines represent snowmobile trails. 15b

:...... t : ". N : ...... , : "''I. : : ..... :.: :.: """ ..... :.• :.• "'f,'# :. : 'f"f. :. :. :'f'f. .: .: .: " . .... " .:. . :. f'f •• : : .... • - • I, ~ _ : 'f,••• : = : f"f : = :. ·fff. :. - : ...... : ::. ~ ...... : = .f.•.. : ~ , - -= ,,~ = ", """ -= ",", ""'" =- ,\'\" ...... = ",,\' I., -= \" ", '" = ",", -=... ",", ~" ...... ~ ~ S.. .. . o 100 m . 16a · Figure 4. Locations of pheasant No. 2-10 observed by radio-telemetry before (wide, broken line) and after (solid line) snomobiling as an example of possible movement on 20 February, Barringer Slough, Iowa. Dotted lines represent snowmobile trails. 16b

. . N + .

· · . ·

o 100 m 17

three instances were interpreted as possibly representing movement because the general trend of triangulated locations was toward areas off the snowmobile trails. However, no birds left the area of the snowmobile trails.

Pheasant Nos. 1-3, 2-10, and 2~12 were the only birds for which at least five tri.angulated roost-site locations were known. No major roost-site changes occurred during the 2 week experimental period. No roost-site changes were suspected in any other radio-marked birds. The principal habitat type used both day and night by the pheasants during December, January, and February was dense cattail. Feeding activity occurred in adjacent crop fields and in the cattail stands. Seeds of aquatic annuals were available as a food source in the latter areas as th.ese seeds were observed in the crop and gi zzard contents of hunter-ki 11 ed cock ph.easants. Dai ly activi ty patterns of pheasants were visually observed during live-trapping efforts and were occasionally monitored by telemetry prior to and during snowmobiling. Birds tended to stay in cattails except for midmorning feeding in adjacent crop fields. This feeding behavior occurred on most days and lasted about 1 hour. Tempera­ ture and wind velocity had no apparent effects on these patterns. But, birds fed most actively in crop fields following a greater than 5 cm snowfall. No effect on this pattern was observed because of snowmobile activity. 18

DISCUSSION

There are several approaches possible for determining the effect(s) of snowmobiles on wildlife. In this study, local movements of pheasants were monitored relative to snowmobile activity and essentially no effect was found. It is therefore assumed that population levels and structure would not change in response to controlled snowmobile activity confined . to trails. White-tailed deer have been shown to increase their heart rate when approached by a snowmobile, although the response is difficult to predict with respect to distance between the animal and machine. This increased metabolic rate could result in energetic.stress, as deer are at a low in their metabolic rhythm pattern during winter as part of an energy con­ servation strategy (Personal communication, A. Moen, Department of Natural Resources, Cornell University, Ithaca, New York). Are these results applicable to the ring-necked pheasant? Gates and Hale (1974) stated that "In the wild, it would appear that pheasants may be adapted to a period of negative energy balance in winter, modified by temperature and food availability, ...• " This is based only on weight data of their own and several other studies. However, Kabat et al. (1956) working with penned pheasants, and Anderson (1972) with wild birds, felt pheasants normally gain weight in winter. When annual energetic patterns are quantified in birds, the effect of snowmobiling on metabolic changes will be more fully understood. If energetic stress could be documented, 19 it would still be necessary to demonstrate whether such stress would ultimately affect survival, recruitment, age structure, or other population parameters. Red fox (Newman and Merriam 1972) and white-tailed deer (Lavigne 1976) have been shown to increase travel on snowmobile trails under certain snow conditions. Bollinger et al. (1972), Dorrance et al. (1975), and Lavigne (1976) have demonstrated an initial avoidance of snowmobile areas, but also a subsequent habituation to them, by white-tailed deer. However, it seems unreasonable to expect ring-necked pheasant behavioral responses to be similar to those of deer or fox. It is assumed that pheasants showed little movement in response to snowmobile activity due to the security of the dense cattail habitat. In all trials, the snowmooile passed within 80 m of each radioed pheasant. One might speculate that the birds also have the learned and (or) instinctive knowledge that other locations, or movement itself, are a greater risk to their survival. Pheasants, some radio-marked, wintering in grass waterways, brush piles, and hedgerows in south-central Iowa showed a different response to snowmobile activity. Four instances of snowmobiling between 1000-1600 hours resulted in pheasants flying or running at the approach of a snow­ mobile. One instance of nighttime snowmobiling resulted in no movement in three radio-marked hens (Personal communication, R. George, Iowa Conservation Commission, -Chari ton). The same snowmobil e was used in both the northern and southern Iowa stUdies. 20

Many reasons for the observed difference in response for two geograph~ ically separate pheasant populations could be postulated, including genetic differences, habitat differences, differences in habituation to snow.­ mobiles, etc. It is suggested that variation in response of the two pheasant populations is primarily due to birds responding differently in two distinct habitats. Northern Iowa cattail habitat is much denser than the strip cover found in southern Iowa. Pheasants are therefore less vulnerable to disturbance in the large marshes. Based on 3 days of snowmobiling in a Wisconsin woodlot, Bollinger et al. (1972) concluded that effects of snowmobiling on eastern cottontails was also dependent on habitat type. The differences in reaction of pheasants to snowmobiling in northern and southern Iowa highlight a basic limitation in extrapolating the results of this study. Technically, the experimental unit was not individual pheasants, but was nine, radio-marked hens wintering in Barringer Slough during February 1978. Therefore, there was no experi­ mental replication. It is believed that the reactions of hen pheasants in Barringer Slough have been adequately determined, but this study presents no experimental basis for predicting reactions of other pheasants. One can infer that the reactions of pheasants wintering in other large cattail sloughs would be similar. Birds wintering in other habitats such as farmgroves, brushy draws, or small sloughs may show different responses. 21

PART II. EFFECTS OF SNOWMOBILE ACTIVITY ON WETLAND VEGETATION 22

STUDY AREA

Smith's Slough Game Management Area, Clay County, Iowa is a semi­ permanent, slightly brackish marsh owned and managed by the Iowa Conservation Commission. Smith's Slough can be classified as a IV-B-2 wetl and accordi ng to the system of Stewart and Kantrud (1971). Domi nant species in terms of percentage cover and density in the cattail areas

were Typha glauca and ~ latifolia. ~ angustifolia was also present. During the 1977 field sampling of the sedge meadows, the species of Carex present were not in flower, but possibly two different species were present. During 1978, Carex lacustris was the only species of Carex in flower; it was thought to be the only species of Carex present on the sampling plots, and it was most likely the dominant species in 1977 also. Hereafter, these species will be referred to simply as Carex. Also a dominant plant in the sedge meadows was bluejoint (Calamagrostis canadensis). In areas, bur reed (Sparganium eurycarpum) and Eleocharis palustris were dominant. All plant species were identified according to Fassett (1972). Approximately 85 percent of the study area was dense cattails, 5 percent sedge meadow, and 10 percent mudflat or open water. Hayden (1943) and Glover (1949) give a detailed description of the area. Temperature and precipitation were below normal for winters 1976-77 and 1977-78 as recorded at the u.S. Weather Bureau Station at Spencer, Iowa, approximately 28 km west of the study area (Table 3). Table 3~ Temperature (C) and precipitation (cm) data recorded at Spencer, Iowa for winters 1976-77 and 1977-78 (Environmental Data Service 1976, 1977, 1978).

Month Average Temperature Total Precipitation Maximumsnow Date of temperature departure precipitation departure depth on maximum from normal from normal ground snow depth

Decellber 1976 -9.6 -3.1 1.47 -0.41 12.7 9

January. 1977 -15.7 -6.1 0.74 -0.84 7.6 20 N w February 1977 -'3.2 .±3..Ji 1.91 -0.51 trace 4

Mean or lota 1 -9.6 -4.3 4.12 .. 1.76

December 1977 P47.5 ...1.8 1.27 -0.59 7.6 11

January 1978 -15.1 -6.1 1.63 +0.20 6.0 25

February 1978 -12.1 -5.2 0.69 -1.73 no data no data

Mean or Total -11.6 -4.3 3.59 -2.12 24

METHODS

Snowmobile Treatments

On 21 and 27 January 1977, trail Nos. 1, 2, and 3 (Fig. 5) were established with a Bombardier Skidozer SV 200 snowmobile trail groomer. Total. length of the three trails was 1070 m, and each trail was approximately 3.5 m wide. Trails crossed relatively uniform stands of cattail, sedge meadows, and mudflats, and trail establishment leveled all standing litter. On 15 December 1978, trail Nos. 1, 2, and 3 were re­ established and new trails, Nos. 4, 5, 6, and 7, were made with the groomer. All trails except No.1 were also re-groomed twice during the second winter to simulate typical public use. Total length of all trails was 2945 m. During the winter of 1976-77, no snowmobiling was done because of tnsufficient snow. In 1977-78, a low-intensity treatment of approximately 5 trips per day, a high-intensity treatment of approximately 13 trips per day, and a treatment of trail grooming without snowmobiling were assigned to specific trails (Fig. 5, Table 4). These intensities are similar to those suggested by Gleason et al. (1972), but far less than those estimated by Dorrance et al. (1975). A 1977 Massey-Ferguson Whirlwind 340 snowmobile was used in all treatments. 25a Figure 5. Locations of vegetative zones and snowmobile trails, Smith's Slough, Iowa. Trail Nos. 1, 2, and 3 were established in winters 1976-77 and 1977-78. Trail Nos. 4, 5, 6, and 7 were established in winter 1977-78. Areas indicated as mudflat refer to 1976-77; these same areas were areas of open water in 1978. Location of other vegetative zones refers to both years. 25b

SMITH'S SLOUGH o

'I:'~'W--UPLAND

CATTAIL 26

Table 4. Snowmobile treatments assigned to each trail for vegetation study during 1976-77 and 1977-78, Smith's Slough, "Iowa. Snowmobiling was done on 34 days between 3 January and 23 february, 1978. An asterisk denotes trails that were not established in 1976-77.

Trail Vegetative No. times No. times Snowmobiles Snowmobiles No. zones groomed groomed per season per day sampled 1976-77 1977-78 (1978)

1 cattail, sedge, 1 1 0 0 mudflat 2 cattail, sedge) 1 3 183 5.4 mudflat 3 cattail, sedge, 1 3 448 13.2 mudflat 4 sedge * 3 182 5.4 5 sedge * 3 439 12.9 6 sedge * 3 181 5.3 7 cattail * 3 445 13.1

Vegetation Measurements

In August 1977, vegetation on and off trails was sampled on a series of regularly spaced sampling sites. Distance between sampling sites was 13 m in the cattail zone, 3 m in the sedge zone, and 3 m in the mudflat zone, and number of sites sampled per zone was 44, 23, and 20 respectively. Sampling at regular intervals maximized ease of sampling. This also 27 minimized disturbance on trails to be sampled again the following year by eliminating trampling during establishment of sampling sites prior to taking actual measurements. Each sampling site consisted of a 1 m2 plot on the center of the 2 trail and a 1 m plot located at a fixed distance off the trail. In the cattail zone, this off-trail plot was 5 m from the center of the chosen on~trail plot, on a line perpendicular to the long axis of the trail. This distance was 3 m in the sedge and mudflat zones. These distances were thought to result in paired plots having similar environmental con­ ditions, yet potential effects due to the treatment along the border of the trail were avoided. The first off-trail plot on each trail was ran­ domly assigned to one side of the trail. Thereafter, off-trail plots were alternated between sides. In June 1978, vegetation sampling procedures were similar to those of the previous year, except that sampling sites were located randomly. Off-trail plots in all vegetative zones were situated 6 m from the center of on-trail plots on a line perpendicular to the trail. Five pairs of plots were sampled in the sedge zone on trails nos. 1 and 2. Ten pairs of plots were sampled in other zone and trail combinations. Densities of cattails, sedges, grasses, and bur reed were determined on each plot by actual stem counts. Heights of 16 cattail plants in 1977 and 8 plants in 1978 were recorded in a systematic sampling pattern in

each plot. In 1978, ~/ater depth was recorded for each plot in the cattail zone. In both years, heights of eight sedge plants were recorded on each plot. At stem densities less than 16 or 8, the number of plants measured 28

was equal to the density. On mudflats exposed during the drought in 1976-77, percentage-cover estimates using the quadrat or releve method (Mueller-Dombois and Ellenberg 1974:45-66) were determined for each species. In both years, only stands visually determined to be representative of the particular vegetation type were sampled so that possible confound­ ing effects of environmental and genetic differences might be minimized. Analysis of variance and general linear model procedures were used for all statistical analyses (Barr et al. 1976). Probability levels of 0.10 or less were considered significant in statistical tests. Statistical analysis between years was not done because measurements taken during August of one year are not compatible with those taken in June of the next. 29

RESULTS

General Observations

Species frequencies on and off the trails are listed in Tables 5 and 6. There were no obvious effects caused by trail grooming and (or) snowmobiling. Although, for nearly all non-dominant species,frequencies are too low to allow meaningful statistical comparisons. No attempt was made to compare species composition on and off trails because a 1 m2 plot is probably too small to accurately describe the species composition of herbaceous communities (Mueller~Dombois and Ellenberg 1974:47-54). No major effects of snowmobile trail grooming without snowmobiling on plant density or height could be visually detected during the 1977 growing season. But, during spring after trail grooming with snow­ mobiling, it seemed that cattail plants on trails were slightly shorter than those off trails, and that density of Care x was greater on trails "than off trails. The only other visual difference during June 1978 was that litter had been leveled on trails, but was still standing off trails. 30

Table 5. Comparison of species frequency in plots on and off snowmobile trails during August 1977, Smith's Slough, Iowa. Frequency is the number of plots in which a species occurred divided by the total number of plots sampled (N).

Species Cattail zone S~dge meadow zone Mudflat zone (N=44} {N=23} {N=20} On Off On Off On Off

Asclepias incarnata 4 0 Bidens sp. 4 0 5 a Calamagrostis canadensis 78 74 Carex 2 0 91 91 a 5 Eleocnaris palustris 100 85 Impatiens capensis 9 13

L~copus sp. 4 4 Lysimachia thyrsiflora 17 13 Phragmites communis a 13 Ploygonum coccineum 65 74 Polygonum natans 13 13 Polygonum punctatum 13 13 Polvgonum unidentified 2 2 43 48 Rorippa islandica 0 2 0 20 Sagittaria latifolia 30 26 40 40 Scirpus fluviatilis 25 14 13 9 55 65 Scirpus validus 9 5 70 70 31

Table 5. (Continued)

Species Cattail zone Sedge meadow zone Mudflat zone (N=44) (N=23) (N=20) On Off On Off On Off

Scutellaria e~ilobiifolia 9 4 Sium suave 25 25

Sparganium eurycarpum 5 5 4 4 100 100

Stachys tenuifolia 30 4 Typha spp. 100 100 17 4 a 5 Unidentified dicots a 1 9 4 32

Table 6. Comparison of species frequency in plots on and off snowmobile trails during June 1978, Smith1s Slough, Iowa. Frequency is the number of plots in which a species occurred divided by the total number of plots sampled (N).

Species Cattail zone Sedge meadow zone (N=50) (N=30) . On Off On Off

Calamagrostis canadensis 53 47 Carex 100 100 Labiatae unidentified 2 a 13 30 Polygonum unidentified 4 2 40 30 Sagittaria latifolia 13 17

Scir~us fluviatilis 0 6 3 7

Scir~us validus a 2

Sparganium eurycar~um 4 8 23 3 Typha spp. 100 100 23 13 Unidentified dicots 2 6 13 20 33

Measured Effects

No differences (p > 0.10) in densities of cattail, Carex, or mudflat species, including bur reed, were detected on groomed trails without snow­ mobiling in either year. However, a 12 cm decrease in cattail height on the trail was detected the first year (P < 0.05, Table 7), but no signifi­ cant difference occurred the second year (Tabl~ 8). Carex height was 14 cm greater on the trails the first year, but 14 cm less on trail No. 1 the second year (P < 0.10, Tables 7 and 9). Bluejoint density was 2 41 stems per m greater on the trails the first year (p < 0.05), but there was no significant difference the second year associated with trail No.1 (Tables 7 and 9).

Table 7. Effects of snowmobile trail groo~ing without subsequent snow­ mobiling on density· (stems per m ) and height (cm) of wetland vegetation in Smith's Slough, Iowa, 1976-77. Measurements were made on 44 pairs of plots in the cattail zone, 23 in the sedge­ meadow zone, and 20 in the mudflat zone. P represents the probability of a greater £ value. -

Variable On-trail Off-trail Difference P

Density of cattail 38.6 36.5 2.1 0.62 Mean height of cattail 224.0 235.6 -11.6 0.006

Density of Carex 26.0 19.9 6~1 0.13 Mean height of Carex 117.0 104.1 13.6 0.008 Density of bluejoint 113.0 72.2 40.8 0.03 Density of bur reed 29.7 27.6 2.1 0.69 34

Table 8. Effects of sno~obil;ng on density (stems per m2) and. height (em) of cattail in Smith1s Slough, low'a, 1977-78. Measurements were made on 10 pairs of pl_ots on each trail. P represents the probability of a greater [ value.

Variable Trail Snowmobile On-trail Off-trail Difference P trips

Density of 1 a 31.2 29.5 1.7 0.77 catta i 1 2 183 19.0 29.3 -10.3 0.06 3 448 19.4 31.7 -12.3 0.03 6 181 45.4 47.9 -2.5 0.69 7 445 40.6 64.0 -23.4 0.04 Mean All 31.1 40.5 -9.4 0.003 Mean height 1 a 78.9 73.6 5.3 0.17 of cattail 2 183 64.7 74.7 ...:10.0 0.04 3 448 79.5 87.1 -7.6 0.23 6 181 103.3 122.0 -18.7 0.06 7 445 106.6 137.8 -31.2 0.003 Mean All 86.7 99.0 -12.3 0.0001 35

2 Table 9. Effects of s~owmobiling on density (stems per m ) and height (cm) of Carex, and density of bluejoint in Smith's Slough, Iowa, 1977-78. Measurements were made on 10 pairs of plots for trail Nos. 1 and 2, and 20 pairs for trail Nos. 4 and 5. ~ represents the probability of a greater F value.

Variable Trail Snowmobile On-trail Off-trail Difference P trips

Density of 1 0 7.6 24.2 -16.6 0.18 Carex 2 183 66.2 18.8 47.4 0.04 4 182 93.1 31.0 62.1 0001004 5 439 92.9 38.4 54.5 0.003 Mean All 74.3 30.3 44.0 0.0001 Density of 1 0 19.2 85.8 -66.6 0.14 bluejoint 2 183 137.0 76.8 60.2 0.24 4 182 1.9 0.8 1.1 0.55 5 439 3.9 2.6 1.3 0.33 Mean All 28.0 28.2 -0.2 0.98 Mean height 1 0 63.7 77.2 -13.5 0.10 of Carex 2 183 74.4 66.9 7.5 0.23 4 182 74.6 71.0 3.6 0.20 5 439 70.2 069.1 1.1 0.75 Mean All 71.3 70.7 0.6 0.79 36

In 1978, there were differences (f < 0.005) in both mean height and density of cattail and bluejoint in off-trail plots associated with different trails. This intertrail variation was independent of any treatment applied to the trails by snowmobiling, and was the result of genetic differences in the plants or their phenotypic repponse to local site conditions. In combining statistics for all trails, then, dif­ ferences in mean height and density of these two species between on­ trail and off-trail plots may be confounded. However, an effect from snowmobiling was seen when a comparison of individual trail means was made for c-attai 1 areas. In summary, snowmobiling caused a 23 percent decrease in cattail density, 12 percent (12cm) decrease in cattail height, and a 44 percent increase in Carex density. Snowmobiling had no significant effect on bluejoint density or Carex height {Tables 7 and 9}. No differences in response of marsh vegetation were detected between high and low snow­ mobiling intensities. Additionally, there was no interaction between the effects of water depth on ca tta i 1 hei ght or dens i ty and the response of cattails to sno~~obiling (f> 0.20). 37

DISCUSSION

Plant Response

Nelson and Deitz (1966) and Weller (1975) reported that cutting and subsequent flooding of cattail stems resulted in death of some plants and reduced growth in others. These results can be explained on the basis of the role of aerenchyma in atmospheric gas exchange with living plant parts (especially rhizomes) by way of standing cattail litter. By cutting and submerging the litter, gas exchange is inter­ rupted. Gas exchange through aerenchyma is thought to be most critical inh latifolia and.l:.. glauca (Mc Donald 1955; Marsh 1962; Bedish 1967). It is assumed that snowmobiling causes a similar interruption of gas exchange in cattails and a resultant decreased rate of metabolism during spring rhizome growth. Thus, decreases in stem density and plant height observed during summer are the result of retarded spring growth.

Smith's Slough had little water during the 1977 growing season, but was near maximum \'1ater-holding capacity during spring of 1978. The critical period for cattail shoot development is probably during spring when water levels tend to be at a maximum. When aerenchyma gas exchange is interrupted under high-water conditions, cattail plants are respiring anaerobically. The height of the water column through which the cattail plants must grow, then, would seem to be the determining factor affecting cattail response to snowmobiling. Effects during 1978 are probably 38

maximum, because litter had been compacted to ground level and subsequent water level was high. However, no interaction between the effects of water depth on cattail height or density and the response of cattails

to sno~mobiling was detected (f. > 0.20) with statistical analysis using the general linear model procedure (Barr et al. 1976). Plants on the trails were observed to be in flower and it is not felt that the 12 cm decrease in height for 2 consecutive years would contribute to a long-term reduction in stand vigor with no further snow­ mobiling. Only further observation can demonstrate whether continued annual snowmobiling would result in greater cumulative effects. It appears that trail grooming alone does not compact and (or) shred cattail litter enough to greatly affect gas exchange. Also. reduction in cattail stern density did not occur in the trail-groonling-only treatment during 1976-77. This study was not sufficiently replicated so long term effects on stem density cannot be predicted. Weller (1975) reported that winter cutting of cattails with subsequent flooding resulted in decreased stem densities for up to six years.

The lack of any effect of snowmobiling on bluejoint is consistent with the findings of Walejko et al. (1972) for forage grasses. Carex, however, responded with increased stem density on the snowmobile trails. This may possibly be fhe result of increased soil temperatures or increased light availability to growing shoots in spring due to com­ paction and shredding of the litter. No satisfactory explanation is known for the discrepancy in the trail grooming without snowmobiling 39

experiments whereby increased density of bluejoint occurred in 1977 but not in 1978, or of an increase in height of Carex in 1977 but a decrease in 1978. In these instances, drought conditions may have caused confounding effects which mask the true effects of trail grooming. Alternatively, these instances may be chance occurrences related to the sampling scheme. Mudflat conditions are excellent for seed germination, but because of the often short-term nature of such conditions, perennials such as bur reed and ~ palustris appear to be responding as annuals. Therefore, it is not surprising to observe a lack of effect of winter trail groom­ ing on mudflat vegetation during the subsequent growing season.

Snowmobiling and Habitat Management In Cattail Sloughs

Interspersion is an essential element in habitat management (Leopold 1932:131-132; Kelker 1964; Patton 1975), particularly in marshes where interspersion of cattail stands with open water is important to optimum wildlife production (Weller and Spatcher 1965). Snowmobiling on desig­ nated trails was not a viable technique for substantially decreasing density of cattails in Smith's Slough during 1977-78. Should subsequent seasons of snowmobiling reduce stem densities, then desirable openings may be developed over time. Such open water areas may provide travel lanes for wintering deer, or increase amounts of brood habitat for waterfowl. Muskrats (Ondatra zibethica) are an important component of 40

, especially in altering habitat (Weller and Spatcher 1965; Weller and Fredrickson 1974; Weller 1975), and muskrat population levels must be considered carefully before prescribing snowmobiling as a habitat management technique. Due to drought conditions muskrats were nearly non-existent in Smith's Slough during 1976-78, and their inter­ action with the effects of snowmobiling was essentially nil. None of the observed changes in plant height are believed to be large enough to substantially affect the structural component of the habitat for most wildlife, including marsh nesting birds. The obvious exception is the possible impairment of nest building on the trails by such species as yellow-headed blackbirds (Xanthocephalus xanthocephalus) long-billed marsh wrens (Telmatodytes Ealustris), American coots (Fulica americana), and redheads (Aythya americana) which use previous years' litter in their nests. The magnitude of this effect would be dependent on the percentage of slough that is covered by snowmobile trails.

Different conditions such as soil characteristics, water chemistry, and weather in other areas may alter responses of aquatic vegetation to snowmobiling. In particular, 1 m or more of snow in the marsh before trail establishment could result in substantially less leveling of standing litter and a possible decrease in magnitude of effects. 41

CONCLUSIONS AND IMPLICATIONS

In this study, pheasant hens did not flush when approached by a snowmobile. Assuming that public use could be confined to an established trail system, there would be no adverse effects of major significance on the pheasant populations wintering in the large sloughs of northern Iowa. It has also been observed that snowmobile noise is relatively localized to the trail area and therefore would only stress few pheasants ener­ getically, even if physiological stress were to be demonstrated. Addi­ tionally, such snowmobiling would not result in a serious alteration of wildlife habitat within the limits tested. However, cattail height and density did decrease, and Carex- density increased in response to snowmobiling.

As with any intrusion into a natural system, all the effects on its functioning are not known. Would snowmobile activity affect fledging success of great-horned owls (Bubo virginianus), or conception rates in mink (Mustela vison)? A nearly infinite list of biological questions can be posed, and remain unanswered at present. However, there may be sociological factors of more importance than biological factors to consider when managing public lands. It is suggested that the role of snowmobiling on public lands should be examined for its merits as a form of outdoor recreation.

lilt is the expansion of transport without a corresponding 42

growth of perception that threatens us with qualitative bankruptcy of the recreational process. Recreational

development is a job not of building roads into lovely country, but of building receptivity into the still unlovely human mind ll (Leopold 1966:295).

This reasoning should not be viewed as a scapegoat for banning snow­ mobiling. Rather, it should be the impetus for expanding efforts towards changing public values and beliefs about recreational experiences. The need to re-emphasize outdoor recreation in terms of outdoor awareness has never been greater, or the potential for impact more potent. 43

LITERATURE CITED

Anderson, W.L. 1972. Dynamics of condition parameters and organ measurements in pheasants. Illinois Nat. Hist. Surv. Bull. 30(8):455-498.

Barr, A.J., J.H. Goodnight, J.P~ Sall, and J~T~ Helwig. 1976. A user1s guide to SAS 76. Sparks Press, Raleigh, North Carolina. 329 pp. Bedish, J.W. 1967. Cattail moisture requirements and their significance to marsh management. Am. Midl. Nat. 78(2):288-300. Bollinger, J.G., O.J. Rongstad, A. Soom, and T. Larson. 1972. Final report: snowmobile noise effects on wildlife. Univ. Wisconsin, Madi son. 89 pp. Brander, R.B., and W.H. Cochran. 1972. Radio-location telemetry. Pages 95-103 in R.H. Giles, ed. Wildlife:M~n~gement Techniques. 3rd ed. The \A!ildlife Society, \~ashington, D.C. Bugliarello, G., A. Alexandre, J. Barnes, and C. Wakstein. 1976. The impact of noise pollution: a socio-technological introduction. Pergamon Press, Inc., New York. 461 pp. Bury, R.L. 1978. Impacts of snowmobiles on wildlife. Trans. N. Am. Wildl. Nat. Resour. Conf. 43: in press. Bury, R.L., R.C. Wendling, and S.F. McCool. 1976. Off-road recreation vehicles: a research summary. Texas Agric. Exp. Stn. 'M.P-1277. 84 pp. Doan, K.H. 1971. Effect of snowmobiles on fish and wildlife resources. Proc. Int. Assoc. Game, Fish and Conserve Commissioners 60:97-103. Dorrance, M.J., P.J. Savage, and D.E. Huff. 1975. Effects of snow­ mobiles on white-tailed deer. J. Wildl. Manage. 39(3):563-569. Dwyer, T.J. 1972. An adjustable radio-package for ducks. Bird-Banding 43(4):282-284. Environmental Data Service. 1976. Climatological Data, Iowa. 87(12). Natl. Oceanic and Atmos. Adm., Asheville, North Carolina. Environmental Data Service. 1977. Climatological Data, Iowa. 88(1, 2, and 12). Natl. Oceanic and Atmos. Adm., Asheville, North Carolina. Environmental Data Service. 1978. Climatological Data, Iowa. 89(1 and 2). Natl. Oceanic and Atmos. Adm., Asheville, North Carolina. 44

Farris, A.L., E.D. Klonglan, and R.C. Nomsen. 1977. The ring-necked pheasant in Iowa. Iowa Conserve Comm., Des Moines. 147 pp. Fassett, N.C. 1972. A manual of aquatic plants (revised). Univ. Wisc. Press, Madison. 405 pp. Gates, J.M., and J.B. Hale. 1974. Seasonal movement, winter habitat use, and population distribution of an east central Wisconsin pheasant population. Wisconsin Dept. Nat. Resour. Tech. Bull. No. 76. 55 pp. Gleason, G., L. Twardzik, R. Duddles, G. Lemieux, and R. Gross. 1972. Relationship of snowmobiles to the environment (a panel discussion). Int. Snowmobile Congo Proc. 4:145-178. Glover, F.A. 1949. Nesting and production of waterfowl in northwest Iowa~ with special reference to the blue-winged teal (Anas discors Linnaeus). Ph.D. Thesis. Iowa State Coll., Ames. 263 pp. Hayden, A. 1943. A botanical survey in the Iowa Lake Region of Clay and Palo Alto Counties. Iowa State Coll. J. Sci. 17(3):277-416. Heezen, K.L., and J.R. rester. 1967. Evaluation of radio-tracking by triangulation with special referenc~ to deer movements. J. Wildl. Manage. 31(1):124-141. Hume, R.A. 1976. Reactions of goldeneyes to boating. Br. Birds 69(5): 178~179. Kabat, C., R.K. Meyer, K.G. Flakas, and R.L. Hine. 1956. Seasonal variation in stress resistance and survival in the hen pheasant. Wisconsin Conserve Dept. Tech. B~ll. No. 13. 48 pp~ Kelker, G.H. 1964. Appraisal of ideas advanced by Aldo Leopold thirty years ago. J. Wildl. Manage. 28(1):180-184. Lavigne, G.R. 1976. Winter response of deer to snowmobiles and selected natural factors. M.S. Thesis, Univ. Maine, Orono. 69 pp. Leopold, A. 1932. Game management. Charles Schribners' Sons, New York. 481 pp. Leopold, A. 1966. A sand county almanac. Oxford Univ. Press, Inc. New York. 295 pp.

Marsh, L.C. 1962. Studies in the genus~ byeh~: I. metaxenia, xenia, and heterosis. II. interspecific hy rldlzation and the origin of T. glauca. III. autecology, with special reference to the role of aerenchyma. Unpublished Ph.D. Thesis. 138 pp. Syracuse Univ., Syracuse, New York. Diss. Abst. 23:4509-4510. 45

Mc Donald, M.E. 1955. Cause and effects of a die-off of emergent vegetation. J. Wildl. Manage. 19(1):24-35. Mueller-DomOois, D., and H. Ellenberg. 1974. Aims and methods of vegetation ecology. John Wiley and Sons, New York. 547 pp. Nelson, N.f., and R.H. Deitz. 1966. Cattail control methods in Utah. Utah State Dept. Fish and Game publ. No. 66-2. 31 pp. Newman, P.W., and H.G. Merriam. 1972. Ecological effects of snowmobiles. Can. Field-Nat. 86(3):207-212. Patton, D.R. 1975. A diversity index for quantifying habitat edge. Wildl. Soc. Bull. 3(4) :171-173. Schmid, W.O. 1971. Modifications of the subnivean microclimate by snowmobiles. Pages 251-255 in A.O. Haugen, ed. Proceedings of the snow and ice in relation to wildlife and recreation symposium. Iowa Coop. Wildl. Res. Unit, Iowa State Univ., Ames. Stewart, R.E., and H.A. Kantrud. 1971. Classification of natural and lakes in the glaciated prairie region. u.s. Fish Wildl. Servo Resour. Pub 1. No. 92. 57pp. U.S. Congress, Senate Committee on Interior and Insular Affairs, Sub­ committee on Parks and Recreation. 1971. Snowmobiles and other off-road vehicles. U.S. Govt. Printing Office, Washington, D.C. 109 pp. Walejko, R.N., J.W. Pendleton, G.H. Tempas, R.E. Rand, and W.H. Paulson. 1972. Effect of snowmobile traffic on established stands of non­ forest vegetation. Agron. Abstr. 64:166. Walejko, R.N., J.W. Pendleton, W.H. Paulson, R.E. Rand, G.H. Tempas, and D.A. Schlough. 1973. Effect of snobmobile traffic on alfalfa. J. Soil and Water Conserve 28(6):272-273. Weller, M.W. 1975. Studies of cattail in relation to management for marsh wildlife. Iowa State J. Res. 49(4):383-412.

~Je 11 er, M. H., and L.H. Fredri ckson. 1974. Avi an ecology of a managed glacial marsh. Living Bird 12:269-291. Weller, M.W., and C.S. Spatcher. 1965. Role of habitat in the distri­ bution and abundance of marsh birds. Iowa State Univ. Agric. Home Econ. Stn. Spec. Rep. No. 43. 31 pp.

Wright, G.A., and DJ~. Speake. 1975. Compatibility of the eastern wild turkey with recreational activities at Land Between the Lakes, Kentucky. Proc. Southeastern Assoc. Game and Fish Commissioners 29: 578-584. 46

ACKNOWLEDGEMENTS

The Iowa Conservation Commission, through the Iowa Cooperative Wildlife Research Unit, provided funding, field quarters, and equipment which involved efforts of A. Farris, R. George, W. Rybarczyk, W. Souer, and J. Wooley. The time, equipment, and encouragement of D. O'Brien, S. Pitt of the Palo Alto County Conservation Board, and C. Fraley of the Clay County Conservation Board can be singled out as the most valuable contribution made in the field. T. Parker of Massey-Ferguson, Inc. kindly provided a snowmobile during the winter of 1977-78. For cooperation in planning and reporting the study, as well as a field visit, R. Dahlgren, A. Farris, R. Moorman, and A. van der Valk of Iowa State University are sincerely thanked. D. Cox provided statistical assistance, and has attempted to teach me the necessity of knowing what questions to ask before attempting to answer them. J. Bednarz, R. Kenyon,

R. Martens, V.P. McCrow, R. Munke~, and D. Stephenson provided able minds and bodies during various stages of the project. E. Klaas was able to bear the brunt of innumerable trials and tribulations from the project's inception, through field work, and until the final report was completed. His efforts were not always fully appreciated at the time. And, Mary Ann Sojda was always there. Of course, she will always be appreciated. This work was dedicated to the hope that Augie, Baron, Charlie, and friends may continue to have a rooster to trail and a blue-wing to fetch. 47

APPENDIX A

Figures on the following pages represent locations not included in the text, of pheasants Nos. 1-1, 1-3, 1-6, 1-10, 2-10, and 2-12 observed by radio-telemetry before (wide, broken line) and after (solid line) snowmobiling during February 1978, Barringer Slough Iowa. Description of movement is subjective. Dotted lines represent snowmobile trails.

On figures where no sno~rrnobile trails are shown, the trails are located 100-200 m west of the area depicted in the figure. 48

10 FEBRUA~Y

\\~ 1-3 \}UIII; no movement 2-10 :no movement

N + o 100 m I I

11 FEBRUARY

·· · 2-10 no movement . N . + .

•• II. II. II •• II •• II ......

q 10,0 m ~."", """'t, I.,.,.,., 49

.. ·· 12 FEBRUARY · ·. · ......

. .. .

~\\ 1-3 .. '~/II 11111 ... no movement 11111.. I;; = N \" .... : + ...... ,.... , ': o 100 m -""" ': .. """ ': I """ : ...... , .... " :- .. '",~

.. 13 FEBRUARY

..

~~...... 2-10 § ~ no movement ......

• .. • ...... T 4f \

N ...... " : ... ""., : ."'~ ,. ': o + 100 m .. I I """ 50

13 FEBRUARY ~~~~ l : ~ II/II 2- 1 2 : : :: //// - : : :: II/II : ' ..... , :: III nom 0 v em e n t : ".,,:: '"~ . - """: 1,/ : .: """ :: II/II : : ~ //i// : - 0: "" $ 1///: •••••• :: 1///: ....:: 1/// : '.:: //1/ : •••• - 1/1 • •••••• S 111// ; •••• - II/ •••• :: 1/11 '. :: IIA.. t_,. ~ ~~ '. ::- ~" ... :: ~ :: ~: $ ",... : ::- ,'"~ . :: ",... : :: ,'" . :: ~: N :: ~: s ~: ~ ::$ "...~: r,.. : o 1 00 m ::= ",~,: "" : I I :: "... "',,: ...-----...... :::: ~"... "" ~~ :: :: "... ',.,.~

... 14 FEBRUARY . ..

...... n .... 1-3 .... ;'1'" 'bl N .. ::: :: I",I,,, P 0 5 5 , .. e movement.. i. :: ~\'I.J : .. ~ "'" :: \\\\\ : .. '" '" ~\\ ~ """ 100 m """ " '. " '##, : "I! 51

;. -- : : .-: 1L : : :.. \\,\\1\~\\= = 15 fEBRUARY : : \\\\\\ \\\\\ = .. .. \\\\\ - : : \\\\\ \\\\ = .. :\\\\\ - : ~ = : \\\\\\ - : \\\\\ : \\\\\\\ N \\\\\l\\\\\\

,,\\\\\\\\\\\\\\\\ . \\\\\ ~\\\\ ~~~, ~~~; ~~; ~~~; -'~; - ~~; : ~~; 1-3 : ,~; ; "; no m0 vern e n t ,~, '~'; '~; ";"; I ...... I'., III •••••••• II. rf :.~'" ~~, o 100 m : "; I I : '" : '" ,~~ - : " - .. .. 16 FE BRUARY

,~ ~ N ~ ~ ~ ~ ~ + ~ -=- ~ 1-3 ~ ~ ~ no movement ~ ~ ~ ~ 11111 ~ 1///// ~ /1/1//// ~ 1111/ ~ 11//// ~ II/II ~ //////////// ~ //1// -=- II/II ~ II/II ~ II/II ~ ////Ift:- o 100 m I 52

.. .. 16 FEBRUARY

2-10

a 100 m I

... 1"6 FEBRUARY

.. ..

. .. .. : N : + ...... o 100 m .. I ,-.. 53

17FEB~lJARY

...... : N +

2-12

o 100 m I I

19 FEBRUARY N

. + : 2-10 no

1- 6 no movement

o t 54

19 FEBRUARY

~ ~ ~ ~ ~ N ~ ~ 1-10 ~ ~ + ~ o movement ~ ~ ~ ~ ~ oS""""""""" I"" III""""""""" III III"

100 m

.

.

N no movement ...... : + """'. : : ""'... , : ...... " : ." ..... ;; a 100 m 55

21 FEBRUARY

N +

a 100 m I

21 FEBRUARY

N .•.... + ..... ~

a m I 56

......

21 FEBRUARY...... / ...... ;/ ...... ; ...... s- ...... :o~ .:0 ~ ~ ...... ~ .... ~ ...... ~~ ...... ~ .... ~ ~...... ~ ~ ~ ~ 2-12 ~ ./'/ . Ililit~ no movement

......

o 100 m N~ I I

23 FEBRUARY

N +

2-10 possible

''' .. •••• .". .. o -" ·····100 .m ------', " ..... 57

: . 23 FEBRUARY . or...~ . : \\\~= :. \\\-\\\\ = : \\\\\\\\ = : \\\\ = N ~ \\\\ = \\\\\\ -= \\\\\\ -= . ~ \\\\\\ = ~ -= · ~"Il = 2-12 · 'III/ = '1lll'I,.. =_ · '1/ . _ no movement "· ... t.. ·: '1111 = ···· .. r.. : 'tIl = "'... ,~ · - · - · - ·: 'III =- : IIII~ ·• .L -,,. · . 100 m · . · . I · . · . 58

APPENDIX B

Figures on the following pages represent inconlplete triangulations of bearings to pheasants Nos. 1~2, 1-3, 1-4, 1-10, 2-1, 2-5, 2-10, and 2-12 observed by radio-telemetry before (wide, oroken line) and after (solid line) snowmobiling during February 1978, Barringer Slough, Iowa. Dotted lines represent snowmobile trails. On figures where no snowmo­ bile trails are shown, the trails are located 100-200 m west of the area depicted in the figure. Description of movement has not been attempted (see pages 10-12). 59

.. : " 10· FEBRUARY : 2-0 ---I'd

,~. '" "~ ~"" '" '" '" '" '" " " ...... ,..: 2-12

N + .

o, 100, m ~, . ,~ ',""

': 11 FEBRUARY·

...... I"" § "" ''lJ...... :::: "'" "," \<] ...... \ ...... N ...... 1-3~ '" ~ '" '" ...... : ...... : ..... ,;

o 100 m I I "" "" ., '" 60

11 FEBRUARY

.. . N nn + ...... o 100 m ...... : ""'.

12 FEBRUARY

N + .

••••• ...... o '. 100 m I I '.'~" " bl

12 FEBf~UARY

2-10 ...... N! ...... ; '-" T "'" "'" ..... '.""'" """ '" ...... " .. , : 'f. .... , ... .; 100 o IT("'" '" I "" '" "'" .....

13 FEBRUARY - -- 11111 -= lilliE ":III - 11111 -= III - - 2-1 . : . : '" """ "'" N+ . '.".~ :

. . o 100 m I I """ """ . . 62

,. ...,. 13 FEbRUARY ...

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