Naturwissenschaften

, Volume 97, Issue 6, pp 555–565

Internal dispersal of seeds by waterfowl: effect of seed size on gut passage time and germination patterns

  • Jordi Figuerola
  • Iris Charalambidou
  • Luis Santamaria
  • Andy J. Green
Original Paper

DOI: 10.1007/s00114-010-0671-1

Cite this article as:
Figuerola, J., Charalambidou, I., Santamaria, L. et al. Naturwissenschaften (2010) 97: 555. doi:10.1007/s00114-010-0671-1

Abstract

Long distance dispersal may have important consequences for gene flow and community structure. The dispersal of many plants depends on transport by vertebrate seed dispersers. The shapes of seed shadows produced by vertebrates depend both on movement patterns of the dispersers and on the dynamics and effects of passage through the disperser’s gut (i.e. the retention time, survival and germination of ingested seeds). A combination of experiments with captive waterbirds and aquatic plant seeds was used to analyse the following: (a) the effects of inter- and intra-specific variation in seed size and duck species on seed retention time in the gut and (b) the relationship between retention time and the percent germination and germination rates of seeds. Among the three Scirpus species used, those with smaller seeds showed higher survival after ingestion by birds and longer retention times inside their guts than those with larger seeds. For Potamogeton pectinatus, only seeds from the smaller size class (<8 mg) survived ingestion. Retention time affected the percent germination and germination rate of Scirpus seeds but in a manner that varied for the different plant and bird species studied. We recorded both linear and non-linear effects of retention time on percent germination. In addition, germination rate was positively correlated with retention time in Scirpus litoralis but negatively correlated in Scirpus lacustris. Small seed size can favour dispersal over larger distances. However, the effects of retention time on percent germination can modify the seed shadows produced by birds due to higher percent germination of seeds retained for short or intermediate periods. The changes in dispersal quality associated with dispersal distance (which is expected to be positively related to retention time) will affect the probability of seedling establishment over longer distances and, thus, the spatial characteristics of the effective seed shadow.

Keywords

Dispersal qualityEffects of seed ingestion by vertebratesEndozoochoryGermination rateSeed dispersalEffective seed shadowSeed size

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Jordi Figuerola
    • 1
  • Iris Charalambidou
    • 2
    • 3
  • Luis Santamaria
    • 2
    • 4
  • Andy J. Green
    • 1
  1. 1.Department of Wetland EcologyEstación Biológica de Doñana, CSICSevillaSpain
  2. 2.Netherlands Institute of Ecology-KNAWMaarssenThe Netherlands
  3. 3.Unit of Environmental Studies, CCEIAUniversity of Nicosia (Intercollege)NicosiaCyprus
  4. 4.IMEDEA, CSIC-UIBEsporlesSpain