Technical Note 424

May 2008
Suggested Citation:

Harrell, D. 2008. Peak lek attendance for greater sage-grouse within the northern Bighorn 

Basin, Wyoming. Technical Note 424. U.S. Department of the Interior. Bureau of Land 

Management, Cody Field Office, Wyoming. 12 pp. www.blm.gov/nstc/library/techno2.htm.

Production services provided by:

Bureau of Land Management

National Operations Center

Information and Publishing Services Section

P.O. Box 25047

Denver, CO 80225

Available online at:

www.blm.gov/nstc/library/techno2.htm

BLM/WY/ST-08/0013+1110
Peak Lek Attendance for Greater Sage-Grouse 

within the Northern Bighorn Basin, Wyoming

Technical Note 424

By:

Destin Harrell

Wildlife Biologist

Bureau of Land Management

Cody Field Office, WY

Cover photo by Dave Goswick

May 2008

Technical Note 424

May 2008
Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming iii

I would like to thank the Wyoming Game 

and Fish Department for providing access to 

lek data and facilitating survey efforts. I am 

grateful to Lisa Marks and Brian Latta, who 

provided many edits and contributions, Eve 

Warren, who offered early advice, and Linda 

Hill and Janine Koselak from the National 

Operations Center, who were helpful in refining 

this document. I would also like to thank 

the staff of the Bureau of Land Management, 

Cody Field Office, for supporting this 

analysis and all who 

reviewed this study 

and made it better. 

I am also appreciative of pictorial and 

review contributions 

by Dave Goswick.

Acknowledgments 

Dave Goswick
Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming

Contents

Abstract vii

Introduction 1

Methods 3

Results 5

Discussion 7

Literature Cited 11

Dave Goswick
Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming vii

Abstract

Lek attendance surveys were analyzed to gain 

a better understanding of the life history of 

greater sage-grouse (Centrocercus urophasianus)

on lands administered by the Bureau of Land 

Management’s Cody Field Office (northern 

Bighorn Basin, WY). The frequency distributions of sampled high observations were 

analyzed relative to the range of days in the lek 

attendance season from 1958 through 2005. 

The mean frequency distributions for male 

and female high observations were considered 

lek attendance peaks. The female peak had 

a mean high observation frequency around 

April 9 and the male peak had a mean high 

observation frequency around April 13. These

peaks were significantly separated (P < 0.0001). 

Computation of a 95 percent confidence 

interval suggests the male peak may be between 

2.83 and 5.07 days later than the female 

peak. These local results are relatively early in 

the lek attendance period when compared to 

other observations in Wyoming and suggest 

that after the female peak attendance, a peak 

in male attendance closely follows. Local 

identification of peak attendance periods may 

help improve local 

nesting, fledging, and 

brood-rearing period 

inference. Existing life 

history information, 

combined with local 

peak female attendance 

data, suggests that peak 

nest initiation for the 

Bighorn Basin may begin 

April 12, peak incubation 

may begin April 21, and 

peak fledging/broodrearing activity may 

begin May 16. Improved 

inference may also lead 

to improved decisions 

regarding habitat 

management and 

conservation.

Dave Goswick
Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming

Introduction

The greater sage-grouse (Centrocercus 

urophasianus), hereafter referred to generally 

as sage-grouse, is adapted to vegetation 

communities dominated by woody sagebrush 

(Artemisia spp.). Sage-grouse populations and 

occupied habitat have been declining from the 

species’ former range and numbers (Connelly 

and Braun 1997; Schroeder et al. 2004; Stiver 

et al. 2006). Differences in local and regional 

abiotic variables may influence when sagegrouse mate, nest, fledge, and move to winter 

habitat (Patterson 1952; Schroeder 1997).

Mating occurs each spring on traditional 

display areas called leks, where males attract 

females through mating displays exhibiting 

sexually dimorphic plumage (Young 1994; 

Connelly et al. 2003). This gathering provides 

an opportunity to count individuals and to 

monitor trends in lek attendance. Average or 

high male observations have been used as an 

indicator for population trends (Connelly et 

al. 2004; Walsh et al. 2004). The frequency 

distribution of these male and female high 

observations may also be useful when 

attempting to estimate peak lek 

attendance periods. 

Generally female sage-grouse start to attend 

leks around early to late March; peak hen 

attendance may be as early as the middle of 

March and vary throughout the sage-grouse’s 

range (Connelly et al. 2004). Soon after peak 

hen attendance occurs, their numbers may 

drop relatively quickly until only a small 

number of hens attend a lek each day, then 

a gradual increase in subadult males tends to 

appear (Connelly et al. 2004). The male peak 

attendance period has been reported to be 

approximately 3-5 weeks later than the 

female peak (Eng 1963; Jenni and Hartzler 

1978; Emmons and Braun 1984; Connelly 

et al. 2004).

Prior to this study, analyses estimating the 

male or female peak sage-grouse lek attendance 

periods were absent in the Bighorn Basin, 

WY. Past studies in other regions have 

reported male and female peak lek attendance 

based on results from radio collared sagegrouse or short-term observations of a 

relatively small representative lek sample. 

Where baseline data have not been collected, 

the female lek attendance peak is the closest 

approximation of when females on average 

begin their reproductive timeline (Patterson 

1952). If local female peak lek attendance was 

better known, life history information could 

be used to produce a timeline extrapolation 

of local nesting, fledging, and brood-rearing 

periods. An estimate of this timeline may 

provide decisionmakers the opportunity to 

avoid disturbing these sensitive life history 

periods by minimizing sources of disturbance, 

stress, and mortality. 

The most relevant sage-grouse life history 

study for the Bighorn Basin was conducted 

by Patterson (1952) in southern Wyoming. 

On leks ranging between 1,951 and 2,438 

meters (6,400 and 8,000 feet) above sea level, 

Patterson (1952) found that male attendance 

was at its highest in mid-April, peaking the 

third week of April. There was not much 

evidence for female peak attendance; however, 

there were substantial observations of other 

life history elements related to fledglings. 

Nesting activity commenced on or around 
Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming

April 20 and terminated by July 1 (Patterson 

1952). Females retired to nesting areas and 

commenced egg-laying within a few days after 

mating, requiring an interval of approximately 

35–40 days between breeding and hatching 

(Patterson 1952). According to Patterson 

(1952), hens began to lay eggs a few days after 

mating; 9 days were observed for completing 

an average clutch of 7.5 eggs (each egg laid 

approximately every 1.3 days), and a 25- to 

27-day incubation period was common, with 

peak hatching occurring the last week of 

May. Patterson’s life history study offers an 

opportunity to initiate extrapolation of 

nesting and brood-rearing periods where 

this information has not been studied. 

Normally, lek monitoring is conducted in 

each of three periods: late March or early 

April (i.e., March 20-April 7), mid-April (i.e., 

April 10-20), and late April (i.e., April 22-30) 

(Connelly et al. 2003). Monitoring may 

coincide with both peak female attendance 

(early counts) and maximum male attendance 

(middle or late counts) (Connelly et al. 2003). 

Since sage-grouse attendance varies among 

years and monitoring results vary with survey 

effort, Wyoming attempted to standardize 

search methodology by conducting lek monitoring according to the “Sage-Grouse Lek 

Survey and Search Methodology” developed by 

the Wyoming Game and Fish Department’s 

Sage-Grouse Working Group in March 1998 

(Easterly 2000). By 1999, lek monitoring 

data in the Bighorn Basin were collected using 

this methodology (Christiansen 2005). 

In recent years, the Wyoming Game and 

Fish Department has produced an annual 

sage-grouse lek monitoring report analyzing 

trends in these average male and female lek 

attendance data and using these trends to 

indicate sage-grouse population changes for 

the northern Bighorn Basin. These reports 

have shown slight declines in average male 

high counts (Easterly 2000; Christiansen 

2005). Declines in abundance and distribution may be a result of habitat degradation 

and its negative effects on nesting success and 

recruitment (Holloran et al. 2005). Currently 

lek counts provide the best index of breeding 

population levels and make long-term data 

sets available for trend analysis (Emmons and 

Braun 1984; Braun and Beck 1996; Connelly 

and Braun 1997; Braun and Johnson 1999; 

Connelly et al. 2003; Stiver et al. 2006). 

However, short-term lek monitoring data 

may only reflect gross population changes and 

may provide misleading results (Connelly et 

al. 2003). Long-term trends in lek attendance 

data may be better indicators of relative 

sage-grouse population status, as population 

size fluctuates and confounds trend analyses 

in shorter time intervals (Walsh et al. 2004). 

In the northern Bighorn Basin, where leks are 

generally lower in elevation, ranging between 

1,300 and 1,700 meters (4,265 and 5,577 

feet) above sea level, sage-grouse attendance 

and nesting periods may be influenced by 

different elevation and climate combinations 

(Patterson 1952). Life history demographics 

observed by Patterson (1952) suggest female 

peak attendance may be in early April. Since 

survival and reproduction is affected by disturbance to this reproduction timeline, which 

begins during the female peak lek attendance 

period, high male and female lek observation 

frequency distribution data from 1958 

through 2005 were analyzed to determine 

when the male and female peak lek 

attendance occurs. 

Lisa Marks
Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming

Methods

Source data ranging from 1958 through 

2005 came from the Wyoming Game and 

Fish Department’s sage-grouse lek attendance 

database for leks in the northern Bighorn 

Basin and north of the Greybull River to the 

Montana State line, which is the boundary 

for lands administered by the Bureau of Land 

Management’s Cody Field Office (figure 1). 

Data from 1958 through 1998 were not 

subject to the systematic data collection 

standards found in the “Sage-Grouse Lek 

Survey and Search Methodology” developed 

by the Wyoming Game and Fish Department’s 

Sage-Grouse Working Group in March 1998 

(Easterly 2000; Connelly et al. 2003). 

Beginning in 1999 these data standards 

were implemented more consistently, with 

monitoring conducted in early March and 

extending into early May. Optimally, three lek 

visits (which involved recording the number 

of male and female sage-grouse observed, 

separated by 7–10 days) were made for 

“count” leks and as time allowed, many 

additional leks were also monitored during 

each annual lek attendance season (Easterly 

2000; Christiansen 2005). 

Figure 1. Map of the sage-grouse lek study area.
Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming

These historical lek attendance data were 

queried for activity, highest number of males 

observed, highest number of females observed, 

date collected, and number of surveys conducted 

per year. For this study, a “high observation” 

was defined as the greatest abundance of male 

or female sage-grouse observed at least once on 

a single lek during a year’s mating season and 

should not be confused with other definitions 

used for surveys and other analyses such as 

“counts” or “surveys” in lek monitoring. When 

there were multiple equal high observations 

for a lek within a year, the data were excluded 

from the analysis as a rule.

Male and female high observations and the 

date observed were queried and binned as 

frequencies (date of high observations through 

the lek attendance period). Histograms were 

produced for each data set showing the male 

and female frequency distribution. Statistical 

analyses within the frequency distribution 

were truncated or limited to observations 

from March 20 through April 30 (normally 

the lek monitoring period) (Connelly et al. 

2003). This truncation was an attempt to help 

control for the biases of potential sampling 

selectivity. The frequency distributions were 

approximately normal, and a two-tailed 

t-test assuming unequal variances was 

used to compare the means of these 

two frequency distributions. The null 

hypothesis (H1=H2) for significance 

was set at α = 0.05 and a 95 percent 

confidence interval was calculated. 

Statistical analyses were conducted 

using Microsoft Office Excel 2003 and 

VassarStats: Web Site for Statistical 

Computation (Lowry 2007).

Destin Harrell
Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming

Figure 2. Frequency and moving average (dashed line) 

of female high observations for data collected from 

1958 through 2005 for each date within the range of 

observation. 

Figure 3. Frequency and moving average (dashed line) 

of male high observations for data collected from 1958 

through 2005 for each date within the range of 

observation.

Results

The sampling period ranged from 1958 

through 2005 (48 years), during which males 

were observed at 101 leks and females were 

observed at 95 leks. There were 2,565 total 

sage-grouse lek observations; 727 total high 

male observations and 492 total female high 

observations. From March 20 through April 

30, there were 636 high observations for 

males and 466 high observations for females. 

All male high observations ranged from 

March 1 through May 26 and all female high 

observations ranged from March 9 through 

May 25. The mean female high observation 

(peak), when rounded to the nearest day, 

occurred on April 9 or 39.87 days into the 

male range (figure 2). The mean male high 

observation (peak), when rounded to the 

nearest day, occurred on April 13 or 

43.82 days into the male range (figure 3). 

A two-tailed t-test assuming unequal variances 

showed the mean male and female high 

observation frequency distributions differed 

significantly from each other; therefore, the 

null hypothesis was rejected (t = -6.97; 

P < 0.0001). The female high observation 

frequency distribution had a standard deviation 

of 8.96, a standard error of 0.41, and a 

median of 39 days. The male high observation 

frequency distribution had a standard 

deviation of 9.74, standard error of 0.39, 

and a median of 44 days. 

A 95 percent confidence interval of the 

difference in mean high observation dates 

between male and female sage-grouse was 

between 2.83 and 5.07 days. Thus, 95 percent 

of all 95 percent confidence intervals computed 

from this population in exactly the same way 

35

30

25

20

15

10

5

0

Date

9-Mar

12-Mar15-Mar18-Mar21-Mar24-Mar27-Mar30-Mar

2-Apr5-Apr8-Apr

11-Apr14-Apr17-Apr20-Apr23-Apr26-Apr29-Apr

2-May5-May8-May

11-May14-May17-May20-May23-May

Frequency

35

30

25

20

15

10

5

0

Date

1-Mar4-Mar7-Mar

10-Mar13-Mar16-Mar19-Mar22-Mar25-Mar28-Mar31-Mar

3-Apr6-Apr9-Apr

12-Apr15-Apr18-Apr21-Apr24-Apr27-Apr30-Apr

3-May6-May9-May

12-May15-May18-May21-May24-May

Frequency
 Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming

would contain the observed difference in 

means. There is sufficient evidence to conclude 

that the mean high observation of male 

(April 13) and female (April 9) sage-grouse 

differs significantly, and it appears that the 

mean dates of male high observations were 

later by 2.83 and 5.07 days on average than 

those of female high observations. 

Before data truncation, kurtosis values (which 

are a measure of “peakedness”) were leptokurtic. 

A leptokurtic distribution has a more acute 

peak around the mean, or a higher probability 

than a normally distributed variable to have 

values near the mean. Females showed a 

greater peak, with positive values of 1.05 for 

females and 0.18 for males. After truncation, 

the frequency distribution showed negative 

kurtosis values, indicating a relatively less 

peaked distribution (male = -0.60 and 

female = -0.40). The untruncated lek 

observation frequency distribution showed 

an average sampling effort into mid-April, 

or 51.34 days into the total sampling range 

(April 12), and the kurtosis value was 0.29. 

This mean value is between the male and 

female peaks and is less leptokurtic or 

platykurtic (a platykurtic distribution has a 

smaller peak around the mean).

Dave Goswick
Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming

Discussion

Although peak attendance may shift across 

years, this analysis of relatively long-term 

high observation lek attendance data suggests 

that on average there is a female attendance 

peak around April 9 and a male attendance 

peak around April 13, and that the male peak 

closely follows the female peak. This study 

assumes that the frequency distributions of 

high lek observations indicates the relative lek 

attendance season and peaks for males and 

females. The frequency distributions also show 

the relative occurrence of high observations 

throughout the lek attendance period. From 

March 1 through May 26, it may be possible 

to observe a peak lek attendance on a given 

lek for males and that for females this period 

may be from March 9 through May 25. This 

range of variability may be associated with 

weather pattern changes and disturbance from 

predators or human activity. The pronounced 

female peak is relatively similar to the male 

peak, suggesting the female attraction to leks 

for fertilization needs may correlate and be 

urgently associated with phenological development of suitable nesting conditions. The 

female peak may also be related to female 

attraction to leks by male display efforts 

encouraged by female attendance and male 

competitive interactions. There may be 

smaller embedded activity peaks; however, 

these data were only analyzed for one peak 

representing each frequency distribution.

The female peak attendance suggests that 

hens may begin nest initiation activity around 

April 12 (3 days after mating) and begin 

incubating nests around April 21 (9 days to 

complete an average clutch). This is about a 

week earlier than the higher elevation leks in 

the Patterson (1952) study. Peak separation 

was less than 1 week (2.83 to 5.07 days) and 

not 3 to 5 weeks as reported elsewhere (Eng 

1963; Jenni and Hartzler 1978; Emmons and 

Braun 1984; Connelly et al. 2004). Peak lek 

attendance for the northern Bighorn Basin 

appears to be relatively early, and the peaks 

are more proximal than those that have been 

reported for Wyoming and other Western 

States (Patterson 1952; Connelly et al. 2004). 

These results suggest that the male peak follows the female peak closely and slowly tapers 

off as the season advances. If diminished 

intrasexual competition contributes substantially to the male peak, then there should 

be a larger male and female peak separation 

(Mercedes 1983; Beehler and Foster 1988; 

Trail 1990). The results of the present study 

showed a significant separation of less than 

a week; this suggests male intrasexual competition and female sexual selection may be 

mechanisms keeping the two peaks close to 

each other yet separate (Cox and Le Boeuf 

1977; Mercedes 1983; Beehler and Foster 

1988; Trail 1990; Hartzler and Jenni 1998). 

A study exploring the period in which most 

copulation occurs and how closely it is associated with female peak attendance and a study 

investigating peak fledging and brood-rearing 

activity would be very helpful to managers 

who currently must extrapolate female nest 

initiation, fledging, and brood-rearing periods 

(Eng 1963; Schroeder 1997). Since there are 

currently small data sets on these periods, 

applying life history observations by Patterson 

(1952) provides nonlocal data for local 

nesting, fledging, and brood-rearing activity 

estimates, which are not ideal. 
Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming

More current and local information would 

improve the accuracy of these estimates. The 

present study indicates 

when females are 

most frequently 

attending leks, presumably for mating. 

If April 9 is indeed 

the local female 

attendance peak, 

much of the broodrearing activity may 

actually be earlier 

than June as reported 

by Patterson (1952) 

and may occur or 

begin around 

May 16 through 

May 18 (25 to 27 

days for incubation) 

in the northern 

Bighorn Basin. 

These types of 

estimates could be 

used until more 

direct data are 

collected from 

nesting fledging, and brood-rearing studies. 

Currently, lek counts are conducted in the 

northern Bighorn Basin, within a monitoring 

period guideline of early March through early 

May. This period does not incorporate all lek 

attendance and may be excluding attendance 

during the early and later periods (Walsh et 

al. 2004). If females attend leks to mate, early 

and late attendance by females suggest that 

nesting activity could begin anytime from 

March 9 through May 25. Early female attendance may be a result of natural annual nest 

initiation variability and adult females nesting 

earlier than yearlings (Schroeder 1997). Late 

attendance may be due to renesting attempts 

after a failed nest (Connelly et al. 1993). 

Milder climate associated with lower elevation 

in the northern Bighorn Basin may be a 

possible explanation for the earlier attendance 

peaks and life history activities.

Adult and juvenile survival and reproduction 

rates have been identified as limiting factors 

for sage-grouse populations (Johnson and 

Braun 1999). Avoiding local sensitive life 

history periods may attenuate the effects 

on sage-grouse from harmful disturbances 

(Crawford et al. 2004). Using peak attendance 

information along with life history information 

could help determine local sensitive periods 

when sage-grouse are vulnerable to disturbances 

affecting survival and reproduction. 

When specific life history details are considered 

and efforts are made to work outside of 

sensitive periods, disturbances such as habitat 

manipulations may be tolerated better by 

sage-grouse (Connelly et al. 2000; Lyon and 

Anderson 2003). Evidence from designed 

experiments with sage-grouse has shown 

that adult and juvenile survival demographic 

factors may respond positively to habitat 

manipulations when designed appropriately 

(Johnson and Braun 1999). Activities such as 

mowing and prescribed burning that achieve 

low sagebrush reduction levels and are 

implemented outside of the lek attendance 

and nesting season may benefit adult and 

juvenile survival by providing a more diverse 

habitat condition (Johnson and Braun 1999; 

Aldridge and Boyce 2007). 

Similar considerations should be applied for 

habitat disturbances that are distant from 

leks, which also appears to be important for 

sage-grouse. Holloran and Anderson (2005) 

showed nest distribution is spatially related 

to lek locations. They also showed greater 

nest success in lower densities, suggesting 

that the use of available sage-grouse habitat 

distant from leks may reduce mechanisms 

of enhanced detection by predators around 

leks (Holloran and Anderson 2005). Also, 

evidence that habitat regulations for sagegrouse appear to be applied homogeneously 

throughout a region further illustrates the 

need for also considering habitat impacts 

during sensitive life history periods on habitat 

distant from leks (LaMontagne et al. 2002). 

These studies suggest the BLM’s current 

0.4-km (1/4-mi) no surface occupancy buffer 

and 3.2-km (2-mi) seasonal surface disturbing 

stipulations may be insufficient to maintain 

activity at a lek and contain a lesser percentage 

of nests (LaMontagne et al. 2002; Holloran 

and Anderson 2005). 

Dave Goswick
Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming

Lek attendance and nesting periods are 

vulnerable times for sage-grouse and they may 

be sensitive to surface-disturbing activities, 

which take many forms (Lyon and Anderson 

2003; Crawford et al. 2004). Care should be 

taken when disturbing sage-grouse habitat 

regardless of the exact distance from a lek. 

Vegetation treatments and new development 

should incorporate the appropriate treatment 

season and spatial placement to minimize nest 

destruction and lek attendance disturbance 

and to maintain quality habitat for the longterm. Results from this study, along with the 

growing body of sage-grouse life history data, 

can be used to make better informed decisions 

on activities overlapping the lek attendance 

and nesting seasons. 

In this analysis, past data were pooled for 

a large sample size that includes many leks 

over many years, increasing the precision of 

the analysis. An even greater sample size may 

show smaller peaks currently indistinguishable 

from these data. As this data set incorporates 

longer periods of time, smaller increments of 

time should be compared to analyze whether 

or not peak lek attendance periods are shifting, 

perhaps from climate change. 

Beginning in 1980, sampling efforts were 

intensified and therefore may better represent 

this period’s population. Observations from 

before 1980 were still included in the analysis 

to help reduce effects of variability among 

years. Such variability may be explained by 

the natural fluctuations in lek attendance 

activity framed by various constraining factors: 

climate, anthropogenic disturbance, phenology, 

physiology, and behavior. Females attempting 

to nest early may lose their eggs to cold 

weather or depredation, may return to the 

lek to mate, and then may reinitiate nesting 

(Jenni and Hartzler 1978). Males may also 

be less fertile later in the season, limiting the 

possibility of renesting and decreasing the 

potential for late broods (Eng 1963). 

Potential sources of bias and error exist 

common to historical data. The pooled data 

were collected from leks that occur within a 

wide range of environmental variables. 

Unfavorable weather may disrupt scheduled 

visits to observe certain leks. High observations 

were sometimes determined by single or many 

lek surveys for the season or by using multiple 

observers, producing differential visual detection rates. Male and female detection rates are 

different, where observers may be more likely 

to inaccurately detect females. Leks may have 

been selected for known historically high 

observations. The high observation date is 

based on the Gregorian calendar and the 

associated error involved with this calendar 

system, specifically leap year corrections. 

All of these variables certainly have an effect 

on the precision and accuracy of the results; 

however, sources of error such as these do not 

eliminate the usefulness of these data, and 

interpretation should acknowledge all sources 

of bias (Walsh et al. 2004; Bart 2005). Results 

still show a significant difference between 

peaks of high male and female sage-grouse lek 

attendance and help describe their temporal 

separation during the lek attendance season. 

In the future, efforts to improve systematic 

random sampling of sage-grouse lek attendance 

throughout the season may produce more 

precise and accurate results that further limit 

bias. The amount of lek attendance data 

continues to increase and taking advantage of 

these growing data sets by using them to determine peak attendance periods is important 

for sage-grouse conservation (Schroeder 1997).
Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming 11

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Dave Goswick
12 Peak Lek Attendance for Greater Sage-Grouse within the Northern Bighorn Basin, Wyoming

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