Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.64898/2026.10.12.758461

Camouflage functions of juvenile giant panda colouration in forest environments

LI, Z.·Kelley, L. A.·Stevens, M.
View original source ↗Export metadata ↓

Abstract

The contrasting black-and-white coloration of the giant panda (Ailuropoda melanoleuca) has long attracted attention. Recent works suggest this contrasting pattern may generate camouflage-relevant visual effects. However, most previous studies have focused on adult pandas, whereas juveniles may face greater predation risk and may therefore represent a more ecologically relevant life stage for testing concealment hypotheses. We investigated whether juvenile panda coloration provides the potential for camouflage through background matching or disruptive coloration, and how this potential is shaped by vegetation cover, illumination and background position. We used life-sized juvenile panda models with natural and experimentally modified coloration by adjusting the relative proportions and spatial arrangement of white, black, and grey patches. Models were photographed in temperate woodland environments at ground level and against canopy backgrounds, under sunny and cloudy conditions, with and without vegetation occlusion. We quantified colour and luminance contrast, as well as edge-disruption metrics, using dichromatic canid and felid visual models. Natural juvenile panda coloration influences target-background contrast and edge-disruption, although these effects varies with vegetation, lighting, background height and visual model. Vegetation cover significantly reduced contrast and increased edge disruption metrics, while bright light condition only increased the metrics of edge disruption. Background position affected camouflage-relevant metrics in a context- and observer-dependent manner: under vegetation occlusion, canopy placement reduced chromatic contrast under felid-like vision, whereas ground-level placement reduced luminance contrast under both visual models. Alterations to patch extent and boundary arrangement modified camouflage-relevant metrics under specific environmental conditions, suggesting that the natural arrangement of pelage boundaries may enhance concealment under specific conditions. Overall, our findings support the hypothesis that juvenile giant panda coloration can produce visual effects consistent with potential camouflage, while highlighting the importance of habitat structure and viewing context in shaping camouflage.

Explore related subjects

animal behavior and cognitionPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

LI, Z., Kelley, L. A., Stevens, M.. 2026-10-18. Camouflage functions of juvenile giant panda colouration in forest environments. https://doi.org/10.64898/2026.10.12.758461

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Capturing the rhythm: methodological choices shape inference from circadian activity data

Abstract 1. Statistical tools and analytical decisions for analysing animal activity data are often limited and poorly justified, particularly with respect to model choice, sampling design and temporal aggregation. These shortcomings can constrain our ability to draw accurate and biologically meaningful inferences about behaviour. 2. We interrogated 24 h activity data taken from individual males and females derived from five Drosophila melanogaster populations to generate a general framework for collecting and analysing activity data that systematically compares common model classes, continuous verses fragmented sampling strategies, and alternative temporal aggregation choices (time-bin sizes). 3. Our analyses identified generalised additive mixed models (GAMMs) applied to high-frequency continuous data with small-moderate bin sizes (1-5 minutes) as providing the most robust and interpretable inference for our complex, high-frequency activity data. 4. However, our interrogation of the data set confirmed that analytical and sampling decisions need to be tailored to the study species, the timing of activities and the nature of the behaviour of interest. Accordingly, polynomial and cosinor generalised linear models, increased but biologically targeted snapshot sampling, and bin sizes smaller than one hour yielded adequate analyses with similar biological conclusions when appropriately matched to the system. 5. Our approach provides an accessible decision-making framework for activity analyses that allows researchers across behavioural, ecological and evolutionary studies to justify and optimise choices about data collection and modelling. Such an approach improves the biological relevance of inference and supporting the use of modern tracking and analytical technologies.

animal behavior and cognition↗
bioRxiv2026

Greylag geese (Anser anser) initiate group flight based on the number and identities of callers

Social animals need to maintain cohesion when they move, and movement decisions are influenced by social organization and ecological or individual needs. To maintain synchrony during collective movement, the use of signals, including vocal signals, is often necessary. Greylag geese are gregarious and vocal before and during flight. We observed instances of naturally occurring flight initiation attempts in a free-living population of greylag geese -n = 133 birds- to investigate the decision-making process in this species, including the role vocalisations play in flight decisions. We recorded the number of participants in flight-initiation attempts, their vocal behaviour -using two call types specific to flight initiation signalling: Locomotion and Pre-flight calls-, the outcome of those attempts, in addition to the resulting flying group size and composition. We found that the identities and number of flock members joining in the calling chorus predicted both the probability of successful flight and the resulting flying group size. The number of Locomotion callers was associated with an increased probability of success, as well as larger flying group size, including both family and non-family fliers. The number of Pre-flight callers was also associated with a higher probability of successful flight, but its effect on the increase in flying group size was marginal. Successful departures were more probable when the family members of the initiator responded vocally. Overall, our findings are consistent with a system where the decision to fly is made individually using two distinct vocal signals to estimate the number of voters and at least the identities of social partners and progeny. In species where temporal and spatial group cohesion varies both seasonally and diurnally, individuals priorities appear to be maintaining proximity to mates and family members, followed by maximizing the size of flight groups.

animal behavior and cognition↗
bioRxiv2026

Relative reward memories retain multidimensional information in bumblebees

Previously, we showed that bumblebees encode reward value relative to local alternatives and, when comparing options learned in separate contexts, retrieve only their ordinal rank rather than absolute reward magnitude (Solvi et al., 2022). However, that study, like related work across species, varied reward along a single dimension. Natural rewards such as nectar are multidimensional, yet how such rewards are represented in relative memory remains unknown. We tested this by training bumblebees in separate contexts with rewards varying in two intrinsic dimensions, sucrose concentration and NaCl content, and then comparing options never encountered together. When only sucrose concentration varied, bees showed no preference between options that had each been locally better, despite differing in absolute concentration. With multidimensional rewards, however, this equivalence no longer held: bees preferred an option that had been locally better on both sucrose and NaCl over one better on only sucrose or only NaCl. A two-dimensional advantage also produced a stronger preference than a one-dimensional advantage 48 h after training. Thus, the ordinal rank we previously identified captures only part of the relative reward representation: with multidimensional rewards, bumblebees also retain information about the dimensions on which an option had been locally better.

animal behavior and cognition↗