Review Warring brothers: The complex interactions between wolves (Canis lupus) and dogs (Canis familiaris) in a conservation context Nicolas Lescureux ⇑ , John D.C. Linnell Norwegian Institute for Nature Research, Postboks 5685 Sluppen, 7485 Trondheim, Norway article info Article history: Received 23 October 2013 Received in revised form 14 January 2014 Accepted 19 January 2014 Keywords: Wolf Dog Phylogenetics Hybridization Competition Predation Disease transmission Conflicts Wild-domestic boundaries abstract Although both wolves and dogs have been the subjects of numerous studies in many disciplines, the com- plex relationships between them have not yet been synthesized within a common review, and neither has it been placed in a holistic conservation context. Information and data are spread across numerous publications from different disciplines that rarely interact. Dogs have become the most common carni- vore and their population is still increasing. In a context of wolf recovery in multi-use landscapes, there is a growing concern among conservationists for the potential negative impact of dogs on wolf conserva- tion. With this paper we aim to review the numerous and complex interactions existing between wolves and dogs, using literature from disciplines as diverse as history, archeology, anthropology, genetics, ecol- ogy, and epidemiology in order to better understand the wolf–dog relationship and its potential impact on wolf conservation. Starting with their phylogenetic relationship and following a summary of the cur- rent knowledge on the dog’s ancestry we explore how dogs can represent a direct threat for wolves through hybridization, disease transfer and competition. The review highlights a number of ways in which dogs can impact wolf conservation, although a general lack of data and conclusive studies is a com- mon theme that emerges for many topics. Then we analyse how dogs can mitigate human–wolf conflicts through their role as livestock guardians or wolf hunters. Finally we describe the complex phenomenon of wolf predation on dogs before discussing the wolf–dog relationships in general, with a special focus on including a more anthropological perspective. The review highlights the diversity of interactions between wolves and dogs, that can be both negative and positive for wolf conservation. However, more important than these direct impacts, the review highlights how the wolf–dog relationship challenges human attempts to construct simple dichotomies between wild and domestic, or between nature and culture. The borders between these concepts are in fact much more fluid and elusive than is often appreciated, and wolf conservation must adapt to this more complex reality. Ó 2014 Elsevier Ltd. All rights reserved. Contents 1. Introduction ......................................................................................................... 233 2. Methods ............................................................................................................ 233 3. Wolves and dogs: ancestors and descendents .............................................................................. 233 4. Dogs as a threat to wolf conservation..................................................................................... 234 4.1. Hybridization between wolves and dogs ............................................................................. 234 4.2. Disease transmission between wolves and dogs ....................................................................... 235 4.3. Wolf–dog competition ........................................................................................... 237 5. Dogs as a tool to help conserve wolves ................................................................................... 237 5.1. Livestock guarding dogs .......................................................................................... 237 5.2. Dogs used for hunting wolves ..................................................................................... 238 6. Wolf predation on dogs ................................................................................................ 239 http://dx.doi.org/10.1016/j.biocon.2014.01.032 0006-3207/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Address: 293 rue des Oiseaux de Passage, 34 980 Saint Gély du Fesc, France. Tel.: +33 664365126. E-mail addresses: nicolas.lescureux@gmail.com (N. Lescureux), john.linnell@nina.no (J.D.C. Linnell). Biological Conservation 171 (2014) 232–245 Contents lists available at ScienceDirect Biological Conservation journal homepage: www.elsevier.com/locate/biocon