The hazel grouse Tetrastes bonasia is a Galliformes species of major conservation interest and threatened throughout Europe. However, little information is currently available on its sanitary status ...both in the Alps and worldwide. Considering that gastrointestinal parasites are one of the factors negatively impacting on Galliformes population dynamics, the objective of this study is to fill the gaps of knowledge on the parasite-fauna of the Alpine hazel grouse. Twenty-nine hazel grouse were collected in the French Alps during the period 1987–2019 (no samples collected during 1997–1999). All birds were searched for gastrointestinal parasites utilizing conventional parasitological techniques. Prevalence, intensity of infection and abundance (mean number of parasites) were calculated for each parasite species. In addition, parasite richness was evaluated. Forty-one percent (CI95%: 23.4–59.3) of birds harboured parasites, belonging to seven parasite species. Capillaria caudinflata was the most common with a prevalence of 27.6% (CI95%: 11.3–43.8), whereas Eimeria spp. was found with a prevalence of 10.3% (CI95%: 0–21.4). For both parasites, the majority of the infected animals show low parasite load. A low prevalence (3.4% – CI95%: 0–10.1) was detected for Capillaria anatis, Heterakis gallinarum, Raillietina sp., Dispharynx nasuta and Trematodes. To our knowledge, this is the first report of C. anatis and D. nasuta in the hazel grouse, and in general one of the few article providing information on hazel grouse parasite community. Overall, the parasite richness was very low, with 75% of the infected birds carrying one parasite species, 17% two species and only one bird (8%) with three species. This study increases the scarce literature available on the hazel grouse parasites. The epidemiological descriptors reported are particularly useful to compare the parasite-fauna of the hazel grouse across locations and time periods.
•Factors affecting chick mortality of hazel grouse was studied in a temperate forest.•Mortality of chicks is lower in dense understory cover and natural deciduous forest.•Moreover, distance from ...forest road and overstory cover were important variables.•Understory cover and natural deciduous forest should be maintained for the species.
Between March 2006 and September 2013, hazel grouse Bonasa bonasia (35 hens and 157 chicks) were equipped with radio transmitters in a temperate forest, South Korea to document factors influencing chick mortality. We recorded habitat composition, mortality rates, and cause of death. Among 157 hazel grouse chicks, 75 survived and 58 were killed by predators. The mean spring–summer survival of chicks was 48% and mortality due to predation was 37%. According to the habitat composition analysis, natural deciduous forest was used by hazel grouse chicks significantly more often than the other forest types. The top-ranked model (r2=0.76) for hazel grouse chick mortality included understory cover, forest type, distance from the nearest forest road, and overstory cover as the dominant variables for the mortality of hazel grouse chicks. This model had an Akaike weight of 0.72, which suggests strong model certainty. This study suggests that forest managers who want to protect of hazel grouse should aim for denser understory cover and higher portions of natural deciduous forest.
The population dynamics of Hazel Grouse were studied by presence/absence recording at stationary sites along fixed routes (110 km) in the central part of Šumava (Bohemian Forest, Czech Republic) from ...1972 to 2019. The 100 km2 study area covered altitudes between 600 m (Rejštejn) and 1253 m above sea level (Mt. Sokol). Our database contained indices of Hazel Grouse occupancy: positive sites/visited sites for a yearly increasing number of Hazel Grouse occurrence sites (n = 134) for 48 years. We used a loglinear Poisson regression method to analyze the long-term population trend for Hazel Grouse in the study area. In the period from 1972 to 2006 we found a stable Hazel Grouse population (p = 0.83). From 2006–2007 to 2019, the population index dropped (−3.8% per year, p < 0.05). This decline is assumed to be influenced by habitat loss due to succession, resulting in older, more open forest stands, by strongly increasing forestry and windstorm “Kyrill”, followed by clear cutting, bark beetle damage, and the removal of pioneer trees in spruce plantations, which diminished buds and catkins, the dominant winter food of Hazel Grouse. The influence of disturbance by increasing tourist activities and/or predation is also discussed. Our results could help to optimize the conservation efforts for Hazel Grouse in the Bohemian Forest.
Habitat, climate, and human disturbances have important effects on wildlife, and these are especially critical for threatened species. In this study, we used infrared camera traps to monitor the ...population dynamics of the hazel grouse (
) from 2012 to 2021 in northeast China and explore the effects of habitat, climate, and human disturbance on their distribution. We analyzed 16 environmental variables related to significant differences between presence recordings and absence recordings within and between seasons. Temperatures and roads influenced the distribution of the hazel grouse, but topography and vegetation types did not. The hazel grouse preferred deciduous forest and oak forest from spring to autumn. This study provides ecological information to help guide the mountain habitat management of the hazel grouse in national parks.
The Hazel Grouse (Tetrastes bonasia) is considered an indicator of the naturalness and heterogeneity of the forest environment. This species occurs in various woods and forages on a variety of ...plants. The aim of this study was to verify the hypothesis that, in Norway spruce-dominated forest stands, the Hazel Grouse compensates for habitat poverty using non-forest areas and harsh topography, which deliver food resources and shelter for the birds. We compared 14 environmental and topographic variables in forest patches occupied and unoccupied by the Hazel Grouse in the Tatra Mountains (South Poland). Multivariate modelling showed that crucial factors for Hazel Grouse occurrence in spruce-dominated high-mountain forests were southern or western exposures, the presence of streams or glades and a multilayer forest structure with lower plant species richness in the undergrowth layer. Moreover, this species avoided clearcuts and depended either on wild sites (with a high share of deadwood and treefall gaps in mature stands at higher altitudes) or juvenile stands. The results of our study confirmed that gaps in forests and diverse topography could compensate the Hazel Grouse for habitat deficiency. These findings may be important for effective protection of this species in high-mountain spruce-only dominated forests.
Recent studies show that light detection and ranging (LiDAR) derived habitat variables significantly increase the performance and accuracy of species distribution models (SDMs). In particular, the ...structure of complex habitats such as forest can be accurately parametrized by an area‐wide, LiDAR‐based vegetation profile. However, evidence of specific applications of such models in real‐world conservation management still remains sparse. Here, we developed a resource selection SDM for hazel grouse (Bonasa bonasia L.) in a Swiss nature park with the aim to map habitat suitability and to inform the park management about habitat improvement measures. We used remote sensing, particularly LiDAR to derive ecologically relevant forest vegetation characteristics at the local scale and used them as predictors in an ensemble SDM approach. The predicted habitat suitability was mainly affected by local, fine grained vegetation structure. Average vegetation height, shrub density and canopy height variation contributed most to the habitat quality for hazel grouse. This clearly shows how LiDAR provides the means to develop ecologically interpretable predictor variables of forest habitat structure and that these predictors can be used to reliably map local‐scale habitat quality, indicated by high model performance scores (median AUC of 0.918). This improves spatial conservation planning, and at the same time, provides meaningful information to derive habitat improvement measures that can be implemented in the field by foresters. Hazel grouse occurrence in the park is restricted to a few highly suitable, disjunct habitat patches. Therefore, conservation management should increase the connectivity of suitable habitat with the aim to stimulate an increase and better exchange of individuals in the regional hazel grouse population. Habitat improvements can be achieved by forestry measures that regularly integrate early successional forest stages into production forests. They should contain stands with a shrub density of around 30% as well as heterogeneous stands in terms of vegetation height.
Recent studies show that LiDAR‐derived habitat variables significantly increase the performance and accuracy of species distribution models (SDMs). In particular, the structure of complex habitats such as forest can be accurately parametrized by an area‐wide, LiDAR‐based vegetation profile. However, evidence of specific applications of such models in real‐world conservation management still remains sparse. In our study, we developed a SDM for the rare hazel grouse by using LiDAR‐derived species‐specific, forest habitat parameters. The outstanding model performance suggests that small‐scale habitat suitability for hazel grouse is mainly affected by local, fine‐grained vegetation structure. Therefore, LiDAR provides the means to develop ecologically interpretable predictor variables of forest structure. They can be used to reliably map fine‐grained habitat quality at different scales. This clearly shows that regional species conservation can substantially benefit from the growing availability of airborne LiDAR data which facilitate the planning of spatially explicit habitat measures.
The population sizes and the breeding success of Finnish tetraonids have been decreasing for decades. In this study, the presence of a grouse hen with a brood in a landscape was used to indicate ...habitat‐related breeding success. We combined the locations of 938 black grouse (Tetrao tetrix), 388 capercaillie (T. urogallus), and 917 hazel grouse (Tetrastes bonasia) broods after the breeding season in mid‐August with landscape data by employing Geographic Information System and grouse data derived from the Finnish wildlife triangle censuses conducted during 1997–2004. Two large study areas with different landscape structures, northern forest‐mire area and southern cultivated area, were selected for the investigation. The presence of grouse broods was positively related to the amount of old coniferous mixed forest. Grouse broods may prefer this forest habitat because of a rich understorey cover and a rich bilberry field layer offering a diversity of insects as food. Broods had a strong positive response to the amount of forest habitat. The effect of forest fragmentation on the broods’ distribution did not increase even with decreasing forest habitat. We suggest that there are several ecological causes for the observed spatial correlations. Predation on nests and broods by generalist predators is presumably high in human‐modified open and semi‐open landscapes. Against our expectations, the effect of landscape composition on grouse broods was more marked in the northern than in the southern study area, most likely because predator populations are more food‐regulated in the north. This finding supports the alternative prey hypothesis. Further, large drained and reforested peatland mire areas had a negative impact on grouse broods in the north. In the drainage areas, decreased availability of vegetation cover and insect food, increased predation risk, and drowning of chicks in ditches may increase brood mortality.
► Nest survival of hazel grouse were studied in southern edge of their distribution. ► Understory cover and natural deciduous forest were important factors influencing hazel grouse nesting. ► ...Understory cover and natural deciduous forest should be considered in forest management for conservation of hazel grouse.
The survival of 86 clutches laid by hazel grouse Bonasa bonasia hens was studied using radio telemetry to evaluate the importance of key vegetation variables for nest survival between March 2003 and June 2009 in a 3000ha study area of temperate forest in South Korea. The nest sites in the forest stands differed from that in the study area with dense understory cover and low visibility. Daily nest survival rates increased with understory cover, higher proportion of natural deciduous forest, and decreased with nest conspicuousness. Nest survival rates were not correlated with tree density, basal area, mid-story cover, and overstory cover. The results did not reveal any differences in the daily nest survival rate between first breeders and older hens. Habitat management that protects the remaining understory cover and natural deciduous forest is key to stabilizing threatened hazel grouse populations in temperate forests.
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