What happens to dead birds left in a cave and its vicinity for a quarter of a century? A taphonomic experiment

Abstract

This paper describes a bird carcass-monitoring experiment carried out in a limestone cave and its immediate vicinity in southern Poland for almost a quarter of a century. Some specimens deposited outside the cave were preserved almost intact, others were only a little weathered. Soft tissues and remnants of feathers were preserved in some of the samples inside the cave. Stages of bone modifications that can occur in a cave have been distinguished and illustrated for the first time. Also, bird bones from owl pellets have been used in a carcass-monitoring experiment for the first time. Bone modifications in the form of wrinkling, bending and/or collapsing of the bone surface were recorded only on the bones of birds that decomposed inside the cave, and not on bones that had been isolated from owl pellets prior to their deposition in the cave. Therefore, it is postulated that avian – and possibly also small mammal – bones that have been defleshed, either by people or animals, have a greater chance to survive and fossilize than bones deposited as complete carcasses in a cave. This agrees with the generally accepted notion that larger assemblages of small vertebrates in caves are usually the result of predator accumulation.

Keywords:

• Bird bones
• cave corrosion
• weathering
• traces of digestion
• fossilization
• taphonomy

Acknowledgments

The paper was presented at the ICAZ Taphonomy Working Group meeting, Paris, France, 2016, organized by Jean Philip Brugal and Christiane Denys.