Is It Necessary Managing Carnivores to Reverse the Decline of Endangered Prey Species? Insights from a Removal Experiment of Mesocarnivores to Benefit Demographic Parameters of the Pyrenean Capercaillie.
Mesopredator control has long been used to alleviate the effect of elevated predation pressure on vulnerable, threatened or valuable species. However, the convenience of using mesopredator controls is technically questionable and scientifically-sound research is therefore required to evaluate the impact of predation on prey case by case. In this study we evaluated the effect of the alteration of terrestrial mesopredator dynamics on the demographic parameters of a relict capercaillie Tetrao urogallus aquitanicus population currently in decline for which the impact of predation has not previously been assessed. We used a six-year mesocarnivore removal experiment (2008-2013) together with seven-years of previous demographic information on capercaillies (1999-2007) within a before-after control-impact (BACI) design to evaluate the effect of mesocarnivore removal on capercaillie demographic parameters and on spatial behaviour of the most frequent predatory mesocarnivores of the capercaillie (Martes spp. and red fox Vulpes vulpes). Using a dynamic site-occupancy approach, the reduction of mesocarnivore population levels as a result of removal was clear for marten species, mainly during key months for capercaillie reproduction, but not for the red fox. Our results show that the breeding success of capercaillies was enhanced in areas where carnivores were removed and was inversely related to the occupation level of the studied mesocarnivores, although being only significant for Martes spp. Moreover, capercaillie predation rates were lower and adult survival seemingly higher in treatment during the removal phase. Cost-effective, long-term management interventions to ensure the recovery of this threatened capercaillie population are discussed in the light of the results. At our study area, the decision for implementing predation management should be included within a broader long-term conservation perspective. In this regard, a more feasible and sustainable management intervention in ecological and economic terms may be to balance the impact of mesocarnivores on capercaillies through the recovery of apex predators.
Ministry of Agriculture, Food and Environment, Madrid, Spain; TRAGSATEC, Madrid, Spain.
Rubén
R
Moreno-Opo
MUSIA, La Plana, Lleida, Spain; Association for the Conservation of Capercaillie (ACU), Buseu, Baix Pallars, Spain.
Iván
I
Afonso
Institute of Research in Game Resources-CSIC, Ciudad Real, Spain.
José
J
Jiménez
ETSI de Montes. University Politécnica Madrid, Madrid, Spain.
Mariana
M
Fernández-Olalla
Association for the Conservation of Capercaillie (ACU), Buseu, Baix Pallars, Spain; Alt Pirineu Natural Park, Llavorsí, Spain.
Jordi
J
Canut
Departament d´Agricultura, Ramaderia, Pesca, Alimentació i Medi Ambient, Generalitat de Catalunya, Barcelona, Spain.
Diego
D
García-Ferré
TRAGSATEC, Madrid, Spain.
Josep
J
Piqué
Ministry of Agriculture, Food and Environment, Madrid, Spain.
Francisco
F
García
Association for the Conservation of Capercaillie (ACU), Buseu, Baix Pallars, Spain.
Job
J
Roig
Ministry of Agriculture, Food and Environment, Madrid, Spain; TRAGSATEC, Madrid, Spain.
Jaime
J
Muñoz-Igualada
Ministry of Agriculture, Food and Environment, Madrid, Spain.
Luis Mariano
LM
González
Research Unit of Biodiversity, Oviedo University, Mieres, Spain; Grimsö Wildlife Research Station, Swedish University of Agricultural Sciences, Riddarhyttan, Sweden.
José Vicente
JV
López-Bao
D000818:Animals; D060435:Carnivory; D056727:Endangered Species / Q000706:statistics & numerical data*; D020387:Food Chain; D005589:Foxes; D046094:Galliformes; D011155:Population Control; D011235:Predatory Behavior; D013030:Spain