Taphonomy of pollen associated with predation

The pollen contents of owl pellets were studied in order to use them as modern analogues in the interpretation of fossil sediments which accumulated through predation. Firstly, experiments were conducted to follow pollen through a trophic predation cycle and to observe any physical alterations. Neither pollen in mouse droppings nor that in raptor pellets showed any clear signs of damage as result of digestion by gastric juices. However, clear fracturing of grass pollen grains were observed in one case. The cause of fracturing is unknown and although chewing action of rodents may be considered as one possibility, further research is necessary to study this phenomenon and its significance. Further, it was found that chemical preparation of pellets to extract pollen resulted in the formation of high ratios of small organic nodules. A thin but very resistant superficial debris covering was found on many pellet pollen grains, but it could not be firmly established if it is caused by digestive action in the stomachs of raptors or by the laboratory procedure. Further, the pollen composition of pellets in the natural setting was studied to throw light on alterations on pollen assemblages in the predation process. The modern analogues show differences in pollen composition between accumulation sites and the pollen rain of the study area. They help to identify several problems of predation bias such as seasonal variations, and site locality, which should be considered in environmental interpretations of fossil material.