Acoustic individuality in the hissing calls of the male black grouse (Lyrurus tetrix)

Acoustic individuality may well play a big role during the mating season of many birds. Black grouse (Lyrurus tetrix) produces two different long-distance calls during mating on leks: rookooing and hissing calls. The first one represents low frequency series of bubbling sounds and the second one represents hissing sound. This hissing represents a signal not produced by the syrinx. We analyzed 426 hissing calls from 24 individuals in Finland and Scotland. We conducted cross-validated discrimination analyses (DFA). The discrimination model classified each call with almost 78% accuracy (conventional result) and the validated DFA revealed 71% output, that is much higher than classification by chance (4%). The most important variables were Frequency 95%, 1st Quartile Frequency, Aggregate Entropy and Duration 90%. We also tested whether between individual variation is higher than within individual variation using PIC (Potential for individual coding) and we found that all acoustic parameters had PIC > 1. We confirmed that hissing call of black grouse is individually distinct. In comparison to the signals produced by the syrinx, non-vocal sounds have been studied rarely and according to our knowledge, this is the second evidence of vocal individuality in avian hissing sounds which are not produced by syrinx. Individuality in the vocalization of the male black grouse may aid females in mating partner selection, and for males it may enable competitor recognition and assessment. Individually distinct hissing calls could be of possible use to monitor individuals on leks. Such a method could overcome problems during traditional monitoring methods of this species, when one individual can be counted multiple times, because catching and traditional marking is problematic in this species.

Species structure of small game hunting in the Kirov region at the beginning of the XXI century

An assessment of the species structure and size of small game prey for the spring and autumn-winter hunting seasons on the territory of the Kirov region was made, using a questionnaire survey based on the analysis of the prey of 3220 individuals. Small game includes such species (groups of species) as mallard, Northern shoveler, pintail, teal-whistle, teal cracker (Garganey), Eurasian wigeon, diving ducks, white-fronted goose, bean goose, wood grouse, black grouse, hazel grouse, woodcock, double snipe, snipe, corncrake, wood pigeon, turtle doves, white hare, European hare. The average index of production by species and groups of species per 1 hunter, who went hunting in the spring and autumn-winter seasons, has been calculated. The size of game catch during the spring hunting was 135.8 thousand individuals, in the autumn-winter hunting season -470 thousand individuals. The summation of the results obtained made it possible to estimate the volume of the total (annual) catch of small game in the amount of almost 606 thousand individuals. The main species are the mallard, hazel grouse, white hare, woodcock, black grouse, Eurasian wigeon, teal cracker (Garganey), Northern shoveler, wood grouse, white-fronted goose, bean goose, teal-whistle, their total share is 94.88% of the annual production of small game. The first five species can be assessed as the most massive in production (or popular), the share of each of them is over 10% of the total production, and in total they amount to 70.4%.

Evaluation of Spatio-Temporal Patterns of Predation Risk to Forest Grouse Nests in the Central European Mountain Regions

We evaluated the spatiotemporal patterns of predation risk on black grouse nests using artificial nests that were monitored by camera traps in mountain areas with a small extant (Ore Mts.) and already extinct (Jeseníky Mts.) black grouse population. The overall predation rate of artificial nests was 56% and we found significant differences in survival rate courses over time between both study areas (68% Ore Mts. vs. 41%, Jeseníky Mts.). Within the time required for successful egg incubation (25 days), nest survival probability was 0.32 in the Ore Mts. and 0.59 in Jeseníky Mts. The stone marten (Martes foina) was the primary nest predator in both study areas (39% in total), followed by common raven (Corvus corax, 25%) and red fox (Vulpes vulpes, 22%). The proportion of depredated nests did not differ between habitat types (i.e., open forest interior, clearing, forest edge), but we recorded the effect of interaction of study area and habitat. In Ore Mts., the main nest predator was common raven with seven records (37%). The Eurasian jay (Garrulus glandarius) was responsible for most predation attempts in Jeseníky Mts. (five records, i.e., 83%), while in the Ore Mts., most predation attempts were done by red fox (six records, i.e., 38%).

Biased sex-ratio in woodland grouse population of the Tatra National Park, suggested by molecular sexing of non-invasive samples

Sex ratio (ratio between the number of male and female individuals in a population) is an important factor contributing to the survival rates of the population in wild. Imbalanced sex ratio is often the cause of diminished survival rates of endangered species. The analysis of DNA collected through noninvasive methodologies effectively allows to monitor populations of rare species or species that are difficult to observe in the wild. Such method was used to determine the sex ratio in populations of the capercaillie (Tetrao urogallus) and black grouse (Lyrurus tetrix) in the Tatra National Park. We collected over 250 samples (mostly excrement) in the area of the Tatra National Park and identified species via microsatellite genotyping and determined the sex using fragments of the CHD gene. We found that the majority of the samples belonged to male specimens irrespective of the species suggesting a large deviation from an equal sex ratio in wild populations of capercaillie and black grouse in the Tatra National Park. Our results point out the fundamental contribution of genetic assessment of sex ration to monitor the viability of both species in the Tatra National Park.