Journal of Ornithology

, Volume 161, Issue 1, pp 333–339 | Cite as

Photography as a tool for avian morphometric measurements

  • Heather M. WilliamsEmail author
  • Samantha B. Wilcox
  • Andrea J. Patterson
Original Article


Accurate morphometric measurements of birds are frequently needed in studies to provide an index of body size. However, obtaining these measurements in the field can be challenging and inter-observer repeatability of taking these measurements using calipers has been questioned in the literature. Here we present a method for measuring tarsus length and bill length, width and depth using digital photography with open source software (ImageJ), and we compare the repeatability and handling time of the digital measurements with those traditionally made using calipers. The digital method was more or equally repeatable than manual measurements of bill and tarsus and its repeatability was independent of measurement length, making it especially suited to making shorter measurements. While digital and manual measures were highly correlated for all body measures, the digital method produced slightly higher measurements in all cases meaning digital and manual measurements may not be directly comparable. Morphometric measurements made from digital photographs were possible with a significantly shorter bird handling time, can be completed by less experienced fieldworkers, and create a permanent record that can be later verified, making them a useful alternative to traditional manual measurements of unfeathered skeletal body parts which can be clearly visualized in photographs.


Bill length Bill width Bird banding Digital measurement Morphometry Tarsus 


Fotografie als Hilfsmittel für morphometrische Messungen bei Vögeln

Präzise morphometrische Messungen von Vögeln werden häufig in Untersuchungen benötigt, um ein Maß für die Körpergröße zu bekommen. Jedoch kann das Erheben solcher Messwerte im Feld eine Herausforderung darstellen und die Wiederholbarkeit zwischen den Beobachtern, die diese Messungen mit einer Schieblehre durchführen, wurde in der Fachliteratur oft in Frage gestellt. Hier zeigen wir eine Methode zur Messung der Tarsus- und Schnabellänge, -breite und -höhe mittels Digitalfotografie und einer Open-Source-Software (ImageJ). Weiterhin haben wir die Wiederholbarkeit und Handhabungszeit zwischen den digitalen und traditionellen Messungen mit einer Schieblehre miteinander verglichen. Die digitale Methode zeigte eine genauso gute oder sogar bessere Wiederholbarkeit wie bzw. als die manuelle Messung von Schnabel und Tarsus. Die Wiederholbarkeit war unabhängig von der Messdauer, was die Digitalfotografie besonders für schnelle Messungen geeignet macht. Während die digitalen und manuellen Messungen für alle Körpermaße stark miteinander korrelierten, ergab die digitale Methode immer etwas höhere Messwerte. Dies bedeutet, dass digitale und manuelle Messungen möglicherweise nicht direkt miteinander vergleichbar sind. Morphometrische Messungen anhand Digitalfotografien waren mit signifikant geringeren Handhabungszeiten der Vögel möglich, können durch weniger erfahrene Feldbeobachter durchgeführt werden und schaffen eine dauerhafte Aufzeichnung für spätere Überprüfungen. Dies macht die Digitalfotografie zu einer hilfreichen Alternative zur traditionellen, manuellen Messung von unbefiederten Körperteilen, die sich auf Fotos klar sichtbar abbilden lassen.



We are very grateful to Ramya Sridhar, Alyssa Gooding, Joseph Toth, and Logan Fahrenkopf for field assistance in taking photographs, and to Gayle Lazoration, Ryan Kayhart, Peggy Keller, Cindy Marino, and Emilia Rebollo for making manual measurements. We thank the reviewers for their thoughtful comments which have improved the quality of this manuscript. We especially thank the volunteers, members, and Board of Directors at Braddock Bay Bird Observatory for funding and operating the research station. HW is grateful for support from the National Science Foundation (1556577). All procedures performed in studies involving animals were in accordance with the ethical standards of the institution or practice at which the studies were conducted and all experiments comply with the current laws of the country in which they were performed.

Supplementary material

10336_2019_1728_MOESM1_ESM.docx (29 kb)
Supplementary material 1 (DOCX 29 kb)
10336_2019_1728_MOESM2_ESM.xlsx (17 kb)
Supplementary material 2 (XLSX 16 kb)


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Copyright information

© Deutsche Ornithologen-Gesellschaft e.V. 2019

Authors and Affiliations

  1. 1.Department of Environment and SustainabilityState University of New York at BuffaloBuffaloUSA
  2. 2.Department of Biological SciencesState University of New York at BuffaloBuffaloUSA
  3. 3.Braddock Bay Bird ObservatoryRochesterUSA

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