From the Field Notes of Colonel Aubrey Fitch-Harrington, FRS

Observations Upon the Fauna of Southern Africa — Volume III (In Preparation)

“The Flap-necked Chameleon (Chamaeleo dilepis) changes colour. The author had previously listed the purpose of this change as: camouflage. He has crossed this out. The colour changes serve: thermal regulation — the animal darkens in cold to absorb heat, lightens in heat to reflect it; communication — courtship, territory assertion, and stress signalling, the specific patterns readable by other chameleons; and in some circumstances a general background matching that might incidentally reduce visibility. The camouflage interpretation is not incorrect in all cases. It is incomplete in most, and incorrect in the case the author directly observed, in which the animal turned bright orange-yellow in the middle of open ground with nothing nearby that orange-yellow would assist against. The eyes move independently through three hundred and sixty degrees. The tongue reaches one and a half times the body length and accelerates at forty-one g — the fastest muscular acceleration documented in any vertebrate. The author notes that this is the fourth time in this volume he has crossed out camouflage as a primary explanation for something. He is developing a policy.”

The chameleon was green when he found it.

It was on a branch at the path’s edge — not hiding, exactly, but not announcing itself either, doing the specific thing that green animals on green branches do, which is occupy a space without particularly advertising the occupancy. The Colonel noted it: Flap-necked Chameleon, adult, branch at 1.2m, green colouration, camouflage effective.

He was writing this when the chameleon turned yellow.

Not gradually. In the time it took him to look from his notebook to the animal, it had moved from the specific green of the branch it was sitting on to a yellow that matched nothing in the immediate vicinity. Then — as he watched directly — it shifted further toward orange, a warm orange that was both vivid and entirely without context in the grey-brown shade of the path’s edge vegetation.

The Colonel lowered his notebook.

The chameleon was orange. The branch was brown-grey. The surrounding vegetation was a variety of greens and ochres. Nothing in the available landscape was orange.

He wrote: Colour change: camouflage purpose unclear. Animal turned orange. Nothing orange nearby. Investigating.

He had approached the branch when the colour changed, which was the relevant fact.

He stood at the path’s edge and read the reference. The colour change in response to approach: stress signalling. The specific sequence — green to yellow to orange — documented as a threat-to-self response, the chameleon expressing its assessment of the situation in the only language available to it, which was colour, directed at the Colonel, who had been reading it as camouflage.

“It is not hiding,” Cetshwayo said.

“It changed colour when I approached.”

“Yes. It is telling you something.”

The Colonel looked at the orange chameleon in the middle of open ground. He crossed out camouflage effective in his field note. He wrote: Stress response. Colour change on approach: communication, not concealment. The animal was announcing itself, not hiding. The author was reading the wrong signal.