Proceedings of the Seventh Mountain Lion Workshop

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94 REDUCING PUMA ATTACKS · Fitzhugh et al. Table 1. Calculations of non-fatal attacks by pumas in the U.S. and Canada between 1890 and 1969 that might not have been detected. Source Beier (1991) 1970-1990 Our data 1970-2001 Ratio NF/F from 1970 onward × Fatal attacks 1890- 1969 = Calculated non-fatal attacks − Attacks detected 1890-1969 PROCEEDINGS OF THE SEVENTH MOUNTAIN LION WORKSHOP = Calculated attacks not detected 31÷5 = 6.2 4 25 13 12 69÷12 = 5.75 4 23 21 2 western U.S. It is certain that attacks occurred in Latin America for which no records are available. Written accounts of attacks occur in some obscure publications, not susceptible to easy location. One example is the killing of Henry Ramsey in 1876 (Hunter 1922:110). That account was found by scanning the table of contents of a county history that was in a fund-raising auction of “white elephant” donations. All of these missing accounts would, of course, fail Beier’s criterion of verification, and perhaps other criteria as well. We believe we can use the 16 fatal attacks that meet Beier’s criteria as a complete count, not requiring statistical measures of variability. The 92 Beier-quality non-fatal attacks probably include a large majority of all nonfatal attacks (Table 1). They should be representative, and probably can be treated as a complete count. However, they were not sampled according to a statistical design. The remaining 116 attacks and 155 encounters have unknown statistical properties, with variable report quality and amounts of information. Beier (1991) estimated that he might have missed finding 12 non-fatal accounts between 1970 and 1990. He did this by assuming that he found all the accounts from 1970 to 1990, and multiplying the ratio of non-fatal to fatal attacks during that period by the number of fatal attacks from 1890 to 1969. We discovered 8 of the 12 missing accounts, and also 3 more between 1970 and 1990, so we recalculated the potentially missing non-fatal accounts (Table 1). These were calculated through 2001, as the 2002 data are yet incomplete. The analysis in Table 1 assumes a constant rate of attacks across years. Puma populations, prey populations, and the number, age, sex, and group size of people at risk may have changed considerably since 1890. These factors may affect the attack rate. Thus, the calculation may be invalid to the degree that these parameters have changed. Even if the analysis in Table 1 is valid, the number of fatal attacks is small enough that a change in even one attack can alter the calculation of non-detected non-fatal attacks. Because there is a chance that we may have missed some fatal attacks prior to 1970 (and especially prior to 1950 as discussed later), this is a tentative calculation that serves only to illustrate that there likely are some incidents we have not found, but that number is relatively small. We will return to this topic later with respect to possible bias caused by Beier’s verification criterion. Comparing Verified and Unverified Data Figure 1 shows the relationship through time between the 15 Beier-quality fatal attacks, the 86 non-fatal attacks, and the 27 non-verified, non-fatal attacks, 1890-1999. The Beier-quality non-fatal attack curve
Figure 1. A comparison of patterns of fatal and non-fatal attacks that conform to Beier’s (1991) criteria with non-verified non-fatal attacks. diverges from the other two beginning in 1950. All three types of data have been subject to the same bias from a conscious increase in collecting attack reports beginning with Barnes (1960), our effort from 1984 (Fitzhugh and Gorenzel 1986), and intensive searches beginning about 1990 (Beier 1991) and increasing in 1998-2001 (Danz 1999, Deuerbrouck and Miller 2001, Etling 2001).The Beier-quality fatal attacks curve (Figure 1) began to exceed past levels in the 1970s, and increased even more in the 1990s. We confirmed that Beier documented all the verified fatal attacks since 1890, and Figure 1 shows that the nonverified, non-fatal attacks coincide closely with Beier-quality fatal attacks. The difference in the shape of the curves in Figure 1 may be partly attributable to an increase in agency funding, staffing, and attention to puma incidents beginning in about 1950, allowing for more verification and recording of non-fatal incidents (Harley Shaw, personal communication). Thus, the post-1950 non-verified data may be depressed because a greater proportion of those incidents were verified than happened pre-1950. The post-1950 verified non-fatal PROCEEDINGS OF THE SEVENTH MOUNTAIN LION WORKSHOP REDUCING PUMA ATTACKS · Fitzhugh et al. 95 Figure 2. Non-fatal to fatal attack ratios. Bars represent a 20-year running average beginning with 1890-1909, 1900-1919, etc., except that 1990 represents only 1990-1999. Includes only data that conform to Beier’s (1991) criteria. The zero value at 1890 represents a 20-year period, 1890-1909, with no verified non-fatal attacks. The zero value at 1950 represents a 20-year period, 1950- 1969, without fatal attacks. (N = 101; 15 = fatal, 86 = non-fatal.) data would have increased by the same amount. The proportional change in the Beierquality non-fatal attack curve after 1949, applied to higher numbers of non-fatal incidents compared with fatal incidents, magnifies the visual comparison between the curves, although prior to 1950 the nonfatal curve is only slightly higher than the fatal curve. The effect of magnification can be removed by examining proportions directly, using non-fatal to fatal ratios by 20year periods (Figure 2). The 1960-1990 ratios seem consistent, with an average value of 6.5. The 1890-1930 average is less, at 2.4 (including 1890-1909, when there were no recorded non-fatal attacks), but is more variable. Only the 1940-1959 ratio seems unusually high, created by the first big increase in non-fatal attacks, which occurred during the 1950s, while no fatal attacks occurred 1950-1959. While non-
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PROCEEDINGS OF THE SEVENTH MOUNTAIN
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TABLE OF CONTENTS Preface..........
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COUGAR PREDATION ON PREY IN YELLOWS
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PREFACE vii PREFACE The Wyoming Gam
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ix IN MEMORY
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2 STATUS OF MOUNTAIN LION POPULATIO
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4 STATUS OF MOUNTAIN LION POPULATIO
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CALIFORNIA MOUNTAIN LION STATUS REP
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8 CALIFORNIA MOUNTAIN LION STATUS R
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10 CALIFORNIA MOUNTAIN LION STATUS
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12 CALIFORNIA MOUNTAIN LION STATUS
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COLORADO MOUNTAIN LION STATUS REPOR
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16 COLORADO MOUNTAIN LION STATUS RE
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FLORIDA FISH AND WILDLIFE CONSERVAT
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20 FLORIDA STATUS REPORT · Lotz an
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26 IDAHO MOUNTAIN LION STATUS REPOR
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28 IDAHO MOUNTAIN LION STATUS REPOR
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30 MONTANA MOUNTAIN LION STATUS REP
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32 NEVADA MOUNTAIN LION STATUS REPO
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40 NEW MEXICO MOUNTAIN LION STATUS
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42 NEW MEXICO MOUNTAIN LION STATUS
Page 54 and 55: 44 SOUTH DAKOTA MOUNTAIN LION STATU
Page 60 and 61: 50 TEXAS MOUNTAIN LION STATUS REPOR
Page 62 and 63: 52 UTAH MOUNTAIN LION STATUS REPORT
Page 64 and 65: PROCEEDINGS OF THE SEVENTH MOUNTAIN
Page 70 and 71: WASHINGTON COUGAR STATUS REPORT RIC
Page 72 and 73: 62 WASHINGTON COUGAR STATUS REPORT
Page 74 and 75: WYOMING MOUNTAIN LION STATUS REPORT
Page 76 and 77: 66 WYOMING MOUNTAIN LION STATUS REP
Page 82 and 83: 72 CRYPTIC COUGARS · Tischendorf F
Page 84 and 85: 74 CRYPTIC COUGARS · Tischendorf C
Page 86 and 87: 76 CRYPTIC COUGARS · Tischendorf A
Page 88 and 89: 78 CRYPTIC COUGARS · Tischendorf f
Page 90 and 91: 80 CRYPTIC COUGARS · Tischendorf b
Page 92 and 93: 82 CRYPTIC COUGARS · Tischendorf N
Page 94 and 95: 84 CRYPTIC COUGARS · Tischendorf C
Page 96 and 97: 86 CRYPTIC COUGARS · Tischendorf m
Page 98 and 99: 88 IMPROVING OUR UNDERSTANDING OF M
Page 100 and 101: 90 REDUCING PUMA ATTACKS · Fitzhug
Page 110 and 111: 100 REDUCING PUMA ATTACKS · Fitzhu
Page 112 and 113: 102 REDUCING PUMA ATTACKS · Fitzhu
Page 114 and 115: 104 A CONCEPTUAL MODEL AND APPRAISA
Page 116 and 117: 106 MOUNTAIN LION MOVEMENTS AND PER
Page 118 and 119: 108 PRELIMINARY RESULTS OF FLORIDA
Page 120 and 121: 110 ECOLOGICAL SIGNIFICANCE AND EVO
Page 122 and 123: 112 MOUNTAIN LION BED, CACHE AND KI
Page 130 and 131: 120 EFFECT OF ROADS ON HABITAT USE
Page 132 and 133: 122 COUGAR ECOLOGY AND COUGAR-WOLF
Page 134 and 135: 124 ARE PUMAS OPPORTUNISTIC SCAVENG
Page 136 and 137: 126 COUGAR PREDATION ON PREY IN YEL
Page 138 and 139: 128 COUGAR TOTAL PREDATION RESPONSE
Page 140 and 141: 130 CHARACTERISTICS OF COUGAR HARVE
Page 146 and 147: 136 DEFINING AND DELINEATING DE FAC
Page 148 and 149: 138 MANAGEMENT OF COUGARS (PUMA CON
Page 150 and 151: 140 PROJECT CAT (COUGARS AND TEACHI
Page 152 and 153: 142 ESTIMATING COUGAR ABUNDANCE USI
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144 PRESENCE AND MOVEMENTS OF LACTA
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146 RECONCILING SCIENCE AND POLITIC
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148 PUMA MANAGEMENT IN WESTERN NORT
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150 MOUNTAIN LIONS AND BIGHORN SHEE
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152 DISPERSAL IN MALE PUMAS · Laun
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162 ASSESSING GPS RADIOTELEMETRY RE
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164 FUNCTIONAL RESPONSE OF COUGARS
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166 DEPREDATION TRENDS IN CALIFORNI
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168 PUMA ACTIVITY AND MOVEMENTS IN
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170 MOUNTAIN LION SURVEY TECHNIQUES
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172 CRITICAL COUGAR CROSSING AND BA
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174 LIST OF PARTICIPANTS Chris Beld
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176 LIST OF PARTICIPANTS Steve Fitz
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178 LIST OF PARTICIPANTS Mollie Hog
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180 LIST OF PARTICIPANTS Cheryl Le
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182 LIST OF PARTICIPANTS Ryan Nelso
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184 LIST OF PARTICIPANTS Harley Sha
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186 LIST OF PARTICIPANTS Patricia W
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