Evolutionary Camouflage

This week I am discussing disruptive colouration as a means of camouflage. Disruptive colouration is when an organism uses contrasting markings to break up the outline of their body against its background (Skelhorn & Rowe, 2016). This method is used by prey, to increase the chances of survival, but it is also used by predator to increase the likelihood of getting a meal (Merilaita & Lind, 2005).   Cuthill et al. (2006) describes three types of disruptive colouration. The first one being differential blending, which is when patches in the pattern of the organism match the background, be it colour or texture. The second type is maximum disruptive contrast, where flanking pattern colours are often highly contrasting, creating a confusion effect. Lastly, having markings at the edge of the organism’s body helps it blend in with their background (Cuthill et al., 2006). Unlike background matching, disruptive colouration is said to be one of the least researched methods of...

As discussed last week, background matching or concealing colour, as it is also known, is the relationship between the organism and its background (Dimitrova & Merilaita, 2010). An animal must have an appearance matching one specialised environment in, “Colour, lightness or pattern” (Merilaita, 2010). Last week I touched on the importance of an organism using background matching to avoid predators and the significance this plays in the evolution and natural selection of specific species (Dimitrova & Merilaita, 2010). This week I would like to show you some of these amazing camouflaging evolutions.   I would like to start with Crab spiders ( Thomisus onustus ), which colour matches with flowers ( Thery & Casas, 2002) . They do this not only to hide from predators, such as birds, but also from their prey (which can be called aggressive mimicry), which are various pollinating insects including; bees, wasps and flies . Thery & Casas (2002) used spectroradio...

There are many different types of camouflage including; background matching, disruptive colouration, countershading, masquerading, motion dazzling and distractive markings (Stevens & Merilaita, 2011). This week I will discuss background matching as a means of camouflage. When an organism’s colouring or patterns match its habitat , it can be called concealing colouration, general colour resemblance (Caro, 2005) or background matching (Ruxton et al ., 2004). It is surmised that the reason for this evolutionary trait is that the better an organism blends in with its settings, the lower the likelihood of being detected by predators (Caro, 2005). This is part of natural selection, as the animal that can hide in plain sight without discovery is less likely to be eaten (Dimitrova & Merilaita, 2009). Therefore, they are more likely to produce young, pass on their background matching genes and continue their linage.   Background matching is an amazing way of concealin...

Camouflage and mimicry are used by plants and animals alike throughout the natural world (Niu, Sun & Stevens 2018). It can help an organism hide in plain sight, mimic other more toxic creatures in self-defence or lure prey to a predator (Skelhorn & Rowe 2016).  Over the next few weeks we’ll explore these in more detail but today I would like to talk about the how and why of this fascinating and amazing thing. So, how did camouflage evolve? Why did an organism suddenly need to hide from predators? And in some cases, why did predators need to outsmart their prey? I was recently introduced to the Light Switch Theory (Parker 2011) when I read an article for my Evolutionary Biology tutorial. Parker (2011), states that the first image-based eye was developed in the Cambrian period, about 521 MA. This has been found in fossils in Canada known as the Burgess fauna and flora. These fossils show each of the phyla that exist today, which there are 37 in total. Before organi...