He was on their track.

Immediately it was answered by a chorus of howls from the bush on the swamp side, but still far away.

There was no need of command; the pony sprang forward with a snort and the colt followed, and after a few minutes' running, passed her.
"Whow-oo-oo-oo-ow" rose the long cry of the pursuer, summoning help, and drawing nearer.
"Wow-ee-wow," came the shorter, sharper answer from the swamp, but much nearer than before and more in front.

They were trying to head off their prey.
Ranald tugged at his colt till he got him back with the pony.
"It is a good road," he said, quietly; "you can let the pony go.

I will follow you." He swung in behind the pony, who was now running for dear life and snorting with terror at every jump.
"God preserve us!" said Ranald to himself.