By Guest Author 21/08/2020

Recently, the Science Media Centre ran the first round of its 2020 SAVVY Video Competition for science researchers. With twelve entries, ranging from infant nutrition to the science of bell-ringing, we judges were incredibly impressed by the creativity and quality of submissions. This week, we’re featuring the work of first place prize winner, PhD candidate Morgane Merien.

My name is Morgane Merien, I am a PhD student at the University of Auckland. My research focuses on camouflage in our native stick insects. From the 18th of June to the 23rd of July 2020, I took part in the SAVVY video production workshops hosted by the Science Media Centre and presented by video producer Baz Caitcheon. In these workshops, participants learn how to plan, film and edit short videos using only a smartphone or tablet. It is a great skill to learn, especially to use in science communication! For my video, I decided to interview my fellow lab member, PhD student Cass Mark-Chan.

The relationship between predators and their prey are an important factor in influencing natural selection. Predation can be divided into five different parts: detection, identification, contact, capture, and finally consumption (Endler, 1981). Prey are under selection to evolve anti-predator strategies to thwart this process at any of the stages. As such, many adaptations are aimed at stopping or minimizing detection and identification. To avoid being detected by predators, organisms may evolve camouflage strategies. Effective camouflage serves to make the organism unrecognisable from their environment (Cuthill et al, 2005). Camouflaged organisms will be influenced by evolutionary pressure to remain undetected. Therefore, understanding how various camouflage strategies work helps us to elucidate predator-prey relationships within a system of visually guided predators and prey (Troscianko, Skelhorn & Stevens, 2017).

Dead oak leaf butterfly (Wikimedia CC0)

The three major visual camouflage strategies are background-matching, disruptive colouration, and masquerade. As the name suggests, background-matching is a strategy where an organism closely matches the visual components of their background (Endler, 1984). The organism blends in with the colour, pattern, luminance, and texture of its background, which makes it undistinguishable from the environment when viewed through the visual system of the receiver (the one looking) (Stevens, 2007). As such, the efficiency of background-matching depends on the degree of fidelity between the organism and the background (Stevens, Lown & Wood, 2014). Close resemblance can be achieved in a number of ways, either through background selection, actual colour change, or behavioural choices. Disruptive colouration is a camouflage strategy whereby organisms display high contrast colour patterns that break up the edges of the animal’s shape and create false boundaries. This strategy anticipates that predators visually identify their prey through characteristic shape and size (Troscianko, Skelhorn & Stevens, 2017). Disruptive colouration therefore disrupts how organisms view and classify their prey. In masquerade, rather than avoiding detection, organisms aim to avoid recognition by resembling an object common to their environment that is often inedible and inanimate, such as a twig, a leaf, or even bird-droppings (Allen & Cooper, 1985). This strategy is adaptive as receivers (such as predators or prey) detect but then misidentify the masquerading organism as an innocuous object (Skelhorn et al, 2010). The strategy of masquerade relies on predators having had previous experience with the object that the organism is masquerading as.

Camuflagem Perfeita (Wikimedia CC0)

Insects display some of the most remarkable examples of camouflage and mimicry in the animal kingdom. The diversity of camouflage strategies in insects has played an important role in their evolutionary success. The colour patterns of insects have been studied extensively throughout the past decades to understand the evolution and ecology of camouflage.

Cass is also conducting research on camouflage. Her organism of interest is the beautiful North Island lichen moth, Declana atronivea. This striking moth has intricate black and white markings on its wings, alluding to the possibility that it is using its colouration as protection through camouflage. Cass is undertaking research to find out which type of camouflage strategy the moth is using, and how this helps it avoid predators. Through this research, we are also uncovering more knowledge on the ecology and life history of this awesome moth.

Watch Morgane’s prize-winning video entry here.