Molinari-Jobin A.,KORA |
Kery M.,Swiss Ornithological Institute |
Marboutin E.,ONCFS |
Molinari P.,Italian Lynx Project |
And 8 more authors.
Animal Conservation | Year: 2012
Inferring the distribution and abundance of a species from field records must deal with false-negative and false-positive errors. False-negative errors occur if a species present goes undetected, while false-positive errors are typically a consequence of species misidentification. False-positive observations in studies of rare species may cause an overestimation of the distribution or abundance of the species and distort trend indices. We illustrate this issue with the monitoring of the Eurasian lynx in the Alps. We developed a three-level classification of field records according to their reliability as inferred from whether they were validated or not. The first category (C1) represents 'hard fact' data (e.g. dead lynx); the second category (C2) includes confirmed data (e.g. tracks verified by an expert); and the third category (C3) are unconfirmed data (e.g. any kind of direct visual observation). For lynx, which is a comparatively well-known species in the Alps, we use site-occupancy modelling to estimate its distribution and show that the inferred lynx distribution is highly sensitive to presence sign category: it is larger if based on C3 records compared with the more reliable C1 and C2 records. We believe that the reason for this is a fairly high frequency of false-positive errors among C3 records. This suggests that distribution records for many lesser-known species may be similarly unreliable, because they are mostly or exclusively based on unconfirmed and thus soft data. Nevertheless, such soft data form a considerable part of species assessments as presented, for example in the International Union for Conservation of Nature Red List. However, C3 records can often not be discarded because they may be the only information available. When inferring the distribution of rare carnivores, especially for species with an expanding or shrinking range, we recommend a rigorous discrimination between fully reliable and un- or only partly reliable data, in order to identify possible methodological problems in the distribution maps related to false-positive records. © 2011 The Authors. Animal Conservation © 2011 The Zoological Society of London. Source
Chapron G.,Swedish University of Agricultural Sciences |
Kaczensky P.,University of Veterinary Medicine Vienna |
Linnell J.D.C.,Norwegian Institute for Nature Research |
Von Arx M.,KORA |
And 76 more authors.
Science | Year: 2014
The conservation of large carnivores is a formidable challenge for biodiversity conservation. Using a data set on the past and current status of brown bears (Ursus arctos), Eurasian lynx (Lynx lynx), gray wolves (Canis lupus), and wolverines (Gulo gulo) in European countries, we show that roughly one-third of mainland Europe hosts at least one large carnivore species, with stable or increasing abundance in most cases in 21st-century records. The reasons for this overall conservation success include protective legislation, supportive public opinion, and a variety of practices making coexistence between large carnivores and people possible. The European situation reveals that large carnivores and people can share the same landscape. Source