The Database of In Vivo Bite Force Studies



This database provides a record of published analyses of voluntary in vivo bite-force performance from conscious vertebrates (not including humans).


It aims to:

  • provide a resource for researchers wishing to evaluate the current body of literature
  • advertise the breadth and diversity of research into bite force performance
  • encourage more explicit communication of methods by researchers
  • highlight past and current inconsistencies in methods used
  • facilitate reaching a consensus on a universally accepted set of methods which will make comparisons amongst studies more meaningful


Bite-force can be important as:

  • a measure of whole-organism performance and fitness
  • a measure of sexual dimorphism, male dominance, and reproductive success
  • a comparison for predictions based on theoretical or computer-based skull mechanics


Bite force is typically measured by placing a special device in the animal’s mouth after it has been encouraged to gape (e.g. by tapping lightly on the snout). The device generally comprises a pre-calibrated transducer with bite plates that converts strain into an electrical signal that can be quantified. Typically, several bites are obtained from each animal, and the most forceful bites are used to compare peak performance.


To date about half of the >120 studies have focused on lizards but, there are also studies on crocodylians, tuatara, bats, rodents, sharks, hyenas, and birds. Direct comparisons amongst studies are currently hampered by a lack of consensus with respect to methods used (e.g. whether the bite plates of a transducer and covered with leather, rubber, textile, or nothing at all).


The database includes an entry for each known analysis incorporating:

  • the full citation
  • an internet link to the publication
  • the species investigated
  • a broader taxonomic category
  • details of the devise used (if specified)
  • details of the substrate used to cover the bite bars (if specified)
  • substrate category
  • the part of the jaws used to apply the bites (if specified)
  • details of methods used to standardize out-lever (if specified)
  • out-lever control category
  • whether bite force trials were filmed


Some of these variables can plotted against one another to generate graphs, e.g. year vs taxon investigated, to show the cumulative number of analyses on lizards.


Anyone who uses this database for research purposes should cite the following publication where the database was first used and reported:


Lappin AK, Jones MEH. 2014. Reliable quantification of bite-force performance requires use of appropriate biting substrate and standardization of bite out-lever. Journal of Experimental Biology 217: 4303-4312. DOI: 10.1242/jeb.106385,


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Funding and support

This database was first conceived during a research trip by Marc Jones to Kris Lappin’s lab in California funded by a University College London Bogue Fellowship. It was constructed with support from eResearch South Australia. Additional support was received from an Australian Research Council Discovery Early Career Researcher Award DE130101567 (grant awarded to Marc Jones), a Biotechnology and Biological Sciences Research Council grant BB/E007465/1 (awarded to Susan E. Evans, UCL), the Environment Institute, and the Biological Sciences Department at California State Polytechnic University.