Mammalian Biology 77 (2012) 1–5 Contents lists available at SciVerse ScienceDirect Mammalian Biology journal homepage: www.elsevier.de/mambio Original Investigation Reproductive state does not influence activity budgets of eusocial Ansell’s mole-rats, Fukomys anselli (Rodentia, Bathyergidae): A study of locomotor activity by means of RFID Charlotte K.M. Schielke a,∗ , Sabine Begall a , Hynek Burda a,b a Department of General Zoology, Faculty of Biology, University of Duisburg-Essen, 45117 Essen, Germany b Department of Forest Protection and Game Management, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, 165 21 Prague 6, Czech Republic article info Article history: Received 28 February 2011 Accepted 23 September 2011 Keywords: Ansell’s mole-rats Activity Longevity RFID abstract Ansell’s mole-rats (Fukomys anselli) live in families of a breeding pair and several overlapping generations of their non-breeding offspring. Locomotor activity of 47 Ansell’s mole-rats from six laboratory families was recorded for a week using radio frequency identification (RFID). This technique allowed monitoring each animal’s activity without isolating them from other members of their family. Animals were active about 17% of the recording time, and older animals were significantly less active than younger ones. Females tended to be slightly more active than males. There was no significant difference in the amount of activity between breeding and non-breeding individuals. Consequently, the activity pattern does not seem to account for previously reported differences in longevity between breeding and non-breeding animals. © 2011 Deutsche Gesellschaft für Säugetierkunde. Published by Elsevier GmbH. All rights reserved. Introduction A trade-off between survival and reproduction is central to most life-history theories. Reproduction is expected to cause a decrease in future survival in many animal species (Harmann 1957; Wong 2001; Monaghan and Haussmann 2006). Eusocial hymenopterans and termites are an exception to this pattern with reproductive queens significantly exceeding the average lifespan of workers (cf. Hölldobler and Wilson 1990). The strictly subter- ranean mole-rat Fukomys anselli (Rodentia, Bathyergidae) from Zambia, represents a mammalian exception to this general trade- off. It is one of only a few mammalian species known to date that live in eusocial systems (reviewed in Burda et al. 2000). In contrast to the expected trade-off between reproduction and life expectancy, breeding individuals in F. anselli and F. mechowii live on average twice as long as their non-breeding same-sex counter- parts (Dammann and Burda 2006; Dammann et al. 2011). However, the proximate factors to explain this unusual feature are not yet known. Laboratory studies are well suited to investigate senescence pat- terns since extrinsic factors influencing lifespan such as predation, ∗ Corresponding author at: Department of General Zoology, Faculty of Biology, University of Duisburg-Essen, Universitätsstr. 5, 45117 Essen, Germany. Tel.: +49 201 183 3198; fax: +49 201 183 3768. E-mail address: charlotte.schielke@uni-due.de (C.K.M. Schielke). food availability, or climatic conditions can be excluded and the focus can be set on intrinsic mechanisms. According to the ‘rate of living’ theory, energy turnover and lifespan are negatively corre- lated (Pearl 1928), but discussions about the decrease of physical integrity (and thus life expectancy) caused by high energy turnover are controversial (Speakman et al. 2004). Subterranean mammals in general show low overall activity (Jarvis 1973; Hickman 1980; Bandoli 1987; Cameron et al. 1988; Lovegrove 1988; Benedix 1994; Zuri and Terkel 1996; ˇ Skliba et al. 2007), and low metabolic rates (Contreras and McNab 1990; Buffenstein 2000; Zelová et al. 2007). Mole-rats of at least two genera of the family Bathyergidae grow remarkably old compared to other mammals of the same size (reviewed in Dammann and Burda 2007; Edrey et al. 2011). Here, we tested the hypothesis that the energy turnover accounts not only for the prolonged lifespan of the breeding animals but also for the observed differences in mean lifespan between reproductive and non-reproductive F. anselli. We focus on individual locomotor activity as a marker and cor- relate of energy turnover. As activity in social animals has to be studied within the context of their social unit (because isolated animals may be less or more active due to isolation stress whereas the animals in larger groups may be more active due to stimulation and disturbance by other group members), we used radio frequency identification (RFID) to record activity of individual family mem- bers within their colony. The aim of this study was to determine whether activity of F. anselli correlates with social and/or repro- ductive status and age. 1616-5047/$ – see front matter © 2011 Deutsche Gesellschaft für Säugetierkunde. Published by Elsevier GmbH. All rights reserved. doi:10.1016/j.mambio.2011.09.004