Compared Modelling of the Climate Influence on Black Grouse Population Dynamics in Europe
Black Grouse in central Europe, a victim of Global Climate Change ? by Michèle LONEUX, Department of Ethology and Animal Psychology, University of Liège(Belgium). Musée de Zoologie, Quai van Beneden, 22, B-4020 LIEGE. Michele.Loneux@ulg.ac.be
The Black Grouse (Tetrao tetrix, Tetraonidae) is an emblematic bird with spectacular lekking behaviour and great tourist lure. A species with northern-montain range, it is ecologically demanding and a bioindicator of its habitat quality and biodiversity. Its populations are fluctuating, but they are also declining since the end of the seventies. The species is threatened with extinction in Central Europe, compared to the alpine and nordic populations which seem better. Many European teams have been involved for long time in Black Grouse Research to understand the reasons for decline. Our study follows this path too. The species is adapted to roughclimate and to cold and snowy winters. Such climatic conditions seem to fail in Central and West Europe. As the climate is recognized as the principal extrinsic factor acting on population fluctuation, we have firstly related yearly local meteorological variables to the yearly census of Black Cocks in the Hautes Fagnes Nature Reserve. This population is followed for more than thirty years. Our analysis is a Poisson Modelling by step-wise multiple regression.
Highly significative results have led to an extension of this modelling approach to five other European Black Grouse populations followed for twenty or thirty years: in Sallandse Heuvelrug (NL), Lüneburger Heide (D), Lange Rhön (D), Satzung/Erzgebirge (D, at the Czekian boundary) and in the North Pennines (UK).
The originalities of our work come from the use of continuous long time series of data set, the use of local climatological data, registered in the study area or in its close vicinity, and the use of specific time periods related to the life cycle of the bird.
Our significative results confirm the negative effect of mild winter, the negative effect of rainfall during breeding and hatching time, and the positive effect of high temperature during hatching time for the four populations in lowland of Europe : in Belgium, The Netherlands, North Germany and Central Germany (Rhön). The two other populations (Erzgebirge and North Pennines) present other caracteristics.
The global climate change has led us to look for eventual trends among the local meteorological variables used in the modelling.
The comparison of yearly values of the variables and of past and actual standard means for monthly temperature and monthly rainfall reveals significative trends or differences for the explanatory variables taken into account by the statistical modelling.
To conclude, the climatic factors explain very well the observed fluctuations for the last twenty or thirty years, and the general decline of Black Grouse, observed even in protected areas, could be partly influenced by the new climatic trends.
The species is suffering from the global climate change in addition to attacks on its habitat and tranquility. Its medium term survival in lowland areas depends on the improvement of its habitat's quality and carrying capacity, under all points of vue. This improvement depends on manager's decisions about the management of the areas where the species is living, which are natural reserves or not.
Compared Modelling of the Climate Influence on Black Grouse Population Dynamics in Europe
Black Grouse in central Europe, a victim of Global Climate Change ? by Michèle LONEUX, Department of Ethology and Animal Psychology, University of Liège(Belgium). Musée de Zoologie, Quai van Beneden, 22, B-4020 LIEGE. Michele.Loneux@ulg.ac.be
The Black Grouse (Tetrao tetrix, Tetraonidae) is an emblematic bird with spectacular lekking behaviour and great tourist lure. A species with northern-montain range, it is ecologically demanding and a bioindicator of its habitat quality and biodiversity. Its populations are fluctuating, but they are also declining since the end of the seventies. The species is threatened with extinction in Central Europe, compared to the alpine and nordic populations which seem better. Many European teams have been involved for long time in Black Grouse Research to understand the reasons for decline. Our study follows this path too. The species is adapted to roughclimate and to cold and snowy winters. Such climatic conditions seem to fail in Central and West Europe. As the climate is recognized as the principal extrinsic factor acting on population fluctuation, we have firstly related yearly local meteorological variables to the yearly census of Black Cocks in the Hautes Fagnes Nature Reserve. This population is followed for more than thirty years. Our analysis is a Poisson Modelling by step-wise multiple regression.
Highly significative results have led to an extension of this modelling approach to five other European Black Grouse populations followed for twenty or thirty years: in Sallandse Heuvelrug (NL), Lüneburger Heide (D), Lange Rhön (D), Satzung/Erzgebirge (D, at the Czekian boundary) andin the North Pennines (UK).
The originalities of our work come from the use of continuous long time series of data set, the use of local climatological data, registered in the study area or in its close vicinity, and the use of specific time periods related to the life cycle of the bird.
Our significative results confirm the negative effect of mild winter, the negative effect of rainfall during breeding and hatching time, and the positive effect of high temperature during hatching time for the four populations in lowland of Europe : in Belgium, The Netherlands, North Germany and Central Germany (Rhön). The two other populations (Erzgebirge and North Pennines) present other caracteristics.
The global climate change has led us to look for eventual trends among the local meteorological variables used in the modelling.
The comparison of yearly values of the variables and of past and actual standard means for monthly temperature and monthly rainfall reveals significative trendsor differences for the explanatory variables taken into account by the statistical modelling.
To conclude, the climatic factors explain very well the observed fluctuations for the last twenty or thirty years, and the general decline of Black Grouse, observed even in protected areas, could be partly influenced by the new climatic trends.
The species is suffering from the global climate change in addition to attacks on its habitat and tranquility. Its medium term survival in lowland areas depends on the improvement of its habitat's quality and carrying capacity, under all points of vue. This improvement depends on manager's decisions about the management of the areas where the species is living, which are natural reserves or not.