Examples of chimaeric camouflage (in predators) and chimaeric mimicry (in prey): the tiger (Panthera tigris) and the caterpillar of the lobster moth (Stauropus fagi)

@ptexis @jeremygilmore @ludwig_muller @christiaan_viljoen @matthewinabinett @simontonge @paradoxornithidae @tonyrebelo @dinofelis @botswanabugs @pelagicgraf @kakariki14 @magicsonic @lefebvremax @marina_gorbunova @beartracker @louloubeney

Please also see https://www.youtube.com/watch?v=NfcGwk9dBlY&t=5s.

CONCEPTUAL FRAMEWORK

A chimaera is any mythical beast composed of incongruous parts, i.e. like a composite of different animals (https://www.merriam-webster.com/dictionary/chimera).

What is the relevance of the concept of a chimaera in the real world of natural history?

Well, incongruity in the composite appearance of a real animal can, in biological terms, have adaptive value.

For predators, the obvious value of the incongruity in question is in camouflage-colouration. This is because

  • camouflage basically disrupts any search-image for the predator on the part of the prey, and
  • any incongruity within the camouflage pattern can potentially further disrupt the search-image.

An example of chimaeric camouflage is Panthera tigris (https://www.inaturalist.org/taxa/41967-Panthera-tigris), in which the pattern of striping is oddly heterogeneous on various parts of the body.

For prey, the obvious adaptive value of the incongruity in question is in bewildering the predator, delaying identification of the prey by the predator, and thus buying time for escape.

Mimicry, in this context, is the false resemblance between a species of prey and some other species, usually better-defended from predation.

This deception can be effective even if there is no precise resemblance between the mimic and any particular species of model, as explained by Philip E Howse (https://www.goodreads.com/author/list/4543260.Philip_E_Howse). Thus, confusion can be achieved in conjunction with mimicry of dangerous models.

Given the trade-off between precise mimicry on one hand, and a confusing appearance on the other, it is possible for a prey species to gain adaptive benefit by vaguely mimicking several different models within a single body.

An example of chimaeric mimicry is Stauropus fagi (https://www.inaturalist.org/taxa/451846-Stauropus-fagi).

Let us now examine each of these spp. in turn.

PANTHERA TIGRIS

In the public mind, the camouflage-colouration of Panthera tigris is one of fairly uniform striping (https://www.gettyimages.com.au/detail/photo/fur-pattern-of-endangered-tiger-dist-asia-but-royalty-free-image/139820422?adppopup=true and https://www.naturepl.com/stock-photo-bengal-tiger-panthera-tigris-tigris-stalking-deer-ranthambore-np-nature-image01234677.html and https://www.shutterstock.com/image-photo/during-patrolling-her-territory-this-pregnant-1474249925).

However, a closer examination shows that the striping is a patchwork of at least four categories, on various parts of the figure, as follows:

The following illustrate the heterogeneity, within each individual, of these patterns:

https://www.inaturalist.org/observations/215448957

https://www.flickr.com/photos/ipilot777/5912555495/

https://www.inaturalist.org/observations/184031493

https://www.inaturalist.org/observations/180925182

In summary, what I point out in this Post is that, in its adaptive colouration,

  • P. tigris is like a composite animal, and
  • this internal incongruity presumably enhances its camouflage.

STAUROPUS FAGI

Howse (2010, https://books.google.com.au/books/about/Butterflies.html?id=A0_dRgAACAAJ&redir_esc=y), on page 119, describes the caterpillar of S. fagi as follows:

"The young caterpillar is black and has three pairs of very long jointed legs (the true legs), bearing an unmistakeable resemblance to an ant. When it is larger, the caterpillar is pale brown and is said to resemble a lobster...To my eye, the only possible inference of a lobster is in the long, thin-jointed, stick-like front legs...Hugh Newman, in his book 'British Moths and Their Haunts' describes it thus: 'It is almost a beefsteak red with a ridged back like some prehistoric monster, while the whole of the hind portion is flattened and somewhat resembles the expanded head of an angry cobra. When touched or alarmed it will bend back this tail portion if its body while at the same time rearing up its front parts and waving its abnormally long legs in a threatening manner'...what Newman fails to mention is that the last pair of false legs are modified to give the appearance of a bifid tongue, adding credence to an image of a snake head at one end of the body. What is also striking is that this 'head' is very similar indeed to the last bulbous segment of a scorpion's tail, which contains...a sharply curved barb. At the other end, the rounded head with waving legs is very indicative of a spider. This caterpillar is doubly ambiguous, and perhaps triply so, the whole ensemble of deception suggesting a spider with snake and scorpion features."

In a caption in the same page, Howse (2010) states:
"Caterpillar of ...Stauropus fagi...with elongated forelegs and a bulbous head that resembles the legs and body of a large spider. Viewed upside down, the swollen terminal abdominal segments are seen more clearly to resemble both a snake's head with teeth and forked tongue and the bulbous sting of a scorpion."

The following illustrate the caterpillar of S. fagi:

https://www.youtube.com/watch?v=AFcE2Va1INw

https://www.youtube.com/watch?v=hM18oVn-BSg

http://www.pyrgus.de/Stauropus_fagi_en.html

https://www.flickr.com/photos/frank-deschandol/32249491647

https://www.leps.it/indexjs.htm?SpeciesPages/StauroFagi.htm

https://www.flickr.com/photos/frank-deschandol/32249491647

https://www.alamy.com/lobster-moth-stauropus-fagi-larva-image1835995.html

https://www.alamy.com/lobster-moth-stauropus-fagi-larva-image1835995.html

DISCUSSION

The observation I have made here about P. tigris may be original, despite the familiarity of this felid.

I have previously pointed out an example of chimaeric mimicry in another felid (https://explorebioedge.com/2016/03/10/chimaera-mimicry-in-juvenile-cheetah/ and https://explorebioedge.com/2016/01/30/photo-insight-template/).

In the case of the insect, my account reflects that of Howse (2010). The only original aspect of my coverage here is the chimaeric analogy.

Publicado el 08 de septiembre de 2024 por milewski milewski

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