text: There are some potential drawbacks for the palynological analysis of middens, however, as the diverse taphonomic vectors can complicate interpretations if they are not adequately considered and controlled for. Pollen spectra from pellets - reflecting the animal’s needs or preferences on a particular day - may contrast strongly with pollen spectra preserved in hyraceum, and which thought to be primarily brought to the midden via the fur of the hyraxes (which is collected as it moves through the vegetation around its shelter) and the wind. The degree to which dietary biases affect pollen spectra in pellets is a subject that is not fully understood. While Scott and Cooremans have shown that at the biome scale, fresh pellets reflect vegetation of the region from which they were collected, including the seasonal variations within vegetation types, most published studies also indicate significant differences both between modern pellets, and between modern pellets and surface sediment samples from the same site. A number of options might explain this, but it is assumed that as any given pellet represents what was eaten in the last day(s), there will be substantial inter-seasonal and inter-annual variation in the pollen preserved.
  In most fossil pollen archives, wind-pollinated plants may dominate the natural pollen rain. Pollen production, however, is likely to have a less significant influence on the pollen that hyraxes ingest, and considering the wide variety of plants that they may eat, it may be possible to control for the taxon over-representation resulting from a production bias while still attaining a reasonable representation of the local vegetation.
  A study from the Lower Omo Basin of Ethiopia collected several dozen pellets from different areas around the study site, aggregated them into a single sample, and compared them to the local vegetation. 
  Structured studies to clarify the relative influence of regional (aeolian) and local (fur) signals in the pollen preserved in hyraceum remain to be completed. At least in some cases, aeolian inputs appear to be negligible as some middens that have accumulated in vertical cracks - precluding the incorporation of pellets and direct contact with the animals - have been found to be devoid of pollen. If aeolian pollen does represent a small percentage of the pollen preserved in hyraceum then it might be inferred that hyraceum pollen assemblages reflect primarily local vegetation cover from within the animals’ primary feeding range.