On the analysis of mark-recapture data: a reply to Henle (2005)

Forum On the analysis of mark-recapture data: a reply to Henle (2005) Benedikt R. Schmidt 1,2 , Michael Schaub 3,4 , Bradley R. Anholt 5 Henle (2005) criticizes for a second time our analyses of toad mark-recapture data. We still believe that Dr. Henle’s arguments are based on misunderstandings of basic issues in mark- recapture methodology. For example, Dr. Henle argues that only data from toads captured at the last capture occasion are available for analy- sis (p. 13, i.e. bold-faced capture histories in Dr. Henle’s table 1). This argument is, like many others, at odds with mark-recapture the- ory (see Williams et al., 2002, for an excellent overview). All marked animals are informative regardless of whether they are ever recaptured or not. We stand by our analyses and conclusions in Schmidt and Anholt (1999) and Schmidt et al. (2002; also see Frétey et al., 2004). We find no convincing argument in Henle (2005) nor in Dr. Henle’s earlier critique. Further discussion of various ways to deal with temporary emigra- tion and an in-depth assessment of bias can be found in our Statistical Report published in the journal Ecology (Schaub et al. 2004). 1 - Zoologisches Institut, Universität Zürich, Winterthur- erstrasse 190, 8057 Zürich, Switzerland e-mail: [email protected] 2 - KARCH, Naturhistorisches Museum, Bernastrasse 15, 3005 Bern, Switzerland e-mail: [email protected] 3 - Schweizerische Vogelwarte, 6204 Sempach, Switzer- land 4 - Conservation Biology, Zoology Institute, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland 5 - Department of Biology, University of Victoria, PO Box 3020, Victoria, B.C., Canada, V8W 3N5 Last but not least, Dr. Henle seems to as- sociate us with Paul Kammerer, a well-known case of scientific fraud and misconduct. We pre- sume that this comparison was not an inten- tional attack on our integrity, scientific or oth- erwise. References Frétey, T., Cam, E., Le Garff, B., Monnat, J.-Y. (2004): Adult survival and temporary emigration in the common toad. Can. J. Zool. 82 : 859-872. Henle, K. (2005): Analysis of recapture data from breeding populations of amphibians: on temporary emigration, model assumptions, bias, and common toads. Amphibia- Reptilia 26 : 7-16. Schaub, M., Gimenez, O., Schmidt, B.R., Pradel, R. (2004): Estimating survival and temporary emigration in the multistate capture-recapture framework. Ecology 85 : 2107-2113. Schmidt, B.R., Anholt, B.R. (1999): Analysis of sur- vival probabilities of female common toads, Bufo bufo . Amphibia-Reptilia 20 : 97-108. Schmidt, B.R., Schaub, M., Anholt, B.R. (2002): Why you should use capture-recapture methods when estimat- ing survival and breeding probabilities: on bias, tem- porary emigration, overdispersion, and common toads. Amphibia-Reptilia 23 : 375-388. Williams, B.K., Nichols, J.D., Conroy, M.J. (2002): Analy- sis and management of animal populations. San Diego, Academic Press. Editorial note : The last manuscript written by Klaus Henle and published in Amphibia-Reptilia, Vol. 26, No. 1, pp. 7-16 (2005) is a forum paper and has been erroneously presented as a full article. © Koninklijke Brill NV, Leiden, 2005. Amphibia-Reptilia 26 (2005): 269 Also available online - www.brill.nl