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Conservation genetics is based on the need to maintain genetic variation, which retains deleterious recessive mutations in a heterozygous state and provides adaptive potential in a changing environment. Typically, levels of variation in natural populations are assessed with neutral markers such as microsatellites. Adaptive genetic variation, however, is likely to respond to microevolutionary forces (mutation, natural selection and random genetic drift) in a different way. Hence we need to study the relationship between neutral microsatellite markers and genes of adaptive significance. We present simple models that illustrate the difficulty of inferring levels of adaptive genetic variation from molecular markers, and hence evolutionary potential and fitness from microsatellite markers.
Major histocompatibility complex (MHC) variation at the class IIβ (B-LB) gene was surveyed both within and among populations of red grouse Lagopus lagopus scoticus from northeastern Scotland. Variation among individuals was assayed by direct DNA sequencing, with 13 unique alleles being resolved among 10 unrelated individuals. All nucleotide substitutions were non-synonymous (amino acid changing) substitutions. Variation among five populations was screened using single stranded conformational polymorphism (SSCP). Twelve B-LB alleles were resolved, with low levels of genetic structure between the populations. This is in contrast to the considerable genetic differentiation observed among the same populations determined from microsatellite DNA analysis. Both the patterns of nucleotide substitution within individuals, and the discrepancy between MHC and microsatellite derived patterns of population genetic structure highlight that balancing selection is acting to maintain variation in the grouse MHC. The significance of MHC dynamics and diversity is discussed in the context of grouse ecology and conservation.
Genetic variation in a Chinese grouse Bonasa sewerzowi population was assessed using five microsatellite markers. The mean number of alleles and allelic richness were comparable with what has been observed in other grouse, e.g. black grouse Tetrao tetrix and capercaillie T. urogallus, populations studied with the same markers regardless of whether these populations were isolated or from within the continuous range of the respective species. However, the proportion of heterozygotes and FIS observed in Chinese grouse were more similar to isolated than to continuous grouse populations suggesting that the Chinese grouse population may show genetic signs of habitat fragmentation and relative isolation. Furthermore, demographic analyses indicated that the studied Chinese grouse population would not persist without immigration. We suggest that excess heterozygosity is a sign of a sink deme within a metapopulation system.
The aim of our study was to identify fine-scale genetic population structure of capercaillie Tetra urogallus populations in the Bavarian Alps, Germany. We studied five local populations and estimated genetic variation using 10 polymorphic microsatellite markers. We found no differences in the number of alleles per locus or the degree of heterozygosity between pairs of populations, but significant genetic variation among all populations. We detected significant genetic differentiation for pairs of populations separated by distances as short as 10 km. Genetically detected effective population sizes agreed with field data for relative population densities. Populations of peripheral study areas bordering the dairy-farming lowlands tended to show sink characteristics with immigration exceeding emigration. Our study confirmed that microsatellites have the potential to detect dispersal sources and sinks at a local scale and the results of studies like ours may help to develop improved, effective conservation plans for capercaillie.
In 1999 and 2001, we compared the population characteristics of capercaillie Tetrao urogallus, black grouse T. tetrix and hazel grouse Bonasa bonasia inside the pristine forest reserve State Natural Reserve ‘Pinezhskiy’ in northwestern Russia and in the logged forests surrounding the reserve. We also compared the abundance of mammalian predators and birds of prey. The August density of capercaillie was lower in logged forests than in the reserve (P = 0.05), but black grouse tended to be more abundant in the logged area (P = 0.08). For hazel grouse, no difference in abundance was found between the reserve and the logged area. Reproductive success of all three grouse species was generally higher in the logged area than in the reserve. A winter track survey indicated low abundance (< 1 track/10 km/24 hours) and no difference in density of small and mediumsized mammalian predators between the reserve and the logged area. The only exception was red fox Vulpes vulpes whose tracks were recorded only in the logged area. Buzzards Buteo spp. and goshawk Accipiter gentilis were the most numerous birds of prey. Goshawk tended to be more common in the reserve (P = 0.09), whereas buzzards were seen more often in the logged area (P = 0.1). Tracks of mountain hare Lepus timidus was twice as abundant in the logged forest (P = 0.02), whereas tracks of red squirrel Sciurus vulgaris was almost 10 times more numerous in the reserve (P < 0.001) than in the logged area. Judged by the remains found, the majority (72%) of grouse were killed by birds of prey. Our study suggests that reproduction of all three species of forest grouse in this region remains stable or increases following logging. We hypothesise that this may be due to the type of logging performed and to differences in the composition of predators and of prey other than grouse inside and outside the reserve.
Studies in Fennoscandia and Central Europe have shown that in spring male capercaillie establish more or less exclusive home ranges around leks. Thus, such territorial spacing behaviour might limit the number of males at leks. However, the results of our study in the Pinega Reserve, a pristine boreal forest in northwestern Russia, during the springs of 2000 and 2001 do not support this hypothesis. Home ranges of radio-collared birds (N = 11) at a lek with > 25 attending males were almost completely overlapping. The ranges of adults were of the same general size (47.5 ha) and were distributed within the same distance (ca 1 km) from the lek centre as reported elsewhere. Also, as found in other studies, yearlings and two-year olds did not have well-defined ranges; yearlings visited other leks and adults returned to the same lek and daytime ranges in successive years. The inter-lek distance between the three large leks was longer (4.0 km) than reported from smaller leks in two study areas in Norway (2.0 and 2.1 km). However, the inter-lek zone beyond the two 1 km radii of adjacent leks appeared not to be occupied by adult males attending these leks. In spite of largely overlapping ranges, adults tended to avoid each other. The mean distance between eight of 10 possible pair combinations of five males located simultaneously within their combined ranges were significantly farther apart (P < 0.05) than random pair distances. Thus, a system of hierarchical dominance may act to adjust the day-to-day positions of neighbours, but it has little effect on the number of males attending a lek.
In this paper, we report on breeding site fidelity for a small, localized population of greater sage-grouse Centrocercus urophasianus inhabiting a highly altered and fragmented landscape in north-central Washington, USA. One hundred sixteen greater sage-grouse were captured, fitted with radio transmitters and monitored during 1992–1998. Of 19 males captured as adults and nine captured as yearlings, one and four, respectively, were observed visiting two different leks. Of 78 females, 24 were observed visiting at least two leks, and eight visited at least three leks. Although the incidence of multiple lek visitation was similar to what has been reported for other regions, the average of 10.2 km distance between neighbouring leks was substantially further in north-central Washington. Average distance between a female's first nest and her renest was higher for yearlings (6.3 km) than for adults (2.0 km). Successful females moved an average of 1.6 km and unsuccessful females moved 5.2 km to nest in subsequent years. Most distances between consecutive nests were <3.0 km, but some females, including adults, moved > 20 km. These data suggest that fidelity of greater sage-grouse to nesting areas in north-central Washington is substantially lower than has been found for other populations. Although the relationship between behaviour of greater sage-grouse and regional habitat fragmentation is a possible explanation for these observations, we were not able to detect a correlation between fidelity and local habitat availability.
Anthropogenic resources related to recreational activities and tourism infrastructure may greatly affect wildlife species in the Alps. In this paper, we explore the effects of mountain tourism in the Bavarian Alps, Germany, on the spatio-temporal distribution of corvids in the post-fledging period in summer and autumn. We contrast corvid point-counts in the surroundings of 28 popular mountain huts (hut areas) with those in 22 similar areas rarely visited by humans (control areas). Carrion crows Corvus corone and magpies Pica pica were exclusively observed at huts, and jays Garrulus glarularius occurred in more hut areas than in controls. Alpine choughs Pyrrhocorax graculus, jays and nutcrackers Nucifraga caryocatactes were more numerous at huts than in control areas. Ravens Corvus corax were equally common, but like Alpine choughs, they spent more time foraging in hut than in control areas. Multivariate analyses confirmed that corvid incidence was significantly related to tourist use. However, corvids visited huts regardless of the actual numbers of humans present. Our results suggest that corvids opportunistically adjust their range use to the availability of resources offered by tourism. Mountain huts and other places frequented by humans may thus contribute to an increased carrying capacity for corvids at higher elevations. This may have major ramifications for other species that corvids prey upon or compete with. Mountain tourism in the Alps may thus conflict with conservation efforts for threatened species such as grouse (Tetraonidae).
The capercaillie Tetrao urogallus is widely accepted as a species seriously suffering from fragmentation of forests and habitat loss. Foresters as well as conservationists agree on the need and principles for maintaining viable populations, but the proposed management means often differ. The approach currently favoured by Finnish foresters is to manage capercaillie leks and their surroundings using methods that differ from those used in intensive forestry. It may be desirable to prove that forests with capercaillie leks also favour other forest bird species and biodiversity in general. During the last 16 years (1987–2002), forest birds have been censused and capercaillie leks were mapped in the 465-km2 study area in southern Finland. Most of the study area consists of spruce-dominated mature forests. The remainder of the landscape is a mixture of variously aged forests, agricultural areas, lakes and scattered human settlements with a gradient from an agricultural-forest mosaic to forest-dominated areas. The old-growth forest bird species three-toed woodpecker Picoides tridactylus, pygmy owl Glaucidium passerinum and red-breasted flycatcher Ficedula parva were more abundant within 300 m and 1,000 m radii around capercaillie lek sites than in non-lek control sites. Also the overall species richness of breeding forest birds was higher in the vicinity of capercaillie leks. On a larger scale (100 × 100 km squares), using the wildlife triangle scheme developed in Finland, we show that the density of capercaillie closely coincides with a wildlife richness index describing the total abundance of 15 other forest-dwelling mammal and bird species with diverse ecology and habitat requirements. Capercaillie is a flagship species for foresters, and can be considered a good candidate for an umbrella species for wildlife in taiga forests.
We assessed sex ratio, annual survival rates and patterns of seasonal mortality of female and male willow ptarmigan Lagopus lagopus in northwestern British Columbia. Annual sex ratio of birds on the breeding area did not statistically differ from a 1:1 ratio over eight years, although in six of the eight years males were more numerous. Over eight years, annual survival, based on return rates of banded birds, was 41–63% for males and 30–54% for females. We analysed seasonal patterns of mortality using radio-tagged birds. During four springs and summers, female survival varied from 74 to 97%. They suffered the highest mortality during late prelaying, incubation and pre-fledging brood rearing periods, and most were killed by raptors. Broodless females survived better (100%) than females accompanied by broods (77%). No radio-tagged males died during two breeding seasons. Survival for both sexes was lower in autumn/winter (40–60%) than in spring/summer (75–100%). In autumn, the highest mortality for both sexes occurred during the late brood rearing and winter moult periods, coinciding with the autumn raptor migration. Both sexes had similar mortality rates over winter, despite separating by habitat. Another peak in male mortality occurred in late winter/early spring during the period of transient territoriality, whereas no females were killed during this time. From 1.4 to 3 times as many males as females were killed by hunters. Higher mortality of males during the hunting season and in late winter may balance the higher mortality of females during the breeding season, resulting in a breeding sex ratio that is close to unity.
From mid-March through mid-August 1998–2000, we studied greater sage-grouse Centrocercus urophasianus nesting habitat in northeastern California, USA. We located nest sites of 45 radio-marked hens, which had an average nest success of 40.2%. The radio-marked grouse used low sagebrush Artemisia arbuscula cover type less than expected; big sagebrush A. tridentata wyomingensis and mixed shrub cover types were used in proportion to their availability. Grouse used sites with habitat characteristics similar to random sites for nesting. However, successful nests differed from unsuccessful nests in several respects. Mean distance between nest and lek was greater for successful nests ( = 3,588 m, SE = 811 m, N = 20) than for unsuccessful nests ( = 1,964 m, SE = 386 m, N = 20). Rock cover was greater at successful nests ( = 27.7%, SE = 4.6%) than at unsuccessful nests ( = 14.49%, SE = 3.04%). Total shrub height was greater at successful nests ( = 65.5 cm, SE = 4.7) than at unsuccessful nests ( = 49.2 cm, SE = 1.7). The height of visual obstruction was greater at successful nests ( = 40.2 cm, SE = 2.6) than at unsuccessful nests ( = 32.5 cm, SE = 2.0). Our results suggest that sage-grouse use more diverse vegetation than previously reported, and we conclude that either this represents a natural behaviour for sage-grouse in this area, or we observed a selection response to a landscape altered by human activity.
We investigated the response of greater sage-grouse Centrocercus urophasianus populations to different levels of exploitation. From 1995 through 2002 we monitored breeding populations in areas closed to hunting, open to limited hunting (1-bird daily bag limit; 7-day season), and open to moderate hunting (2-bird daily bag limit; 23-day season). We used three approaches to assess the effects of hunting on sage-grouse populations. Results were consistent regardless of the method used and indicated that overall, areas closed to hunting had greater rates of increase for breeding populations than areas open to hunting (P = 0.018). Limited or moderate rates of exploitation apparently slowed population recovery for sage-grouse. These effects may have been more pronounced for grouse occupying relatively xeric habitats close to human population centers or highly fragmented habitats. Our results suggest that hunting seasons for sage-grouse should generally be conservative and reflect both sage-grouse population trend and quality of habitat occupied by the population.
We conducted a 3-year study of helminth parasites to assess their effect on the lesser prairie-chicken Tympanuchus pallidicinctus. Helminth parasites were found in most of the examined wild prairie chicken carcasses: 95% had eye worm Oxyspirura petrowi, 92% had stomach worm Tetrameres sp., and 59% had caecal worm Subulura sp. Few parasite burdens or incidences of infection were related to prairie chicken body mass, gender, age or season of collection. Droppings from transmitter-equipped prairie chickens were examined for parasite eggs and the data were used to determine which free-ranging prairie chickens harboured parasites. Telemetry data from 46 heavily parasitized and 52 lightly parasitized or parasite-free prairie chickens indicated no difference between mean daily movements, monthly home ranges, clutch sizes, nest success or survival. No adverse impacts were evident in the lesser prairie-chicken population from the incidences or burdens of the helminth parasites found in our study.
We radio-marked 56 ruffed grouse Bonasa umbellus in northern Minnesota, USA, during 1963–1965 and 2001–2002. Of these, we estimated the daily survival rate of 49 individuals (32 females and 17 males; of which 27 were grey phase and 22 were red phase) during the breeding and non-breeding seasons. We investigated whether daily survival varied by age, colour phase, gender, season and transmitter type. A model representing an interaction between colour phase and season fit the data best (AICc = 154.760) and was 77% more likely than any of our other a priori models. Daily survival rates were identical during the breeding season (0.998; SE = 0.002 for both colour phases), but higher for red-phased (0.994; SE = 0.003) than for grey-phased (0.980; SE = 0.007) birds during the non-breeding season. The daily estimate of grouse survival pooled across all individuals and seasons was 0.994 (SE = 0.002), which yielded an annual survival probability of 0.111 (SE = 0.082). The estimated annual survival rate was 0.010 (SE = 0.132) for grey-phased birds and 0.206 (SE = 0.146) for red-phased birds. There was no difference in survival rates between the two study periods. Our estimated annual survival rates were similar to other rates reported for ruffed grouse.
By use of radio-tracking, we studied hazel grouse Bonasa bonasia in the southeastern French Alps from 1998 to 2002. The Kaplan-Meier annual survival rate of adult males (N = 41) was 0.72 (95% C.I.: 0.59 - 0.85), and 0.60 for adult females (N = 15; 95% C.I.: 0.40 - 0.91). For juveniles (sexes combined; N = 29) the survival over nine months (15 September-15 June) was 0.74 (95% C.I.: 0.58–0.90). The seasonal pattern of survival was different for the two sexes. Adult male survival during November-April (S = 0.76; N = 38) was lower than during May-October (S = 0.95; N = 41). Only three of 16 male deaths (ages combined) occurred in summer. Female survival (ages combined) during November-April (S = 0.90; N = 16) was higher than during May-October (S = 0.70; N = 16). Five of six females died between May and July, i.e. during egg laying, incubation or brood rearing. Raptors, red foxes Vulpes vulpes or pine martens Martes martes accounted for most mortality of adults. The estimated annual survival rates were high compared to those reported for more northern populations, and the difference may be due to an extensive, dense and well-structured habitat that reduces the ability of raptors to kill hazel grouse. The high survival rates may explain the range expansion currently occurring in the southeastern French Alps.
Winter flock size, food abundance and habitat variables were determined for hazel grouse Bonasa bonasia vicinitas near the southern edge of the species' range in South Korea. Most of the hazel grouse formed sexually mixed flocks with a mean flock size of 4.21 ± 0.87 (SD) in winter. Understory coverage was higher at foraging sites than at random sites. Group size was inversely correlated with understory coverage, and hazel grouse foraging alone used sites with more cover than hazel grouse foraging in flocks in both mixed forest and coniferous plantations. Groups were larger in forests with less understory coverage, but larger groups were also found at sites with more food. The winter diet of hazel grouse was mainly buds and catkins of trees in the genera Salix, Betula and Almts.
The occurrence of hazel grouse Bonasa bonasia in forest patches in a heavily human-impacted landscape with a matrix dominated by agricultural fields in northeastern China was documented four times during autumn and spring 2000–2002. The occurrence of hazel grouse in fragmented landscapes in Europe is influenced by patch isolation, size and composition. In China, we found that patch composition and size, and their interaction, best explained the pattern of hazel grouse occurrence, with a greater probability that grouse were found in larger patches with more deciduous trees. In contrast to results from Europe, isolation distance was not an important explanatory variable. In addition, hazel grouse in China used patches with a higher deciduous component. Thus, although still vulnerable to habitat fragmentation, Asian hazel grouse seem to be less vulnerable than European hazel grouse. One reason may be that Asian hazel grouse are adapted to more open, deciduous-dominated habitats and form flocks in winter, which may allow them to move more freely over open habitats to forest patches. Continued habitat fragmentation and the planting of small forest patches to coniferous-dominated forest are detrimental to hazel grouse in the study area. Future plantings should contain more deciduous trees and consideration to the landscape effects reported here should be given.
In this study, the distribution of and principal threats to Caucasian black grouse Tetrao mlokosiewiczi in the Eastern Karadeniz Mountains, Turkey, are examined. A total of 36 observation sites was selected in such a way as to represent the whole range of the study area. Observations were carried out from May 1993 to July 2002. The results show that the Caucasian black grouse is present in the Eastern Karadeniz Mountain from Salarut Yayla in the Ziyaret Mountains in the west to Çukunet Yayla in the Kariçal Mountains in the east. Principal threats to the species were determined to be habitat degradation, habitat loss and fragmentation (e.g. intensive forestry practices, wood smuggling, road construction, mountain summer house (yayla) construction, fuel-wood utilization of shrubs, intensive and extensive grazing and hay production), small population size, poaching, egg collection, fox predation and outdoor activities.
A principal focus of ecological research should be to learn the influence of scale on ecological processes and to determine appropriate spatial and temporal scales with which to study the problem of interest. To date, little attention has been given to scale issues in grouse research, and we conclude that this is a major weakness. The problem affects not only our interpretations of individual events and processes, but also our interpretation of relative effects of various factors and processes, which likely act at different scales. Investigators should provide evidence for the choices made for the scale of resolution/grain used in field studies and analyses, and should conduct analyses at multiple scales. The current research problem also hinders the quality of forecasts that can be made about management interventions. To help illustrate the effect that scale of resolution can have upon research results, we provide two examples on grouse, one temporal and the other spatial.
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