"The Springbok (Antidorcas marsupialis) is named, with admirable directness, for what it does. The pronking — a vertical leap with arched back, all four feet leaving the ground simultaneously — serves, in the author's considered view, primarily as an alarm signal, cascading through the herd when a threat is detected. The animal can reach eighty-eight kilometres per hour and sustain high speed for distances that render pursuit largely theoretical. Historical accounts of the great trekbokke — mass migrations of springbok across the Karoo, documented in the nineteenth century — describe numbers the author finds, on careful consideration of the sources, somewhat difficult to reconcile with his field experience. He notes them here for completeness."
There were thirty of them.
The Colonel had counted twice, because thirty seemed both too few and too precise. But thirty it was — a mixed herd moving through the open grassland in the loose, alert way of animals that are never entirely at rest even when nothing is happening. He had his notebook. He had his position downwind. He had, as was his custom, assessed the available threat landscape and found the morning adequate.
Then one pronked.
The Colonel's pencil was ready. He looked for the predator — the reflex of the prepared observer, the scan for what had triggered the alarm. He looked left. He looked right. He looked at the sky, which was empty of eagles. He looked at the drainage line, which was empty of everything he could identify as threatening.
The herd pronked.
Not one or two — all thirty, in a cascade that moved through the group in the time it took the Colonel to redirect his field glasses. Thirty animals in the air simultaneously, backs arched, and as they went he saw for the first time what happened — a white he had not noticed in the standing animals, a crest that emerged from somewhere along the spine as each one leapt, there in the air and then gone again as they landed. A flash of white, repeated thirty times, too fast to track individually.
He looked for the predator.
There was no predator.
He wrote: Cascade pronking. No visible threat. Searching for trigger. White visible during leap — dorsal? Investigate.
He looked up in time to see one of them chase a small dust devil across the open ground — sprinting after the whirl of dust, pronking through it, running in a brief circle when it dissolved. The Colonel wrote: Behaviour resisting current classification. Then he looked back at the herd.
They had stopped pronking. They were grazing. The morning had resumed its ordinary quality as though nothing had occurred.
Cetshwayo was beside him. The Colonel had been so intent on the alarm scan that he had not registered Cetshwayo's arrival, which was, he had found, the usual way Cetshwayo arrived.
"The white," the Colonel said, not as a question.
"From the back," Cetshwayo said. "A pocket. It opens when they jump. There is a smell also."
The Colonel looked at the herd. At the animals now grazing, their spines unmarked, the white invisible at rest.