Molecular dietary analyses of western capercaillies (Tetrao urogallus) reveal a diverse diet

Conservation strategies centered around species habitat protection rely on species’ dietary information. One species at the focal point of conservation efforts is the herbivorous grouse, the western capercaillie (Tetrao urogallus), which is an indicator species for forest biodiversity conservation. Non-molecular means used to study their diet are time-consuming and at low taxonomic resolution. This delays the implementation of conservation strategies including resource protection due to uncertainty about its diet. Thus, limited knowledge on diet is hampering conservation efforts. Here, we use non-invasive environmental DNA (eDNA) metabarcoding on DNA extracted from faces to present the first large-scale molecular dietary analysis of capercaillies. Facal samples were collected from seven populations located in Norway (Finnmark, Troms, Trøndelag, Innlandet) and France (Vosges, Jura, Pyrenees) (n = 172). We detected 122 plant taxa belonging to 46 plant families of which 37.7% of the detected taxa could be identified at species level. The average dietary richness of each sample was 7 ± 5 SD taxa. The most frequently occurring plant groups with the highest relative read abundance (RRA) were trees and dwarf shrubs, in particular, Pinus and Vaccinium myrtillus, respectively. There was a difference in dietary composition (RRA) between samples collected from the different locations (adonis pseudo F5,86 = 11.01, r2 = 0.17, p = 0.001) and seasons (adonis pseudo F2,03 = 0.64, r2 = 0.01, p = 0.036). Dietary composition also differed between sexes at each location (adonis pseudo F1,47 = 2.77, r2 = 0.04, p = 0.024), although not significant for all data combined. In total, 35 taxa (36.8% of taxa recorded) were new capercaillie food items compared with existing knowledge from non-molecular means. The non-invasive molecular dietary analysis applied in this study provides new ecological information of capercaillies’ diet, improving our understanding of adequate habitat required for their conservation

Ecologie et dynamique des populations du Grand Tetras dans les Pyrenees, avec des references spatiales a la biologie de la reproduction chez les poules. Quelques applications a sa conservation

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 82845 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Phylogeography of the Capercaillie in Eurasia: What is the status of the Pyrenean-Cantabrian population?

International audienc

Modélisation de la dynamique du grand tétras des Pyrénées françaises pour sa gestion adaptative

Ce document présente un modèle intégré de dynamique de population développé pour la gestion adaptative du grand tétras dans les Pyrénées françaises. Ce modèle comprend deux classes d’âge pour les femelles et trois pour les mâles et inclut cinq sous-populations distinctes. Il couvre la période 2004-2019. Sa structure et son ajustement reposent sur de multiples sources de données collectées par l’Observatoire des Galliformes de Montagne. Un suivi d’abondance des mâles sur lek au printemps, en très grande majorité de 2 ans et plus, est utilisé pour renseigner le niveau global de la population du massif pyrénéen sur la période 2010-2019. Des suivis par comptage au chien en fin d’été apportent de l’information sur l’évolution du succès reproducteur et de l’abondance des femelles et des mâles en fin d’été. Le suivi d’individus équipés d’émetteurs VHF ou GPS a également permis l’estimation des taux de survie. Enfin, les tableaux de chasses ont été intégrés dans le modèle. L’analyse de ce modèle révèle que la population est actuellement en décroissance de l’ordre de 2% par an. L’effectif des mâles chanteurs sur leks est de 1852 [1693-2026] individus, soit environ 25% en deçà de la valeur cible retenue par la stratégie nationale d’actions en faveur du grand tétras (2500 mâles sur lek à l’issue de la période 2012-2021). La dynamique de la population apparait comme très sensible au taux de survie des femelles adultes, dont l’estimation pour les Pyrénées est faible en comparaison des valeurs observées ailleurs en Europe. Une baisse de la densité des mâles pourrait également impacter négativement la fécondité. Malheureusement les données à disposition ne permettent pas de tester correctement cette hypothèse. Sur la base de ces résultats, des options de gestion de la population Pyrénéenne sont proposées pour lutter contre la dynamique décroissante observée, avec notamment pour cible la réduction de la mortalité causée par les câbles et clôtures

Genomic analysis of geographical structure and diversity in the capercaillie (Tetrao urogallus)

The capercaillie is widespread throughout the boreal forests of northern Eurasia but faces serious conservation challenges in the southernmost mountain ranges, where the populations are fragmented and some are critically endangered. To develop effective conservation strategies for these populations, it is essential to have information on both their genetic diversity and the genetic structure of the species. In this work, we used a reduced representation (ddRAD) genomic sequencing technique to analyze the genetic structure of the capercaillie across its European range and to assess the inbreeding levels in some of the most threatened populations. Our population structure analysis suggested the existence of two evolutionarily significant units, one formed by the two populations from the Iberian Peninsula and the other by the populations from the rest of Europe. Genetic diversity showed a significant decrease in the Iberian populations with respect to the other European populations. An isolation-with-migration model supported these results and allowed us to estimate the parameters of the population tree. The inbreeding coefficients estimated for the Iberian capercaillies showed relatively low levels in the Pyrenees. However, some individuals with very high inbreeding values were detected in the Cantabrian Mountains, suggesting that some of its subpopulations are substantially isolated. The population structure results and the genomic monitoring method we used to assess inbreeding levels may be crucial for the conservation and recovery of the most endangered capercaillie populations.Funding provided by: Ministerio para la Transición Ecológica y el Reto DemográficoCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100019408Award Number: Funding provided by: Junta de Castilla y LeónCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100014180Award Number: Funding provided by: Gobierno del Principado de AsturiasCrossref Funder Registry ID: http://dx.doi.org/10.13039/100011941Award Number: Funding provided by: MCIN/AEI/10.13039/501100011033**Crossref Funder Registry ID: Award Number: PID2020-113586GB-I0

Short-term response to the North Atlantic Oscillation but no long-term effects of climate change on the reproductive success of an alpine bird

International audienceDeciphering the effects of climatic conditions on population dynamics is of major importance in understanding how organisms are likely to be affected by climate changes. Using data from broad-scale annual censuses between 1990 and 2007, we show that winter and summer North Atlantic Oscillations affect several breeding success indicators of the Black Grouse () in the French Alps. We did not find any trend in hen counts or breeding indexes over the study period. Surprisingly for a bird specialised in cold climates, we show that Black Grouse optimise their reproductive output for positive values of the winter NAO corresponding to the average NAO index of the last 30 years. Extreme NAO values lead to lower breeding success, indicating that the grouse may be more able to track trends in climate than an increase in the frequency of extreme years. Our result show that, at least from a short-term perspective, Black Grouse productivity is not threatened by a trend towards warmer climatic conditions in the Alps, but may be affected by an increased frequency of extreme years. We advocate the use of the NAO as a climate proxy rather than using heavily noised and biased local climate descriptors in studies focusing on the global response to climate over a large spatial scale