Monitoring black grouse Tetrao tetrix in Isère, northern French Alps: cofactors, population trends and potential biases

Wildlife management benefits from studies that verify or improve the reliability of monitoring protocols. In this study in Isère, France, we tested for potential links between the abundance of black grouse (Tetrao tetrix) in lek–count surveys and cofactors (procedural, geographical and meteorological cofactors) between 1989 and 2016. We also examined the effect of omitting or considering the important cofactors on the long–term population trend that can be inferred from lek–count data. Model selections for data at hand highlighted that the abundance of black grouse was mainly linked to procedural cofactors, such as the number of observers, the time of first observation of a displaying male, the day, and the year of the count. Some additional factors relating to the surface of the census sector, temperature, northing, altitude and wind conditions also appeared depending on the spatial or temporal scale of the analysis. The inclusion of the important cofactors in models modulated the estimates of population trends. The results of the larger dataset highlighted a mean increase of +17 % (+5.3 %; +29 %) of the abundance of black grouse from 1997 to 2001, and a mean increase in population of +47 % (+16 %; +87 %) throughout the study period (1989–2016). We discuss the hypothesis of plausible links between this past increase in the number of black grouse and the ecological impact of the winter storm ‘Vivian’. Findings from our study and the ecological phenomena that were concomitant with the observed population trend provide opportunities to strengthen the monitoring and management of black grouse in the Alps.

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RAPD molecular markers to study populations of black grouse Tetrao tetrix in the Alps

Wildlife Biology ◽

10.2981/wlb.1997.015 ◽

1997 ◽

Vol 3 (1) ◽

pp. 269-296

Author(s):

Marco Bagliacca ◽

Alessio Valentini ◽

I. Cappuccio

Keyword(s):

Molecular Markers ◽

Black Grouse ◽

Tetrao Tetrix ◽

The Alps

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Evaluating the effect of varying clutch frequency in nesting trend estimation of sea turtles

Amphibia-Reptilia ◽

10.1163/156853808785111968 ◽

2008 ◽

Vol 29 (3) ◽

pp. 361-369 ◽

Cited By ~ 6

Author(s):

Yiannis Matsinos ◽

Antonios Mazaris ◽

John Pantis

Keyword(s):

Sea Turtle ◽

Potential Effect ◽

Individual Variability ◽

Population Trend ◽

Population Trends ◽

Mean Values ◽

Abundance Estimates ◽

The Mean ◽

Stochastic Events

Abstract In sea turtle studies, population trend assessments are primarily based on monitoring of beach nesting. Annual nesting abundances are usually estimated by dividing the total number of nests laid during a season by the mean number of clutches deposited annually by nesting turtles, termed clutch frequency. The estimated numbers of annual nester are used for drawing population trends. In the present study, we evaluate the potential effect of individual variability in clutch frequency and successful nest construction, in estimating annual nesting abundance and nesting population trends. We estimate annual nesting abundance and trends by using constant values of clutch frequency. We further develop a stochastic model that simulates breeding performance as an individual based process to produce estimates of annual female abundances. As the next step, we draw population trends by using abundance estimates produced by the model. Our results indicate that nesting abundance estimations are highly affected by stochasticity in nesting behavior. Long term nesting population trends followed annual fluctuations in nester abundance, leading to a great variability in the produced patterns. Our results indicate that population trend estimations which are based on observed numbers of females nesting annually and mean values of clutch frequency are unreliable due to the exclusion of stochastic events that increment nesting performance, thus should be viewed with increased caution. We conclude that more data are needed to be collected in order to produce accurate estimates of sea turtle nesting population tends.

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Size and spacing of grouse leks: comparing capercaillie (Tetrao urogallus) and black grouse (Tetrao tetrix) in two contrasting Eurasian boreal forest landscapes

Canadian Journal of Zoology ◽

10.1139/z09-093 ◽

2009 ◽

Vol 87 (11) ◽

pp. 1032-1043 ◽

Cited By ~ 8

Author(s):

Jørund Rolstad ◽

Per Wegge ◽

Andrey V. Sivkov ◽

Olav Hjeljord ◽

Ken Olaf Storaunet

Keyword(s):

Forest Dynamics ◽

Large Scale ◽

Landscape Scale ◽

Tetrao Urogallus ◽

Black Grouse ◽

Surrounding Area ◽

Social Attraction ◽

Tetrao Tetrix ◽

Habitat Affinities

Capercaillie ( Tetrao urogallus L., 1758) and black grouse ( Tetrao tetrix L., 1758 (= Lyrurus tetrix (L., 1758))) are two sympatric Eurasian lekking grouse species that differ markedly in habitat affinities and social organization. We examined how size and spacing of leks in pristine (Russia) and managed (Norway) forests were related to habitat and social behavior. Leks of both species were larger and spaced farther apart in the pristine landscape. Capercaillie leks were regularly spaced at 2–3 km distance, increasing with lek size, which in turn was positively related to the amount of middle-aged and older forests in the surrounding area. Black grouse leks were irregularly distributed at shorter distances of 1–2 km, with lek size explained by the size of the open bog arena and the amount of open habitat in the surroundings. At the landscape scale, spatial distribution of open bogs and social attraction among male black grouse caused leks to be more aggregated, whereas mutual avoidance in male capercaillie caused leks to be spaced out. In the pristine landscape, large-scale and long-term changes in forest dynamics owing to wildfires, combined with an aggregated pattern of huge bog complexes, presumably provide both grouse species with enough time and space to build up bigger lek populations than in the managed landscape.

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Effects of density on lek-site selection by Black Grouse Tetrao tetrix in the Alps

Bird Study ◽

10.1080/00063657.2016.1180503 ◽

2016 ◽

Vol 63 (2) ◽

pp. 187-195 ◽

Cited By ~ 1

Author(s):

Luca Nelli ◽

Marco Murru ◽

Alberto Meriggi

Keyword(s):

Site Selection ◽

Black Grouse ◽

Tetrao Tetrix ◽

The Alps ◽

Effects Of Density

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Gran Paradiso: Erkenntnisse aus der sich natürlich regulierenden Steinbockpopulation|Gran Paradiso: Conclusions from the naturally regulated Capricorn population

Schweizerische Zeitschrift fur Forstwesen ◽

10.3188/szf.2007.0349 ◽

2007 ◽

Vol 158 (11) ◽

pp. 349-352

Author(s):

Grégory Amos ◽

Ambroise Marchand ◽

Anja Schneiter ◽

Annina Sorg

Keyword(s):

Nineteenth Century ◽

Population Density ◽

National Park ◽

Optimal Management ◽

Capra Ibex ◽

Large Fluctuations ◽

The Alps ◽

Gran Paradiso ◽

Gran Paradiso National Park

The last Capricorns (Capra ibex ibex) in the Alps survived during the nineteenth century in the Aosta valley thanks to the royal hunting reservation (today Gran Paradiso national park). Capricorns from this reservation were successfully re-introduced in Switzerland after its Capricorn population had disappeared. Currently in Switzerland there are 13200 Capricorns. Every year 1000 are hunted in order to prevent a large variation and overaging of their population and the damage of pasture. In contrast, in the Gran Paradiso national park the game population regulates itself naturally for over eighty years. There are large fluctuations in the Capricorn population (2600–5000) which are most likely due to the climate, amount of snow, population density and to the interactions of these factors. The long-term surveys in the Gran Paradiso national park and the investigations of the capacity of this area are a valuable example for the optimal management of the ibexes in Switzerland.

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Contrasting long-term population trends of beach-nesting shorebirds under shared environmental pressures

Biological Conservation ◽

10.1016/j.biocon.2021.109178 ◽

2021 ◽

Vol 260 ◽

pp. 109178

Author(s):

Eunbi Kwon ◽

Samantha Robinson ◽

Chelsea E. Weithman ◽

Daniel H. Catlin ◽

Sarah M. Karpanty ◽

...

Keyword(s):

Population Trends ◽

Environmental Pressures

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Harvest rate of sooty shearwaters (Puffinus griseus) by Rakiura Māori: a potential tool to monitor population trends?

Wildlife Research ◽

10.1071/wr02034 ◽

2004 ◽

Vol 31 (3) ◽

pp. 319 ◽

Cited By ~ 13

Author(s):

Jane Catherine Kitson

Keyword(s):

New Zealand ◽

Cross Section ◽

Large Scale ◽

Population Change ◽

Population Trends ◽

Harvest Rate ◽

General Index ◽

Careful Screening ◽

Potential Tool

Sooty shearwaters (tītī, muttonbird, Puffinus griseus) are highly abundant migratory seabirds, which return to breeding colonies in New Zealand. The Rakiura Māori annual chick harvest on islands adjacent to Rakiura (Stewart Island), is one of the last large-scale customary uses of native wildlife in New Zealand. This study aimed to establish whether the rate at which muttonbirders can extract chicks from their breeding burrows indicates population trends of sooty shearwaters. Harvest rates increased slightly with increasing chick densities on Putauhinu Island. Birders' harvest rates vary in their sensitivities to changing chick density. Therefore a monitoring panel requires careful screening to ensure that harvest rates of the birders selected are sensitive to chick density, and represents a cross-section of different islands. Though harvest rates can provide only a general index of population change, it can provide an inexpensive and feasible way to measure population trends. Detecting trends is the first step to assessing the long-term sustainability of the harvest.

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Habitat factors related to wild rabbit population trends after the initial impact of rabbit haemorrhagic disease

Wildlife Research ◽

10.1071/wr05107 ◽

2006 ◽

Vol 33 (6) ◽

pp. 467 ◽

Cited By ~ 27

Author(s):

Carlos Calvete ◽

Enrique Pelayo ◽

Javier Sampietro

Keyword(s):

Habitat Quality ◽

Population Trends ◽

Wild Rabbit ◽

Pest Species ◽

Predator Species ◽

Rabbit Population ◽

Habitat Factors ◽

Rabbit Haemorrhagic Disease ◽

Haemorrhagic Disease

The European wild rabbit (Oryctolagus cuniculus) is an introduced pest species in Australia and New Zealand. Rabbits have a devastating negative impact on agricultural production and biodiversity in these countries, and Rabbit Haemorrhagic Disease (RHD) is currently included in control strategies for rabbit populations. On the other hand, the European wild rabbit is a key native prey species in the Iberian Peninsula. Since the arrival of RHD, however, rabbit populations have undergone dramatic decreases and several predator species at risk of extinction are currently dependent on the rabbit population density. Therefore, from the point of view of biodiversity conservation, evaluating habitat correlates and trends of rabbit populations after the first RHD epizootic is of great interest to improve the long-term control or promotion of wild rabbit populations. We estimated the relationship between habitat factors and long-term population trends as well as the relationships between habitat factors and rabbit abundance 2 and 14 years after the arrival of RHD in several Iberian rabbit populations. We observed that only 26% of surveyed populations seemed to experience an increase in rabbit abundance over the last 12 years and that this increase was higher in the low-rabbit-abundance areas of l992, leading to high rabbit abundance in 2004. Our results suggested that short- and long-term impacts of RHD were related to habitat quality. The initial impact of RHD was higher in more suitable habitats, but increasing long-term population trends were positively related to good habitat quality.

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