FSD 2010 - Nathan

5th International Symposium-Workshop on Frugivores and Seed Dispersal (1985-2010)

Ran Nathan

Department of Evolution, Systematics and Ecology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel

Website

rnathan(a)cc.huji.ac.il

Activities

In the late 1980s, as an undergraduate student and a keen birder, I planned to study bird ecology but eventually found myself fascinated by seed dispersal by wind. These winds have carried me all through my MSc, PhD and post-doctoral work. This topic is still one of the leading research themes in my lab, combining models, fieldwork, and genetics to address questions of wind dispersal mechanisms and consequences, with special emphasis on long-distance dispersal (LDD) events. In the early 2000s, however, I switched back to my original plan to study birds, first through the easy link of bird-mediated seed dispersal of fleshy-fruited desert plants, but later continued to seed-dispersal-free studies of bird foraging and migration. Along the way, I also learned, with the help of my superb students, that harvester ants and fruit bats are also stunning creatures to study, and our studies at these fronts have been at least as interesting and exciting as our studies on seeds and birds. From this seemingly unstructured mixture, movement ecology has emerged as a unifying framework developed to study movement of any type and organisms of any kind. Movement of organisms is one of the most fundamental features of life on earth and we feel it is a great privilege to be engaged so deeply in such a fascinating field of research.

Abstract

A movement ecology approach for studying seed dispersal by frugivorous animals

The movement ecology framework asserts that the movements of an organism, of any kind, can be described by only four basic components. Three components are properties of the focal individual: The internal state affecting its motivation to move, and the motion and navigation capacities accounting for its ability to move in various ways and directing its moves by sensing and responding to the environment, respectively. A fourth component lumps all external factors associated with the abiotic and biotic environment influencing movement. The generality assertion implies that the movement of seeds dispersed by a frugivore, and the movement of the frugivore itself, can be described mechanistically by identifying the parameters that make for the same four components in each of the two entities. More specifically, the case of animal-mediated seed dispersal constitutes an inner movement ecology scheme (of the dispersed seed) nested within an outer movement ecology scheme (of the frugivore). This view advocates a vector-based rather than a seed-based approach to studying seed dispersal by frugivores (or any other vector). Applying the movement ecology approach to seed dispersal by frugivorous birds and bats points at the importance of spatial scale, and helps to identify the key morphological, behavioral and ecological features that underlie the formation of complex seed shadow.

Related references (More Abstract and pdf)

Nathan, R. 2008. An emerging movement ecology paradigm. Proceedings of the National Academy of Sciences of the United States of America 105:19050-19051.

Nathan, R., W. M. Getz, E. Revilla, M. Holyoak, R. Kadmon, D. Saltz, and P. E. Smouse. 2008. A movement ecology paradigm for unifying organismal movement research. Proceedings of the National Academy of Sciences of the United States of America 105:19052-19059.

Nathan, R., F. M. Schurr, O. Spiegel, O. Steinitz, A. Trakhtenbrot, and A. Tsoar. 2008. Mechanisms of long-distance seed dispersal. Trends in Ecology & Evolution 23:638-647.

Nathan, R. 2006. Long-distance dispersal of plants. Science 313:786-788. Abstract

Spiegel, O., and R. Nathan. 2007. Incorporating dispersal distance into the disperser effectiveness framework: frugivorous birds provide complementary dispersal to plants in a patchy environment. Ecology Letters 10:718–728. Abstract