Effects of acclimatisation on behavioural repeatability in two behaviour assays of the guppy Poecilia reticulata
Establishing behavioural repeatability is important in animal personality research; however, a range of factors can influence repeatability. Experimental design, particularly acclimation time, is important in managing a subject’s stress prior to the onset of behavioural observations. Acclimatisation also ensures we capture “normal” behaviour and promotes consistency in the subject’s responses between observations. The importance of acclimatisation prior to an assay is widely recognised by animal researchers; however, acclimation time varies dramatically across personality studies. Here, we investigated the effects of acclimatisation time on the repeatability of activity and emergence behaviour in feral and domestic populations of lab-reared guppy, Poecilia reticulata. Contrary with expectations and previous findings, we found highest repeatability in guppy activity levels after 2 h of acclimation to the test arena. In the emergence assay, fish exposed to 10 min of acclimatisation showed highest repeatability; however, all acclimation periods produced high repeatability, suggesting that the emergence assay generates robust behavioural responses irrespective of acclimation time. The outcomes were broadly consistent across both populations. These results show that methodology can impact the findings of animal personality research and needs to be considered carefully for each assay. We recommend that researchers investigate appropriate acclimatisation times for their study species prior to commencing research.
Animal personality is individual differences in behaviour that are maintained through time and across contexts. Thus, demonstrating the repeatability of behavioural differences between individuals is imperative to establishing animal personality. To estimate repeatability, individuals are assessed multiple times on the same task to ensure there are consistent differences between individuals. When carrying out repeated observations, acclimatisation time should be considered to minimise stress levels of an animal prior to the behavioural assay. We assessed a range of acclimation times on emergence and activity behaviour in two populations of guppies. While individual variation in emergence behaviour was repeatable across a range of acclimation times, activity levels in guppies became significantly more repeatable after 2 h of acclimatisation. These results show that considering proper acclimation time is important when performing behavioural experiments and should be properly calibrated by researchers prior to conducting personality research.
KeywordsMethodology Activity Emergence Personality Behavioural plasticity Population
We thank members of ‘The Fish Lab’ at Macquarie University for assistance with fish feeding, Dr. Andrew Allen for his assistance on our statistical analysis and anonymous reviewers for valuable feedback on the manuscript, Belinda Showler for assistance with analysis and Zac Warham for his work in creating the custom analysis program. This research was funded by the Department of Biological Sciences at Macquarie University.
This research was funded by the Department of Biological Sciences at Macquarie University.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
No animals died during the experiments. All procedures performed in studies involving animals were approved by, and in accordance with the guidelines outlined by the Macquarie University Animal Ethics committee (Approval No. ARA 2013/024).
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