4.3.1.3 — Mammals: Marine Mammals

Migration is observed in all orders of marine mammals. General distribution maps for most species are compiled in the "Handbook of Marine Mammals of the World" (Ridgway & Harrison 1981-1999). Maps have been digitised for CMS Appendix I and most of CMS Appendix II species. However, these maps do not contain information about migration, and some of them do not reflect the present situation. Considerable differences to more recent distribution maps have been found for the monk seal (Monachus monachus, see Figure A2.17). At present, satisfactory maps on a global scale do not seem to be available, and a recent study on small whales by Culik (2001) did not reveal better maps. There is an urgent need to compile new maps, which should integrate the considerable amount of distribution data gathered by new monitoring techniques such as satellite tracking (Breonce 2001) or genetic population studies (see Figure A2.24, and references therein). These maps should be compiled in GIS format, which would make it possible to record complexities of migration patterns, in particular for species with sexual segregation.

This document should be quoted as part of the publication "Riede, K. (2001): The Global Register of Migratory Species ­ Database, GIS Maps and Threat Analysis. Münster (Landwirtschaftsverlag), 400 pp." + CD

 by Klaus Riede