The quality of visual information that is available to an animal is limited by the size of its eyes. Differences in eye size can be observed even between closely related individuals, yet we understand little about how this affects vision. Insects are good models for exploring the effects of size on visual systems because many insect species exhibit size polymorphism. Previous work has been limited by difficulties in determining the 3D structure of eyes. We have developed a novel method based on x-ray microtomography to measure the 3D structure of insect eyes and to calculate predictions of their visual capabilities. We used our method to investigate visual allometry in the bumblebee Bombus terrestris and found that size affects specific aspects of vision, including binocular overlap, optical sensitivity, and dorsofrontal visual resolution. This reveals that differential scaling between eye areas provides flexibility that improves the visual capabilities of larger bumblebees.

It is generally accepted that, when moving in groups, animals process information to coordinate their motion. Recent studies have begun to apply rigorous methods based on Information Theory to quantify such distributed computation. Following this perspective, we use transfer entropy to quantify dynamic information flows locally in space and time across a school of fish during directional changes around a circular tank, i.e. U-turns. This analysis reveals peaks in information flows during collective U-turns and identifies two different flows: an informative flow (positive transfer entropy) based on fish that have already turned about fish that are turning, and a misinformative flow (negative transfer entropy) based on fish that have not turned yet about fish that are turning. We also reveal that the information flows are related to relative position and alignment between fish, and identify spatial patterns of information and misinformation cascades. This study offers several methodological contributions and we expect further application of these methodologies to reveal intricacies of self-organisation in other animal groups and active matter in general. * emanuele.crosato@sydney.edu.au arXiv:1705.01213v1 [q-bio.QM] 3 May 2017 Nagy et al. [55] used a variety of correlation functions to measure directional dependencies between the velocities of pairs of pigeons flying in flocks of up to ten individuals, reconstructing the leadership network of the flock. As has been shown later, this network does not correspond to the hierarchy between birds [56]. Information transfer has been extensively studied in flocks of starlings, by observing the propagation of direction changes across the flocks [20,19,2]. More recently, Rosenthal et al. [69] attempted to determine a communication structure of a school of fish during its collective evasion manoeuvres manifested through cascades of behavioural change. A functional mapping between sensory inputs and motor responses was inferred by tracking fish position and body posture, and calculating visual fields.Rather than consider semantic or pragmatic information, many contemporary studies employ rigorous information theoretic measures that quantify information as uncertainty reduction, following Shannon [24], in order to deal with the stochastic, continuous and noisy nature of intrinsic information processing in natural systems [28]. Distributed information processing is typically dissected into three primitive functions: the transmission, storage and modification of information [38]. Information dynamics is a recent framework characterising and measuring each of the primitives information-theoretically [49,41]. In viewing the state update dynamics of a random process as an information processing event, this framework performs an information regression in accounting for where the information to predict that state update can be found by an observer, first identifying predictive information from the past of the process as information storage, then predictive information from other sour...

The quality of visual information that is available to an animal is limited by the size of its eyes. Differences in eye size can be observed even between closely related individuals but we understand little about how this affects visual quality. Insects are good models for exploring the effects of size on visual systems because many species exhibit size polymorphism, which modifies both the size and shape of their eyes. Previous work in this area has been limited, however, due to the challenge of determining the 3D structure of eyes. To address this, we have developed a novel method based on x-ray tomography to measure the 3D structure of insect eyes and calculate their visual capabilities. We investigated visual allometry in the bumblebee Bombus terrestris and found that size affects specific aspects of visual quality including binocular overlap, optical sensitivity across the field of view, and visual resolution in the dorsofrontal visual field. This holistic study on eye allometry reveals that differential scaling between different eye areas provides substantial flexibility for larger bumblebees to have improved visual capabilities. List of abbreviations:az. -Azimuth CC -Crystalline cone el. -Elevation EV -Eye volume FOV -Field of view ITW -Inter-tegula width IO -Inter-ommatidial microCT -micro-computed tomography NV -Normal vector