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Wild vertebrates usually avoid ground disturbed by humans with uncertain effects on their distribution and density. We report on a natural experiment that confirms and extends previous conclusions about how the local distribution of capercaillie is affected by track‐based disturbance. We surveyed the birds' droppings in two periods, before and after a predicted increase in disturbance adjacent to an expanding Scottish village, and model the probability of finding droppings in relation to period plus two disturbance gradients – distance to a much disturbed 'entry zone' with a high density of tracks lying adjacent to the village, plus distance to the nearest track. Throughout the study, no droppings were found within the entry zone and their density was depressed up to 400 m from it. Density of droppings was also depressed within 100–120 m of tracks but, compared to a notional scenario without tracks, was threefold greater on ground 120–250 m from tracks. Although the number of cocks counted at the lek in spring showed a small increase, there was an almost threefold decline in the probability of finding capercaillie droppings on and within about 40 m of tracks. We infer that, after the development, birds were less likely to use or cross tracks in pursuit of their daily living requirements, with unknown consequences for their population dynamics and vital rates. Our results have implications for refuge design. Birds on roughly half of a 50 ha refuge should be undisturbed by direct effects of track‐based activities. However, birds shifting away from tracks may themselves cause local increases in density and associated, indirect disturbance such that a refuge would need to be over 300 ha to keep half of it undisturbed. [ABSTRACT FROM AUTHOR]

The population size of capercaille Tetrao urogallus in Scotland was estimated from annual counts of males at 151 known spring lek sites and 45 counts of males, females and their broods in August during the period 2010–2020, combined with published survival estimates. Population size declined from an estimated 580 birds (95% CL: 462–698) in 2011 to 304 (239–369) in 2020 and the extinction probability was 23% after 25 years, 95% after 50 years and 100% after 100 years. Removing mortality associated with collisions against fences lowered extinction probabilities to 0, 3 and 40% respectively, emphasizing fence removal as a management priority. Greatest declines occurred in Deeside and Donside, Morayshire and Ross‐shire and Perthshire and Trossachs. In the Badenoch and Strathspey stronghold, where an estimated 83% of males remain, numbers of occupied leks and lekking males have decreased in the last five years and are associated with reduced breeding success over the last 10 years. Our estimates of population size are only half that derived from the last official national survey in winter 2015/2016. We discuss possible reasons for this difference including underestimates from lek‐based surveys linked to male detection probabilities. Finally, we recommend improvements to the current annual monitoring scheme, including repeat counts at leks and use of novel remote acoustic devices and restoration of annual brood counts in remaining key forests. [ABSTRACT FROM AUTHOR]

The article focuses on a study that describes the development of a real-time polymerase chain reaction (PCR) assay to distinguish between faecal droppings from black grouse and two other tetraonid species that can occur sympatrically in Great Britain. The results from the assay were compared with those obtained using conventional hot-start, end point PCR followed by sequencing. Both in terms of the number of identifications made and concomitantly, the sequencing approach proved to be more successful than that of real-time PCR.

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. [ABSTRACT FROM AUTHOR]

Conservation and management of habitat is central to the conservation of grouse. Identifying thresholds of biotic and a biotic risks that may reduce habitat quality is therefore a component of habitat management of grouse. We propose that dietary phytochemicals, specifically plant secondary metabolites (PSMs), represent an ecological risk to grouse, which are not often considered in the management of grouse. Most species of grouse consume PSMs, which have negative consequences at some concentration. Moreover, several studies provide evidence that the risks posed by PSMs will likely increase under projected climate change scenarios. We discuss potential risks of PSMs for grouse and propose theoretical models, which can be used to test current and future physiological, behavioural and ecological risks of PSMs. We propose that dose-response thresholds can be used to predict and monitor the synergistic risks of PSMs and climate change for grouse. We further suggest that identifying dose-response thresholds to PSMs is needed in the management of vertebrate herbivores in general. [ABSTRACT FROM AUTHOR]

Effective wildlife management requires knowledge about the areas th at are most important within the distribution range or specific management unit of the focal species. Using the spatial conservation planning tool, Zonation, and spatial data on Finnish forests, we present a fast and relatively simple way to objectively prioritise large areas for our focal species, the capercaillie Tetrao urogallus. We constructed the capercaillie lekking landscape prioritisation using published knowledge on the species' habitat and connectivity requirements, and validated the results via comparison to capercaillie lekking-site data. The results show that connectivity considerations both at the home range and the population scale are essential in prioritisation of areas suitable for capercaillie lekking sites. In addition, inclusion of negative connectivity to agri-urban areas further enhances the congruence between the known lekking sites and the areas of high priority (48.7% of known leks falling into the best 20% priority category). We conclude that our approach can be used in several stages of spatial wildlife conservation planning: as a preliminary analysis to find areas subjected to more detailed inventories and modelling, in combination with other analytical tools, or as the main instrument enabling informative use of readily available data in operational large-scale land-use planning. The advantages of our approach include: 1) the ability to execute relatively simple and objective analyses covering wide spatial extents at a high resolution, 2) the possibility to incorporate several ecologically realistic species-specific connectivity components into the analyses, and 3) the potential to help managers target wildlife surveys or conservation and management operations. [ABSTRACT FROM AUTHOR]

In black grouse Tetrao tetrix the survival of juveniles from hatching until recruitment is a critical determinant of population growth. The proportion of juvenile survivors from hatching until recruitment declines continually, but juvenile mortality rates are commonly highest during approximately the first 10 days after hatching. Likely causes of mortality include adverse weather, predation and availability of food. Little is known, however, about how individual properties, such as body mass of hen or chicks and properties of the brood rearing environment (e.g. vegetation characteristics or weather conditions) interact with each other and/or with fluctuating levels of predator abundance in determining early brood survival, simply because such data are very scarce. Using an information-theoretic approach, our paper identifies determinants of early daily survival rates of black grouse chicks in a managed forest landscape of central Finland. During the three years of our study, the proportion of hens losing their broods within 10 days after hatching varied between 0.08 and 0.36.The variation in daily survival rates of chicks was largely mediated by a combination of four key explanatory variables. Brood survival clearly increased with the extent of bilberry Vaccinium myrtillus cover, and was further affected by interactions of temperature and hatching date as well as temperature and chick body mass. Low temperatures consistently resulted in lower daily survival rates. An increase in temperature, however, was more beneficial for early hatchers and heavy chicks. There was no difference in survival between broods from yearling and adult hens and we found no effect of predator density, be it as main effect or as interaction with other variables, on the daily survival rates of chicks. Improving black grouse breeding success can be regarded as a key management target which may be critical for their recovery. Our results suggest that such management should favour protection or local recovery of bilberry, as well as integrate weather and climate changes into the equation of hunting management. [ABSTRACT FROM AUTHOR]