An automated barcode tracking system for behavioural studies in birds

Abstract

Recent advances in technology allow researchers to automate the measurement of animal behaviour. These methods have multiple advantages over direct observations and manual data input as they reduce bias related to human perception and fatigue, and deliver more extensive and complete datasets that enhance statistical power. One major challenge that automation can overcome is the observation of many individuals at once, enabling whole‐group or whole‐population tracking. We provide a detailed description of an automated system for tracking birds. Our system uses printed, machine‐readable codes mounted on backpacks. This simple, yet robust, tagging system can be used simultaneously on multiple individuals to provide data on bird identity, position and directionality. Furthermore, because the backpacks are printed on paper, they are very lightweight. We show that our method is reliable, relatively easy to implement and monitor, and with proper handling, has proved to be safe for the birds over long periods of time. We describe the deployment procedure of this system for a captive population of songbirds. We test different camera options, and discuss their advantages and disadvantages. In particular, we highlight how using single‐board computers to control the frequency and duration of image capture makes this system affordable and adaptable to a range of study systems and research questions. The ability to automate the measurement of individual positions has the potential to significantly increase the power of both observational and experimental studies. The system can capture both detailed interactions (using video recordings) and repeated observations (e.g. once per second for the entire day) of individuals over long timescales (months or potentially years). This approach opens the door to tracking life‐long relationships among individuals, while also capturing fine‐scale differences in behaviour.

Winter associations predict social and extra-pair mating patterns in a wild songbird

“…Information about fine-scale associations within flocks would help to conclusively show that social interactions with future extra-pair mates differ from other close neighbours. To fully understand whether and how prior social associations affect mating patterns, studies using more advanced tracking technologies [64] are needed to capture finer-scale patterns of social preferences. Furthermore, studies examining how differences in winter social structure (e.g.…”

Early-life social environment predicts social network position in wild zebra finches

“…However, we still know relatively little about why stress appears to programme individuals to be more socially gregarious and less choosy. Captive experiments in which finer details about the directionality of inter-individual interactions can be captured, facilitated by recent innovations in long-term high-resolution tracking individuals [95], could provide new insights into the mechanisms-how do stressed individuals end up being more central and well-connected? A combination of new technology and methods, and additional targeted field studies, will hopefully allow us to determine whether the differences that have been observed are caused by the decisions of the stressed individuals themselves or the behaviour of others towards them.…”

“…After each swap, we recalculated the network, thus producing 10 000 random networks. Significance was calculated by comparing the observed coefficient value to the distribution of coefficient values from the randomized networks (following [59], see also [61]). For effects that were significant in Boogert et al [28], we used a one-tailed significance test, whereas we used a two-tailed test for effects that were not significant in Boogert et al [28].…”

Linking the fine‐scale social environment to mating decisions: a future direction for the study of extra‐pair paternity

“…In addition to formalizing the analysis of social data, studies in the field of social network analysis have stimulated the development of tools and technologies for studying animals at fine scales over long periods of time. Approaches such as individual‐tracking using PIT tags (Farine & Sheldon, ), barcodes (Alarcon‐Nieto et al, ), proximity loggers (Ryder et al, ), and GPS tracking data (Kays et al, ), are facilitating a revolution in the resolution of data that can be collected on between‐individual interactions. When combined with long‐term studies, these will hopefully provide the data required to address these exciting new questions.…”