What are Honest Signals?

Signalling Theory is an area of study within evolutionary biology that looks at the communication between heterospecific or homospecific individuals. This communication can either be honest or dishonest, depending on the purpose of signalling.

Honest Signals are phenotypic expressions, including physiological structures as well as behaviors, that directly influence the observers behaviors in ways that will benefit the signaller. What distinguishes a signal from a cue is that it benefits the signaller, while a cue only benefits the observer. What makes the signal "honest" is that it is positively correlated with the intention of both the sender and the receiver.

Navigate through this website to learn more about two different types of honest signals found in two different species. You will be surprised to find many overlapping functions of honest signalling between two species of completely different phylogenies.

The two examples chosen here each represent one or more of the different types of Honest Signalling, which include:

- Warning conspecifics of the approach of a predator

- Signalling to the predator that it has been detected

- Signalling fitness to either predator or a possible mate

Aposematism in Granular Poison Frogs:

[Rana punta de flecha granulada 3] retrieved November 29, 2015 from: http://es.reinoanimalia.wikia.com/wiki/Archivo:Rana_punta_de_flecha_granulada_3.png

Granular Poison Frogs (Oophaga granulifera) utilize aposematism as it’s sole defense mechanism against predation. Aposematism describes the use of coloration as an antipredator adaptation that honestly signals the frogs toxicity towards potential predators. The typical aposematic color of these species is a bright orange back and the upper arms as well as green to blue-green belly, lower arms, and hind legs (Savage 2002).

Stotting:

[Leaping Springbok Kalahari] retrieved November 29, 2015 from: http://animal.memozee.com/view.php?tid=2&did=1095&lang=kr

Stotting, also known as pronking or pronging, describes a springing or jumping behavior displayed by quadrupeds, primarily gazelles, llamas and goats. This behavior can serve many different functions. It can signal to predators that the signaller is not worth pursuing, as it is both physically fit and has detected the predator. It can alarm the herd of the approach of a predator. It can be used to display fitness to a potential mate. There are variations in exact behavioral topography between and within species.

Unfortunately, not much research has been done on this specific behavior. There is much space for further investigation in the ontogenetic and phylogenetic development of this behavior.

 

Both aposematism as well as stotting are good exemplars of how different species utilize behavioral signals to convey information to conspecifics, as well as predators. There are many similarities between both behaviors, such as the propensity of both to convey accurate (or “honest”) signals and messages to other individuals, be it about the toxicity of the organism (as is the case in aposematism) or the fitness of the individual (as is the case in stotting). In addition to the similarities, there are also stark contrasts. Although aposematism may be an honest signal of toxicity in some poisonous frogs, some varieties toxicity is inversely related to their toxicity, implying that this signal is infact a dishonest one, something inherently different from the purely honest nature of stotting behavior in quadrupeds. This blog will highlight information about both examples of signaling across disparate species aimed at addressing Niko Tinbergen’s 4 questions, and ultimately, will demonstrate the similarities, and differences, between these two fascinating cases of signaling in animal contexts.