Black Grouse Research Articles

Black grouse (Lyrurus tetrix) population status, reasons for decline and potential conservation measures from Western and Central Europe to Fennoscandia: a literature review

The long-term decline of the black grouse population throughout Europe is influenced by many factors that affect populations differently depending on the distribution range, from Central Europe to the Scandinavian countries. Therefore, we analyzed available literature sources to describe the main reasons for the population decline of this species and to suggest conservation measures. In total, 228 pieces of literature from 1955 to 2024 were analyzed for this study. Based on the literature analysis, it is clear that the drivers of population decline differ across the distributional range. In Central Europe, where the population is declining rapidly, habitat loss and forest fragmentation are crucial factors, as is the negative impact of tourism. In Scandinavia, where the population is gradually declining, decreasing breeding success and increasing chick mortality rates are generally considered the main negative factors. However, these factors also affect black grouse populations in Central Europe. It is crucial to acknowledge that a significant proportion of the contributing factors, such as predation and habitat loss, can be attributed to human activities. Therefore, it is necessary to emphasize that environmental protection should work hand in hand with wildlife managers to improve the situation.

Eurasian Goshawk nesting in relation to prey numbers in Telemark, southern Norway

Cover photo: Eurasian Goshawk Accipiter gentilis eating a Hooded Crow Corvus cornix. Photo: Kjetil Salomonsen. In southern Norway, the breeding density of Eurasian Goshawk Accipiter gentilis has typically ranged between 2–4 pairs per 100 km2. However, not all territorial pairs attempt to nest each year. In a ca. 2000 km2 forest-dominated study area in central parts of Telemark County, the highest number of nesting attempts recorded per year during 1991–2022 was 46, and the highest number of successful nesting attempts was 40. The nesting success of Goshawks increased with age and was 66.7% for juveniles (n = 12), 79.3% for subadults (n = 82) and 89.4% for adult females (n = 736). The annual proportion of young Goshawk females (juveniles and subadults) depended on the annual proportion of recorded replacements of old females and was positively related to mean temperatures in April. The annual proportion of recorded substitutions was positively correlated with population indices of several important prey species, particularly forest grouse, and without a time-lag. In a multiple regression model, the relative change in the recorded number of Goshawk nesting attempts, compared to the previous year, was positively correlated with a population index for thrush spp. and a combined index for Wood Pigeon Columba palumbus and Hooded Crow Corvus cornix, without a time-lag, and with a combined index for Capercaillie Tetrao urogallus and Black Grouse Lyrurus tetrix, with a one-year time-lag. The one-year time-lag with grouse was most evident when only successful nesting attempts were considered. We conclude that the breeding densities of Goshawk in Telemark are rather stable, and we conclude that annual variation in the number of recorded nesting attempts to a large extent reflects the effects of variation in prey density on the body condition of female Goshawks.

Selenium nanoparticles affect chicken offspring's intestinal health better than other selenium sources

This study aimed to assess the effects of maternal diets containing various selenium (Se) sources on the intestinal mucosal function in the jejunum of chicken offspring. A total of 630, 18-wk-old Hy-Line Grey hens and 70 18-wk-old Hy-Line Grey breeders were randomly allocated into 7 groups, with 5 replicates in each group (18 hens and tow roosters). After 4 wk of Se depletion, the birds were fed either a nonsupplemented basal diet (control) or the same basal diet supplemented with 0.15 mg/kg selenium nanoparticles (Nano-Se), 0.30 mg/kg Nano-Se, 0.30 mg/kg selenocysteine (Sec), 0.30 mg/kg sodium selenite (SS), 0.30 mg/kg selenomethionine (SeMet), or 0.15 mg/kg Nano-Se + 0.15 mg/kg Sec, for 8 wk. Frtilized eggs were collected and incubated during the final week of the experiment. Jejunal tissues from embryonic d 18 and the hatch day were collected for analysis, and the 7-d survival rate of the offspring was recorded. Compared to the control, the maternal diet of 0.30 mg/kg Nano-Se, 0.30 mg/kg Sec, and 0.30 mg/kg SeMet significantly increased the survival of 7-day-old offspring (P < 0.05). The maternal diet supplemented with 0.30 mg/kg Nano-Se significantly increased intestinal villus height and the villus height/crypt depth ratio in chicks at embryonic d 18 and in 1-day-old (P < 0.05). The maternal diet containing 0.30 mg/kg Nano-Se and Sec increased the mRNA expression levels of tight junction proteins in 1-day-old offspring (P < 0.05). Supplemental 0.30 mg/kg Nano-Se significantly increased the mRNA expression levels of marker genes in intestinal enteroendocrine, stem, and Paneth cells (P < 0.05). In 1-day-old chicks, the number of intestinal goblet cells, as well as the mRNA expression levels of intestinal mucin2 (Muc2) and goblet cell differentiation factors (Spdef and C-myc), were the highest in diets supplemented with 0.30 mg/kg Nano-Se. Moreover, the expression levels of intestinal Muc2 and Spdef in chicks at embryonic d 18 was the highest with 0.30 mg/kg Nano-Se supplementation (P < 0.05). Supplementing with 0.30 mg/kg Nano-Se significantly reduced reactive oxygen species levels and decreased the mRNA expression levels of apoptosis-related genes in 1-day-old chicks (P < 0.05). Additionally, 0.30 mg/kg Nano-Se supplementation significantly down-regulated NLRP3 pathway gene expression in 1-day-old chicks (P < 0.05). In conclusion, maternal dietary supplementation with Nano-Se improved jejunal microarchitecture, antioxidant levels, and the expression of tight-junction protein in chicken offspring along with supporting goblet cell development by inhibiting the NLRP3 signaling pathway.

Becoming-with the bog born: emotional collectives in ecological fieldwork

AbstractFieldwork in ecology education does things. By employing Donna Haraway’s concept becoming-with companion species and Cathrine Hasse’s emotional collectives to explore fieldwork practice on a bog in Sweden, a piece of the doings will be told. The aim of this study is to explore how ecology fieldwork affords emotional engagement and facilitates growth of ecological literacy in the emotional collectives of students, teachers and nonhumans to become-with each other. The study is based on an overnight field trip with upper-secondary students experiencing black grouse lekking and the ecology of a bog. The empirical material consists of video and audio recordings. In the study, becoming-with is operationalised through the notion of emotional collectives. The result shows three orientations of becoming-with: mimetic, anthropomorphic and fact oriented. Overall, this is a story of fieldwork as a practice of producing companion species; how becoming-with companion species works in practice, how companion species come to matter as emergent ecological literacy.

Research Note: Dynamics of black grouse (Tetrao tetrix) infestation with various Eimeria species

The black grouse (Tetrao tetrix) is an endangered species facing challenges in breeding and reintroduction programs, including parasitic infestations. This study aimed to assess natural infestations by various Eimeria species and infestation dynamics in female, male, and young black grouse kept in a stationary aviary. Faecal samples were collected from adult grouses between April and the time of chicks' hatching and rearing (September). Faecal samples from young birds were collected from the hatching for a period of 1 year. The prevalence of Eimeria spp. was determined by a qualitative method (Fulleborn's flotation) and a quantitative method (McMaster's method with Raynaud's modification). The following Eimeria species were identified: E. lyruri, E. nadsoni and E. nonbrumpti. The average percentages of Eimeria spp. in the cock were 80.52%, 9.27%, and 10.21%, respectively; in the hen, they were 86.19%, 9.28%, and 4.53%, respectively; in the young black grouses they were 84.60%, 9.34% and 6.06%, respectively. The highest E. lyruri infestation was observed in the cock in June (144227 OPG) and July (129365 OPG). In the hen, the infestation intensity increased in May (304302 OPG) and then decreased in June (39583 OPG). Furthermore, an additional increase was observed in July (216533 OPG). Two increases in infestation intensity were also observed in young birds, with peaks in January (91387 OPG) and July (126178 OPG). A positive strong correlation was identified between Eimeria spp. in the cock and the young birds. A statistically significant positive correlation was identified in the hen between E. lyruri and E. nadsoni. No correlation was demonstrated between the infestation intensity and the age of the birds or season of the year in all the grouses under study. Despite some attempts, a comprehensive approach to the issue of coccidiosis in the black grouse as a disease that may affect the success of reintroduction has yet to be established. It seems crucial to monitor the level of Eimeria spp. invasion, and the proposed faecal sampling scheme is an important tool for achieving this goal.

Assessing the effects of drainage and forest structure on presence and absence of fledglings of boreal grouse

Anthropogenic factors threaten biodiversity of natural habitats globally, including boreal forest habitats of culturally important game species, such as grouse. Forestry and intense draining of wetlands have resulted in landscape fragmentation of the peatlands and the forests in terms of their structure (a mosaic of differently managed small stands), and the loss and alteration of natural grouse habitats, which impacts on fitness parameters are still partly unexamined. We used grouse brood location data from the Finnish wildlife triangle censuses from 2017 to 2020 to study how forest structure and drainage affect breeding success of four grouse species. We calculated environmental characteristics (forest and landscape structure, peatlands and their drainage status) around individual brood observations with different buffer sizes and used them to explain brood size variation and the probability of complete failure (female with no brood). While the most important buffer zones differed by species, brood sizes were generally linked to habitats that offer shelter and food. Black grouse brood size increased when the proportions of deciduous trees and xeric heath forests increased. Hazel grouse broods were largest in spruce-dominated mires and herb-rich forests. Willow grouse brood size decreased with increasing proportion of poorer barren heath forest habitat. Capercaillie brood size decreased as a function of drainage ditch length. In Capercaillie and Black grouse, females without broods were overrepresented (zero-inflation), and the zero excess was related to habitats that differed from those of brooded females. These results suggest that forest management methods and peatland drainage can have a negative effect on offspring production of boreal grouse species. Restoration of natural peatlands and less invasive management such continuous cover forestry should enhance environmental conditions for grouse.

Richard Maack's Vilyui expedition in the study of avifauna and gallinaceous birds (Gallinaceae) of Eastern Siberia

The article is dedicated to the 170th anniversary of the Vilyuisk (Yakutia) expedition organised by the Siberian (Irkutsk) branch of the Imperial Russian Geographical Society (1853-1885). It was led by Richard Karlovich Maack (Germ. Richard Otto Maack), a Russian naturalist of German origin and explorer of Siberia and the Far East. It also contains some information on the Pribaikalia and Transbaikalia, taken along the way during the subsequent Amur (1855-1856) and Ussuri (1859-1960) expeditions. The route, dates, and composition of the expedition are described and the contribution of the scientist to various fields of natural science and, above all, to the study of vertebrates of the region is evaluated. Scientists have identified the habitat of amphibians and reptiles (4 species), birds (121), mammals (34), which is relatively large against the background of regional studies conducted in Eastern Siberia at that time. According to the lists of bird species published in the fundamental work of the scientist "Vilyuisky district of the Yakut region" [1883-1887], the distribution of 5 species of Gallinaceous birds (Gallinaceae) in the middle of the XIX century was revealed – Hazel Grouse, Western and Black-billied Capercaillies, Black Grouse, Willow Ptarmigan. For Transbaikalia and Pribaikalia, the habitat of two more species is noted - Gray and Bearded Partridges. The Common Pheasant was accounted for by R. K. Maack only in the Amur region and the Amur region (Far East). In general, over the century and a half of the history of studying Gallinaceous birds, their species composition has practically not changed in the researcher's work area. In Yakutia, it was replenished with species from the eastern and southern regions, living there Rock Partridge and Siberian Grouse. On the scale of Eastern Siberia, only the Pheasant is currently supplementing the Gallinaceous birds list as a new species in the region, documented in the south of Eastern Siberia – in the Eastern Sayan bordering the Baikal region and in some places of Transbaikalia (not yet precisely confirmed).

Distribution of the black grouse, capercaillie, and hazel grouse (Tetraonidae) at the northern edge of their species range in the Nenets Autonomous Area

This paper presents data on the distribution of the black grouse Lyrurus tetrix (L., 1758), capercaillie Tetrao urogallus (L., 1758), and hazel grouse Tetrastes bonasia (L., 1758) in the Nenets Autonomous Area (the northeast of the European Russian Federation). The study has revealed trends indicating an expansion of the distribution range of these species to the north. According to our observations, black grouse, capercaillie, and hazel grouse in the Malozemelskaya Tundra are located further north than in the published data – about 40 km for black grouse, 20 km for capercaillie, and 20 km for hazel grouse. In the Malozemelskaya Tundra, the northernmost black grouse and capercaillie were found in spruce forest islands, while the hazel grouse inhabited riverine floodplain forests. In the Bolshezemelskaya Tundra, the capercaillie was the only grouse bird found further north compared to the published data, in the extremely northern islands of the forest within the Shapkina River valley. In the Bolshezemelskaya Tundra, new registrations of the grouse (200 km) and ruffed grouse (100 km) were noted to the east of the known data, indirectly indicating an expansion of the distribution area of these birds to the north in the regions adjacent to the Nenets Autonomous Area. It was noted that the trends of expansion of the range of distribution of black grouse to the north are unidirectional with positive trends in air temperature in the Nenets Autonomous Area and with the processes of gradual overgrowth of woody vegetation in treeless areas located between the forest tundra and northern spruce forest islands.

Identification of potential suitable areas and conservation priority areas for representative wild animals in the Greater and Lesser Khingan Mountains.

Species geographic distribution and conservation priority areas are important bases for insitu biodiversity conservation and conservation decision-making. In view of the urgency of endangered species protection, eight representative endangered species in the typical forest ecosystem of the Greater and Lesser Khingan Mountains were studied. Based on 1127 occurrence points and environmental data collected from 2016 to 2021, used BIOMOD2 and Zonation to reconstruct the potential distribution area and identify conservation priority areas of eight species (Tetrao parvirostris, T. tetrix, Gulo gulo, Alces alces, Martes zibellina, Moschus moschiferus, Lynx lynx, Lutra lutra). The results showed potential distribution areas for almost all species concentrated in the northern part of the Greater Khingan Mountains (GKM) and the central part of the Lesser Khingan Mountains (LKM). The potential distribution areas of each species were as follows: black-billed capercaillie, 102,623 km2; black grouse, 162,678 km2; wolverine, 63,410 km2; moose, 140,287 km2; sable, 112,254 km2; Siberian musk deer, 104,787 km2; lynx, 139,912 km2; and Eurasian otter, 49,386 km2. Conservation priority areas (CPAs) clustered in the north GKM and central LKM and totaled 220,801 km2, and only 16.94% of the CPAs were currently protected by nature reserves. We suggest that the Chinese government accelerate the integration of existing protected areas in the northern GKM and establish a larger GKM National Park based on cost-effective multi-species protection.

Unraveling the characteristic spatial scale of habitat selection for forest grouse species in the boreal landscape

The characteristic spatial scale at which species respond strongest to forest structure is unclear and species-specific and depends on the degree of landscape heterogeneity. Research often analyzes a pre-defined spatial scale when constructing species distribution models relating forest variables with occupancy patterns. This is a limitation, as forest characteristics shape the species use of habitat at multiple spatial scales. To explore the drivers of this relationship, we conducted an in-depth investigation into how scaling forest variables at biologically relevant spatial scales affects occupancy of grouse species in boreal forest. We used 4,790 grouse observations (broods and adults) collected over 39,303 stands for 15 years of four forest grouse species (capercaillie, black grouse, hazel grouse, and willow grouse) obtained from comprehensive Finnish wildlife triangle census data and forest variables obtained from Airborne Laser Scanning and satellite data originally sampled at 16 m resolution. We fitted Generalized Additive Mixed Models linking grouse presence/absence in the Finnish boreal forest with forest stand structure and composition. We estimated the effects of predictor variables aggregated at three spatial scales reflecting the species use of the landscape: local level at stand scale, home range level at 1 km radius, and regional level at 5 km radius. Multi-grain models considering forest-species relationships at multiple scales were used to evaluate whether there is a specific scale at which forest characteristics best predict local grouse occupancy. We found that that the spatial scale affected the predictive capacity of the grouse occupancy models and the characteristic scale of habitat selection was the same (i.e., stand scale) among species. Different grouse species exhibited varying optimal spatial scales for occupancy prediction. Forest structure was more important than compositional diversity in predicting grouse occupancy irrespective of the scale. A limited number of forest predictors related to availability of multi-layered vegetation and of suitable thickets explained the occupancy patterns for all the grouse species at different scales. In conclusion, modeling grouse occupancy using forest predictors at different spatial scales can inform forest managers about the scale at which the species perceive the landscape. This evidence calls for an integrated multiscale approach to habitat modelling for forest species.

Occurrence and molecular characterization of Escherichia coli strains isolated from black grouse (Lyrurus tetrix) from the Karkonosze National Park in Poland

The purpose of this study was to characterize Escherichia coli (E. coli) strains isolated from wild black grouse (Lyrurus tetrix), carried out due to the crossing of hiking trails with wild bird habitats from the Karkonosze National Park. Twenty-seven E. coli isolates were obtained from fecal samples collected during the winter months of 2017 and 2018. The strains were assigned to their relevant phylo-groups and the prevalence of virulence genes characteristic of APEC strains (irp2, astA, iss, iucD, papC, tsh, vat, cva/cvi, stx2f) was checked using PCR analysis. In addition, the phenotypic and genotypic resistance to antibiotics was determined. The entire study provided a better understanding of the potential bacteriological threat to wild birds of the Karkonosze National Park. The results showed that 55.6% of the strains belonged to phylo-group B1 (15/27), 33.3% to group B2 (9/27) and 11.1% to group D (3/27). Among the virulence genes tested, irp2 was detected in 25.9% of isolates (7/27), vat in 22.2% (6/27) and iucD in 3.7% (1/27). The tested E. coli strains showed susceptibility to most antimicrobials, only 14 (51.9%) of them were intermediate resistant or resistant to sulfamethoxazole. The presence of none of the tested genes responsible for resistance to selected antibiotics was identified. Our research indicates a low level of transfer of antimicrobial substances to the natural environment and confirms the effectiveness of the Karkonosze National Park’s activities to protect and restore black grouse habitats.

Diet Composition Explains Interannual Fluctuations in Reproductive Performance in a Lowland Golden Eagle Population

Food supply stands out as one of the most critical drivers of population demographics by limiting reproductive rates. In this study, we assessed fluctuations in diet composition and monitored various reproductive parameters over a nine-year period in a Golden Eagle population in an Eastern European peatland. The identification of 2439 prey specimens from 84 species revealed that the studied eagles primarily preyed upon birds (constituting 78.3% of prey numbers and 67.2% of prey biomass) and less on mammals (21.6% and 32.8%, respectively). Grouse emerged as the most important prey group (31% and 27%), followed by waterfowl (17%) and hares (8% and 14%). The most significant prey species, both in terms of numbers and weight, were the Black Grouse, Mountain Hare, Common Crane, and Capercaillie. The share of the Black Grouse decreased, while those of the White-fronted Goose, Roe Deer, and hares increased. The food niche, as measured by the Levins’ index, was broad (6.6), and it expanded during the study. On average, 58.3% of Golden Eagle pairs initiated breeding annually, with 69.1% successfully completing it, and 0.41 young per occupied territory were produced annually; there was pronounced interannual variation in reproductive performance. These fluctuations were associated with the shares of White-fronted Goose, Capercaillie, Mountain Hare and Roe Deer in the diet, suggesting that these species may be gaining increasing importance for the Golden Eagle, particularly following the decline of the Black Grouse.

The Abundance оf Black Grouse in Northern Eurasia

This paper presents the estimate results of the average annual abundance of black grouse (Lyrurus tetrix L., 1758), made on the material of data bank (ISEA SB RAS) for groups of physico-geographical countries within the borders of the USSR 1990. On the East European and West Siberian plains, value of grouse abundance and total number were calculated on average separately for the first and second half of summer and in winter, mainly from 1960 to 2020, for physicogeographical countries – only for the first half of summer. The under-accounting of birds was revealed in the second half of summer on the both plains territory, which was made up with the help of additional calculations. As a result, value of the abundance and total number of birds were obtained for natural zones and subzones within Russia and the USSR, separately on the East European and West Siberian plains. A significant similarity of the grouse stock estimation results by weighted averages, separately by landscape groups, and by a simple average for the entire territory of a physico-geographical country or several of them in the first half of summer is shown. The second method of stock assessment compared with the first one gave results that differ for those plains within confidence intervals at a confidence level of 0.1. On the groups of physico-geographical countries territories in the first half of summer, the highest average annual values of the abundance and number of black grouse are appropriate of the European territory and the Urals as a whole, as well as in Western Siberia. The lowest values are typical for Central Asia and Kazakhstan.

Zvýšení biologické kvality jedinců tetřívka obecného (Lyrurus tetrix) připravovaných pro záchranné programy

In the middle of the twentieth century, a downward trend in grouse numbers in Central Europe became evident. Along with the decrease in the number of birds, the fragmentation and subsequent shrinking of the range of forest fowls such as the capercaillie (Tetrao urogallus), the black grouse (Lyrurus tetrix) and the hazel grouse (Bonasa bonasia) began to manifest itself. This trend continues until now and the occurrence of these species in the Czech Republic and Central Europe in general is threatened. One of the segments of saving the species in situ is the support of the population by artificially reared or translocated individuals. First of all, however, it is necessary to solve the problem of the biological quality of the individuals used, which largely depends on the state of their digestive tract, the quality of the food and the development of behavioral patterns necessary for the intake of natural food in the wild. Therefore, analyzes were made of the food supply of black grouse in the wild and potential feed components for black grouse in aviary breeding (Wendes method – dry matter, N substances, fats, ash, fibre, BNLV, expressed in %). Subsequently, on the basis of the analysis results, a recipe of a feed mixture of seeds, dried shoots, fruits of woody plants and dried insects was prepared, suitable for rearing and preparing grouse birds for adaptation to natural conditions. It presents a diversified food consisting of six types of cereals, two types of legumes, four types of oil seeds and another four types of seeds, fruits and dried shoots. The feed mixture of natural plant components was supplemented with an animal component – dried developmental stages of mealworm (Tenebrio molitor).

Identifying and locating carotenoids in supra-orbital combs of male black grouse (Lyurus tetrix) using Raman and transmission electron microscopy: A histological study using rehydrated tissue samples.

Colourful signals have long been implicated as indicators of individual quality in animals. Bare-skin signals are an understudied aspect of avian colouration compared with plumage studies, despite displaying rapid changes in size and colour in response to different environmental or physiological stressors. Even fewer studies have focused on the underlying histology of these structures and the importance this plays in the resulting skin colour. Using the Black Grouse (Lyrurus tetrix), we identified the underlying structure of individual dermal spikes, which make up the red supra-orbital comb (a known integumentary signal of male quality), and highlight visual structural differences between combs of different sizes. In addition, we used Raman spectroscopy to indicate the presence of carotenoids within the tissue, something that had previously only been inferred through characteristic reflectance patterns. An increased understanding of the structural basis of colour of featherless parts of the skin opens up exciting new avenues for interpreting the information content of integumentary signals.

Distribution of grouse and their predators in peatland forest landscapes: A case for ecological integrity

Natural peatland forest landscapes have been transformed and fragmented by forestry and agriculture worldwide, which undermines their ecological functioning and resilience. In Northern Europe, such transformations are apparently linked with observed long-term declines of forest dwelling grouse; those declines have not been effectively addressed by conservation. We asked how site factors, in combination with forest management and predation risk, shape grouse distributions in such landscapes in the breeding season. The data were collected by single-visit snapshot mapping of the capercaillie (Tetrao urogallus), black grouse (Lyrurus tetrix), hazel grouse (Tetrastes bonasia), and the signs of their potential predators across seven peatland forest areas (156 km2 in total) around large bogs in Estonia. We modelled the presence of grouse species in relation to landscape gradients, forest stand characteristics, and predator occurrence. The species were partly segregated along the bog-fen forest gradient (on different types of peat soils) and by stand composition; most capercaillie hens dispersed up to 2.5 km from lekking sites. All species avoided recently thinned forests, except breeding capercaillie in transitional mire sites (their preferred habitat). When the other factors were accounted for, the grouse neither avoided densely ditched areas nor predator vicinity at a forest scale (ca. 20-ha), which may expose the birds to unperceived risks. Our results indicate that conserving all three grouse species in peatland forest landscapes requires maintaining the edaphic and stand-structural diversity of the forests. Frequent thinning and dense predator populations are detrimental, and may require large refuge habitats to buffer their influence. Sustaining viable grouse populations serves as a clear target for ecosystem management in drained peatland landscapes.

The Implications in Meat Quality and Nutrition by Comparing the Metabolites of Pectoral Muscle between Adult Indigenous Chickens and Commercial Laying Hens.

Aged chickens are often a secondary dietary choice, owing to the poor organoleptic qualities of their meat. With regard to the meat quality of chickens, the metabolic profiles of pectoral muscle in Guangyuan grey chickens (group G) and Hy-Line grey hens (group H) aged 55 weeks were compared via ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A total of 74 metabolites were identified with differential changes in the ion model. Lipids and lipid-like molecules comprised the largest proportion among the different metabolites. The content of myristic acid and palmitic acid were found to be higher in the pectoral muscle of group G, while group H showed significantly higher levels of glycerophospholipid molecules, such as LPC(18:2/0:0), Pi(38:5), Pc(16:0/16:0), and Pe(16:1e/14-hdohe). KEGG pathway analysis indicated that the abundant metabolites in group G were mainly involved in energy metabolism and fatty acid biosynthesis and metabolism, whereas those of group H were mainly attributed to the metabolism of unsaturated fatty acids and amino acids. Overall, the differences in lipid and amino acid metabolism in pectoral muscle appear to be responsible for the difference in meat quality between indigenous chickens and commercial laying hens.

Food Products and Dishes on the Table of Władysław IV Vasa, King of Poland and Grand Duke of Lithuania

Based on the data of the kitchen accounts of 1632–1633 and other relevant sources, the article aims to shed light on the assortment of the food products and beverages supplied to the kitchen of Władysław IV Vasa, King of Poland and Grand Duke of Lithuania, and the dishes that used to be cooked for the ruler. The analysis shows that beef, mutton, piglets, meat of domestic birds, wild animals (hares, deer), and wild birds (most often black grouse, hazel grouse, partridges, thrushes, pigeons) were delivered to the court kitchen of the ruler. Interestingly, turkeys were supplied to the kitchen of Władysław IV Vasa very often, not only during feasts. During fasts, different types of fish were consumed, but the salmon was purchased only on special occasions. The analysis also reveals the assortment of dairy products, bread, cereals, sweets, local vegetables, local and imported fruit, spices, and beverages. The sources even reveal ingredients of some dishes and pastries cooked for the ruler’s table: meat jelly, pâté, stews of various meats and vegetables (olla pulreda), rice pudding (bianka), Easter cake, and others.The cuisine of Władysław IV Vasa shared some features with Western European Renaissance cuisine: it followed the fashion of eating wild birds and sweets and consuming imported spices. The influence of French cuisine was more pronounced, although the French elite began to abandon the abundant consumption of imported spices during that period.

Black Grouse Hissing Calls Show Geographic Variability across the Distribution Area.

The black grouse is a species whose population development requires constant monitoring due to a rapidly declining trend, especially in Central Europe. Variability in the voices of geographically separated populations can aid in counting within individual populations. This has been investigated with the black grouse. However, the variability of the acoustic behavior of black grouse between populations was investigated for the first time. In total, 82 male black grouse were recorded during the lekking season in four countries: the Czech Republic, Scotland, Finland, and Russia. We analyzed recordings of hissing calls, i.e., the non-vocal signal. DFA analysis correctly classified almost 70% of the recordings. The results indicate a certain degree of difference between the grouse populations from the four countries examined. The mean frequency of hissing calls for populations was 1410.71 ± 170.25 Hz, 1473.89 ± 167.59 Hz, 1544.38 ± 167.60 Hz, and 1826.34 ± 319.23 Hz in the Czech Republic, Finland, Russia, and Scotland, respectively. Populations from Scotland and Russia have greater intra-variability compared to grouse from the Czech Republic and Finland, indicating that population density is not the principal factor in the geographical variability of black grouse hissing calls. Range-level differences enhance knowledge and facilitate the assessment of species evolution.

The influence of sample size on two approaches to estimate Black Grouse Lyrurus tetrix population size using non‐invasive sampling methods

Population size is an important parameter to monitor for species conservation and management. This is especially important for rare and endangered species, as declines can give information about anthropogenic impacts and the need for new conservation measures. To estimate population size, various methods of analysis can be used, for which sample size is an important factor. Sample size is particularly important to consider when applying non‐invasive sampling strategies such as sampling faeces or feathers/hairs as a source of DNA, as a means to limit disturbance and stress for the species of concern. We investigated a Black Grouse Lyrurus tetrix population in the eastern part of the Alps, in East Tyrol (Austria), and estimated population size using two approaches: capture–recapture and rarefaction. With a set of 12 polymorphic microsatellite markers, we identified genotypes from faeces and feathers (backed up with 23 tissue samples) and checked for population substructure and gene flow among sampling sites. We estimated population size using four different models from the two approaches (molecular capture–recapture: TIRM, TIRMpart; rarefaction: hyperbolic function – Kohn, exponential function – Eggert). To evaluate the impact of sample size on the estimations, we used the full dataset of 500 samples (‘complete’ dataset) and half the dataset of 250 samples (‘half’ dataset). We also estimated the population size for each sex separately using complete and half datasets to check for sex‐specific differences in population size. We found similar results in three of four models (capture–recapture: capwire TIRM, capwire TIRMpart; rarefaction: rarefaction Kohn). Using just half of the data increased the uncertainties in the estimation of population size in all models used and deviations were particularly large in females, which indicated a sex bias. Only the complete dataset of males had an observation rate of more than two observations/individual, and this observation rate meets the recommendation for using the capwire models. This indicates that, for species with different sex‐specific detectability, larger sample sizes do not generally imply higher observation rates. We conclude that calculating the observation rates and population‐size estimations for each sex separately can improve overall population‐size estimation, especially in species with biased sex ratios and those that exhibit sex‐specific behaviour.