Seed predation

Seed predators (granivores) can consume large proportions of newly produced weed seeds. Prevent or limit seed additions to the seed bank and thus reduce future weed problems is an important ecosystem service. However, the level of seed predation is spatially and temporally variable. One of the factors contributing to this variability is the identity of seed predators. Granivorous mice, birds, ants, crickets, and carabid beetles differ substantially in activity patterns, dispersal abilities, food preferences, seed predation efficiency, overwinter survival strategy, etc. Consequently, they differ in the levels and patterns of seed predation. Knowing which seed predator is active is relevant, for example, to explain the overall level of seed predation, spatial and temporal variability and differences in seed predation between weed species. Knowing the identity of the seed predator is also relevant to understand the response to biotic and abiotic factors, crop management or landscape complexity.

The identity of the main seed predators varies strongly from region to region. A specific seed predator may be absent from a location because that location simply falls outside the fundamental ecological niche of that species or because the size of the niche has been reduced by biotic, abiotic or human-induced constraints. Knowing which factors limit the distribution of which seed predator can help to design measures to promote seed predators. Unfortunately, for most seed predators, natural and present distribution patterns are unknown.

Simple techniques exist to determine whether seed predation is caused by vertebrates or invertebrates (exclusion cages; presence/absence data). It may even be possible to distinguish between the main types (selective exclusions). More complicated, laborious or expensive techniques are required to determine the identity (e.g., camera trapping) and densities (pitfall traps, nest counts, bird sightings, rodent life traps, footprint traps) of the seed predators involved. Depending on interests, experience and facilities, different protocols can be designed to maximize information output.

The objective of this joint research effort is to gain insight in the distribution of seed predators in different member states, by;

  • Identifying the main granivores
  • Relating the identity of the granivores to environmental and management factors, and landscape context

A proposal was submitted in 2014 for collaborative research on granivore identity. Click here to see it

Joint activities

Proposal for a joint experiment

Proposal for a joint experiment to determine the variability in granivore identity

Protocol for joint experiment

Level 1 protocol. Differentiating between vertebrates and invertebrates

Paula Westerman

Wageningen University and Research
Biointeraction and plant health - Field Crops
P.O. box 16, 6700 AA Wageningen
Tel: +31 320 2 91164