Predicting kill sites of an apex predator from GPS data in different multiprey systems

Oliveira, Teresa (author), Carricondo-Sanchez, David (author), Mattisson, Jenny (author), Vogt, Kristina (author), Corradini, Andrea (author), Linnell, John D. C. (author), Odden, John (author), Heurich, Marco (author), Rodríguez-Recio, Mariano (author), Krofel, Miha (author)

Kill rates are a central parameter to assess the impact of predation on prey species. An accurate estimation of kill rates requires a correct identification of kill sites, often achieved by field-checking GPS location clusters (GLCs). However, there are potential sources of error included in kill-site identification, such as failing to detect GLCs that are kill sites, and misclassifying the generated GLCs (e.g., kill for nonkill) that were not field checked. Here, we address these two sources of error using a large GPS dataset of collared Eurasian lynx (Lynx lynx), an apex predator of conservation concern in Europe, in three multiprey systems, with different combinations of wild, semidomestic, and domestic prey. We first used a subsampling approach to investigate how different GPS-fix schedules affected the detection of GLC-indicated kill sites. Then, we evaluated the potential of the random forest algorithm to classify GLCs as nonkills, small prey kills, and ungulate kills. We show that the number of fixes can be reduced from seven to three fixes per night without missing more than 5% of the ungulate kills, in a system composed of wild prey. Reducing the number of fixes per 24 h decreased the probability of detecting GLCs connected with kill sites, particularly those of semidomestic or domestic prey, and small prey. Random forest successfully predicted between 73%–90% of ungulate kills, but failed to classify most small prey in all systems, with sensitivity (true positive rate) lower than 65%. Additionally, removing domestic prey improved the algorithm’s overall accuracy. We provide a set of recommendations for studies focusing on kill-site detection that can be considered for other large carnivore species in addition to the Eurasian lynx. We recommend caution when working in systems including domestic prey, as the odds of underestimating kill rates are higher.

• Language: English
• Keywords: GPS location clusters, GPS-fix schedule, kill sites, random forest, Eurasian lynx, domestic prey, GLCs, multiprey system
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 12 str.
• Numbering: Vol. 33, iss. 2, art. e2778
• PID: 20.500.12556/RUL-145000
• UDC: 630*156
• ISSN on article: 1939-5582
• DOI: 10.1002/eap.2778
• COBISS.SI-ID: 130503171
• Publication date in RUL: 29.03.2023

Record is a part of a journal

• Title: Ecological applications
• Shortened title: Ecol. appl.
• Publisher: Ecological Society of America, Wiley
• ISSN: 1939-5582
• COBISS.SI-ID: 4294310

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: GPS klastri, GPS telemetrije, plenjenje, evrazijski ris, domače živali, škoda po divjadi