Can seasonal home-range size in pike Esox lucius predict excursion distance? C. M. KNIGHT*†‡, R. E. GOZLAN*§ AND M. C. LUCAS† *Centre for Ecology and Hydrology, Winfrith Technology Centre, Dorchester, Dorset, DT2 8ZD, U.K. and †School of Biological and Biomedical Sciences, University of Durham, Science Laboratories, South Road, Durham DH1 3LE, U.K. (Received 8 September 2007, Accepted 16 June 2008) The hypothesis that vagility, or tendency to move, in pike Esox lucius can be predicted from individual home range was tested using telemetry. Independently of fish size, mean annual excursion distance was positively correlated to winter (002–095 ha) and spring (002–059 ha) home ranges but not summer and autumn home ranges. # 2008 The Authors Journal compilation # 2008 The Fisheries Society of the British Isles Key words: behaviour; dispersal; Esox lucius; radio tracking; telemetry. While episodic long-distance movements and dispersal are significant factors in characterizing population structure, measuring these movements is a difficult task and has rarely been studied in fishes (Muhlfeld & Marotz, 2005). Difficul- ties in predicting when and where an animal will move and finding them once they have moved has precluded many studies from collecting such data reliably and there remains a lack of good empirical data on dispersal and excursion dis- tance in fishes. A large amount of reliable information, however, has been col- lected on home-range size and structure in a wide range of fish species (Minns, 1995). Recent advances in mammalian and avian ecology have found a strong rela- tionship between home-range size and both dispersal distance and distance moved after translocation in an interspecies study (Bowman et al., 2002; Bowman, 2003). It was suggested that home range and long-distance move- ments covaried because both quantify an animal’s vagility or inherent tendency to move. This correlation has not previously been investigated in fishes or between individuals of a single species. Given the limitations on collecting data ‡Author to whom correspondence should be addressed at present address: Norwegian Institute of Water Research (NIVA), Gaustadall  een 21, NO-0349 Oslo, Norway. Tel.: þ47 22 18 51 00; fax: þ47 22 18 52 00; email: carolyn.knight@niva.no §Present address: School of Conservation Sciences, Bournemouth University, Talbot Campus, Fern Barrow, Poole, Dorset BH12 5BB, U.K. Journal of Fish Biology (2008) 73, 1058–1064 doi:10.1111/j.1095-8649.2008.01989.x, available online at http://www.blackwell-synergy.com 1058 # 2008 The Authors Journal compilation # 2008 The Fisheries Society of the British Isles