Point–count method for estimating rock ptarmigan s

Authors: Evelyn Marty Marc MossollTorres

Publish Date: 2011/05/24

Volume: 58, Issue: 1, Pages: 357-363

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Abstract

This paper describes a census technique that gives estimates of rock ptarmigan cocks’ number per unit area during the breeding season This method originated from the need for an effective technique for estimating bird densities in mountainous and inaccessible zones like the Pyrenean chain The bird census was carried out using a point–count method which is recommended for uneven areas To maximize sampling efficiency we established sampling points at 500m distances in order to detect a maximum of calling birds within the sample areas Birds localized at distances 250 m were excluded We postulate that all birds are recorded in a 250m radius around the observer We carried out counts of calling rock ptarmigan cocks in the border between the Principality of Andorra and Ariège Department France from April to June during three consecutive years 2005–2007 The estimated spring density of 104 cocks per 100 ha was higher than densities reported in literature in other parts of the Pyrénées and the Alps Our study provides a useful reference for future monitoring of this species in its mountainous distribution rangeThis study was entirely financed by the Andorran Government and the Fédération Départementale des Chasseurs de l’Ariège the hunting federation of Ariège France We are grateful to Dr Philippe Mourguiart for his statistical assistance and for valuable comments on this manuscript We would like to thank Landry Riba Jordi Sola and JoseMaria Sanchez from the Andorran Government We are enormously grateful to all those who have accompanied us throughout this experience and in particular Thomas Razat Jean Bouilleau Régis Didier Gaèl Aleix Mata and Nicolas Archer for her patience in translating our texts

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