title: Differences in cooperative behavior among Damaraland mole rats are consequences of an age-related polyethism.
abstract: In many cooperative breeders, the contributions of helpers to cooperative activities change with age, resulting in age-related polyethisms. In contrast, some studies of social mole rats (including naked mole rats, Heterocephalus glaber, and Damaraland mole rats, Fukomys damarensis) suggest that individual differences in cooperative behavior are the result of divergent developmental pathways, leading to discrete and permanent functional categories of helpers that resemble the caste systems found in eusocial insects. Here we show that, in Damaraland mole rats, individual contributions to cooperative behavior increase with age and are higher in fast-growing individuals. Individual contributions to different cooperative tasks are intercorrelated and repeatability of cooperative behavior is similar to that found in other cooperatively breeding vertebrates. Our data provide no evidence that nonreproductive individuals show divergent developmental pathways or specialize in particular tasks. Instead of representing a caste system, variation in the behavior of nonreproductive individuals in Damaraland mole rats closely resembles that found in other cooperatively breeding mammals and appears to be a consequence of age-related polyethism.
authors: Department of Zoology, University of Cambridge, Cambridge CB23EJ, United Kingdom; mz338@cam.ac.uk.
authors: Markus
authors: M
authors: Zöttl
authors: Department of Zoology, University of Cambridge, Cambridge CB23EJ, United Kingdom;
authors: Philippe
authors: P
authors: Vullioud
authors: Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, 0028 Pretoria, South Africa; Institute of Biology, University of Neuchatel, Rue Emile-Argand 11, CH-2000 Neuchatel, Switzerland;
authors: Rute
authors: R
authors: Mendonça
authors: Department of Zoology, University of Cambridge, Cambridge CB23EJ, United Kingdom; Kalahari Mole-Rat Project, Kuruman River Reserve, 8467 Van Zylsrus, South Africa.
authors: Miquel
authors: M
authors: Torrents Ticó
authors: Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, 0028 Pretoria, South Africa;
authors: David
authors: D
authors: Gaynor
authors: Kalahari Mole-Rat Project, Kuruman River Reserve, 8467 Van Zylsrus, South Africa.
authors: Adam
authors: A
authors: Mitchell
authors: Department of Zoology, University of Cambridge, Cambridge CB23EJ, United Kingdom; Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, 0028 Pretoria, South Africa;
authors: Tim
authors: T
authors: Clutton-Brock
mesh_terms: D000375:Aging / Q000235:genetics / Q000502:physiology*; D000818:Animals; D001835:Body Weight / Q000235:genetics / Q000502:physiology; D001947:Breeding; D003299:Cooperative Behavior; D005260:Female; D008297:Male; D019577:Mole Rats / Q000235:genetics / Q000502:physiology*; D051381:Rats; D012726:Sexual Behavior, Animal / Q000502:physiology; D012919:Social Behavior
keywords: caste; cooperative breeding; division of labor; eusociality; social mole rats