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.

Assessment of drivers of spatial genetic variation of a ground-dwelling bird species and its implications for conservation.

In modern wildlife ecology, spatial population genetic methods are becoming increasingly applied. Especially for animal species in fragmented landscapes, preservation of gene flow becomes a high priority target in order to restore genetic diversity and prevent local extinction. Within Central Europe, the Alps represent the core distribution area of the black grouse, Lyrurus tetrix. At its easternmost Alpine range, events of subpopulation extinction have already been documented in the past decades. Molecular data combined with spatial analyses can help to assess landscape effects on genetic variation and therefore can be informative for conservation management. Here, we addressed whether the genetic pattern of the easternmost Alpine black grouse metapopulation system is driven by isolation by distance or isolation by resistance. Correlative ecological niche modeling was used to assess geographic distances and landscape resistances. We then applied regression-based approaches combined with population genetic analyses based on microsatellite data to disentangle effects of isolation by distance and isolation by resistance among individuals and subpopulations. Although population genetic analyses revealed overall low levels of genetic differentiation, the ecological niche modeling showed subpopulations to be clearly delimited by habitat structures. Spatial genetic variation could be attributed to effects of isolation by distance among individuals and isolation by resistance among subpopulations, yet unknown effects might factor in. The easternmost subpopulation was the most differentiated, and at the same time, immigration was not detected; hence, its long-term survival might be threatened. Our study provides valuable insights into the spatial genetic variation of this small-scale metapopulation system of Alpine black grouse.

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.

Gastrointestinal parasites of black grouse Lyrurus tetrix: A long-term study (1986-2019) in the French Alps.

This study investigates the gastroenteric parasites community of 336 black grouse Lyrurus tetrix, covering a wide part of the totality of the species range in the French Alps and characterized by a long-term sampling (1986-2019). Parasite community was described using common epidemiological descriptors. Additionally, for the most prevalent parasite, a species distribution model (SDM) was built to understand the main factors influencing parasite occurrence. Ascaridia compar, Capillaria caudinflata, cestodes (Raillietina urogalli, R.cesticillus, and Hymenolepis microps), Eimeria sp. (E. lyruri and E.nadsoni), Corrigia corrigia and Acanthocephalus sp. The most prevalent species was C.caudinflata (P: 33%,CI95%: 28-38), whereas the lowest prevalence was recorded for Acantocephalus sp. (P:0.3%,CI95%:-0.3-0.9).The selected SDM for C.caudinflata includes only 3 variables: BIO11 (Mean Temperature of Coldest Quarter), the latitude of sampled animals and the distance from ski tour way. The distribution of C.caudinflata in the French Alps presents sharply defined areas where there are optimal environmental conditions for maintaining the life cycle of this parasite. These are the colder areas, characterized by higher latitude values and close to the ski tour ways. This study provides a valuable contribution to the scarce literature on wild Galliformes, describing the composition of the gastrointestinal parasite community of the black grouse.

Complete mitochondrial genome of black grouse (Lyrurus tetrix).

We sequenced the entire mitochondrial genome of Lyrurus tetrix for the first time. The mitogenome was 16,677 bp in length, encoded with a standard set of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes plus a putative control region. Almost all genes were encoded on the H-strand except the ND6 and eight tRNA genes. All protein-coding genes initiated with ATG, except for COX1 and ND5 (GTG). An 18-bp-nucleotide deletion occurred in the ND6 of Lyrurus tetrix in contrast to other Galliformes. The total base composition of the mitogenome was 30.4% for A, 30.4% for C, 25.8% for T and 13.4% for G. These results provide basic information for phylogenetic analyses among Galliformes.