Advances in the Study of Behavior, Volume 45 ISSN 0065-3454, http://dx.doi.org/10.1016/B978-0-12-407186-5.00006-9 407 © 2013 Elsevier Inc. All rights reserved. CHAPTER SIX Demography and Social Evolution of Banded Mongooses Michael A. Cant* ,1 , Emma Vitikainen*, Hazel J. Nichols † *Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK † School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK 1 Corresponding author: E-mail: m.a.cant@exeter.ac.uk Contents 1. Introduction 408 1.1. Cooperative Breeders and the Study of Social Evolution 408 2. The Banded Mongoose Study System 411 3. Demography 413 3.1. Group Composition and Dynamics 413 3.2. Intergroup Competition and Sources of Mortality 415 3.3. Relatedness Structure and Inbreeding 416 4. Reproductive Conlict 419 4.1. Patterns of Female Reproduction 419 4.2. Reproductive Control via Eviction 423 4.3. Reproductive Competition among Males 425 4.4. Eviction of Males 427 4.5. Dispersal and Population Consequences of Eviction 427 4.6. The Evolution of Reproductive Skew in Banded Mongooses 428 5. Helping Behavior 430 5.1. Babysitting and Escorting 430 5.2. The Costs of Helping 431 5.3. The Beneits of Helping 433 5.4. The Evolution of Cooperative Care in the Banded Mongoose 435 6. Conclusions 437 6.1. Social Evolution: Theory Meets Reality 437 Acknowledgments 439 References 440