TManual: Assistant for manually measuring length development in structures built by animals

Abstract

Structures built by animals are extended phenotypes, and animal behavior can be better understood by recording the temporal development of structure construction. For most subterranean and wood‐boring animals, these structures consist of gallery systems, such as burrows made by mice, tunnel foraging by termites, and nest excavation in ants. Measurement of the length development of such structures is often performed manually. However, it is time‐consuming and cognitively costly to track length development in nested branching structures, hindering the quantitative determination of temporal development. Here, I introduce TManual, which aids the manual measurement of structure length development using a number of images. TManual provides a user interface to draw gallery structures and take over all other processes handling input datasets (e.g., zero‐adjustment, scaling the units, measuring the length, assigning gallery identities, and extracting network structures). Thus, users can focus on the measuring process without interruptions. As examples, I provide the results of the analysis of a dataset of tunnel construction by three termite species after successfully processing 1125 images in ~3 h. The output datasets clearly visualized the interspecific variation in tunneling speed and branching structures. Furthermore, I applied TManual to a complex gallery system by another termite species and extracted network structures. Measuring the lengths of objects from images is an essential task in biological observation. TManual helps users handle many images in a realistic time scale, enabling a comparative analysis across a wide array of species. TManual does not require programming skills and outputs a tidy data frame in CSV format. Therefore, it is suitable for any user who wants to perform image analysis for length measurements.

Modelling termites’ tunnelling and decision-making behaviors

“…As shown in Fig. 4A, the results of the TLM model (8) compare well with the average tunnel lengths of H. aureus and R. tibialis determined in the experiments [14], [23]. Fig.…”

“…To develop a mathematical model and a decision tree to describe termites tunnelling over time, we collected experimental data provided by Mizumoto et al (2020) [14] and Mizumoto (2023) [23]. We observed the tunnelling of Heterotermes aureus and Reticulitermes tibialis.…”

“…Behaviour and Develop the TB Model • Names of tunnels and branches: The first four types of tunnels are considered as the Primary, Secondary (Primary branch), tertiary (Secondary branch), and Quaternary (Tertiary branch) tunnels [23]. Tunnel names are assigned by their directions and tunnel/branch numbers.…”

“…Since the identification of the groups and measurement of the systems is performed arbitrarily by researchers, results are intuitive and can vary. Recently, Mizumoto (2023) developed a software using Python to measure termite tunnel length manually based on photo analysis [23]. It estimates the tunnel length by detecting the change in subsequent photos.…”

“…We develop a mathematical model to investigate termites tunnelling behavior in experimental arenas inspired and extracted by Mizumoto (2023) [23]. This model can interpret how tunnel length grows and estimates the possible tunnel length over time.…”