Observation resolution critically influences movement-based foraging indices

Michael Kalyuzhny*, Tom Haran, Dror Hawlena

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Movement‐based indices such as moves per minute (MPM) and proportion time moving (PTM) are common methodologies to quantify foraging behavior. Hundreds of studies have reported these indices, many without specifying the temporal resolution of their original data, and others using varying resolutions. This was done despite the likelihood that observation resolution can affect MPM and PTM estimates. Our goal was to empirically determine the sensitivity of these foraging indices to changes in the temporal resolution of the observation. We used a high-speed camera to record movement sequences of 20 Acanthodactylus boskianus lizards. Then, we gradually decreased the resolution of the data and calculated the foraging indices at different temporal resolutions. When considering the range of temporal resolutions that are relevant for field observations with unassisted vision, we found 68% and 48% difference in MPM and PTM estimates, respectively. When using the highest resolution, our estimate of MPM was an order of magnitude higher than all prior reported values for lizards. Our results raise major concerns regarding the use of already published movement-based indices, and enable us to recommend how new foraging data should be collected.

Original languageAmerican English
Article number13636
JournalScientific Reports
Issue number1
StatePublished - 1 Dec 2019

Bibliographical note

Funding Information:
We acknowledge Topaz Halperin for her invaluable comments suggestions, the members of the risk management ecology lab for stimulating discussions, and the support of a European Research Council grant (ERC‐2013‐ StG‐337023 (ECOSTRESS)) to D.H. M.K. is supported by the Adams Fellowship Program of the Israel Academy of Sciences and Humanities.

Publisher Copyright:
© 2019, The Author(s).


Dive into the research topics of 'Observation resolution critically influences movement-based foraging indices'. Together they form a unique fingerprint.

Cite this