An experimental assessment of seed adhesivity on animal furs

Abstract

Epizoochory is widely recognized as an effective long-distance seed dispersal mechanism. Nevertheless, few studies have focused on the investigation of its influencing factors. One of the key aspects of epizoochory is the adhesive interaction between seeds and furs. We describe a new method to quantify experimentally and standardize the adhesivity of seeds to animal fur, as a measure of epizoochorous dispersal potential. The method excludes the impact of animal behaviour and environmental factors, and allows the ranking of species according to their adhesivity score. We measured adhesivity scores for 66 species on the furs of seven mammals. Deep furs with long, rough, undulated hairs implanted at a large angle were most suited for seed adhesion, while seeds adhered less well to shallow furs with short, smooth, straight hairs implanted at small angles. Seeds with specialized adhesive appendages had higher adhesivity scores than seeds with unspecialized appendages and seeds without appendages. However, an interaction effect between certain seed and fur types exists. Although seed morphology is a good predictor for seed adhesivity on fur, less well-adhering seed types often still have relatively high adhesivity scores. Therefore, it is likely that nearly all species are, to some extent, able to disperse epizoochorously.

Soil seed banks near rubbing trees indicate dispersal of plant species into forests by wild boar

“…In the tests of Couvreur et al (2004) adhesivity of seeds in wild boar fur was highly negatively correlated with seed size, whereas -in contrast to all other tested furs -no correlation had been found with appendage length or density. Under the given experimental conditions (seeds were dropped perpendicularly on the fur) the thick-haired, but not very dense fur of wild boar seemed to favour the retention of small, unspecialised seeds more than the retention of seed with appendages.…”

“…Under the given experimental conditions (seeds were dropped perpendicularly on the fur) the thick-haired, but not very dense fur of wild boar seemed to favour the retention of small, unspecialised seeds more than the retention of seed with appendages. The inconsistence between field studies and the experiments of Couvreur et al (2004) elucidates that full understanding of the process of epizoochory requires an integration of knowledge about all influencing factors, e.g. plant traits such as the height of seed exposure and the duration of disseminating period (Fischer et al 1996), as well as animal movement and behaviour like wallowing and grooming.…”

“…In contrast to domestic animals, where epizoochory can be studied combining repeated surveys over time by adhesivity experiments of the same live animal (Fischer, Poschlod & Beinlich 1996, Kiviniemi 1996, Graae 2002, the methods to study epizoochory by wild large mammals are very limited. Couvreur, Vandenberghe, Verheyen & Hermy (2004) used standardized laboratory experiments to quantify seed adhesivity on prepared fur samples of three wild and four domestic mammalian species, including wild boar fur. These experiments al-lowed for a controlled assessment of seed adhesion merely regarding fur and seed traits, while controlling other environmental and behavioural factors such as plant traits, vegetation characteristics, weather, animal movement and wallowing.…”

Role of plant functional traits in determining vegetation composition of abandoned grazing land in north‐eastern Victoria, Australia

“…Many of the introduced annuals were grasses which are commonly dispersed by epizoochory (Dorrough et al 2004), an attribute that was associated with secondary forest. Grazers may be directly responsible for this by importing propagules, both by epizoochory (Couvreur et al 2004) and in faeces (Cosyns et al 2005), or indirectly by disturbing the soil and creating gaps, providing introduced species with establishment opportunities (Hobbs & Huenneke 1992;Dorrough et al 2004). …”

High potential of sub-Mediterranean dry grasslands for sheep epizoochory

“…Long-distance dispersal, although rare [16][17][18][19][20][21], has been consistently identified as an important process determining many aspects in the life history of plant species (i.e. seed mass and seed morphology) [22][23][24][25].…”