Journal of Experimental Biology was alerted by readers and on PubPeer to several issues with J. Exp. Biol. (1997) 200, 2513-2522 (doi.org/10.1242/jeb.200.19.2513).
The graph in Fig. 3A labelled ‘still air’ with N=19 is reused in Fig. 3B with N=35 and labelled ‘14 cm tunnel control’. The control graph in Fig. 7 is labelled with a tunnel length of 7.6 m and N=71, which is different to the identical graph shown in Figs 2, 3 and 5, where it has a length of 3.2 m and N=121. In Fig. 3B, the width of the narrow tunnel is reported to be 7 cm and the 22 cm wide tunnel has a sample size of N=56 but in Fig. 8C of a previous paper by Srinivasan et al. (1996) (doi.10.1242/jeb.199.1.237) showing the same results, the tunnel is 11 cm wide and the sample size for the 22 cm tunnel is N=88.
Unfortunately, the original data, analyses and figure plots are not available to determine the reasons for the discrepancies. The corresponding author, M. V. Srinivasan, says that Fig. 3A and Fig. 3B show the results of the same control experiment but there is an error in the sample size. It is impossible, at this stage, to specify which sample size is the correct one (N=19 or N=35). It appears that Fig. 7 does not contain the correct graph for the searching distribution with the landmark positioned at Unit 9, which was a separate experiment from those described in Figs 2, 3 and 5. The 1996 paper is likely to contain the correct values of the width of the narrow tunnel (11 cm) and the sample size (N=88) in the context of the experiment with the 22 cm wide tunnel in Fig. 3B.
Srinivasan takes sole responsibility for the errors and apologises for any inconvenience caused, but states that the issues do not alter the overall results and conclusions of the paper.
We are publishing this Expression of Concern to make readers aware of the issues and our efforts to resolve them.
See also doi:10.1242/jeb.248084.
