Male Lek Research Articles

Drone Congregation areas of Apis mellifera (hymenoptera: apidae) and Nosema sp. (nosematidae) in Bolivia: first report

Drone Congregation Areas (DCAs) are crucial natural gathering sites for Apis mellifera mating, like male leks in other animals. In these areas, virgin queens and drones from various hives congregate for mating, promoting genetic variability essential for colony adaptation and survival. Identifying drones in DCAs helps to understand the genetic variability within bee populations, which is crucial for promoting colony survival and resilience. Two areas in Villa Montes, Bolivia, were identified as potential DCAs through exploration methods utilizing satellite imagery. Furthermore, drones were captured within these DCAs using an attractive pheromone attached to an unmanned aerial vehicle to assess Nosema infection in the population.

Trends in greater sage‐grouse lek counts relative to existing wind energy development in Wyoming

AbstractRapid increases in wind energy development globally highlight the need to evaluate how electricity generation may impact wildlife. The greater sage‐grouse (Centrocercus urophasianus; hereafter, sage‐grouse) has experienced range‐wide population declines, primarily due to habitat loss and degradation. Studies have documented a negative association between oil and gas development and sage‐grouse populations. However, potential sage‐grouse population declines associated with wind energy development have not been adequately addressed. We investigated the relationship between wind energy infrastructure and changes in male sage‐grouse counted on leks from 2000–2020 in Wyoming, USA, using Bayesian state‐space models. Our study was conducted in central and southwest Wyoming in the vicinity of 10 wind energy facilities that were in proximity to sage‐grouse leks occurring outside of Wyoming's Core Areas (i.e., areas of high breeding densities of sage‐grouse designated for restricted development by the State of Wyoming) and dominated by big sagebrush (Artemisia spp.) communities. Facilities became operational between 1998 and 2010 and had an average of 67 turbines. Covariates describing wind energy infrastructure included distance to the nearest wind turbine, and the number and distribution (clustering) of turbines within 1.0, 2.0, 4.0, 6.0, 8.0, and 10.0 km. We also explored whether males attending leks exhibited lagged responses of 1–7 years following development. We used counts from 78 leks located within 15 km of the 10 wind energy facilities, consisting of 288 counts before and 845 counts after development. We expected that trends in male lek attendance would experience a delayed negative response following wind energy development like other forms of anthropogenic features. However, we failed to detect a relationship between male sage‐grouse lek attendance and proximity to, density of, or distribution of wind turbines following development in all models. Our findings were based on the average lek in our analysis being 6.5 km from a wind turbine and most turbines were clustered such that undisturbed habitat surrounding leks remained. Therefore, interpretation of our results should be restricted to siting practices of the facilities that we evaluated because direct habitat removal and fragmentation resulting from any form of energy development is unlikely to benefit sage‐grouse populations. Our study evaluated the response of low‐density, peripheral populations of sage‐grouse to wind energy development outside or near the edge of Core Areas. As such, our results should not be extrapolated to higher density sage‐grouse populations occurring in Core Areas.

Thermoregulatory behavior of lekking male desert locusts, Schistocerca gregaria, in the Sahara Desert

Most terrestrial animals are constrained by extreme heat conditions such as midday desert environments, while a few terrestrial ectothermic insects are active in such ecological niches. Sexually mature males of the desert locust (Schistocerca gregaria) in the Sahara Desert remain on the open ground, despite the ground temperatures exceeding their lethal limit, to form leks and to mate incoming gravid females during the daytime. Lekking male locusts apparently suffer from extreme heat stress and greatly fluctuating thermal conditions. The present study examined the thermoregulatory strategies of the lekking male S. gregaria. Our field observations showed that lekking males changed their body orientation toward the sun depending on the temperature and time of day. In the relatively cool morning, males basked by orienting perpendicular to the sun's rays, maximizing the area of body surface exposed to the sun's rays. In contrast, around midday, when the ground surface temperature exceeded lethal high temperatures, some males tended to shelter inside the plants or remain in the shade. However, the remainder stayed on the ground, stilted (i.e., extending their legs to raise their bodies off the hot ground) and oriented parallel to the sun's rays, which minimized radiative heating. Measurements of body temperature throughout the hot middle period of the day confirmed that the stilting posture prevented overheating. Their critical lethal body temperature was as high as 54.7 °C. In this lekking system, gravid females enter male leks by flying. These incoming females usually landed on open ground, whereupon nearby males immediately approached, mounted, and mated the female, implying that males with greater heat-tolerance can increase mating chance. These results suggest that behavioral thermoregulation and physiologically high heat tolerance of male desert locusts allows them to endure extreme thermal conditions for lekking.

Assessing lek attendance of male greater sage‐grouse using fine‐resolution GPS data: Implications for population monitoring of lek mating grouse

AbstractCounts of males displaying on breeding grounds are the primary management tool used to assess population trends in lekking grouse species. Despite the importance of male lek attendance (i.e., proportion of males on leks available for detection) influencing lek counts, patterns of within season and between season variability in attendance rates are not well understood. We used high‐frequency global positioning system (GPS) telemetry data from male greater sage‐grouse (Centrocercus urophasianus; n = 67) over five lekking seasons (2013–2017) at eight study sites in Nevada to estimate lek attendance rates. Specifically, we recorded daily locations of sage‐grouse in relation to mapped lek boundaries and used generalized additive models to assess temporal variation in attendance rates by age class (subadult vs. adult). Average timing of peak attendance occurred on 16 April but varied from March 16, 2014 to April 21 , 2016. Overall, adult males attended leks at higher rates (0.683 at peak) and earlier in the season (19 March) than subadults (0.421 at peak on April 19). Peak attendance probability was positively related to cumulative winter precipitation. Daily probabilities of lek switching differed between adults (0.019 at peak on March 3) and subadults (0.046 at peak on March 22), and lek switching was negatively related to distance to nearest lek. Our results indicate variable patterns in lek attendance through time, and that lek switching may occur at higher rates than previously thought. We demonstrate the use of generalizable daily attendance curves to date‐correct lek counts and derive estimates of male abundance, although such an approach will likely require the incorporation of information on age structure to produce robust results that are useful for population monitoring.

Erratum to: Effectiveness of Wyoming's Sage-Grouse Core Areas: Influences on Energy Development and Male Lek Attendance.

Greater sage-grouse (Centrocercus urophasianus) populations have declined across their range due to human-assisted factors driving large-scale habitat change. In response, the state of Wyoming implemented the Sage-grouse Executive Order protection policy in 2008 as a voluntary regulatory mechanism to minimize anthropogenic disturbance within defined sage-grouse core population areas. Our objectives were to evaluate areas designated as Sage-grouse Executive Order Core Areas on: (1) oil and gas well pad development, and (2) peak male lek attendance in core and non-core sage-grouse populations. We conducted our evaluations at statewide and Western Association of Fish and Wildlife Agencies management zone (MZ I and MZ II) scales. We used Analysis of Covariance modeling to evaluate change in well pad development from 1986–2014 and peak male lek attendance from 958 leks with consistent lek counts within increasing (1996–2006) and decreasing (2006–2013) timeframes for Core and non-core sage-grouse populations. Oil and gas well pad development was restricted in Core Areas. Trends in peak male sage-grouse lek attendance were greater in Core Areas compared to non-core areas at the statewide scale and in MZ II, but not in MZ I, during population increase. Trends in peak male lek attendance did not differ statistically between Core and non-core population areas statewide, in MZ I, or MZ II during population decrease. Our results provide support for the effectiveness of Core Areas in maintaining sage-grouse populations in Wyoming, but also indicate the need for increased conservation actions to improve sage-grouse population response in MZ.

Greater sage‐grouse male lek counts relative to a wind energy development

ABSTRACTWind energy development is an emerging source of anthropogenic disturbance that could affect greater sage‐grouse (Centrocercus urophasianus; sage‐grouse) populations. Our objective was to determine the response of male sage‐grouse attending leks (lek counts) to wind energy development using a before/after–control/treatment study design. We counted males attending each lek within control and treatment areas annually and analyzed peak numbers. We obtained lek count data from 5 treatment and 9 control leks over an 11‐year period. We estimated trends in lek counts pre‐ (2006–2008) and postdevelopment (2009–2016) using a generalized linear mixed negative binomial model. We considered time lags at which the effect of the wind energy development was realized by the male breeding population. Although all lek counts were apparently in decline prior to development and trends on the control and treatment area changed during postdevelopment, we found no negative differences in the relative trends in lek counts between control and treatment areas between pre‐ and postdevelopment periods. We detected a 56% drop in lek counts at treatment leks relative to control leks assuming the effect of the wind energy development was realized between 2010 and 2011 (i.e., 3 yr postdevelopment). Use of a posteriori power analysis estimated similar data sets would have 80% probability of detecting a 28% decrease in the rate of decline of lek counts at treatment leks relative to control leks after development. Our findings suggest males attending leks in close proximity to wind energy development may respond differently compared with leks in close proximity to other forms of anthropogenic features, adding to a growing body of literature regarding the potential effects of energy development on prairie grouse. We recommend additional research and an abundance of caution in designating buffer sizes <1.5 km to avoid measurable effects from wind energy development on males attending leks. © 2017 The Wildlife Society.

Effectiveness of Wyoming's Sage-Grouse Core Areas: Influences on Energy Development and Male Lek Attendance.

Greater sage-grouse (Centrocercus urophasianus) populations have declined across their range due to human-assisted factors driving large-scale habitat change. In response, the state of Wyoming implemented the Sage-grouse Executive Order protection policy in 2008 as a voluntary regulatory mechanism to minimize anthropogenic disturbance within defined sage-grouse core population areas. Our objectives were to evaluate areas designated as Sage-grouse Executive Order Core Areas on: (1) oil and gas well pad development, and (2) peak male lek attendance in core and non-core sage-grouse populations. We conducted our evaluations at statewide and Western Association of Fish and Wildlife Agencies management zone (MZ I and MZ II) scales. We used Analysis of Covariance modeling to evaluate change in well pad development from 1986-2014 and peak male lek attendance from 958 leks with consistent lek counts within increasing (1996-2006) and decreasing (2006-2013) timeframes for Core and non-core sage-grouse populations. Oil and gas well pad development was restricted in Core Areas. Trends in peak male sage-grouse lek attendance were greater in Core Areas compared to non-core areas at the statewide scale and in MZ II, but not in MZ I, during population increase. Trends in peak male lek attendance did not differ statistically between Core and non-core population areas statewide, in MZ I, or MZ II during population decrease. Our results provide support for the effectiveness of Core Areas in maintaining sage-grouse populations in Wyoming, but also indicate the need for increased conservation actions to improve sage-grouse population response in MZ I.

Investigating impacts of oil and gas development on greater sage‐grouse

ABSTRACTThe sagebrush (Artemisia spp.) ecosystem is one of the largest ecosystems in western North America providing habitat for species found nowhere else. Sagebrush habitats have experienced dramatic declines since the 1950s, mostly due to anthropogenic disturbances. The greater sage‐grouse (Centrocercus urophasianus) is a sagebrush‐obligate species that has experienced population declines over the last several decades, which are attributed to a variety of disturbances including the more recent threat of oil and gas development. We developed a hierarchical, Bayesian state‐space model to investigate the impacts of 2 measures of oil and gas development, and environmental and habitat conditions, on sage‐grouse populations in Wyoming, USA using male lek counts from 1984 to 2008. Lek attendance of male sage‐grouse declined by approximately 2.5%/year and was negatively related to oil and gas well density. We found little support for the influence of sagebrush cover and precipitation on changes in lek counts. Our results support those of other studies reporting negative impacts of oil and gas development on sage‐grouse populations and our modeling approach allowed us to make inference to a longer time scale and larger spatial extent than in previous studies. In addition to sage‐grouse, development may also negatively affect other sagebrush‐obligate species, and active management of sagebrush habitats may be necessary to maintain some species. © 2016 The Wildlife Society.

Evaluating forest management intensity on an umbrella species: Capercaillie persistence in central Europe

Deforestation and fragmentation of forests worldwide are negatively impacting biodiversity. The capercaillie (Tetrao urogallus) is an endangered umbrella species of montane forests in central Europe. Despite its status, it has largely been overlooked in forest management planning in the Carpathian Mountains, a biodiversity hotspot within the European Union. Previous investigations of timber management effects on capercaillie have shown contradictory results within Europe; habitat loss and fragmentation due to intensive forest management have been implicated in population declines, while other studies have suggested neutral or positive effects. In Romania, recent changes in forest management have shifted from extensive, selective logging to intensive clearcutting; this change provides the opportunity to assess the effects of harvesting on capercaillie numbers across a full range of forest management intensities, thereby addressing discrepancies in the literature. Across the Southern and Eastern Carpathian mountains from 2009–2011, we used spring counts of capercaillie males at leks to evaluate the impact of forest management, other human activities, and habitat at two spatial scales – stand (∼2ha) and landscape (∼300ha). At the landscape level, the proportion of forest clearcuts and intensity of tourism had significant negative effects on the number of capercaillie males in the lek. In contrast, low intensity selective logging had a positive effect at the local stand (lek) level. Large scale (landscape level) forest clear-cutting had a negative effect on the capercaillie population – areas comprised of clearcuts of 30% reduced male lek counts by 76%. The protection of intact mature and old-growth forests, and forest management practices that emulate natural disturbance processes are recommended to support habitat of this critical umbrella species and associated biodiversity.

An integrated modeling approach to estimating Gunnison sage‐grouse population dynamics: combining index and demographic data

Evaluation of population dynamics for rare and declining species is often limited to data that are sparse and/or of poor quality. Frequently, the best data available for rare bird species are based on large-scale, population count data. These data are commonly based on sampling methods that lack consistent sampling effort, do not account for detectability, and are complicated by observer bias. For some species, short-term studies of demographic rates have been conducted as well, but the data from such studies are typically analyzed separately. To utilize the strengths and minimize the weaknesses of these two data types, we developed a novel Bayesian integrated model that links population count data and population demographic data through population growth rate (λ) for Gunnison sage-grouse (Centrocercus minimus). The long-term population index data available for Gunnison sage-grouse are annual (years 1953–2012) male lek counts. An intensive demographic study was also conducted from years 2005 to 2010. We were able to reduce the variability in expected population growth rates across time, while correcting for potential small sample size bias in the demographic data. We found the population of Gunnison sage-grouse to be variable and slightly declining over the past 16 years.

Annual male lek attendance influences count-based population indices of greater sage-grouse

Populations of greater sage-grouse (Centrocercus urophasianus) are monitored using counts of males displaying on breeding leks (lek counts). When count-based indices are used to assess population growth (λ), an implicit assumption is that detection is constant through time and space. If detection depends on breeding behavior, annual variation in the proportion of individuals that attend a breeding site may lead to a violation of this assumption. We used 8 years of banding data from male sage-grouse in eastern Nevada and capture–mark–recapture analyses to evaluate how temporary absence of males from lek sites during a given year may influence estimates of population trends derived from lek counts. We estimated the proportion of variance in annual lek count trends that corresponded with an independent estimate of λ, versus variance associated with temporary absence. The probability a male sage-grouse attended 1 of our study leks at least once in a given year ranged from a low of 0.56 (±0.22 SE) to a high of 0.87 (±0.11 SE). Variance in annual lek count trends was associated with both realized λ (semipartial R2 = 0.57), and sampling error associated with temporary absence (semipartial R2 = 0.40). We found discrepancies between lek count and realized λ in 3 out of 7 intervals, whereas estimates of λ for the entire study interval were extremely similar between count-based and capture–mark–recapture methods (λ = 0.90 ± 0.05 SE and λ = 0.91 ± 0.05 SE, respectively). Temporary absence was influenced by male density during the previous year and associated with exotic grasslands surrounding leks, although some uncertainty was associated with this latter effect. Lek counts are well suited for estimating λ across multi-year intervals, whereas annual estimates of λ should be viewed cautiously if variation in annual lek attendance is not directly incorporated. © 2013 The Wildlife Society.

Physiological costs enforce the honesty of lek display in the black grouse (Tetrao tetrix)

Females may use condition-dependent sexual traits as reliable cues of male "quality" if the costs of the expression of such traits vary with male "quality", and if there is positive genetic correlation between male traits and condition. However, there are multiple ways of measuring the changes in body condition which reflect physiological costs meaning that the multifaceted nature of the physiological costs associated with the expression of sexual traits has rarely been thoroughly examined. In the lekking black grouse (Tetrao tetrix), mating success is highly skewed towards males defending central territories and having high survival rates to the following year, but the mechanisms underpinning such superior performance remain unclear. In this study, we quantified the changes in five measures of body condition before and after the mating season and related these changes to male lek performance (fighting rate, territory centrality and mating success) to understand the physiological costs of male reproductive effort. Between the two capture sessions, male body mass decreased significantly, blood parasite counts and plasma carotenoid concentration increased substantially while the total immunoglobulin concentration tended to increase. There was no overall impairment of individual body condition as the changes in the five measures of body condition were unrelated. Male fighting rate was unrelated to changes in the condition measures but males losing more body mass defended central territories and had high mating success. Therefore, females preferring central, dominant males may select males better able to afford the energetic costs of lek performance thereby effectively enforcing the honesty of male display.

Experimental chronic noise is related to elevated fecal corticosteroid metabolites in lekking male greater Sage-Grouse (Centrocercus urophasianus).

There is increasing evidence that individuals in many species avoid areas exposed to chronic anthropogenic noise, but the impact of noise on those who remain in these habitats is unclear. One potential impact is chronic physiological stress, which can affect disease resistance, survival and reproductive success. Previous studies have found evidence of elevated stress-related hormones (glucocorticoids) in wildlife exposed to human activities, but the impacts of noise alone are difficult to separate from confounding factors. Here we used an experimental playback study to isolate the impacts of noise from industrial activity (natural gas drilling and road noise) on glucocorticoid levels in greater sage-grouse (Centrocercus urophasianus), a species of conservation concern. We non-invasively measured immunoreactive corticosterone metabolites from fecal samples (FCMs) of males on both noise-treated and control leks (display grounds) in two breeding seasons. We found strong support for an impact of noise playback on stress levels, with 16.7% higher mean FCM levels in samples from noise leks compared with samples from paired control leks. Taken together with results from a previous study finding declines in male lek attendance in response to noise playbacks, these results suggest that chronic noise pollution can cause greater sage-grouse to avoid otherwise suitable habitat, and can cause elevated stress levels in the birds who remain in noisy areas.

The anatomy of population change in a black grouse population 1992–2008

We interrogate an 18-year-long dataset containing counts of displaying male black grouse Tetrao tetrix and incidental counts of females within an 800-km(2) region of Perthshire, Scotland. We examine the trends in the population and investigate how different components of the population might act as signposts of different stages of overall population change. We found statistical evidence for a decline in black grouse numbers between 1992 and 2000, and then a recovery from 2002 to 2008, but little evidence for a link between population change and weather during the decline phase. There was some evidence for a positive relationship between male and female counts. The two main components of male population size, lek size and lek frequency followed the overall population trend while it was increasing, but during the earlier decline, the two became uncoupled, to expose a complex structure within the data. During the decline, when black grouse numbers were approaching their minimum, mean lek size was actually increasing. Small leks lost proportionally more birds than did large leks, and lek longevity was positively correlated with lek size, indicating that maintenance of large leks is crucial in buffering the population against serious declines. During the decline, the spatial arrangement of leks changed, with remnant leks showing tight clustering at larger spatial scales, before expanding out to fill the large areas of unoccupied landscape during the population increase. We discuss these findings in terms of species monitoring and suggest that counts of young males may add much useful demographic information with little extra effort.

Experimental evidence of host race formation inMitourabutterflies (Lepidoptera: Lycaenidae)

A population of herbivorous insects that shifts to a novel host can experience selection pressures that result in adaptation to the new resource. Host race formation, considered an early stage of the speciation process, may result. The current study investigates host shifts and variation in traits potentially involved in the evolution of reproductive isolation among populations of the juniper hairstreak butterfly,Mitoura gryneus. Mitouraare closely associated with their host trees (Cupressaceae) and exhibit host plant fidelity: in addition to larval development and oviposition, host trees support male leks and mating. Female oviposition preference for the natal host, and differential fitness of larvae when reared on natal versus alternate hosts, are indications that specialization and local adaptation to the natal host plant are occurring. Populations with single host plant associations (Juniperus ashei,J. pinchotiiandJ. virginiana) as well as populations with multiple hosts (bothJ. asheiandJ. pinchotii) were examined. Concordance between female preference and larval performance was found forJ. ashei‐associated populations. Population‐level variation in the patterns of female preference and larval performance, both within and among host associations, may reflect differences in the timing and direction of colonization of hosts. For a single nominal species that otherwise exhibits no morphological or phenological differences, the experimental assessment of specialization and host fidelity inM. gryneusprovides strong support for the hypothesis of ongoing host race formation in these butterflies.

Sharp-tailed grouse lek attendance and fidelity in upper Michigan

To assess and improve existing monitoring protocols for sharp-tailed grouse (Tympanuchus phasianellus) in the eastern Upper Peninsula of Michigan, we used data from 58 radio-collared grouse (46 M, 12 F) monitored within 3 openland landscape types: a xeric, conifer-dominated site, a wetland-dominated site, and a site dominated by low-intensity agriculture. We used lek counts and radio telemetry to determine lek attendance rates, factors affecting lek attendance rates, lek fidelity, and inter-sexual variation in these parameters. Our analysis indicated lek attendance varied with respect to sex of bird, day of year, time after sunrise, and wind speed. Peak male lek attendance rates exceeded those of females by up to 40%, and peak lekking activity for both males and females occurred during the second and third weeks of April. Male lekking activity occurred earlier and was sustained longer than that of females. Lekking activity was negatively related to time of day and wind speed. We observed strong lek fidelity as radio-collared birds attended a primary lek 94% of the time, indicating a low probability of multiple counting of individual birds. We also proposed a method to adjust lek count data for the probability that birds are on a lek during lek counts. Our proposed method can be used by researchers and managers to improve estimates of the number of birds attending a lek by reducing the negative bias associated with observed counts. © 2011 The Wildlife Society.

Thresholds and Time Lags in Effects of Energy Development on Greater Sage‐Grouse Populations

ABSTRACT Rapid expansion of energy development in some portions of the Intermountain West, USA, has prompted concern regarding impacts to declining greater sage‐grouse (Centrocercus urophasianus) populations. We used retrospective analyses of public data to explicitly investigate potential thresholds in the relationship between lek attendance by male greater sage‐grouse, the presence of oil or gas wells near leks (surface occupancy), and landscape‐level density of well pads. We used generalized linear models and generalized estimating equations to analyze data on peak male attendance at 704 leks over 12 years in Wyoming, USA. Within this framework we also tested for time‐lag effects between development activity and changes in lek attendance. Surface occupancy of oil or gas wells adjacent to leks was negatively associated with male lek attendance in 5 of 7 study areas. For example, leks that had ≥ 1 oil or gas well within a 0.4‐km (0.25‐mile) radius encircling the lek had 35–91% fewer attending males than leks with no well within this radius. In 2 of these 5 study areas, negative effects of well surface occupancy were present out to 4.8 km, the largest radius we investigated. Declining lek attendance was also associated with a higher landscape‐level density of well pads; lek attendance at well‐pad densities of 1.54 well pads/km2 (4 well pads/mile2) ranged from 13% to 74% lower than attendance at unimpacted leks (leks with zero well pads within 8.5 km). Lek attendance at a well‐pad density of 3.09 well pads/km2 (8 well pads/mile2) ranged from 77% to 79% lower than attendance at leks with no well pad within 8.5 km. Further, our analysis of time‐lag effects suggested that there is a delay of 2–10 years between activity associated with energy development and its measurable effects on lek attendance. These results offer new information for consideration by land managers on spatial and temporal associations between human activity and lek attendance in sage‐grouse, and suggest that regional variation is an important consideration in refining existing management strategies.

English

The direct and indirect impacts of energy development on prairie grouse have been an increasing concern for scientists and land managers. The need to better understand impacts and develop appropriate mitigation measures has led to studies designed to identify specific and cumulative effects of oil and natural gas development on grouse populations and habitats. The purpose of this review is to summarize current knowledge on the effects of oil and gas development and production on prairie grouse based on publications that report empirical evidence about these impacts. It is important to understand the design of each study including use of control and treatment areas, sample sizes, and other factors to assess the strength of inference. Consequently, in addition to reporting general findings, I also provide an evaluation of study design and rigor. Reviewed studies were designed as (i) observational studies, where radio-marked birds were used to assess parameters of interest such as survival and nest success relative to impacts from oil and gas development or (ii) correlative studies evaluating cause and effect relationships such as lek counts and habitat selection in relation to development infrastructure such as well pad or road densities. Most of the currently available information on impacts is focused on lek abandonment and changes in male lek attendance. Fewer studies have examined nest success, nest initiation, survival, other vital rates, or habitat selection. The mechanistic properties of disturbances are not well understood as they relate to oil and gas development and prairie grouse. Based on this literature review, it is suggested that there is a need for further research to more clearly elucidate impacts of oil and gas development on prairie grouse to provide suitable mitigation actions to offset these impacts.

Influence of methoprene and dietary protein on male Anastrepha suspensa (Diptera:Tephritidae) mating aggregations

The Caribbean fruit fly, Anastrepha suspensa (Loew), like many polyphagous tephritids, exhibits a lek polygyny mating system, and juvenile hormone levels and adult diet are known to have important positive effects on male sexual success. Among the potential components of this success are male lek tenure and female response to the sexual signals of lekking males. Male A. suspensa where submitted to four different treatments: (M +P +) application of juvenile hormone analog, methoprene (M) and sugar and hydrolyzed yeast as adult food; (M +P −) application of M and sugar as adult food; (M −P +) no application of M and sugar and hydrolyzed yeast as adult food; and (M −P −) no application of M and sugar as adult food. M +P + males initiated and participated more in aggregations, mated more frequently, and occupied the lek centers more often. They also had fewer unsuccessful mounting attempts than males in all the other treatments. M +P + males also emitted pheromones and acoustically signaled more often and attracted more females than males in other treatments. Male sexual performance was improved due to methoprene, protein supply, and the interaction of methoprene and protein for most of the parameters. Since the success of the sterile insect technique (SIT), a commonly employed technique to control pest tephritids, requires the release of males that can form leks, engage in agonistic sexual interactions, and attract females, these positive effects of protein and methoprene may substantially improve SIT programs.

Lek area characteristics of capercaillie (Tetrao urogallus) in eastern Finland as analysed from satellite-based forest inventory data

Lek area characteristics of capercaillie were studied in eastern Finland. Lekking site data of 42 leks were collected in spring 2000. Satellite images and the Geographical Information System were used to divide the landscape into eight classes and described by means of circles of 11 different sizes (radius 250–4000 m) around the leks. The leks were compared with the average landscape, represented by 50 random points, and studied according to male lek attendance. Mature forests and thinning forests were more abundant and advanced seedling stands less abundant around the leks than in an average landscape. Most of these differences extended up to 750 m distance from the lek. The number of males per lek was best explained by the proportion and patch size of the thinning forests. The effects of landscape structure on the number of cocks were detectable over a wide range, but were strongest within a radius of 1–2 km. The results are discussed in relation to landscape ecology and management applications.